/**
 * Bayan — Inline Analysis Engine (Phase 7.1 Simplified)
 *
 * Dependencies: BayanController (analysis-controller.js)
 * State: local variables only (no external state manager)
 *
 * Architecture:
 *   1. DETECTION — find editable fields
 *   2. ANALYSIS  — debounced via BayanController → background.js
 *   3. OVERLAY   — highlights, tooltip, FAB (never modifies user DOM content)
 *
 * Safety:
 *   - Overlay-only rendering for ALL field types (never replaces innerHTML of user content)
 *   - Trusted Types for Gmail/Google Sites
 *   - Error boundary with graceful pause
 *   - Protected sites: disable contenteditable on Gmail/Docs/Notion
 */

(function () {
  'use strict';

  if (window.location.protocol === 'chrome-extension:') return;

  if (typeof BayanController === 'undefined') {
    console.error('[Bayan] BayanController not loaded.');
    return;
  }

  // ══════════════════════════════════════════════════════════
  // Trusted Types
  // ══════════════════════════════════════════════════════════
  let ttPolicy = null;
  try {
    if (window.trustedTypes?.createPolicy) {
      ttPolicy = window.trustedTypes.createPolicy('bayan-inline-policy', {
        createHTML: (input) => input,
      });
    }
  } catch {}

  function safeHTML(el, html) {
    try {
      el.innerHTML = ttPolicy ? ttPolicy.createHTML(html) : html;
    } catch {
      el.textContent = '';
      const t = document.createElement('template');
      t.innerHTML = html;
      el.appendChild(t.content.cloneNode(true));
    }
  }

  // ══════════════════════════════════════════════════════════
  // Local state (replaces BayanState — simpler, no extra file)
  // ══════════════════════════════════════════════════════════
  const IS_PROTECTED = BayanController.isProtectedSite();

  let activeField = null;
  let lastAnalyzedText = '';
  let suggestions = [];
  let paused = false;
  let floatingBtn = null;
  let tooltip = null;
  let overlayContainer = null;
  let badgeCount = null;
  let observer = null;

  // ══════════════════════════════════════════════════════════
  // 1. DETECTION
  // ══════════════════════════════════════════════════════════

  function isEditableField(el) {
    if (!el?.tagName) return false;
    const tag = el.tagName.toLowerCase();
    if (tag === 'textarea') return true;
    if (tag === 'input') {
      const type = (el.type || '').toLowerCase();
      return ['text', 'search', 'url', ''].includes(type);
    }
    // Contenteditable: allow on non-protected sites
    if (el.isContentEditable && !IS_PROTECTED) return true;
    return false;
  }

  function getFieldText(field) {
    if (!field) return '';
    const tag = field.tagName.toLowerCase();
    if (tag === 'textarea' || tag === 'input') return field.value || '';
    return field.innerText || field.textContent || '';
  }

  // ══════════════════════════════════════════════════════════
  // 2. ANALYSIS (delegates to BayanController)
  // ══════════════════════════════════════════════════════════

  function onFieldInput() {
    if (paused || !activeField) return;

    const text = getFieldText(activeField);

    if (!BayanController.hasArabic(text)) {
      clearHighlights();
      updateBadge(0);
      return;
    }

    updateBadge(-1);

    BayanController.scheduleAnalysis(
      text,
      (result) => {
        try { onAnalysisResult(result); } catch (err) {
          console.warn('[Bayan] Callback error:', err.message);
          handleFailure('callback_error');
        }
      },
      () => getFieldText(activeField)
    );
  }

  function onAnalysisResult(data) {
    if (!activeField) return;

    if (!data) {
      updateBadge(0);
      return;
    }

    suggestions = data.suggestions || [];
    lastAnalyzedText = data.original || getFieldText(activeField);
    updateBadge(suggestions.length);

    if (suggestions.length > 0) {
      renderOverlay(activeField, lastAnalyzedText, suggestions);
    } else {
      clearHighlights();
    }
  }

  // ══════════════════════════════════════════════════════════
  // Error boundary
  // ══════════════════════════════════════════════════════════

  function handleFailure(reason) {
    paused = true;
    clearHighlights();
    BayanController.cancelAll();
    if (badgeCount) {
      badgeCount.textContent = '⏸';
      badgeCount.className = 'bayan-il-badge bayan-il-badge--paused';
    }
    console.warn(`[Bayan] Inline paused: ${reason}. Side Panel still works.`);
  }

