package telegram

import (
	"context"
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"mime"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"sync"
	"time"

	"codex-telegram-bot/internal/codexapp"
	"codex-telegram-bot/internal/store"
)

const (
	telegramDownloadLimit = 20 * 1024 * 1024
	resumeThreadPageSize  = 8
	commandSummaryLimit   = 120
)

type Bot struct {
	tg     *Client
	store  *store.Store
	codex  *codexapp.Client
	logger *log.Logger

	uploadDir      string
	defaultModel   string
	defaultSandbox string
	pollTimeout    time.Duration

	mu      sync.Mutex
	outputs map[string]*outputState
	diffs   map[string]string
}

type outputState struct {
	chatID    int64
	assistant strings.Builder
	sentAny   bool
}

type codexThreadItemView struct {
	Type             string          `json:"type"`
	ID               string          `json:"id"`
	Command          string          `json:"command"`
	CWD              string          `json:"cwd"`
	Status           string          `json:"status"`
	Tool             string          `json:"tool"`
	Server           string          `json:"server"`
	Namespace        string          `json:"namespace"`
	Query            string          `json:"query"`
	Path             string          `json:"path"`
	SavedPath        string          `json:"savedPath"`
	Text             string          `json:"text"`
	AggregatedOutput *string         `json:"aggregatedOutput"`
	ExitCode         *int            `json:"exitCode"`
	DurationMs       *int64          `json:"durationMs"`
	Success          *bool           `json:"success"`
	Arguments        json.RawMessage `json:"arguments"`
	Changes          []struct {
		Path string `json:"path"`
	} `json:"changes"`
}

func NewBot(tg *Client, st *store.Store, codex *codexapp.Client, uploadDir, defaultModel, defaultSandbox string, pollTimeout time.Duration, logger *log.Logger) *Bot {
	if logger == nil {
		logger = log.Default()
	}
	return &Bot{
		tg:             tg,
		store:          st,
		codex:          codex,
		logger:         logger,
		uploadDir:      uploadDir,
		defaultModel:   defaultModel,
		defaultSandbox: defaultSandbox,
		pollTimeout:    pollTimeout,
		outputs:        make(map[string]*outputState),
		diffs:          make(map[string]string),
	}
}

func (b *Bot) Run(ctx context.Context) error {
	if err := b.store.ClearActiveTurns(ctx); err != nil {
		return err
	}
	go b.handleCodexEvents(ctx)

	offset := 0
	for ctx.Err() == nil {
		updates, err := b.tg.GetUpdates(ctx, offset, int(b.pollTimeout.Seconds()))
		if err != nil {
			if ctx.Err() != nil {
				break
			}
			b.logger.Printf("getUpdates: %v", err)
			time.Sleep(2 * time.Second)
			continue
		}
		for _, update := range updates {
			if update.UpdateID >= offset {
				offset = update.UpdateID + 1
			}
			if err := b.handleUpdate(ctx, update); err != nil {
				b.logger.Printf("handle update %d: %v", update.UpdateID, err)
			}
		}
	}
	return ctx.Err()
}

func (b *Bot) handleUpdate(ctx context.Context, update Update) error {
	switch {
	case update.Message != nil:
		return b.handleMessage(ctx, update.Message)
	case update.CallbackQuery != nil:
		return b.handleCallback(ctx, update.CallbackQuery)
	default:
		return nil
	}
}

func (b *Bot) handleMessage(ctx context.Context, message *Message) error {
	if message.PinnedMessage != nil {
		return nil
	}
	if message.Chat.Type != "private" {
		if message.From != nil {
			_ = b.store.Audit(ctx, message.From.ID, "reject_non_private", message.Chat.Type)
		}
		_, err := b.tg.SendMessage(ctx, message.Chat.ID, "This bot only supports one-to-one chats.", SendMessageOptions{})
		return err
	}
	if message.From == nil {
		return nil
	}
	allowed, err := b.store.IsAllowed(ctx, message.From.ID)
	if err != nil {
		return err
	}
	if !allowed {
		_ = b.store.Audit(ctx, message.From.ID, "reject_not_allowed", message.From.Username)
		_, err := b.tg.SendMessage(ctx, message.Chat.ID, "Access denied.", SendMessageOptions{})
		return err
	}

	session, err := b.store.GetOrCreateSession(ctx, message.From.ID, b.defaultModel, b.defaultSandbox)
	if err != nil {
		return err
	}
	if handled, err := b.handleCommand(ctx, message, session); handled || err != nil {
		return err
	}
	return b.continueThread(ctx, message, session)
}

func (b *Bot) handleCommand(ctx context.Context, message *Message, session store.Session) (bool, error) {
	command, args, ok := parseCommand(message.Text)
	if !ok {
		return false, nil
	}
	userID := message.From.ID
	chatID := message.Chat.ID

	switch command {
	case "start", "help":
		return true, b.sendHelp(ctx, chatID)
	case "new":
		_, _, err := b.createNewThread(ctx, userID, chatID, session)
		return true, err
	case "thread", "threads":
		return true, b.sendThreads(ctx, userID, chatID)
	case "resume":
		return true, b.resumeThread(ctx, userID, chatID, args)
	case "rename":
		return true, b.renameThread(ctx, userID, chatID, session, args)
	case "fork":
		return true, b.forkThread(ctx, userID, chatID, session)
	case "archive":
		return true, b.archiveThread(ctx, userID, chatID, session, args)
	case "status":
		return true, b.sendStatus(ctx, userID, chatID, session)
	case "cancel":
		return true, b.cancelTurn(ctx, userID, chatID, session)
	case "workspaces":
		return true, b.sendWorkspaces(ctx, chatID)
	case "workspace":
		return true, b.handleWorkspaceCommand(ctx, userID, chatID, session, args)
	case "model":
		return true, b.handleModelCommand(ctx, userID, chatID, session, args)
	case "sandbox":
		return true, b.handleSandboxCommand(ctx, userID, chatID, session, args)
	case "diff":
		return true, b.sendDiff(ctx, chatID, session)
	default:
		_, err := b.tg.SendMessage(ctx, chatID, "Unknown command. Use /help.", SendMessageOptions{})
		return true, err
	}
}

func (b *Bot) sendHelp(ctx context.Context, chatID int64) error {
	text := strings.Join([]string{
		"Codex Telegram Bot",
		"",
		"/new - start a new Codex thread",
		"/thread or /threads - list recent threads",
		"/resume - choose a recent thread",
		"/resume ID - resume a thread",
		"/rename TITLE or /rename ID TITLE - rename a thread",
		"/fork - fork the active thread",
		"/archive [ID] - archive a thread",
		"/status - show active settings",
		"/cancel - interrupt the active turn",
		"/workspaces - list workspaces",
		"/workspace [ID] - select workspace",
		"/model - choose model and reasoning effort",
		"/sandbox [read-only|workspace-write|danger-full-access] - show or set sandbox",
		"/diff - show the latest streamed diff",
		"",
		"Plain text continues the active thread. Images are staged as local Codex image inputs; other files are staged and sent as paths.",
	}, "\n")
	return b.sendLong(ctx, chatID, text)
}

func (b *Bot) sendThreads(ctx context.Context, userID, chatID int64) error {
	return b.sendResumeChoices(ctx, userID, chatID, 0, 0)
}

func (b *Bot) resumeThread(ctx context.Context, userID, chatID int64, args []string) error {
	if len(args) == 0 {
		return b.sendResumeChoices(ctx, userID, chatID, 0, 0)
	}
	if len(args) != 1 {
		_, err := b.tg.SendMessage(ctx, chatID, "Use /resume to choose a thread, or /resume ID to resume directly.", SendMessageOptions{})
		return err
	}
	id, err := strconv.ParseInt(args[0], 10, 64)
	if err != nil {
		_, sendErr := b.tg.SendMessage(ctx, chatID, "Thread ID must be a number.", SendMessageOptions{})
		return sendErr
	}
	return b.resumeThreadByID(ctx, userID, chatID, id, 0)
}

