// 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.

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

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

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

  // State
  var focusedIndex = -1;       // Index of the focused message in the list
  var selectedSet = new Set();  // Set of selected message DOM elements
  var countBadge = null;        // Selection count badge element

  // --- Helpers ---

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

  function isComposeOrDialogActive() {
    var active = document.activeElement;
    if (!active) return false;

    // Check if focus is in a compose area, search bar, or dialog
    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;
  }

  function setFocus(items, index) {
    // Remove old focus
    var oldFocused = document.querySelector('.or-kb-focused');
    if (oldFocused) oldFocused.classList.remove('or-kb-focused');

    if (index < 0 || index >= items.length) return;

    focusedIndex = index;
    var item = items[index];
    item.classList.add('or-kb-focused');

    // Scroll into view if needed
    item.scrollIntoView({ block: 'nearest', behavior: 'smooth' });
  }

  function toggleSelect(item) {
    if (selectedSet.has(item)) {
      selectedSet.delete(item);
      item.classList.remove('or-kb-selected');
    } else {
      selectedSet.add(item);
      item.classList.add('or-kb-selected');
    }
    updateCountBadge();
  }

  function clearSelection() {
    selectedSet.forEach(function (item) {
      item.classList.remove('or-kb-selected');
    });
    selectedSet.clear();
    updateCountBadge();
  }

  function getActionTargets(items) {
    // If messages are selected, return those. Otherwise return the focused message.
    if (selectedSet.size > 0) {
      return Array.from(selectedSet);
    }
    if (focusedIndex >= 0 && focusedIndex < items.length) {
      return [items[focusedIndex]];
    }
    return [];
  }

  // --- 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 = selectedSet.size;
    if (count === 0) {
      countBadge.style.opacity = '0';
    } else {
      countBadge.textContent = count + ' selected';
      countBadge.style.opacity = '1';
    }
  }

  // --- Actions ---
  // Each action simulates what a user would do in OWA to perform the operation.
  // We click the message to select it in OWA, then trigger the toolbar action.

  function performAction(targets, actionFn) {
    if (targets.length === 0) return;

    // Process targets one at a time with a small delay between each
    var i = 0;
    function processNext() {
      if (i >= targets.length) {
        // After all targets processed, clear selection
        clearSelection();
        return;
      }
      var target = targets[i];
      i++;

      // Click the message to make it OWA-selected
      target.click();

      // Small delay to let OWA register the selection, then perform action
      setTimeout(function () {
        actionFn(target);
        // Delay before next target
        setTimeout(processNext, 150);
      }, 100);
    }
    processNext();
  }

  function actionDelete(targets) {
    performAction(targets, function () {
      // Find and click the delete button in the toolbar
      var deleteBtn = document.querySelector(
        '[aria-label*="Delete" i][role="button"], [aria-label*="delete" i][role="menuitem"]'
      );
      if (deleteBtn) {
        deleteBtn.click();
      } else {
        // Fallback: try dispatching Delete key
        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 {
        // Try context menu approach
        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) {
    // For move, we just need to trigger OWA's move dialog on the current selection
    if (targets.length > 0) {
      // Click the first target to ensure something is selected
      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) {
    // Open context menu on the focused/selected element
    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;
        }
      }
      // Close context menu if not found
      document.body.click();
    }, 300);
  }

  // --- Key handler ---

  function handleKeydown(e) {
    // Skip if keyboard mode is off or compose/dialog is active
    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
    if (focusedIndex < 0 || focusedIndex >= items.length) {
      // Find the currently OWA-selected item, or start at 0
      for (var f = 0; f < items.length; f++) {
        if (items[f].getAttribute('aria-selected') === 'true') {
          focusedIndex = f;
          break;
        }
      }
      if (focusedIndex < 0) focusedIndex = 0;
    }

    var handled = true;
    var targets;

    switch (key) {
      case 'j':
      case 'ArrowDown':
        if (shift) {
          // Select current and move down
          if (focusedIndex >= 0 && focusedIndex < items.length) {
            if (!selectedSet.has(items[focusedIndex])) {
              toggleSelect(items[focusedIndex]);
            }
          }
          if (focusedIndex < items.length - 1) {
            setFocus(items, focusedIndex + 1);
            toggleSelect(items[focusedIndex]);
          }
        } else {
          if (focusedIndex < items.length - 1) {
            setFocus(items, focusedIndex + 1);
          }
        }
        break;

      case 'k':
      case 'ArrowUp':
        if (shift) {
          // Select current and move up
          if (focusedIndex >= 0 && focusedIndex < items.length) {
            if (!selectedSet.has(items[focusedIndex])) {
              toggleSelect(items[focusedIndex]);
            }
          }
          if (focusedIndex > 0) {
            setFocus(items, focusedIndex - 1);
            toggleSelect(items[focusedIndex]);
          }
        } else {
          if (focusedIndex > 0) {
            setFocus(items, focusedIndex - 1);
          }
        }
        break;

      case 'x':
      case ' ':
        // Toggle select on focused message
        e.preventDefault(); // Prevent page scroll on Space
        if (focusedIndex >= 0 && focusedIndex < items.length) {
          toggleSelect(items[focusedIndex]);
        }
        break;

      case '#':
        // Delete selected/focused messages
        targets = getActionTargets(items);
        actionDelete(targets);
        break;

      case 'e':
        // Archive selected/focused messages
        targets = getActionTargets(items);
        actionArchive(targets);
        break;

      case 'I':
        // Shift+i — Mark as read
        if (shift) {
          targets = getActionTargets(items);
          actionMarkRead(targets);
        } else {
          handled = false;
        }
        break;

      case 'U':
        // Shift+u — Mark as unread
        if (shift) {
          targets = getActionTargets(items);
          actionMarkUnread(targets);
        } else {
          handled = false;
        }
        break;

      case 'v':
        // Move selected messages
        targets = getActionTargets(items);
        actionMove(targets);
        break;

      case 'Escape':
        // Deselect all
        clearSelection();
        break;

      case 'Enter':
      case 'o':
        // Open focused message in reading pane
        if (focusedIndex >= 0 && focusedIndex < items.length) {
          items[focusedIndex].click();
        }
        break;

      default:
        handled = false;
    }

    if (handled) {
      e.stopPropagation();
      // Only preventDefault for keys we handle (except Enter which OWA should also process)
      if (key !== 'Enter' && key !== 'o') {
        e.preventDefault();
      }
    }
  }

  // --- Cleanup stale selections when message list re-renders ---

  function setupListObserver() {
    var listObserver = new MutationObserver(function () {
      // Remove stale entries from selectedSet (elements no longer in DOM)
      selectedSet.forEach(function (item) {
        if (!document.contains(item)) {
          selectedSet.delete(item);
        }
      });
      updateCountBadge();

      // Reset focusedIndex if the focused item is gone
      var focusedEl = document.querySelector('.or-kb-focused');
      if (!focusedEl || !document.contains(focusedEl)) {
        focusedIndex = -1;
      }
    });

    // Watch the message list container for child changes
    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;

    // Only tear down and restart if the keyboard setting itself changed
    if (wasEnabled !== isEnabled) {
      stop();
      start(settings);
    }
  }

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

    // Clean up DOM state
    clearSelection();
    var focused = document.querySelector('.or-kb-focused');
    if (focused) focused.classList.remove('or-kb-focused');
    focusedIndex = -1;

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

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