// Outlook Relook — Gmail-Style Keyboard Navigation & Multi-Select
// Adds keyboard focus cursor and multi-select to OWA's message list.
// Gated by the keyboardMultiSelect setting.
//
// Tracks selections by stable message ID (data attribute or aria-label)
// rather than DOM element reference, since OWA frequently re-renders rows.

window.OutlookRelook = window.OutlookRelook || {};

window.OutlookRelook.Keyboard = (function () {
  'use strict';

  var OR = window.OutlookRelook;
  var currentSettings = {};
  var cleanupFns = [];

  // State — track by ID strings, not DOM references
  var focusedId = null;          // ID of the focused message
  var selectedIds = new Set();   // Set of selected message IDs
  var countBadge = null;

  // --- Message ID extraction ---
  // OWA messages have various attributes we can use as stable IDs.
  // Try data-convid, data-itemid, id, or fall back to aria-label.

  function getMessageId(el) {
    return el.getAttribute('data-convid')
      || el.getAttribute('data-itemid')
      || el.getAttribute('data-tid')
      || el.getAttribute('id')
      || el.getAttribute('aria-label')
      || null;
  }

  function getMessageItems() {
    var items = document.querySelectorAll(
      '[role="listbox"] [role="option"], [role="list"] [role="listitem"]'
    );
    return Array.from(items);
  }

  function findItemById(items, id) {
    if (!id) return -1;
    for (var i = 0; i < items.length; i++) {
      if (getMessageId(items[i]) === id) return i;
    }
    return -1;
  }

  function isComposeOrDialogActive() {
    var active = document.activeElement;
    if (!active) return false;
    var tag = active.tagName.toLowerCase();
    if (tag === 'input' || tag === 'textarea') return true;
    if (active.getAttribute('contenteditable') === 'true') return true;
    if (active.closest('[role="dialog"]')) return true;
    if (active.closest('[role="search"]')) return true;
    if (active.closest('[aria-label*="compose" i]')) return true;
    if (active.closest('[aria-label*="New message" i]')) return true;
    return false;
  }

  // --- Visual state application ---
  // Re-applies focus and selection classes to current DOM elements
  // based on the ID-based state. Called after every key action and
  // by the MutationObserver when OWA re-renders.

  function applyVisualState(items) {
    // Clear all visual markers first
    var oldFocused = document.querySelectorAll('.or-kb-focused');
    for (var f = 0; f < oldFocused.length; f++) oldFocused[f].classList.remove('or-kb-focused');
    var oldSelected = document.querySelectorAll('.or-kb-selected');
    for (var s = 0; s < oldSelected.length; s++) oldSelected[s].classList.remove('or-kb-selected');

    if (!items) items = getMessageItems();

    // Apply focus
    if (focusedId) {
      var focusIdx = findItemById(items, focusedId);
      if (focusIdx >= 0) {
        items[focusIdx].classList.add('or-kb-focused');
      }
    }

    // Apply selections
    selectedIds.forEach(function (id) {
      var idx = findItemById(items, id);
      if (idx >= 0) {
        items[idx].classList.add('or-kb-selected');
      }
    });

    updateCountBadge();
  }

  // --- Focus management ---

  function getFocusedIndex(items) {
    if (!focusedId) return -1;
    return findItemById(items, focusedId);
  }

  function setFocus(items, index) {
    if (index < 0 || index >= items.length) return;
    focusedId = getMessageId(items[index]);
    applyVisualState(items);
    items[index].scrollIntoView({ block: 'nearest', behavior: 'smooth' });
  }

  // --- Selection management ---

  function toggleSelect(items, index) {
    if (index < 0 || index >= items.length) return;
    var id = getMessageId(items[index]);
    if (!id) return;

    if (selectedIds.has(id)) {
      selectedIds.delete(id);
    } else {
      selectedIds.add(id);
    }
    applyVisualState(items);
  }

  function clearSelection() {
    selectedIds.clear();
    var oldSelected = document.querySelectorAll('.or-kb-selected');
    for (var i = 0; i < oldSelected.length; i++) oldSelected[i].classList.remove('or-kb-selected');
    updateCountBadge();
  }

  function getActionTargets(items) {
    var targets = [];
    if (selectedIds.size > 0) {
      selectedIds.forEach(function (id) {
        var idx = findItemById(items, id);
        if (idx >= 0) targets.push(items[idx]);
      });
    } else {
      var fi = getFocusedIndex(items);
      if (fi >= 0) targets.push(items[fi]);
    }
    return targets;
  }