func (b *Bot) sendResumeChoices(ctx context.Context, userID, chatID int64, page int, messageID int) error {
	if page < 0 {
		page = 0
	}
	threads, err := b.store.ListThreadsPage(ctx, userID, false, resumeThreadPageSize+1, page*resumeThreadPageSize)
	if err != nil {
		return err
	}
	if len(threads) == 0 && page > 0 {
		return b.sendResumeChoices(ctx, userID, chatID, page-1, messageID)
	}
	if len(threads) == 0 {
		text := "No threads yet. Use /new."
		if messageID != 0 {
			_, err := b.tg.EditMessageText(ctx, chatID, messageID, text, EditMessageTextOptions{})
			return err
		}
		_, err := b.tg.SendMessage(ctx, chatID, text, SendMessageOptions{})
		return err
	}
	threads = b.syncThreadTitles(ctx, threads)
	hasNext := len(threads) > resumeThreadPageSize
	if hasNext {
		threads = threads[:resumeThreadPageSize]
	}
	text := resumeThreadListText(threads, page)
	markup := resumeThreadMarkup(threads, page, hasNext)
	if messageID != 0 {
		_, err := b.tg.EditMessageText(ctx, chatID, messageID, EscapeHTML(text), EditMessageTextOptions{ParseMode: "HTML", ReplyMarkup: markup})
		return err
	}
	_, err = b.tg.SendMessage(ctx, chatID, EscapeHTML(text), SendMessageOptions{ParseMode: "HTML", ReplyMarkup: markup})
	return err
}

func (b *Bot) resumeThreadByID(ctx context.Context, userID, chatID int64, id int64, messageID int) error {
	thread, err := b.store.GetThreadByID(ctx, userID, id)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			text := "Thread not found."
			if messageID != 0 {
				_, editErr := b.tg.EditMessageText(ctx, chatID, messageID, text, EditMessageTextOptions{})
				return editErr
			}
			_, sendErr := b.tg.SendMessage(ctx, chatID, text, SendMessageOptions{})
			return sendErr
		}
		return err
	}
	resumed, err := b.codex.ResumeThread(ctx, thread.CodexThreadID)
	if err != nil {
		return b.sendError(ctx, chatID, "Could not resume Codex thread", err)
	}
	thread, err = b.applyCodexThreadTitle(ctx, thread, resumed)
	if err != nil {
		return err
	}
	if err := b.store.SetActiveThread(ctx, userID, thread.ID); err != nil {
		return err
	}
	text := fmt.Sprintf("Active thread ID %d: %s", thread.ID, threadDisplayTitle(thread))
	if messageID != 0 {
		_, err = b.tg.EditMessageText(ctx, chatID, messageID, EscapeHTML(text), EditMessageTextOptions{ParseMode: "HTML"})
		return err
	}
	_, err = b.tg.SendMessage(ctx, chatID, EscapeHTML(text), SendMessageOptions{ParseMode: "HTML"})
	return err
}

func (b *Bot) renameThread(ctx context.Context, userID, chatID int64, session store.Session, args []string) error {
	if len(args) == 0 {
		_, err := b.tg.SendMessage(ctx, chatID, "Use /rename TITLE for the active thread, or /rename THREAD_ID TITLE.", SendMessageOptions{})
		return err
	}

	var thread store.Thread
	titleArgs := args
	var err error
	if len(args) > 1 {
		if id, parseErr := strconv.ParseInt(args[0], 10, 64); parseErr == nil {
			thread, err = b.store.GetThreadByID(ctx, userID, id)
			if err != nil {
				if errors.Is(err, sql.ErrNoRows) {
					_, sendErr := b.tg.SendMessage(ctx, chatID, "Thread not found.", SendMessageOptions{})
					return sendErr
				}
				return err
			}
			titleArgs = args[1:]
		}
	}
	if thread.ID == 0 {
		thread, err = b.activeThread(ctx, userID, session)
	}
	if err != nil {
		return b.sendNoActiveThread(ctx, chatID, err)
	}

	title := normalizeThreadTitle(strings.Join(titleArgs, " "))
	if title == "" {
		_, err := b.tg.SendMessage(ctx, chatID, "Thread title cannot be empty.", SendMessageOptions{})
		return err
	}
	if err := b.codex.SetThreadName(ctx, thread.CodexThreadID, title); err != nil {
		return b.sendError(ctx, chatID, "Could not rename Codex thread", err)
	}
	if codexThread, readErr := b.codex.ReadThread(ctx, thread.CodexThreadID); readErr == nil {
		thread, err = b.applyCodexThreadTitle(ctx, thread, codexThread)
		if err != nil {
			return err
		}
		title = thread.Title
	} else {
		b.logger.Printf("read renamed thread %s: %v", thread.CodexThreadID, readErr)
		if err := b.store.SyncThreadTitle(ctx, userID, thread.ID, title); err != nil {
			return err
		}
	}
	_, err = b.tg.SendMessage(ctx, chatID, fmt.Sprintf("Renamed thread ID %d: %s", thread.ID, title), SendMessageOptions{})
	return err
}

func (b *Bot) forkThread(ctx context.Context, userID, chatID int64, session store.Session) error {
	thread, err := b.activeThread(ctx, userID, session)
	if err != nil {
		return b.sendNoActiveThread(ctx, chatID, err)
	}
	forked, err := b.codex.ForkThread(ctx, thread.CodexThreadID)
	if err != nil {
		return b.sendError(ctx, chatID, "Could not fork Codex thread", err)
	}
	title := codexThreadTitle(forked, "fork of ID "+strconv.FormatInt(thread.ID, 10))
	local, err := b.store.CreateThread(ctx, userID, forked.ID, thread.WorkspaceID, title)
	if err != nil {
		return err
	}
	if err := b.store.SetActiveThread(ctx, userID, local.ID); err != nil {
		return err
	}
	_, err = b.tg.SendMessage(ctx, chatID, fmt.Sprintf("Forked active thread to #%d.", local.ID), SendMessageOptions{})
	return err
}

func (b *Bot) archiveThread(ctx context.Context, userID, chatID int64, session store.Session, args []string) error {
	var thread store.Thread
	var err error
	if len(args) > 0 {
		id, parseErr := strconv.ParseInt(args[0], 10, 64)
		if parseErr != nil {
			_, sendErr := b.tg.SendMessage(ctx, chatID, "Thread ID must be a number.", SendMessageOptions{})
			return sendErr
		}
		thread, err = b.store.GetThreadByID(ctx, userID, id)
	} else {
		thread, err = b.activeThread(ctx, userID, session)
	}
	if err != nil {
		return b.sendNoActiveThread(ctx, chatID, err)
	}
	if err := b.codex.ArchiveThread(ctx, thread.CodexThreadID); err != nil {
		return b.sendError(ctx, chatID, "Could not archive Codex thread", err)
	}
	if err := b.store.ArchiveThread(ctx, userID, thread.ID); err != nil {
		return err
	}
	_, err = b.tg.SendMessage(ctx, chatID, fmt.Sprintf("Archived thread #%d.", thread.ID), SendMessageOptions{})
	return err
}

func (b *Bot) sendStatus(ctx context.Context, userID, chatID int64, session store.Session) error {
	workspace := "(none)"
	if session.ActiveWorkspaceID != 0 {
		if ws, err := b.store.GetWorkspaceByID(ctx, session.ActiveWorkspaceID); err == nil {
			workspace = fmt.Sprintf("%s (%s)", ws.Label, ws.Path)
		}
	}
	thread := "(none)"
	if session.ActiveThreadID != 0 {
		thread = fmt.Sprintf("ID %d", session.ActiveThreadID)
		if active, err := b.store.GetThreadByID(ctx, userID, session.ActiveThreadID); err == nil {
			if synced, syncErr := b.syncThreadTitle(ctx, active); syncErr == nil {
				active = synced
			} else {
				b.logger.Printf("sync status thread title %s: %v", active.CodexThreadID, syncErr)
			}
			thread = fmt.Sprintf("ID %d: %s", active.ID, threadDisplayTitle(active))
		}
	}
	model := session.Model
	if model == "" {
		model = "(Codex default)"
	}
	turn := session.ActiveTurnID
	if turn == "" {
		turn = "(none)"
	}
	effort := session.ReasoningEffort
	if effort == "" {
		effort = "(model default)"
	}
	text := fmt.Sprintf("Workspace: %s\nThread: %s\nModel: %s\nReasoning effort: %s\nSandbox: %s\nActive turn: %s", workspace, thread, model, effort, session.Sandbox, turn)
	_ = userID
	return b.sendLong(ctx, chatID, text)
}

func (b *Bot) cancelTurn(ctx context.Context, userID, chatID int64, session store.Session) error {
	if session.ActiveTurnID == "" {
		_, err := b.tg.SendMessage(ctx, chatID, "No active turn to cancel.", SendMessageOptions{})
		return err
	}
	thread, err := b.activeThread(ctx, userID, session)
	if err != nil {
		return b.sendNoActiveThread(ctx, chatID, err)
	}
	if err := b.codex.InterruptTurn(ctx, thread.CodexThreadID, session.ActiveTurnID); err != nil {
		return b.sendError(ctx, chatID, "Could not interrupt turn", err)
	}
	_, err = b.tg.SendMessage(ctx, chatID, "Cancellation requested.", SendMessageOptions{})
	return err
}