  // ══════════════════════════════════════════════════════════
  // 3. OVERLAY — always overlay, never modify user content
  //
  // Task 10: ALL field types use overlay rendering.
  // This prevents formatting destruction on Medium, Slack,
  // WordPress, Ghost, Discourse, etc.
  // ══════════════════════════════════════════════════════════

  function renderOverlay(field, originalText, suggs) {
    clearHighlights();
    if (!field || !suggs?.length) return;

    try {
      const rect = field.getBoundingClientRect();
      const cs = window.getComputedStyle(field);

      overlayContainer = document.createElement('div');
      overlayContainer.className = 'bayan-il-overlay';
      overlayContainer.style.cssText = `position:absolute;top:${rect.top + window.scrollY}px;`
        + `left:${rect.left + window.scrollX}px;width:${rect.width}px;height:${rect.height}px;`
        + `font-family:${cs.fontFamily};font-size:${cs.fontSize};line-height:${cs.lineHeight};`
        + `padding:${cs.padding};border:${cs.border};border-color:transparent;`
        + `direction:${cs.direction};text-align:${cs.textAlign};overflow:hidden;`
        + `pointer-events:none;z-index:2147483645;box-sizing:border-box;`
        + `white-space:pre-wrap;word-wrap:break-word;color:transparent;`;

      const sorted = [...suggs].sort((a, b) => a.start - b.start);
      let html = '';
      let pos = 0;

      sorted.forEach((s) => {
        if (pos < s.start) html += esc(originalText.slice(pos, s.start));
        html += `<span class="${errCls(s.type)} bayan-il-error bayan-il-overlay-mark" `
          + `data-bayan-sid="${s.id || ''}" data-bayan-original="${esc(s.original)}" `
          + `data-bayan-correction="${esc(s.correction)}" data-bayan-type="${s.type}" `
          + `data-bayan-start="${s.start}" data-bayan-end="${s.end}" `
          + `style="pointer-events:auto;cursor:pointer;">`
          + `${esc(originalText.slice(s.start, s.end))}</span>`;
        pos = s.end;
      });
      if (pos < originalText.length) html += esc(originalText.slice(pos));

      safeHTML(overlayContainer, html);
      overlayContainer.scrollTop = field.scrollTop;
      overlayContainer.scrollLeft = field.scrollLeft;
      document.body.appendChild(overlayContainer);

      overlayContainer.addEventListener('mousedown', (e) => e.preventDefault());

      field.addEventListener('scroll', syncOverlay);

      overlayContainer.querySelectorAll('.bayan-il-overlay-mark').forEach((mark) => {
        mark.addEventListener('click', (e) => {
          e.stopPropagation();
          showTooltip(mark, activeField);
        });
      });
    } catch (err) {
      console.warn('[Bayan] Overlay error:', err.message);
      handleFailure('render_error');
    }
  }

  function syncOverlay() {
    if (overlayContainer && activeField) {
      overlayContainer.scrollTop = activeField.scrollTop;
      overlayContainer.scrollLeft = activeField.scrollLeft;
    }
  }

  function clearHighlights() {
    if (overlayContainer) { overlayContainer.remove(); overlayContainer = null; }
    hideTooltip();
  }

  // ══════════════════════════════════════════════════════════
  // Tooltip
  // ══════════════════════════════════════════════════════════

  function showTooltip(el, field) {
    hideTooltip();

    const original = el.dataset.bayanOriginal;
    const correction = el.dataset.bayanCorrection;
    const type = el.dataset.bayanType;
    const start = parseInt(el.dataset.bayanStart, 10);
    const end = parseInt(el.dataset.bayanEnd, 10);
    const sid = el.dataset.bayanSid;

    if (!original || !correction) return;

    const suggestion = { id: sid, original, correction, type, start, end };
    const typeLabels = { spelling: 'إملائي', grammar: 'نحوي', punctuation: 'ترقيم' };

    tooltip = document.createElement('div');
    tooltip.className = 'bayan-il-tooltip';
    tooltip.dir = 'rtl';

    safeHTML(tooltip, `
      <div class="bayan-il-tooltip-header">
        <span class="bayan-il-tooltip-badge bayan-il-badge-${type}">${typeLabels[type] || type}</span>
        <button class="bayan-il-tooltip-close" title="إغلاق">✕</button>
      </div>
      <div class="bayan-il-tooltip-body">
        <span class="bayan-il-tooltip-original">${esc(original)}</span>
        <span class="bayan-il-tooltip-arrow">←</span>
        <span class="bayan-il-tooltip-correction">${correction ? esc(correction) : '<s style="opacity:0.5">حذف</s>'}</span>
      </div>
      <div class="bayan-il-tooltip-actions">
        <button class="bayan-il-tooltip-apply" data-action="apply">تطبيق</button>
        <button class="bayan-il-tooltip-ignore" data-action="ignore">تجاهل</button>
      </div>
    `);