  // --- Selection count badge ---

  function createCountBadge() {
    if (!document.body) return null;
    var badge = document.createElement('div');
    badge.className = 'or-kb-selection-count';
    badge.style.opacity = '0';
    document.body.appendChild(badge);
    return badge;
  }

  function updateCountBadge() {
    if (!countBadge) countBadge = createCountBadge();
    if (!countBadge) return;
    var count = selectedIds.size;
    if (count === 0) {
      countBadge.style.opacity = '0';
    } else {
      countBadge.textContent = count + ' selected';
      countBadge.style.opacity = '1';
    }
  }

  // --- Actions ---

  function performAction(targets, actionFn) {
    if (targets.length === 0) return;
    var i = 0;
    function processNext() {
      if (i >= targets.length) {
        clearSelection();
        return;
      }
      var target = targets[i];
      i++;
      target.click();
      setTimeout(function () {
        actionFn(target);
        setTimeout(processNext, 150);
      }, 100);
    }
    processNext();
  }

  function actionDelete(targets) {
    performAction(targets, function () {
      var deleteBtn = document.querySelector(
        '[aria-label*="Delete" i][role="button"], [aria-label*="delete" i][role="menuitem"]'
      );
      if (deleteBtn) {
        deleteBtn.click();
      } else {
        var deleteEvent = new KeyboardEvent('keydown', {
          key: 'Delete', code: 'Delete', bubbles: true, cancelable: true
        });
        document.activeElement.dispatchEvent(deleteEvent);
      }
    });
  }

  function actionArchive(targets) {
    performAction(targets, function () {
      var archiveBtn = document.querySelector(
        '[aria-label*="Archive" i][role="button"], [aria-label*="archive" i][role="menuitem"]'
      );
      if (archiveBtn) {
        archiveBtn.click();
      } else {
        console.warn('[Outlook Relook] Archive button not found');
      }
    });
  }

  function actionMarkRead(targets) {
    performAction(targets, function () {
      var readBtn = document.querySelector(
        '[aria-label*="Mark as read" i][role="button"], [aria-label*="Mark as read" i][role="menuitem"]'
      );
      if (readBtn) {
        readBtn.click();
      } else {
        triggerContextMenuAction(/mark as read/i);
      }
    });
  }

  function actionMarkUnread(targets) {
    performAction(targets, function () {
      var unreadBtn = document.querySelector(
        '[aria-label*="Mark as unread" i][role="button"], [aria-label*="Mark as unread" i][role="menuitem"]'
      );
      if (unreadBtn) {
        unreadBtn.click();
      } else {
        triggerContextMenuAction(/mark as unread/i);
      }
    });
  }

  function actionMove(targets) {
    if (targets.length > 0) {
      targets[0].click();
      setTimeout(function () {
        var moveBtn = document.querySelector(
          '[aria-label*="Move to" i][role="button"], [aria-label*="Move" i][role="menuitem"]'
        );
        if (moveBtn) {
          moveBtn.click();
        } else {
          triggerContextMenuAction(/move to/i);
        }
      }, 100);
    }
  }

  function triggerContextMenuAction(pattern) {
    var focused = document.querySelector('.or-kb-focused');
    if (!focused) return;
    var rect = focused.getBoundingClientRect();
    var contextEvent = new MouseEvent('contextmenu', {
      bubbles: true, cancelable: true,
      clientX: rect.x + 10, clientY: rect.y + 10,
    });
    focused.dispatchEvent(contextEvent);
    setTimeout(function () {
      var menuItems = document.querySelectorAll('[role="menuitem"]');
      for (var j = 0; j < menuItems.length; j++) {
        if (pattern.test(menuItems[j].textContent)) {
          menuItems[j].click();
          return;
        }
      }
      document.body.click();
    }, 300);
  }

  // --- Key handler ---

  function handleKeydown(e) {
    if (!currentSettings.keyboardMultiSelect) return;
    if (isComposeOrDialogActive()) return;

    var items = getMessageItems();
    if (items.length === 0) return;

    var key = e.key;
    var shift = e.shiftKey;