func (b *Bot) sendWorkspaces(ctx context.Context, chatID int64) error {
	workspaces, err := b.store.ListWorkspaces(ctx)
	if err != nil {
		return err
	}
	if len(workspaces) == 0 {
		_, err := b.tg.SendMessage(ctx, chatID, "No workspaces configured. Ask an admin to run scripts/add-workspace.", SendMessageOptions{})
		return err
	}
	var lines []string
	lines = append(lines, "Workspaces:")
	for _, ws := range workspaces {
		marker := ""
		if ws.IsDefault {
			marker = " default"
		}
		lines = append(lines, fmt.Sprintf("#%d %s%s\n%s", ws.ID, ws.Label, marker, ws.Path))
	}
	_, err = b.tg.SendMessage(ctx, chatID, EscapeHTML(strings.Join(lines, "\n")), SendMessageOptions{
		ParseMode:   "HTML",
		ReplyMarkup: workspaceMarkup(workspaces),
	})
	return err
}

func (b *Bot) handleWorkspaceCommand(ctx context.Context, userID, chatID int64, session store.Session, args []string) error {
	if len(args) == 0 {
		return b.sendWorkspaces(ctx, chatID)
	}
	id, err := strconv.ParseInt(args[0], 10, 64)
	if err != nil {
		_, sendErr := b.tg.SendMessage(ctx, chatID, "Workspace ID must be a number.", SendMessageOptions{})
		return sendErr
	}
	return b.setWorkspace(ctx, userID, chatID, session, id)
}

func (b *Bot) setWorkspace(ctx context.Context, userID, chatID int64, session store.Session, workspaceID int64) error {
	workspace, err := b.store.GetWorkspaceByID(ctx, workspaceID)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			_, sendErr := b.tg.SendMessage(ctx, chatID, "Workspace not found.", SendMessageOptions{})
			return sendErr
		}
		return err
	}
	if err := b.store.SetSessionWorkspace(ctx, userID, workspace.ID); err != nil {
		return err
	}
	_ = session
	_, err = b.tg.SendMessage(ctx, chatID, "Workspace set to "+workspace.Label+".", SendMessageOptions{})
	return err
}

func (b *Bot) handleModelCommand(ctx context.Context, userID, chatID int64, session store.Session, args []string) error {
	_ = userID
	if len(args) > 0 {
		_, err := b.tg.SendMessage(ctx, chatID, "Use /model and choose from the buttons.", SendMessageOptions{})
		return err
	}
	return b.sendModelChoices(ctx, chatID, session)
}

func (b *Bot) sendModelChoices(ctx context.Context, chatID int64, session store.Session) error {
	models, err := b.codex.ListModels(ctx)
	if err != nil {
		return b.sendError(ctx, chatID, "Could not list Codex models", err)
	}
	if len(models) == 0 {
		_, err := b.tg.SendMessage(ctx, chatID, "Codex returned no available models.", SendMessageOptions{})
		return err
	}
	model := sessionModelLabel(models, session.Model)
	text := settingsStatusText(model, session.ReasoningEffort) + "\nChoose a model:"
	message, err := b.tg.SendMessage(ctx, chatID, EscapeHTML(text), SendMessageOptions{
		ParseMode:   "HTML",
		ReplyMarkup: modelMarkup(models),
	})
	if err != nil {
		return err
	}
	b.rememberSettingsMessage(ctx, session.TelegramUserID, chatID, message.MessageID)
	return nil
}

func (b *Bot) handleModelCallback(ctx context.Context, callback *CallbackQuery, modelID string) error {
	models, err := b.codex.ListModels(ctx)
	if err != nil {
		_ = b.tg.AnswerCallbackQuery(ctx, callback.ID, "Could not list models.")
		return b.sendError(ctx, callback.Message.Chat.ID, "Could not list Codex models", err)
	}
	var selected codexapp.Model
	found := false
	for _, model := range models {
		if model.ID == modelID {
			selected = model
			found = true
			break
		}
	}
	if !found {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Model is no longer available.")
	}
	if err := b.store.SetSessionModel(ctx, callback.From.ID, selected.ID); err != nil {
		return err
	}
	if err := b.tg.AnswerCallbackQuery(ctx, callback.ID, "Model selected."); err != nil {
		return err
	}
	label := modelLabel(selected)
	if len(selected.SupportedReasoningEfforts) == 0 {
		text := settingsStatusText(label, "") + "\nNo reasoning effort choices are advertised for this model."
		message, err := b.tg.EditMessageText(ctx, callback.Message.Chat.ID, callback.Message.MessageID, EscapeHTML(text), EditMessageTextOptions{ParseMode: "HTML"})
		if err == nil {
			b.rememberSettingsMessage(ctx, callback.From.ID, callback.Message.Chat.ID, message.MessageID)
		}
		return err
	}
	text := settingsStatusText(label, "") + "\nChoose reasoning effort:"
	message, err := b.tg.EditMessageText(ctx, callback.Message.Chat.ID, callback.Message.MessageID, EscapeHTML(text), EditMessageTextOptions{
		ParseMode:   "HTML",
		ReplyMarkup: effortMarkup(selected),
	})
	if err == nil {
		b.rememberSettingsMessage(ctx, callback.From.ID, callback.Message.Chat.ID, message.MessageID)
	}
	return err
}

func (b *Bot) handleEffortCallback(ctx context.Context, callback *CallbackQuery, effort string) error {
	session, err := b.store.GetOrCreateSession(ctx, callback.From.ID, b.defaultModel, b.defaultSandbox)
	if err != nil {
		return err
	}
	if session.Model == "" {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Choose a model first.")
	}
	models, err := b.codex.ListModels(ctx)
	if err != nil {
		_ = b.tg.AnswerCallbackQuery(ctx, callback.ID, "Could not validate effort.")
		return b.sendError(ctx, callback.Message.Chat.ID, "Could not list Codex models", err)
	}
	var selected codexapp.Model
	found := false
	for _, model := range models {
		if model.ID == session.Model {
			selected = model
			found = true
			break
		}
	}
	if !found {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Selected model is no longer available.")
	}
	if !modelSupportsEffort(selected, effort) {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Effort is no longer available for this model.")
	}
	if err := b.store.SetSessionReasoningEffort(ctx, callback.From.ID, effort); err != nil {
		return err
	}
	if err := b.tg.AnswerCallbackQuery(ctx, callback.ID, "Reasoning effort selected."); err != nil {
		return err
	}
	text := settingsStatusText(modelLabel(selected), effort)
	message, err := b.tg.EditMessageText(ctx, callback.Message.Chat.ID, callback.Message.MessageID, EscapeHTML(text), EditMessageTextOptions{ParseMode: "HTML"})
	if err == nil {
		b.rememberSettingsMessage(ctx, callback.From.ID, callback.Message.Chat.ID, message.MessageID)
	}
	return err
}

func (b *Bot) handleSandboxCommand(ctx context.Context, userID, chatID int64, session store.Session, args []string) error {
	if len(args) == 0 {
		_, err := b.tg.SendMessage(ctx, chatID, "Current sandbox: "+session.Sandbox, SendMessageOptions{})
		return err
	}
	sandbox, err := codexapp.NormalizeSandbox(args[0])
	if err != nil {
		_, sendErr := b.tg.SendMessage(ctx, chatID, "Use one of: read-only, workspace-write, danger-full-access.", SendMessageOptions{})
		return sendErr
	}
	if err := b.store.SetSessionSandbox(ctx, userID, sandbox); err != nil {
		return err
	}
	_, err = b.tg.SendMessage(ctx, chatID, "Sandbox set to "+sandbox+".", SendMessageOptions{})
	return err
}

func (b *Bot) sendDiff(ctx context.Context, chatID int64, session store.Session) error {
	if session.ActiveThreadID == 0 {
		_, err := b.tg.SendMessage(ctx, chatID, "No active thread.", SendMessageOptions{})
		return err
	}
	thread, err := b.store.GetThreadByID(ctx, chatID, session.ActiveThreadID)
	if err != nil {
		_, sendErr := b.tg.SendMessage(ctx, chatID, "No active thread.", SendMessageOptions{})
		return sendErr
	}
	b.mu.Lock()
	diff := b.diffs[thread.CodexThreadID]
	b.mu.Unlock()
	if diff == "" {
		_, err := b.tg.SendMessage(ctx, chatID, "No diff has been streamed for this thread.", SendMessageOptions{})
		return err
	}
	return b.sendLong(ctx, chatID, diff)
}