    document.body.appendChild(tooltip);

    const r = el.getBoundingClientRect();
    tooltip.style.top = `${r.bottom + window.scrollY + 6}px`;
    tooltip.style.left = `${r.left + window.scrollX}px`;

    requestAnimationFrame(() => {
      if (!tooltip) return;
      const tr = tooltip.getBoundingClientRect();
      if (tr.right > window.innerWidth) tooltip.style.left = `${window.innerWidth - tr.width - 8}px`;
      tooltip.classList.add('bayan-il-tooltip--visible');
    });

    tooltip.querySelector('[data-action="apply"]').addEventListener('click', () => {
      applyFix(field, suggestion);
      hideTooltip();
    });

    tooltip.querySelector('[data-action="ignore"]').addEventListener('click', () => {
      dismissSuggestion(suggestion);
      hideTooltip();
    });

    tooltip.querySelector('.bayan-il-tooltip-close').addEventListener('click', () => hideTooltip());

    setTimeout(() => document.addEventListener('click', outsideClick, { once: true }), 100);
  }

  function outsideClick(e) {
    if (tooltip && !tooltip.contains(e.target)) hideTooltip();
  }

  function hideTooltip() {
    if (tooltip) { tooltip.remove(); tooltip = null; }
  }

  // ══════════════════════════════════════════════════════════
  // Fix application (overlay-only: modify field value, re-render overlay)
  // ══════════════════════════════════════════════════════════

  function applyFix(field, suggestion) {
    if (!field) return;

    const isInput = field.tagName.toLowerCase() === 'textarea' || field.tagName.toLowerCase() === 'input';
    const text = isInput ? field.value : getFieldText(field);
    const before = text.substring(0, suggestion.start);
    const after = text.substring(suggestion.end);
    const newText = before + suggestion.correction + after;

    const delta = suggestion.correction.length - (suggestion.end - suggestion.start);
    suggestions = suggestions
      .filter((s) => s.id !== suggestion.id)
      .map((s) => s.start >= suggestion.end ? { ...s, start: s.start + delta, end: s.end + delta } : s);

    lastAnalyzedText = newText;

    if (isInput) {
      field.value = newText;
      field.dispatchEvent(new Event('input', { bubbles: true }));
    } else {
      // FIX-17: Use textContent instead of innerText for better compatibility
      // This preserves the DOM structure better than innerText assignment
      field.textContent = newText;
    }

    if (suggestions.length > 0) {
      renderOverlay(field, newText, suggestions);
    } else {
      clearHighlights();
      // FIX-21: Trigger re-analysis after applying last fix
      // This catches any remaining errors that were masked by the fixed one
      setTimeout(() => onFieldInput(), 500);
    }
    updateBadge(suggestions.length);
  }

  function dismissSuggestion(suggestion) {
    suggestions = suggestions.filter((s) => s.id !== suggestion.id);
    if (suggestions.length > 0) {
      renderOverlay(activeField, lastAnalyzedText, suggestions);
    } else {
      clearHighlights();
    }
    updateBadge(suggestions.length);
  }

  // ══════════════════════════════════════════════════════════
  // UI: FAB + Badge
  // ══════════════════════════════════════════════════════════

  function createFloatingBtn() {
    if (floatingBtn) return;

    floatingBtn = document.createElement('div');
    floatingBtn.className = 'bayan-il-fab';
    safeHTML(floatingBtn, `
      <svg width="18" height="18" viewBox="0 0 100 100" fill="none">
        <circle cx="50" cy="50" r="46" fill="url(#blGrad)" />
        <path d="M30 55 Q35 35, 50 30 Q65 35, 70 55 Q65 65, 50 70 Q35 65, 30 55Z" fill="rgba(255,255,255,0.9)" />
        <circle cx="50" cy="42" r="4" fill="url(#blGrad)" />
        <defs>
          <linearGradient id="blGrad" x1="0" y1="0" x2="100" y2="100">
            <stop offset="0%" stop-color="#6366f1"/>
            <stop offset="100%" stop-color="#8b5cf6"/>
          </linearGradient>
        </defs>
      </svg>
      <span class="bayan-il-badge">0</span>
    `);
    floatingBtn.title = 'Bayan — بيان';
    document.body.appendChild(floatingBtn);
    badgeCount = floatingBtn.querySelector('.bayan-il-badge');