    // Initialize focus if not set
    var currentIdx = getFocusedIndex(items);
    if (currentIdx < 0) {
      for (var f = 0; f < items.length; f++) {
        if (items[f].getAttribute('aria-selected') === 'true' ||
            items[f].classList.contains('is-selected')) {
          currentIdx = f;
          focusedId = getMessageId(items[f]);
          break;
        }
      }
      if (currentIdx < 0) {
        currentIdx = 0;
        focusedId = getMessageId(items[0]);
      }
      applyVisualState(items);
    }

    var handled = true;
    var targets;

    switch (key) {
      case 'j':
      case 'ArrowDown':
        if (shift) {
          toggleSelect(items, currentIdx);
          if (currentIdx < items.length - 1) {
            setFocus(items, currentIdx + 1);
            toggleSelect(items, currentIdx + 1);
          }
        } else {
          if (currentIdx < items.length - 1) {
            setFocus(items, currentIdx + 1);
          }
        }
        break;

      case 'k':
      case 'ArrowUp':
        if (shift) {
          toggleSelect(items, currentIdx);
          if (currentIdx > 0) {
            setFocus(items, currentIdx - 1);
            toggleSelect(items, currentIdx - 1);
          }
        } else {
          if (currentIdx > 0) {
            setFocus(items, currentIdx - 1);
          }
        }
        break;

      case 'x':
      case ' ':
        e.preventDefault();
        toggleSelect(items, currentIdx);
        break;

      case '#':
        targets = getActionTargets(items);
        actionDelete(targets);
        break;

      case 'e':
        targets = getActionTargets(items);
        actionArchive(targets);
        break;

      case 'I':
        if (shift) {
          targets = getActionTargets(items);
          actionMarkRead(targets);
        } else {
          handled = false;
        }
        break;

      case 'U':
        if (shift) {
          targets = getActionTargets(items);
          actionMarkUnread(targets);
        } else {
          handled = false;
        }
        break;

      case 'v':
        targets = getActionTargets(items);
        actionMove(targets);
        break;

      case 'Escape':
        clearSelection();
        break;

      case 'Enter':
      case 'o':
        if (currentIdx >= 0 && currentIdx < items.length) {
          items[currentIdx].click();
        }
        break;

      default:
        handled = false;
    }

    if (handled) {
      e.stopPropagation();
      if (key !== 'Enter' && key !== 'o') {
        e.preventDefault();
      }
    }
  }

  // --- Re-apply visual state when OWA re-renders the message list ---

  function setupListObserver() {
    var listObserver = new MutationObserver(function () {
      // Prune IDs that no longer exist in DOM
      var items = getMessageItems();
      var currentIds = new Set();
      for (var i = 0; i < items.length; i++) {
        var id = getMessageId(items[i]);
        if (id) currentIds.add(id);
      }
      selectedIds.forEach(function (id) {
        if (!currentIds.has(id)) selectedIds.delete(id);
      });
      if (focusedId && !currentIds.has(focusedId)) focusedId = null;

      // Re-apply classes to new DOM elements
      applyVisualState(items);
    });

    var checkInterval = setInterval(function () {
      var list = document.querySelector('[role="listbox"], [role="list"]');
      if (list) {
        clearInterval(checkInterval);
        listObserver.observe(list, { childList: true, subtree: true });
      }
    }, 1000);

    cleanupFns.push(function () {
      clearInterval(checkInterval);
      listObserver.disconnect();
    });
  }

  // --- Public API ---

  function start(settings) {
    currentSettings = settings;
    if (!settings.keyboardMultiSelect) return;

    document.addEventListener('keydown', handleKeydown, true);
    setupListObserver();

    console.log('[Outlook Relook] Keyboard navigation started');
    cleanupFns.push(function () {
      document.removeEventListener('keydown', handleKeydown, true);
    });
  }

  function updateSettings(settings) {
    var wasEnabled = currentSettings.keyboardMultiSelect;
    var isEnabled = settings.keyboardMultiSelect;
    currentSettings = settings;

    if (wasEnabled !== isEnabled) {
      stop();
      start(settings);
    }
  }

  function stop() {
    for (var i = 0; i < cleanupFns.length; i++) {
      try { cleanupFns[i](); } catch (e) { /* ignore */ }
    }
    cleanupFns = [];

    clearSelection();
    var focused = document.querySelector('.or-kb-focused');
    if (focused) focused.classList.remove('or-kb-focused');
    focusedId = null;

    if (countBadge) {
      countBadge.remove();
      countBadge = null;
    }
  }

  return { start: start, updateSettings: updateSettings, stop: stop };
})();