package agent

import (
	"context"
	"errors"
	"time"

	rvboxv1 "github.com/rvbox/rvbox/gen/go/rvbox/v1"
	"github.com/rvbox/rvbox/internal/domain"
)

var ErrInvalidReconcileResult = errors.New("invalid reconciliation result")

// ReconcileStore is the narrowly scoped durable operation required after the
// server has confirmed a terminal command. Keeping the interface small lets the
// network loop remain independent of SQLite and of the Windows supervisor.
type ReconcileStore interface {
	DiscardTerminal(context.Context, domain.UUID, time.Time) error
}

// ApplyReconcileResult commits server-authorized terminal discards before the
// session starts new work. It returns the active command IDs that the caller
// must first terminate through the supervisor; marking those terminal is not
// safe until the owned process and output readers have stopped.
func ApplyReconcileResult(ctx context.Context, store ReconcileStore, result *rvboxv1.ReconcileResult, now time.Time) ([]domain.UUID, error) {
	if store == nil || result == nil || now.IsZero() {
		return nil, ErrInvalidReconcileResult
	}
	seen := make(map[domain.UUID]struct{}, len(result.GetTerminateLocalIssueUuids())+len(result.GetDiscardLocalTerminalIssueUuids()))
	terminate := make([]domain.UUID, 0, len(result.GetTerminateLocalIssueUuids()))
	for _, set := range [][]string{result.GetTerminateLocalIssueUuids(), result.GetDiscardLocalTerminalIssueUuids()} {
		for _, text := range set {
			issue, err := domain.ParseUUIDv7(text)
			if err != nil {
				return nil, ErrInvalidReconcileResult
			}
			if _, duplicate := seen[issue]; duplicate {
				return nil, ErrInvalidReconcileResult
			}
			seen[issue] = struct{}{}
		}
	}
	for _, text := range result.GetDiscardLocalTerminalIssueUuids() {
		issue, _ := domain.ParseUUIDv7(text)
		if err := store.DiscardTerminal(ctx, issue, now); err != nil {
			return nil, err
		}
	}
	for _, text := range result.GetTerminateLocalIssueUuids() {
		issue, _ := domain.ParseUUIDv7(text)
		terminate = append(terminate, issue)
	}
	return terminate, nil
}