func (b *Bot) continueThread(ctx context.Context, message *Message, session store.Session) error {
	userID := message.From.ID
	chatID := message.Chat.ID
	input, err := b.messageInput(ctx, userID, message)
	if err != nil {
		return b.sendError(ctx, chatID, "Could not stage Telegram input", err)
	}
	if len(input) == 0 {
		_, err := b.tg.SendMessage(ctx, chatID, "Send text, an image, or a document.", SendMessageOptions{})
		return err
	}

	thread, workspace, err := b.ensureThread(ctx, userID, chatID, session)
	if err != nil {
		return err
	}
	if session.ActiveTurnID != "" {
		if err := b.codex.SteerTurn(ctx, thread.CodexThreadID, session.ActiveTurnID, input); err != nil {
			return b.sendError(ctx, chatID, "Could not append to active turn", err)
		}
		_, err := b.tg.SendMessage(ctx, chatID, "Added to the running turn.", SendMessageOptions{})
		return err
	}

	b.registerOutput(thread.CodexThreadID, chatID)
	turn, err := b.codex.StartTurn(ctx, thread.CodexThreadID, workspace.Path, session.Model, session.ReasoningEffort, session.Sandbox, input)
	if err != nil {
		b.clearOutput(thread.CodexThreadID)
		return b.sendError(ctx, chatID, "Codex turn failed", err)
	}
	if err := b.store.SetActiveTurn(ctx, userID, turn.ID); err != nil {
		return err
	}
	_ = b.store.TouchThread(ctx, thread.CodexThreadID)
	return nil
}

func codexThreadTitle(thread codexapp.Thread, fallback string) string {
	if title := normalizeThreadTitle(thread.Name); title != "" {
		return title
	}
	if title := normalizeThreadTitle(thread.Preview); title != "" {
		return title
	}
	return normalizeThreadTitle(fallback)
}

func (b *Bot) applyCodexThreadTitle(ctx context.Context, thread store.Thread, codexThread codexapp.Thread) (store.Thread, error) {
	title := codexThreadTitle(codexThread, "")
	if title == thread.Title {
		return thread, nil
	}
	if err := b.store.SyncThreadTitle(ctx, thread.TelegramUserID, thread.ID, title); err != nil {
		return thread, err
	}
	thread.Title = title
	return thread, nil
}

func (b *Bot) syncThreadTitle(ctx context.Context, thread store.Thread) (store.Thread, error) {
	if thread.CodexThreadID == "" {
		return thread, nil
	}
	codexThread, err := b.codex.ReadThread(ctx, thread.CodexThreadID)
	if err != nil {
		return thread, err
	}
	return b.applyCodexThreadTitle(ctx, thread, codexThread)
}

func (b *Bot) syncThreadTitles(ctx context.Context, threads []store.Thread) []store.Thread {
	for i := range threads {
		synced, err := b.syncThreadTitle(ctx, threads[i])
		if err != nil {
			b.logger.Printf("sync thread title %s: %v", threads[i].CodexThreadID, err)
			continue
		}
		threads[i] = synced
	}
	return threads
}

func (b *Bot) createNewThread(ctx context.Context, userID, chatID int64, session store.Session) (store.Thread, store.Workspace, error) {
	workspace, err := b.resolveWorkspace(ctx, userID, session)
	if err != nil {
		return store.Thread{}, store.Workspace{}, b.sendWorkspaceMissing(ctx, chatID)
	}
	codexThread, err := b.codex.StartThread(ctx, workspace.Path, session.Model, session.Sandbox)
	if err != nil {
		return store.Thread{}, store.Workspace{}, b.sendError(ctx, chatID, "Could not start Codex thread", err)
	}
	title := codexThreadTitle(codexThread, workspace.Label)
	thread, err := b.store.CreateThread(ctx, userID, codexThread.ID, workspace.ID, title)
	if err != nil {
		return store.Thread{}, store.Workspace{}, err
	}
	if err := b.store.SetActiveThread(ctx, userID, thread.ID); err != nil {
		return store.Thread{}, store.Workspace{}, err
	}
	_, err = b.tg.SendMessage(ctx, chatID, fmt.Sprintf("New thread #%d in %s.", thread.ID, workspace.Label), SendMessageOptions{})
	return thread, workspace, err
}

func (b *Bot) ensureThread(ctx context.Context, userID, chatID int64, session store.Session) (store.Thread, store.Workspace, error) {
	if session.ActiveThreadID != 0 {
		thread, err := b.store.GetThreadByID(ctx, userID, session.ActiveThreadID)
		if err == nil && !thread.Archived {
			if synced, syncErr := b.syncThreadTitle(ctx, thread); syncErr == nil {
				thread = synced
			} else {
				b.logger.Printf("sync active thread title %s: %v", thread.CodexThreadID, syncErr)
			}
			workspace, err := b.store.GetWorkspaceByID(ctx, thread.WorkspaceID)
			return thread, workspace, err
		}
	}
	return b.createNewThread(ctx, userID, chatID, session)
}

func (b *Bot) activeThread(ctx context.Context, userID int64, session store.Session) (store.Thread, error) {
	if session.ActiveThreadID == 0 {
		return store.Thread{}, sql.ErrNoRows
	}
	return b.store.GetThreadByID(ctx, userID, session.ActiveThreadID)
}

func (b *Bot) resolveWorkspace(ctx context.Context, userID int64, session store.Session) (store.Workspace, error) {
	if session.ActiveWorkspaceID != 0 {
		return b.store.GetWorkspaceByID(ctx, session.ActiveWorkspaceID)
	}
	workspace, err := b.store.DefaultWorkspace(ctx)
	if err != nil {
		return store.Workspace{}, err
	}
	if err := b.store.SetSessionWorkspace(ctx, userID, workspace.ID); err != nil {
		return store.Workspace{}, err
	}
	return workspace, nil
}

func (b *Bot) messageInput(ctx context.Context, userID int64, message *Message) ([]codexapp.InputItem, error) {
	var input []codexapp.InputItem
	text := strings.TrimSpace(message.Text)
	if text == "" {
		text = strings.TrimSpace(message.Caption)
	}
	if text != "" {
		input = append(input, codexapp.InputItem{Type: "text", Text: text})
	}
	if len(message.Photo) > 0 {
		photo := largestPhoto(message.Photo)
		path, err := b.stageFile(ctx, userID, photo.FileID, "photo.jpg", "image/jpeg", photo.FileSize)
		if err != nil {
			return nil, err
		}
		input = append(input, codexapp.InputItem{Type: "localImage", Path: path})
	}
	if message.Document != nil {
		path, err := b.stageFile(ctx, userID, message.Document.FileID, message.Document.FileName, message.Document.MimeType, message.Document.FileSize)
		if err != nil {
			return nil, err
		}
		if isImage(message.Document.MimeType, message.Document.FileName) {
			input = append(input, codexapp.InputItem{Type: "localImage", Path: path})
		} else {
			input = append(input, codexapp.InputItem{Type: "text", Text: "User uploaded a file staged at: " + path})
		}
	}
	return input, nil
}

func (b *Bot) stageFile(ctx context.Context, userID int64, fileID, filename, mimeType string, size int64) (string, error) {
	if size > telegramDownloadLimit {
		return "", fmt.Errorf("file exceeds Telegram cloud download limit of 20 MB")
	}
	file, err := b.tg.GetFile(ctx, fileID)
	if err != nil {
		return "", err
	}
	if file.FileSize > telegramDownloadLimit {
		return "", fmt.Errorf("file exceeds Telegram cloud download limit of 20 MB")
	}
	if file.FilePath == "" {
		return "", errors.New("telegram did not return a file path")
	}
	data, err := b.tg.DownloadFilePath(ctx, file.FilePath)
	if err != nil {
		return "", err
	}
	if len(data) > telegramDownloadLimit {
		return "", fmt.Errorf("file exceeds Telegram cloud download limit of 20 MB")
	}
	if filename == "" {
		filename = filepath.Base(file.FilePath)
	}
	if filename == "." || filename == string(filepath.Separator) || filename == "" {
		filename = fileID
		if ext := extensionForMime(mimeType); ext != "" {
			filename += ext
		}
	}
	if err := os.MkdirAll(b.uploadDir, 0o755); err != nil {
		return "", err
	}
	name := fmt.Sprintf("%d_%d_%s", userID, time.Now().UnixNano(), safeFilename(filename))
	path := filepath.Join(b.uploadDir, name)
	if err := os.WriteFile(path, data, 0o644); err != nil {
		return "", err
	}
	return path, nil
}