    floatingBtn.addEventListener('click', (e) => {
      e.stopPropagation();
      if (paused) {
        paused = false;
        updateBadge(0);
        onFieldInput();
        return;
      }
      if (suggestions.length > 0) {
        try {
          chrome.runtime.sendMessage({ type: 'OPEN_SIDEPANEL', text: lastAnalyzedText });
        } catch {}
      }
    });
  }

  function positionFab(field) {
    if (!floatingBtn || !field) return;
    const rect = field.getBoundingClientRect();
    floatingBtn.style.top = `${Math.max(4, rect.top + window.scrollY + 6)}px`;
    floatingBtn.style.left = `${Math.max(4, rect.left + window.scrollX + 6)}px`;
    floatingBtn.classList.add('bayan-il-fab--visible');
  }

  function updateBadge(count) {
    if (!badgeCount) return;
    if (count === -1) {
      badgeCount.textContent = '…';
      badgeCount.className = 'bayan-il-badge bayan-il-badge--analyzing';
    } else if (count === 0) {
      badgeCount.textContent = '✓';
      badgeCount.className = 'bayan-il-badge bayan-il-badge--clean';
    } else {
      badgeCount.textContent = String(count);
      badgeCount.className = 'bayan-il-badge bayan-il-badge--errors';
    }
  }

  // ══════════════════════════════════════════════════════════
  // Utilities
  // ══════════════════════════════════════════════════════════

  function esc(text) {
    const m = { '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#039;' };
    return String(text).replace(/[&<>"']/g, (c) => m[c]);
  }

  function errCls(type) {
    return { spelling: 'bayan-il-spelling', grammar: 'bayan-il-grammar', punctuation: 'bayan-il-punctuation' }[type] || 'bayan-il-spelling';
  }

  // ══════════════════════════════════════════════════════════
  // Field lifecycle (Task 7: no listener tracking leak)
  //
  // Per-field listeners use direct add/remove (NOT _trackedListeners).
  // Global listeners use addEventListener directly (cleaned on unload).
  // ══════════════════════════════════════════════════════════

  function attachField(field) {
    if (activeField === field) return;
    detachField();

    activeField = field;
    suggestions = [];
    if (paused) paused = false;

    createFloatingBtn();
    positionFab(field);

    field.addEventListener('input', onFieldInput);
    // FIX-20: Removed redundant 'keyup' listener (input event already fires on every change)

    if (BayanController.hasArabic(getFieldText(field))) {
      onFieldInput();
    }
  }

  function detachField() {
    if (activeField) {
      activeField.removeEventListener('input', onFieldInput);
      // FIX-20: keyup listener no longer attached
      activeField.removeEventListener('scroll', syncOverlay);
    }
    clearHighlights();
    BayanController.cancelAll();
    activeField = null;
    suggestions = [];
    if (floatingBtn) floatingBtn.classList.remove('bayan-il-fab--visible');
  }

  // ══════════════════════════════════════════════════════════
  // Global listeners
  // ══════════════════════════════════════════════════════════

  document.addEventListener('focusin', (e) => {
    if (isEditableField(e.target)) attachField(e.target);
  }, true);

  document.addEventListener('focusout', () => {
    setTimeout(() => {
      if (!activeField) return;
      if (document.activeElement === activeField) return;
      const a = document.activeElement;
      if (tooltip?.contains(a)) return;
      if (floatingBtn?.contains(a)) return;
      if (overlayContainer?.contains(a)) return;
      if (document.querySelector('.bayan-il-tooltip')) return;
      detachField();
    }, 300);
  }, true);

  window.addEventListener('scroll', () => {
    if (activeField && floatingBtn) positionFab(activeField);
    if (overlayContainer && activeField) {
      const rect = activeField.getBoundingClientRect();
      overlayContainer.style.top = `${rect.top + window.scrollY}px`;
      overlayContainer.style.left = `${rect.left + window.scrollX}px`;
    }
  }, { passive: true });

  window.addEventListener('resize', () => {
    if (activeField && floatingBtn) positionFab(activeField);
  }, { passive: true });

  // ── MutationObserver ──
  observer = new MutationObserver(() => {
    if (activeField && !document.body.contains(activeField)) detachField();
  });
  observer.observe(document.body, { childList: true, subtree: true });

  // ── Log ──
  const mode = IS_PROTECTED ? 'protected' : 'full';
  console.log(`[Bayan] Inline engine v7.1 (mode: ${mode}, TT: ${ttPolicy ? 'yes' : 'no'})`);
})();