/**
 * static/js/instructions.js
 * Renders the pending and consumed instruction panels.
 * Handles add, edit, delete interactions.
 */

import { state } from './state.js';
import { api } from './api.js';
import { toast } from './app.js';

// ── SVG icon helpers ──────────────────────────────────────────────────────

function iconEdit() {
  return `<svg class="icon" viewBox="0 0 24 24"><path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"/><path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"/></svg>`;
}

function iconDelete() {
  return `<svg class="icon" viewBox="0 0 24 24"><polyline points="3 6 5 6 21 6"/><path d="M19 6l-1 14a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2L5 6"/><path d="M10 11v6"/><path d="M14 11v6"/><path d="M9 6V4a1 1 0 0 1 1-1h4a1 1 0 0 1 1 1v2"/></svg>`;
}

function iconCheck() {
  return `<svg class="icon" viewBox="0 0 24 24"><polyline points="20 6 9 17 4 12"/></svg>`;
}

function iconX() {
  return `<svg class="icon" viewBox="0 0 24 24"><line x1="18" y1="6" x2="6" y2="18"/><line x1="6" y1="6" x2="18" y2="18"/></svg>`;
}

// ── Time formatters ───────────────────────────────────────────────────────

function fmtRelativeTime(isoStr) {
  if (!isoStr) return '–';
  const d = new Date(isoStr);
  const diff = Math.floor((Date.now() - d.getTime()) / 1000);
  if (diff < 5)  return 'just now';
  if (diff < 60) return `${diff}s ago`;
  if (diff < 3600) return `${Math.floor(diff / 60)}m ago`;
  if (diff < 86400) return `${Math.floor(diff / 3600)}h ago`;
  return d.toLocaleDateString();
}

function fmtAbsTime(isoStr) {
  if (!isoStr) return '–';
  const d = new Date(isoStr);
  return d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit', second: '2-digit' });
}

/** Refresh all relative-time spans in the lists (called by app.js on a timer). */
export function refreshTimestamps() {
  document.querySelectorAll('[data-ts]').forEach(el => {
    el.textContent = fmtRelativeTime(el.dataset.ts);
  });
}

// ── Card renderer ─────────────────────────────────────────────────────────

function renderPendingCard(item, index) {
  const card = document.createElement('div');
  card.className = 'instruction-card';
  card.dataset.id = item.id;
  card.style.animationDelay = `${index * 30}ms`;

  card.innerHTML = `
    <div class="instruction-card__meta">
      <span class="instruction-card__pos">#${item.position}</span>
      <span class="instruction-card__time" data-ts="${item.created_at}">${fmtRelativeTime(item.created_at)}</span>
    </div>
    <div class="instruction-card__content">${escapeHtml(item.content)}</div>
    <div class="instruction-card__actions">
      <button class="btn btn--ghost btn--icon btn--edit" title="Edit instruction" aria-label="Edit">${iconEdit()}</button>
      <button class="btn btn--danger btn--icon btn--delete" title="Delete instruction" aria-label="Delete">${iconDelete()}</button>
    </div>
    <div class="instruction-card__edit-area" style="display:none; grid-column:1/-1;">
      <textarea class="textarea edit-textarea" rows="3">${escapeHtml(item.content)}</textarea>
      <div style="display:flex;flex-direction:column;gap:var(--space-2)">
        <button class="btn btn--primary btn--sm btn--save" title="Save">${iconCheck()}</button>
        <button class="btn btn--ghost btn--sm btn--cancel" title="Cancel">${iconX()}</button>
      </div>
    </div>
  `;

  const editBtn   = card.querySelector('.btn--edit');
  const deleteBtn = card.querySelector('.btn--delete');
  const cancelBtn = card.querySelector('.btn--cancel');
  const saveBtn   = card.querySelector('.btn--save');
  const editArea  = card.querySelector('.instruction-card__edit-area');
  const content   = card.querySelector('.instruction-card__content');
  const actions   = card.querySelector('.instruction-card__actions');
  const editTA    = card.querySelector('.edit-textarea');

  function showEdit() {
    editTA.value = item.content;
    editArea.style.display = 'flex';
    content.style.display = 'none';
    actions.style.display = 'none';
    editTA.focus();
    editTA.setSelectionRange(editTA.value.length, editTA.value.length);
  }

  function hideEdit() {
    editArea.style.display = 'none';
    content.style.display = '';
    actions.style.display = '';
  }

  editBtn.addEventListener('click', showEdit);
  cancelBtn.addEventListener('click', hideEdit);

  editTA.addEventListener('keydown', (e) => {
    if (e.key === 'Escape') { e.preventDefault(); hideEdit(); }
    if (e.key === 'Enter' && !e.shiftKey) { e.preventDefault(); saveBtn.click(); }
    // Shift+Enter → default browser behaviour (newline)
  });