func (b *Bot) handleCallback(ctx context.Context, callback *CallbackQuery) error {
	if callback.Message == nil {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Unsupported callback.")
	}
	if callback.Message.Chat.Type != "private" {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Use a private chat.")
	}
	allowed, err := b.store.IsAllowed(ctx, callback.From.ID)
	if err != nil {
		return err
	}
	if !allowed {
		_ = b.store.Audit(ctx, callback.From.ID, "reject_callback_not_allowed", callback.From.Username)
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Access denied.")
	}
	session, err := b.store.GetOrCreateSession(ctx, callback.From.ID, b.defaultModel, b.defaultSandbox)
	if err != nil {
		return err
	}
	if workspaceID, ok := ParseWorkspaceCallbackData(callback.Data); ok {
		if err := b.tg.AnswerCallbackQuery(ctx, callback.ID, ""); err != nil {
			return err
		}
		return b.setWorkspace(ctx, callback.From.ID, callback.Message.Chat.ID, session, workspaceID)
	}
	if resumeID, ok := ParseResumeThreadCallbackData(callback.Data); ok {
		if err := b.tg.AnswerCallbackQuery(ctx, callback.ID, "Thread selected."); err != nil {
			return err
		}
		return b.resumeThreadByID(ctx, callback.From.ID, callback.Message.Chat.ID, resumeID, callback.Message.MessageID)
	}
	if resumePage, ok := ParseResumePageCallbackData(callback.Data); ok {
		if err := b.tg.AnswerCallbackQuery(ctx, callback.ID, ""); err != nil {
			return err
		}
		return b.sendResumeChoices(ctx, callback.From.ID, callback.Message.Chat.ID, resumePage, callback.Message.MessageID)
	}
	if modelID, ok := ParseModelCallbackData(callback.Data); ok {
		return b.handleModelCallback(ctx, callback, modelID)
	}
	if effort, ok := ParseEffortCallbackData(callback.Data); ok {
		return b.handleEffortCallback(ctx, callback, effort)
	}
	if approvalID, decision, ok := ParseApprovalCallbackData(callback.Data); ok {
		return b.handleApprovalCallback(ctx, callback, approvalID, decision)
	}
	return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Unknown action.")
}

func (b *Bot) handleApprovalCallback(ctx context.Context, callback *CallbackQuery, approvalID int64, decision string) error {
	approval, err := b.store.GetPendingApproval(ctx, callback.From.ID, approvalID)
	if err != nil {
		_ = b.tg.AnswerCallbackQuery(ctx, callback.ID, "Approval not found.")
		return nil
	}
	if decision == "details" {
		if err := b.tg.AnswerCallbackQuery(ctx, callback.ID, "Details sent."); err != nil {
			return err
		}
		return b.sendLong(ctx, callback.Message.Chat.ID, approval.PayloadJSON)
	}
	if approval.Status != "pending" {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Already resolved.")
	}
	requestID, err := strconv.ParseInt(approval.CodexRequestID, 10, 64)
	if err != nil {
		return b.tg.AnswerCallbackQuery(ctx, callback.ID, "Invalid request id.")
	}
	if err := b.codex.RespondServerRequest(ctx, requestID, approvalResponse(approval, decision)); err != nil {
		_ = b.tg.AnswerCallbackQuery(ctx, callback.ID, "Could not answer Codex.")
		return b.sendError(ctx, callback.Message.Chat.ID, "Could not answer Codex approval", err)
	}
	if err := b.store.ResolvePendingApproval(ctx, callback.From.ID, approval.ID, decision); err != nil {
		return err
	}
	if err := b.tg.AnswerCallbackQuery(ctx, callback.ID, "Sent to Codex."); err != nil {
		return err
	}
	updated := renderApprovalHTML(approval.Kind, json.RawMessage(approval.PayloadJSON), approvalStatusLine(decision))
	_, err = b.tg.EditMessageText(ctx, callback.Message.Chat.ID, callback.Message.MessageID, updated, EditMessageTextOptions{ParseMode: "HTML"})
	return err
}

func (b *Bot) handleCodexEvents(ctx context.Context) {
	for {
		select {
		case <-ctx.Done():
			return
		case event := <-b.codex.Events():
			if event.Err != nil {
				b.logger.Printf("codex event %s: %v", event.Method, event.Err)
				if event.Method == "connection/closed" {
					b.failActiveOutputs(ctx, "Codex connection closed: "+event.Err.Error())
				}
				continue
			}
			if event.ServerRequest {
				if err := b.handleCodexServerRequest(ctx, event); err != nil {
					b.logger.Printf("server request %s: %v", event.Method, err)
				}
				continue
			}
			if err := b.handleCodexNotification(ctx, event); err != nil {
				b.logger.Printf("notification %s: %v", event.Method, err)
			}
		}
	}
}

func parseCodexThreadItem(raw json.RawMessage) (codexThreadItemView, error) {
	var item codexThreadItemView
	if len(raw) == 0 {
		return item, nil
	}
	if err := json.Unmarshal(raw, &item); err != nil {
		return item, err
	}
	return item, nil
}

func renderCodexItemStarted(item codexThreadItemView) string {
	switch item.Type {
	case "commandExecution":
		return SummaryDetailsHTMLLimited(joinNonEmpty("Tool call: command started", commandSummaryLine(item.Command)), commandStartedDetails(item), TelegramHTMLMessageLimit)
	case "fileChange":
		return "Tool call: file change started"
	case "mcpToolCall":
		return joinNonEmpty("Tool call: MCP started", "Tool: "+toolDisplayName(item.Server, item.Tool))
	case "dynamicToolCall":
		return joinNonEmpty("Tool call: started", "Tool: "+toolDisplayName(item.Namespace, item.Tool))
	case "webSearch":
		return joinNonEmpty("Tool call: web search started", "Query: "+item.Query)
	case "imageView":
		return joinNonEmpty("Tool call: image view", "Path: "+item.Path)
	case "imageGeneration":
		return "Tool call: image generation started"
	case "collabAgentToolCall":
		return joinNonEmpty("Tool call: agent started", "Tool: "+item.Tool)
	default:
		return ""
	}
}

func renderCodexItemCompleted(item codexThreadItemView) string {
	switch item.Type {
	case "commandExecution":
		status := ""
		if item.ExitCode != nil {
			status = fmt.Sprintf("Exit code: %d", *item.ExitCode)
		}
		return SummaryDetailsHTMLLimited(joinNonEmpty("Tool call: command finished", commandSummaryLine(item.Command), status), renderCodexItemDetails(item), TelegramHTMLMessageLimit)
	case "fileChange":
		return joinNonEmpty("Tool call: file change finished", fmt.Sprintf("Changed files: %d", len(item.Changes)), "Status: "+item.Status)
	case "mcpToolCall":
		return joinNonEmpty("Tool call: MCP finished", "Tool: "+toolDisplayName(item.Server, item.Tool), "Status: "+item.Status)
	case "dynamicToolCall":
		status := item.Status
		if item.Success != nil {
			status = fmt.Sprintf("success=%t", *item.Success)
		}
		return joinNonEmpty("Tool call: finished", "Tool: "+toolDisplayName(item.Namespace, item.Tool), "Status: "+status)
	case "webSearch":
		return joinNonEmpty("Tool call: web search finished", "Query: "+item.Query)
	case "imageView":
		return joinNonEmpty("Tool call: image view finished", "Path: "+item.Path)
	case "imageGeneration":
		return joinNonEmpty("Tool call: image generation finished", "Status: "+item.Status, "Saved path: "+item.SavedPath)
	case "collabAgentToolCall":
		return joinNonEmpty("Tool call: agent finished", "Tool: "+item.Tool, "Status: "+item.Status)
	default:
		return ""
	}
}

func commandSummaryLine(command string) string {
	command = strings.TrimSpace(command)
	if command == "" {
		return ""
	}
	runes := []rune(command)
	if len(runes) <= commandSummaryLimit {
		return "Command: " + command
	}
	return "Command: " + string(runes[:commandSummaryLimit]) + "..."
}

func commandStartedDetails(item codexThreadItemView) string {
	var lines []string
	if strings.TrimSpace(item.Command) != "" && len([]rune(strings.TrimSpace(item.Command))) > commandSummaryLimit {
		lines = append(lines, "command: "+strings.TrimSpace(item.Command))
	}
	if strings.TrimSpace(item.CWD) != "" {
		lines = append(lines, "cwd: "+strings.TrimSpace(item.CWD))
	}
	return strings.Join(lines, "\n")
}

