import React, { useEffect, useState } from 'react';
import {
  Layers,
  CheckSquare,
  FileText,
  ShoppingCart,
  Brain,
} from 'lucide-react';
import { DashboardStats, SharedList, Thought, User } from './lib/types';
import { api, clearToken, getToken, triggerHaptic } from './lib/api';
import { InstantCaptureBar } from './features/capture/InstantCaptureBar';
import { TriageDeck } from './features/triage/TriageDeck';
import { TasksView } from './features/triage/TasksView';
import { WorkspaceView } from './features/workspace/WorkspaceView';
import { SharedListsView } from './features/lists/SharedListsView';
import { SettingsModal } from './features/settings/SettingsModal';

type ActiveTab = 'triage' | 'tasks' | 'workspace' | 'lists';

export const App: React.FC = () => {
  const [user, setUser] = useState<User | null>(null);
  const [stats, setStats] = useState<DashboardStats>({
    inboxCount: 0,
    tasksOpenCount: 0,
    tasksDoneCount: 0,
    docsCount: 0,
    listsCount: 0,
    discardedCount: 0,
  });
  const [deck, setDeck] = useState<Thought[]>([]);
  const [lists, setLists] = useState<SharedList[]>([]);
  const [activeTab, setActiveTab] = useState<ActiveTab>('triage');
  const [selectedDocId, setSelectedDocId] = useState<string | null>(null);
  const [captureFocusCount, setCaptureFocusCount] = useState(0);
  const [refreshRevision, setRefreshRevision] = useState(0);

  const [showProfileModal, setShowProfileModal] = useState(false);

  const refreshAll = async () => {
    try {
      const [meRes, deckRes, listsRes] = await Promise.all([
        api.getMe(),
        api.getTriageDeck(),
        api.getAllLists(),
      ]);
      setUser(meRes.user);
      setStats(meRes.stats);
      setDeck(deckRes);
      setLists(listsRes);
    } catch {
      // Fallback to quickStart session
      try {
        const qs = await api.quickStart();
        setUser(qs.user);
        const [st, dk, ls] = await Promise.all([
          api.getStats(),
          api.getTriageDeck(),
          api.getAllLists(),
        ]);
        setStats(st);
        setDeck(dk);
        setLists(ls);
      } catch {
        // Offline or waiting for server
      }
    }
  };

  useEffect(() => {
    const init = async () => {
      if (!getToken()) {
        try {
          await api.quickStart();
        } catch {
          // ignore
        }
      }
      await api.flushOfflineQueue();
      await refreshAll();
    };
    init();

    const onOnline = async () => {
      const synced = await api.flushOfflineQueue();
      if (synced > 0) refreshAll();
    };
    window.addEventListener('online', onOnline);
    return () => window.removeEventListener('online', onOnline);
  }, []);

  const handleCaptured = (
    thought: Thought,
    target: 'inbox' | 'task' | 'list_item' | 'document' = 'inbox'
  ) => {
    if (target === 'inbox' && thought.status === 'inbox') {
      setDeck((prev) => [thought, ...prev]);
      setStats((prev) => ({ ...prev, inboxCount: prev.inboxCount + 1 }));
    } else if (target === 'document' && thought.convertedRefId) {
      setSelectedDocId(thought.convertedRefId);
      setActiveTab('workspace');
    }
    setRefreshRevision((r) => r + 1);
    refreshAll();
  };

  const handleOpenDocument = (docId: string) => {
    setSelectedDocId(docId);
    setActiveTab('workspace');
  };

  const handleTriggerAddButton = () => {
    triggerHaptic(20);
    // Scroll smoothly to top and focus capture bar
    window.scrollTo({ top: 0, behavior: 'smooth' });
    setCaptureFocusCount((c) => c + 1);
  };

  const handleLogout = async () => {
    triggerHaptic(20);
    clearToken();
    await api.quickStart();
    await refreshAll();
    setShowProfileModal(false);
  };

  return (
    <div className="min-h-screen bg-canvas text-white flex flex-col font-sans selection:bg-accent/30">
      {/* Top Header Bar */}
      <header className="sticky top-0 z-30 bg-panel/95 backdrop-blur-md border-b border-border shadow-sm">
        <div className="max-w-6xl mx-auto px-3 sm:px-4 py-2 flex items-center justify-between gap-3 sm:gap-6">
          {/* Logo & Headline */}
          <div
            onClick={() => {
              setActiveTab('triage');
              handleTriggerAddButton();
            }}
            className="flex items-center gap-2.5 cursor-pointer group select-none flex-shrink-0"
          >
            <div className="w-7 h-7 bg-accent text-white flex items-center justify-center">
              <Brain className="w-4 h-4" />
            </div>
            <div className="flex flex-col">
              <span className="font-bold text-sm sm:text-base text-white tracking-tight leading-none">
                MindSift
              </span>
              <span className="text-[11px] text-zinc-400 mt-0.5 hidden sm:inline-block">
                Der Kopf frei in drei Sekunden
              </span>
            </div>
          </div>