  saveBtn.addEventListener('click', async () => {
    const newContent = editTA.value.trim();
    if (!newContent) { toast('Content cannot be empty', 'error'); return; }
    saveBtn.disabled = true;
    try {
      await api.updateInstruction(item.id, newContent);
      toast('Instruction updated', 'success');
    } catch (e) {
      toast(e.message, 'error');
    } finally {
      saveBtn.disabled = false;
    }
  });

  deleteBtn.addEventListener('click', async () => {
    if (!confirm('Delete this instruction?')) return;
    deleteBtn.disabled = true;
    try {
      await api.deleteInstruction(item.id);
      toast('Instruction deleted', 'info');
    } catch (e) {
      toast(e.message, 'error');
      deleteBtn.disabled = false;
    }
  });

  return card;
}

function renderConsumedCard(item) {
  const card = document.createElement('div');
  card.className = 'instruction-card instruction-card--consumed';
  card.dataset.id = item.id;

  card.innerHTML = `
    <div class="instruction-card__meta">
      <span class="instruction-card__pos">#${item.position}</span>
      <span class="instruction-card__time">${fmtAbsTime(item.consumed_at)}</span>
      ${item.consumed_by_agent_id
        ? `<span class="instruction-card__consumed-by">→ ${escapeHtml(item.consumed_by_agent_id)}</span>`
        : ''}
    </div>
    <div class="instruction-card__content">${escapeHtml(item.content)}</div>
    <div></div>
  `;
  return card;
}

// ── List renderers ────────────────────────────────────────────────────────

export function initInstructions() {
  const pendingList    = document.getElementById('pending-list');
  const pendingBadge   = document.getElementById('pending-badge');
  const consumedList   = document.getElementById('consumed-list');
  const consumedBadge  = document.getElementById('consumed-badge');
  const clearHistoryBtn = document.getElementById('clear-history-btn');

  function render(instructions) {
    if (!instructions) return;
    const pending  = instructions.filter(i => i.status === 'pending');
    const consumed = instructions.filter(i => i.status === 'consumed').reverse();

    // Pending
    pendingList.innerHTML = '';
    if (pending.length === 0) {
      pendingList.innerHTML = `
        <div class="empty-state">
          <div class="empty-state__icon">◈</div>
          Queue is empty – add an instruction above
        </div>`;
    } else {
      pending.forEach((item, i) => pendingList.appendChild(renderPendingCard(item, i)));
    }
    pendingBadge.textContent = pending.length;
    pendingBadge.className   = `badge ${pending.length > 0 ? 'badge--cyan' : 'badge--muted'}`;

    // Consumed
    consumedList.innerHTML = '';
    if (consumed.length === 0) {
      consumedList.innerHTML = `<div class="empty-state"><div class="empty-state__icon">◈</div>No consumed instructions yet</div>`;
      clearHistoryBtn.style.display = 'none';
    } else {
      consumed.forEach(item => consumedList.appendChild(renderConsumedCard(item)));
      clearHistoryBtn.style.display = '';
    }
    consumedBadge.textContent = consumed.length;
    consumedBadge.className   = `badge ${consumed.length > 0 ? 'badge--amber' : 'badge--muted'}`;
  }

  state.subscribe('instructions', render);

  // Clear history button
  clearHistoryBtn.addEventListener('click', async () => {
    if (!confirm('Clear all consumed instruction history? This cannot be undone.')) return;
    clearHistoryBtn.disabled = true;
    try {
      const res = await api.clearConsumed();
      toast(`Cleared ${res.cleared} consumed instruction${res.cleared !== 1 ? 's' : ''}`, 'info');
    } catch (e) {
      toast(e.message, 'error');
    } finally {
      clearHistoryBtn.disabled = false;
    }
  });
}

// ── Composer ──────────────────────────────────────────────────────────────

export function initComposer() {
  const form    = document.getElementById('composer-form');
  const textarea = document.getElementById('composer-input');
  const btn     = document.getElementById('composer-submit');

  textarea.addEventListener('keydown', (e) => {
    if (e.key === 'Enter' && !e.shiftKey) {
      // Plain Enter → submit (like a chat box)
      e.preventDefault();
      form.requestSubmit();
    }
    // Shift+Enter → default browser behaviour (newline)
  });

  form.addEventListener('submit', async (e) => {
    e.preventDefault();
    const content = textarea.value.trim();
    if (!content) return;

    btn.disabled = true;
    const original = btn.innerHTML;
    btn.innerHTML = '<span class="spinner"></span>';

    try {
      await api.createInstruction(content);
      textarea.value = '';
      textarea.style.height = '';
      toast('Instruction queued', 'success');
    } catch (err) {
      toast(err.message, 'error');
    } finally {
      btn.disabled = false;
      btn.innerHTML = original;
      textarea.focus();
    }
  });

  // Auto-resize textarea
  textarea.addEventListener('input', () => {
    textarea.style.height = 'auto';
    textarea.style.height = textarea.scrollHeight + 'px';
  });
}

// ── Utility ───────────────────────────────────────────────────────────────

function escapeHtml(str) {
  return String(str)
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}