func renderCodexItemDetails(item codexThreadItemView) string {
	var lines []string
	appendKV := func(key string, value any) {
		switch v := value.(type) {
		case string:
			if strings.TrimSpace(v) != "" {
				lines = append(lines, fmt.Sprintf("%s: %s", key, v))
			}
		case *int:
			if v != nil {
				lines = append(lines, fmt.Sprintf("%s: %d", key, *v))
			}
		case *int64:
			if v != nil {
				lines = append(lines, fmt.Sprintf("%s: %d", key, *v))
			}
		case *bool:
			if v != nil {
				lines = append(lines, fmt.Sprintf("%s: %t", key, *v))
			}
		}
	}
	appendKV("type", item.Type)
	appendKV("id", item.ID)
	appendKV("command", item.Command)
	appendKV("cwd", item.CWD)
	appendKV("status", item.Status)
	appendKV("tool", toolDisplayName(item.Namespace, item.Tool))
	appendKV("server", item.Server)
	appendKV("query", item.Query)
	appendKV("path", item.Path)
	appendKV("savedPath", item.SavedPath)
	appendKV("exitCode", item.ExitCode)
	appendKV("durationMs", item.DurationMs)
	appendKV("success", item.Success)
	if len(item.Arguments) > 0 && string(item.Arguments) != "null" {
		lines = append(lines, "arguments: "+string(item.Arguments))
	}
	if len(item.Changes) > 0 {
		for _, change := range item.Changes {
			if change.Path != "" {
				lines = append(lines, "changed: "+change.Path)
			}
		}
	}
	if item.AggregatedOutput != nil && strings.TrimSpace(*item.AggregatedOutput) != "" {
		lines = append(lines, "output:\n"+strings.TrimSpace(*item.AggregatedOutput))
	}
	return strings.Join(lines, "\n")
}

func joinNonEmpty(lines ...string) string {
	out := make([]string, 0, len(lines))
	for _, line := range lines {
		if strings.TrimSpace(line) != "" {
			out = append(out, line)
		}
	}
	return strings.Join(out, "\n")
}

func toolDisplayName(namespace, tool string) string {
	if namespace == "" {
		return tool
	}
	if tool == "" {
		return namespace
	}
	return namespace + "." + tool
}

func truncateForStatus(text string) string {
	runes := []rune(text)
	if len(runes) <= 1200 {
		return text
	}
	return string(runes[:1200]) + "\n..."
}

func (b *Bot) handleCodexNotification(ctx context.Context, event codexapp.Event) error {
	switch event.Method {
	case "error":
		var params struct {
			ThreadID  string `json:"threadId"`
			TurnID    string `json:"turnId"`
			WillRetry bool   `json:"willRetry"`
			Error     struct {
				Message           string `json:"message"`
				AdditionalDetails string `json:"additionalDetails"`
			} `json:"error"`
		}
		if err := json.Unmarshal(event.Params, &params); err != nil {
			return err
		}
		if params.ThreadID != "" && !params.WillRetry {
			if thread, err := b.store.GetThreadByCodexID(ctx, params.ThreadID); err == nil {
				_ = b.store.SetActiveTurn(ctx, thread.TelegramUserID, "")
			}
			message := "Codex error"
			if params.Error.Message != "" {
				message += ": " + params.Error.Message
			}
			if params.Error.AdditionalDetails != "" {
				message += "\n" + params.Error.AdditionalDetails
			}
			if err := b.flushAssistantMessage(ctx, params.ThreadID); err != nil {
				return err
			}
			if err := b.sendOutputBlock(ctx, params.ThreadID, message); err != nil {
				return err
			}
			b.clearOutput(params.ThreadID)
			return nil
		}
	case "item/started":
		var params struct {
			ThreadID string          `json:"threadId"`
			Item     json.RawMessage `json:"item"`
		}
		if err := json.Unmarshal(event.Params, &params); err != nil {
			return err
		}
		item, err := parseCodexThreadItem(params.Item)
		if err != nil {
			return err
		}
		if params.ThreadID != "" && item.Type == "agentMessage" && b.hasAssistantText(params.ThreadID) {
			return b.flushAssistantMessage(ctx, params.ThreadID)
		}
		if params.ThreadID != "" {
			return b.sendOutputHTMLBlock(ctx, params.ThreadID, renderCodexItemStarted(item))
		}
	case "item/agentMessage/delta":
		var params struct {
			ThreadID string `json:"threadId"`
			Delta    string `json:"delta"`
		}
		if err := json.Unmarshal(event.Params, &params); err != nil {
			return err
		}
		if params.ThreadID != "" && params.Delta != "" {
			return b.appendAssistantDelta(ctx, params.ThreadID, params.Delta)
		}
	case "item/completed":
		var params struct {
			ThreadID string          `json:"threadId"`
			Item     json.RawMessage `json:"item"`
		}
		if err := json.Unmarshal(event.Params, &params); err != nil {
			return err
		}
		item, err := parseCodexThreadItem(params.Item)
		if err != nil {
			return err
		}
		if params.ThreadID != "" && item.Type == "agentMessage" {
			if item.Text != "" && !b.hasAssistantText(params.ThreadID) {
				if err := b.appendAssistantDelta(ctx, params.ThreadID, item.Text); err != nil {
					return err
				}
			}
			return b.flushAssistantMessage(ctx, params.ThreadID)
		}
		if params.ThreadID != "" {
			return b.sendOutputHTMLBlock(ctx, params.ThreadID, renderCodexItemCompleted(item))
		}
	case "turn/diff/updated":
		var params struct {
			ThreadID string `json:"threadId"`
			Diff     string `json:"diff"`
		}
		if err := json.Unmarshal(event.Params, &params); err != nil {
			return err
		}
		if params.ThreadID != "" {
			b.mu.Lock()
			b.diffs[params.ThreadID] = params.Diff
			b.mu.Unlock()
		}
	case "turn/completed":
		var params struct {
			ThreadID string `json:"threadId"`
			Turn     struct {
				ID     string `json:"id"`
				Status string `json:"status"`
			} `json:"turn"`
		}
		if err := json.Unmarshal(event.Params, &params); err != nil {
			return err
		}
		if params.ThreadID != "" {
			if thread, err := b.store.GetThreadByCodexID(ctx, params.ThreadID); err == nil {
				_ = b.store.SetActiveTurn(ctx, thread.TelegramUserID, "")
				_ = b.store.TouchThread(ctx, params.ThreadID)
			}
			return b.completeTurnOutput(ctx, params.ThreadID)
		}
	case "thread/name/updated":
		var params struct {
			ThreadID   string  `json:"threadId"`
			ThreadName *string `json:"threadName"`
		}
		if err := json.Unmarshal(event.Params, &params); err != nil {
			return err
		}
		if params.ThreadID != "" {
			title := ""
			if params.ThreadName != nil {
				title = normalizeThreadTitle(*params.ThreadName)
			}
			return b.store.SyncThreadTitleByCodexID(ctx, params.ThreadID, title)
		}
	case "serverRequest/resolved":
		var params struct {
			ThreadID  string `json:"threadId"`
			RequestID string `json:"requestId"`
		}
		_ = json.Unmarshal(event.Params, &params)
	}
	return nil
}

func (b *Bot) handleCodexServerRequest(ctx context.Context, event codexapp.Event) error {
	if event.ID == nil {
		return nil
	}
	switch event.Method {
	case "item/commandExecution/requestApproval", "item/fileChange/requestApproval", "item/permissions/requestApproval":
	default:
		b.logger.Printf("unhandled server request: %s", event.Method)
		return nil
	}
	var params struct {
		ThreadID string `json:"threadId"`
		TurnID   string `json:"turnId"`
		ItemID   string `json:"itemId"`
		Reason   string `json:"reason"`
	}
	if err := json.Unmarshal(event.Params, &params); err != nil {
		return err
	}
	if params.ThreadID == "" {
		return errors.New("approval request missing threadId")
	}
	thread, err := b.store.GetThreadByCodexID(ctx, params.ThreadID)
	if err != nil {
		return err
	}
	pretty, _ := json.MarshalIndent(json.RawMessage(event.Params), "", "  ")
	if len(pretty) == 0 {
		pretty = event.Params
	}
	kind := event.Method
	approval, err := b.store.UpsertPendingApproval(ctx, store.PendingApproval{
		TelegramUserID: thread.TelegramUserID,
		CodexRequestID: strconv.FormatInt(*event.ID, 10),
		CodexThreadID:  params.ThreadID,
		TurnID:         params.TurnID,
		ItemID:         params.ItemID,
		Kind:           kind,
		PayloadJSON:    string(pretty),
	})
	if err != nil {
		return err
	}
	text := renderApprovalHTML(kind, event.Params, "")
	msg, err := b.tg.SendMessage(ctx, thread.TelegramUserID, text, SendMessageOptions{
		ParseMode:   "HTML",
		ReplyMarkup: approvalMarkup(approval.ID),
	})
	if err != nil {
		return err
	}
	return b.store.UpdatePendingApprovalMessage(ctx, approval.ID, msg.Chat.ID, msg.MessageID)
}