          {/* Quick-Capture Input Bubble directly in Header (above Tabs) */}
          <div className="flex-1 max-w-xl mx-auto">
            <InstantCaptureBar
              onCaptured={handleCaptured}
              lists={lists}
              autoFocusTrigger={captureFocusCount}
            />
          </div>

          {/* User Profile Pill */}
          <div className="flex items-center gap-2 flex-shrink-0">
            <button
              onClick={() => {
                triggerHaptic(10);
                setShowProfileModal(true);
              }}
              className="h-8 pl-1 pr-3 rounded-full bg-panel hover:bg-panel-elevated border border-border text-xs font-medium text-white flex items-center gap-2 transition-colors"
              title="Profil & Einstellungen"
            >
              <div className="w-6 h-6 rounded-full bg-accent text-white text-[10px] font-bold flex items-center justify-center">
                {user?.displayName ? user.displayName.slice(0, 1).toUpperCase() : 'U'}
              </div>
              <span className="max-w-[120px] truncate hidden sm:inline">{user?.displayName || 'Konto'}</span>
            </button>
          </div>
        </div>

        {/* Monochrome square tabs attached to header */}
        <nav className="max-w-6xl mx-auto px-1 sm:px-2 overflow-x-auto no-scrollbar border-t border-border">
          <div className="flex items-stretch">
            <button
              onClick={() => {
                triggerHaptic(10);
                setActiveTab('triage');
              }}
              className={`tab-btn ${activeTab === 'triage' ? 'tab-btn-active' : ''}`}
            >
              <Layers className="w-4 h-4" />
              <span>Triage</span>
              {stats.inboxCount > 0 && (
                <span className={activeTab === 'triage' ? 'badge-accent' : 'px-1.5 py-0.5 text-[10px] bg-canvas text-zinc-400 border border-border'}>
                  {stats.inboxCount}
                </span>
              )}
            </button>

            <button
              onClick={() => {
                triggerHaptic(10);
                setActiveTab('tasks');
              }}
              className={`tab-btn ${activeTab === 'tasks' ? 'tab-btn-active' : ''}`}
            >
              <CheckSquare className="w-4 h-4" />
              <span>Aufgaben</span>
              {stats.tasksOpenCount > 0 && (
                <span className={activeTab === 'tasks' ? 'badge-accent' : 'px-1.5 py-0.5 text-[10px] bg-canvas text-zinc-400 border border-border'}>
                  {stats.tasksOpenCount}
                </span>
              )}
            </button>

            <button
              onClick={() => {
                triggerHaptic(10);
                setActiveTab('workspace');
              }}
              className={`tab-btn ${activeTab === 'workspace' ? 'tab-btn-active' : ''}`}
            >
              <FileText className="w-4 h-4" />
              <span>Workspace</span>
              <span className={activeTab === 'workspace' ? 'badge-accent' : 'px-1.5 py-0.5 text-[10px] bg-canvas text-zinc-400 border border-border'}>
                {stats.docsCount}
              </span>
            </button>

            <button
              onClick={() => {
                triggerHaptic(10);
                setActiveTab('lists');
              }}
              className={`tab-btn ${activeTab === 'lists' ? 'tab-btn-active' : ''}`}
            >
              <ShoppingCart className="w-4 h-4" />
              <span>Geteilte Listen</span>
            </button>

          </div>
        </nav>
      </header>

      {/* Main Container */}
      <main className="flex-1 max-w-6xl w-full mx-auto px-3 sm:px-4 pt-3 pb-6">
        {/* Tab View Content */}
        <section>
          {activeTab === 'triage' && (
            <TriageDeck
              deck={deck}
              lists={lists}
              onDeckChange={refreshAll}
              onOpenDocument={handleOpenDocument}
              onFocusCapture={handleTriggerAddButton}
            />
          )}

          {activeTab === 'tasks' && (
            <TasksView
              onRefreshStats={refreshAll}
              onOpenDocument={handleOpenDocument}
              refreshTrigger={refreshRevision}
            />
          )}

          {activeTab === 'workspace' && (
            <WorkspaceView
              initialDocId={selectedDocId}
              onStatsChange={refreshAll}
            />
          )}

          {activeTab === 'lists' && (
            <SharedListsView onRefreshGlobal={refreshAll} />
          )}
        </section>
      </main>

      {/* Profile, Settings, Discord Alarms, Webhooks, Teams & Admin Modal */}
      {showProfileModal && (
        <SettingsModal
          currentUser={user}
          onClose={() => setShowProfileModal(false)}
          onUserUpdated={(u) => {
            setUser(u);
            refreshAll();
          }}
          onLoggedOut={handleLogout}
        />
      )}
    </div>
  );
};

export default App;