func (b *Bot) registerOutput(threadID string, chatID int64) {
	b.mu.Lock()
	defer b.mu.Unlock()
	b.outputs[threadID] = &outputState{chatID: chatID}
}

func (b *Bot) clearOutput(threadID string) {
	b.mu.Lock()
	defer b.mu.Unlock()
	delete(b.outputs, threadID)
}

func (b *Bot) hasAssistantText(threadID string) bool {
	b.mu.Lock()
	defer b.mu.Unlock()
	state := b.outputs[threadID]
	return state != nil && state.assistant.Len() > 0
}

func (b *Bot) failActiveOutputs(ctx context.Context, message string) {
	b.mu.Lock()
	threadIDs := make([]string, 0, len(b.outputs))
	for threadID := range b.outputs {
		threadIDs = append(threadIDs, threadID)
	}
	b.mu.Unlock()

	for _, threadID := range threadIDs {
		if thread, err := b.store.GetThreadByCodexID(ctx, threadID); err == nil {
			_ = b.store.SetActiveTurn(ctx, thread.TelegramUserID, "")
		}
		if err := b.flushAssistantMessage(ctx, threadID); err != nil {
			b.logger.Printf("flush failed output %s: %v", threadID, err)
		}
		if err := b.sendOutputBlock(ctx, threadID, message); err != nil {
			b.logger.Printf("send failed output %s: %v", threadID, err)
		}
		b.clearOutput(threadID)
	}
}

func (b *Bot) sendOutputBlock(ctx context.Context, threadID, block string) error {
	block = strings.TrimSpace(block)
	if block == "" {
		return nil
	}
	if err := b.flushAssistantMessage(ctx, threadID); err != nil {
		return err
	}
	chatID, err := b.outputChatID(ctx, threadID)
	if err != nil {
		return nil
	}
	if err := b.sendLong(ctx, chatID, block); err != nil {
		return err
	}
	b.markOutputSent(threadID)
	return nil
}

func (b *Bot) sendOutputHTMLBlock(ctx context.Context, threadID, htmlText string) error {
	htmlText = strings.TrimSpace(htmlText)
	if htmlText == "" {
		return nil
	}
	if err := b.flushAssistantMessage(ctx, threadID); err != nil {
		return err
	}
	chatID, err := b.outputChatID(ctx, threadID)
	if err != nil {
		return nil
	}
	if err := b.sendHTML(ctx, chatID, htmlText); err != nil {
		return err
	}
	b.markOutputSent(threadID)
	return nil
}

func (b *Bot) appendAssistantDelta(ctx context.Context, threadID, delta string) error {
	if delta == "" {
		return nil
	}
	if _, err := b.outputChatID(ctx, threadID); err != nil {
		return nil
	}
	b.mu.Lock()
	state := b.outputs[threadID]
	if state != nil {
		_, _ = state.assistant.WriteString(delta)
	}
	b.mu.Unlock()
	return nil
}

func (b *Bot) flushAssistantMessage(ctx context.Context, threadID string) error {
	b.mu.Lock()
	state := b.outputs[threadID]
	if state == nil || state.assistant.Len() == 0 {
		b.mu.Unlock()
		return nil
	}
	chatID := state.chatID
	text := state.assistant.String()
	state.assistant.Reset()
	b.mu.Unlock()

	if err := b.sendLong(ctx, chatID, text); err != nil {
		return err
	}
	b.markOutputSent(threadID)
	return nil
}

func (b *Bot) completeTurnOutput(ctx context.Context, threadID string) error {
	if err := b.flushAssistantMessage(ctx, threadID); err != nil {
		return err
	}
	b.mu.Lock()
	state := b.outputs[threadID]
	if state == nil {
		b.mu.Unlock()
		return nil
	}
	chatID := state.chatID
	sentAny := state.sentAny
	delete(b.outputs, threadID)
	b.mu.Unlock()

	if !sentAny {
		_, err := b.tg.SendMessage(ctx, chatID, "Done.", SendMessageOptions{})
		return err
	}
	return nil
}

func (b *Bot) outputChatID(ctx context.Context, threadID string) (int64, error) {
	b.mu.Lock()
	state := b.outputs[threadID]
	if state != nil {
		chatID := state.chatID
		b.mu.Unlock()
		return chatID, nil
	}
	b.mu.Unlock()

	thread, err := b.store.GetThreadByCodexID(ctx, threadID)
	if err != nil {
		return 0, err
	}
	b.registerOutput(threadID, thread.TelegramUserID)
	return thread.TelegramUserID, nil
}

func (b *Bot) markOutputSent(threadID string) {
	b.mu.Lock()
	defer b.mu.Unlock()
	if state := b.outputs[threadID]; state != nil {
		state.sentAny = true
	}
}

func (b *Bot) sendLong(ctx context.Context, chatID int64, text string) error {
	for _, chunk := range ChunkText(text, TelegramHTMLMessageLimit) {
		if err := b.sendHTML(ctx, chatID, EscapeHTML(chunk)); err != nil {
			return err
		}
	}
	return nil
}

func (b *Bot) sendHTML(ctx context.Context, chatID int64, htmlText string) error {
	_, err := b.tg.SendMessage(ctx, chatID, htmlText, SendMessageOptions{ParseMode: "HTML"})
	return err
}

func (b *Bot) sendError(ctx context.Context, chatID int64, prefix string, err error) error {
	_, sendErr := b.tg.SendMessage(ctx, chatID, EscapeHTML(prefix+": "+err.Error()), SendMessageOptions{ParseMode: "HTML"})
	return sendErr
}

func (b *Bot) sendWorkspaceMissing(ctx context.Context, chatID int64) error {
	_, err := b.tg.SendMessage(ctx, chatID, "No workspace configured. Ask an admin to run scripts/add-workspace, then use /workspace.", SendMessageOptions{})
	return err
}

func (b *Bot) sendNoActiveThread(ctx context.Context, chatID int64, err error) error {
	if errors.Is(err, sql.ErrNoRows) {
		_, sendErr := b.tg.SendMessage(ctx, chatID, "No active thread. Use /new.", SendMessageOptions{})
		return sendErr
	}
	return err
}

func parseCommand(text string) (string, []string, bool) {
	text = strings.TrimSpace(text)
	if !strings.HasPrefix(text, "/") {
		return "", nil, false
	}
	fields := strings.Fields(text)
	if len(fields) == 0 {
		return "", nil, false
	}
	name := strings.TrimPrefix(fields[0], "/")
	if before, _, ok := strings.Cut(name, "@"); ok {
		name = before
	}
	return strings.ToLower(name), fields[1:], true
}

func resumeThreadListText(threads []store.Thread, page int) string {
	lines := []string{fmt.Sprintf("Resume a thread (page %d):", page+1), ""}
	for _, thread := range threads {
		lines = append(lines, fmt.Sprintf("Thread ID %d: %s", thread.ID, threadDisplayTitle(thread)))
	}
	lines = append(lines, "", "Choose a button below, or use /resume THREAD_ID directly.")
	return strings.Join(lines, "\n")
}

func resumeThreadMarkup(threads []store.Thread, page int, hasNext bool) *InlineKeyboardMarkup {
	keyboard := make([][]InlineKeyboardButton, 0, 4)
	for _, thread := range threads {
		button := InlineKeyboardButton{
			Text:         fmt.Sprintf("ID %d", thread.ID),
			CallbackData: ResumeThreadCallbackData(thread.ID),
		}
		if len(keyboard) == 0 || len(keyboard[len(keyboard)-1]) >= 4 {
			keyboard = append(keyboard, []InlineKeyboardButton{button})
			continue
		}
		keyboard[len(keyboard)-1] = append(keyboard[len(keyboard)-1], button)
	}
	var nav []InlineKeyboardButton
	if page > 0 {
		nav = append(nav, InlineKeyboardButton{Text: "Prev", CallbackData: ResumePageCallbackData(page - 1)})
	}
	if hasNext {
		nav = append(nav, InlineKeyboardButton{Text: "Next", CallbackData: ResumePageCallbackData(page + 1)})
	}
	if len(nav) > 0 {
		keyboard = append(keyboard, nav)
	}
	return &InlineKeyboardMarkup{InlineKeyboard: keyboard}
}

func normalizeThreadTitle(title string) string {
	title = strings.Join(strings.Fields(title), " ")
	runes := []rune(title)
	if len(runes) > 80 {
		title = string(runes[:80])
	}
	return title
}

func threadDisplayTitle(thread store.Thread) string {
	title := strings.Join(strings.Fields(thread.Title), " ")
	if title == "" {
		title = thread.CodexThreadID
	}
	runes := []rune(title)
	if len(runes) > 90 {
		title = string(runes[:90]) + "..."
	}
	return title
}

func workspaceMarkup(workspaces []store.Workspace) *InlineKeyboardMarkup {
	keyboard := make([][]InlineKeyboardButton, 0, len(workspaces))
	for _, ws := range workspaces {
		text := ws.Label
		if ws.IsDefault {
			text += " default"
		}
		keyboard = append(keyboard, []InlineKeyboardButton{{
			Text:         text,
			CallbackData: WorkspaceCallbackData(ws.ID),
		}})
	}
	return &InlineKeyboardMarkup{InlineKeyboard: keyboard}
}

func modelMarkup(models []codexapp.Model) *InlineKeyboardMarkup {
	keyboard := make([][]InlineKeyboardButton, 0, len(models))
	for _, model := range models {
		callbackData, ok := ModelCallbackData(model.ID)
		if !ok {
			continue
		}
		keyboard = append(keyboard, []InlineKeyboardButton{{
			Text:         modelLabel(model),
			CallbackData: callbackData,
		}})
	}
	return &InlineKeyboardMarkup{InlineKeyboard: keyboard}
}

func effortMarkup(model codexapp.Model) *InlineKeyboardMarkup {
	keyboard := make([][]InlineKeyboardButton, 0, len(model.SupportedReasoningEfforts))
	for _, option := range model.SupportedReasoningEfforts {
		label := option.ReasoningEffort
		if option.ReasoningEffort == model.DefaultReasoningEffort {
			label += " default"
		}
		keyboard = append(keyboard, []InlineKeyboardButton{{
			Text:         label,
			CallbackData: EffortCallbackData(option.ReasoningEffort),
		}})
	}
	return &InlineKeyboardMarkup{InlineKeyboard: keyboard}
}

func modelSupportsEffort(model codexapp.Model, effort string) bool {
	for _, option := range model.SupportedReasoningEfforts {
		if option.ReasoningEffort == effort {
			return true
		}
	}
	return false
}

func modelLabel(model codexapp.Model) string {
	label := model.DisplayName
	if label == "" {
		label = model.ID
	}
	if model.IsDefault {
		label += " default"
	}
	return label
}

func sessionModelLabel(models []codexapp.Model, modelID string) string {
	if modelID == "" {
		return "(Codex default)"
	}
	for _, model := range models {
		if model.ID == modelID {
			return modelLabel(model)
		}
	}
	return modelID
}

func settingsStatusText(model string, effort string) string {
	if effort == "" {
		effort = "(model default)"
	}
	return fmt.Sprintf("Current model: %s\nCurrent reasoning effort: %s", model, effort)
}

func (b *Bot) rememberSettingsMessage(ctx context.Context, userID int64, chatID int64, messageID int) {
	if messageID == 0 {
		return
	}
	if err := b.store.SetSessionSettingsMessage(ctx, userID, chatID, messageID); err != nil {
		b.logger.Printf("settings message store: %v", err)
		return
	}
	if err := b.tg.PinChatMessage(ctx, chatID, messageID, true); err != nil {
		b.logger.Printf("settings message pin: %v", err)
	}
}

func approvalMarkup(id int64) *InlineKeyboardMarkup {
	return &InlineKeyboardMarkup{InlineKeyboard: [][]InlineKeyboardButton{
		{
			{Text: "Approve", CallbackData: ApprovalCallbackData(id, "accept")},
			{Text: "Deny", CallbackData: ApprovalCallbackData(id, "decline")},
		},
		{
			{Text: "Details", CallbackData: ApprovalCallbackData(id, "details")},
			{Text: "Cancel", CallbackData: ApprovalCallbackData(id, "cancel")},
		},
	}}
}

func approvalResponse(approval store.PendingApproval, decision string) any {
	if approval.Kind != "item/permissions/requestApproval" {
		return map[string]any{"decision": decision}
	}

	scope := "turn"
	if decision == "acceptForSession" {
		scope = "session"
	}
	permissions := map[string]any{}
	if decision == "accept" || decision == "acceptForSession" {
		var params struct {
			Permissions map[string]any `json:"permissions"`
		}
		_ = json.Unmarshal([]byte(approval.PayloadJSON), &params)
		if params.Permissions != nil {
			permissions = params.Permissions
		}
	}
	return map[string]any{
		"permissions": permissions,
		"scope":       scope,
	}
}

func renderApprovalHTML(kind string, raw json.RawMessage, status string) string {
	title := "Codex approval requested"
	if strings.Contains(kind, "commandExecution") {
		title = "Codex requests command approval"
	}
	if strings.Contains(kind, "fileChange") {
		title = "Codex requests file change approval"
	}
	if strings.Contains(kind, "permissions") {
		title = "Codex requests permission approval"
	}

	var params map[string]any
	_ = json.Unmarshal(raw, &params)
	lines := []string{title}
	if reason, _ := params["reason"].(string); reason != "" {
		lines = append(lines, "", reason)
	}
	for _, key := range []string{"command", "cwd", "grantRoot", "permissions"} {
		if value, ok := params[key]; ok {
			lines = append(lines, fmt.Sprintf("%s: %s", key, conciseValue(value)))
		}
	}

	summary := strings.Join(lines, "\n")
	details := prettyJSON(raw)
	limit := TelegramHTMLMessageLimit
	if status != "" {
		limit -= len([]rune(status)) + 1
	}
	text := SummaryDetailsHTMLLimited(summary, details, limit)
	if status != "" {
		text += "\n" + EscapeHTML(status)
	}
	return text
}

func approvalStatusLine(decision string) string {
	switch decision {
	case "accept":
		return "Approved."
	case "acceptForSession":
		return "Approved for this session."
	case "decline":
		return "Disapproved."
	case "cancel":
		return "Canceled."
	default:
		return "Resolved: " + decision + "."
	}
}

func conciseValue(value any) string {
	text := fmt.Sprint(value)
	if data, err := json.Marshal(value); err == nil {
		text = string(data)
	}
	text = strings.Join(strings.Fields(text), " ")
	runes := []rune(text)
	if len(runes) > 180 {
		return string(runes[:180]) + "..."
	}
	return text
}

func prettyJSON(raw json.RawMessage) string {
	if len(raw) == 0 {
		return ""
	}
	var value any
	if err := json.Unmarshal(raw, &value); err != nil {
		return string(raw)
	}
	data, err := json.MarshalIndent(value, "", "  ")
	if err != nil {
		return string(raw)
	}
	return string(data)
}

func largestPhoto(photos []PhotoSize) PhotoSize {
	best := photos[0]
	bestScore := best.Width * best.Height
	for _, photo := range photos[1:] {
		score := photo.Width * photo.Height
		if score > bestScore {
			best = photo
			bestScore = score
		}
	}
	return best
}

func isImage(mimeType, filename string) bool {
	if strings.HasPrefix(strings.ToLower(mimeType), "image/") {
		return true
	}
	switch strings.ToLower(filepath.Ext(filename)) {
	case ".jpg", ".jpeg", ".png", ".gif", ".webp":
		return true
	default:
		return false
	}
}

func extensionForMime(mimeType string) string {
	extensions, err := mime.ExtensionsByType(mimeType)
	if err != nil || len(extensions) == 0 {
		return ""
	}
	return extensions[0]
}

func safeFilename(filename string) string {
	base := filepath.Base(filename)
	var builder strings.Builder
	for _, r := range base {
		switch {
		case r >= 'a' && r <= 'z':
			builder.WriteRune(r)
		case r >= 'A' && r <= 'Z':
			builder.WriteRune(r)
		case r >= '0' && r <= '9':
			builder.WriteRune(r)
		case r == '.', r == '-', r == '_':
			builder.WriteRune(r)
		default:
			builder.WriteByte('_')
		}
	}
	if builder.Len() == 0 {
		return "upload"
	}
	return builder.String()
}