import { useEffect, useState } from 'react';
import { supabase } from '../supabaseClient';
import { BookOpen, Map, Flame, LogOut, RefreshCw, Trophy, User } from 'lucide-react';

interface SidebarProps {
  activeTab: 'queue' | 'journey';
  setActiveTab: (tab: 'queue' | 'journey') => void;
  user: any;
}

export default function Sidebar({ activeTab, setActiveTab, user }: SidebarProps) {
  const [streak, setStreak] = useState<any>(null);
  const [syncing, setSyncing] = useState(false);
  const [syncResult, setSyncResult] = useState<string | null>(null);

  const fetchStreak = async () => {
    try {
      const { data: { session } } = await supabase.auth.getSession();
      if (!session) return;

      const res = await fetch(`${import.meta.env.VITE_API_BASE_URL}/api/streak`, {
        headers: {
          'Authorization': `Bearer ${session.access_token}`
        }
      });
      if (res.ok) {
        const data = await res.json();
        setStreak(data);
      }
    } catch (err) {
      console.error('Error fetching streak:', err);
    }
  };

  useEffect(() => {
    fetchStreak();
  }, [user]);

  const handleSync = async () => {
    setSyncing(true);
    setSyncResult(null);
    try {
      const { data: { session } } = await supabase.auth.getSession();
      if (!session) return;

      const res = await fetch(`${import.meta.env.VITE_API_BASE_URL}/api/sync`, {
        method: 'POST',
        headers: {
          'Authorization': `Bearer ${session.access_token}`
        }
      });
      if (res.ok) {
        const data = await res.json();
        setSyncResult(data.message || 'Sync complete!');
        // Refresh streak and state
        fetchStreak();
      } else {
        setSyncResult('Sync failed. Check backend logs.');
      }
    } catch (err) {
      setSyncResult('Sync failed. Server unreachable.');
    } finally {
      setSyncing(false);
    }
  };

  const handleSignOut = async () => {
    await supabase.auth.signOut();
  };

  return (
    <aside className="w-80 h-screen bg-bg-sidebar border-r border-slate-900 flex flex-col justify-between p-6 shrink-0 z-10 relative">
      <div className="space-y-8">
        {/* Brand */}
        <div className="flex items-center gap-3">
          <div className="w-10 h-10 rounded-xl bg-gradient-to-br from-primary-purple to-accent-pink flex items-center justify-center shadow-[0_0_15px_rgba(157,78,221,0.3)]">
            <Trophy className="w-5 h-5 text-white" />
          </div>
          <div>
            <h1 className="text-xl font-bold tracking-tight text-white m-0">AlgoSpaced</h1>
            <span className="text-xs text-slate-500">DSA Repetition</span>
          </div>
        </div>

        {/* Navigation */}
        <nav className="space-y-2">
          <button
            onClick={() => setActiveTab('queue')}
            className={`w-full flex items-center gap-3.5 px-4 py-3 rounded-xl text-sm font-semibold tracking-wide transition-all duration-200 cursor-pointer ${
              activeTab === 'queue'
                ? 'bg-primary-purple text-white shadow-[0_0_15px_rgba(157,78,221,0.25)]'
                : 'text-slate-400 hover:text-white hover:bg-slate-950'
            }`}
          >
            <BookOpen className="w-5 h-5" />
            Daily Review Queue
          </button>
          <button
            onClick={() => setActiveTab('journey')}
            className={`w-full flex items-center gap-3.5 px-4 py-3 rounded-xl text-sm font-semibold tracking-wide transition-all duration-200 cursor-pointer ${
              activeTab === 'journey'
                ? 'bg-primary-purple text-white shadow-[0_0_15px_rgba(157,78,221,0.25)]'
                : 'text-slate-400 hover:text-white hover:bg-slate-950'
            }`}
          >
            <Map className="w-5 h-5" />
            Journey Path
          </button>
        </nav>

        {/* Streak Component */}
        <div className="glass-panel rounded-2xl p-5 border border-slate-900">
          <div className="flex items-center gap-3 mb-4">
            <div className="p-2 rounded-lg bg-orange-500/10 text-orange-400">
              <Flame className="w-5 h-5" />
            </div>
            <div>
              <h3 className="text-xs font-semibold text-slate-400 uppercase tracking-wider">Active Streak</h3>
              <span className="text-2xl font-bold text-white tracking-tight">{streak?.current_streak ?? 0} days</span>
            </div>
          </div>
          <div className="flex justify-between items-center text-xs text-slate-500 border-t border-slate-900/60 pt-3">
            <span>Longest: {streak?.longest_streak ?? 0} days</span>
            {streak?.last_active_date && (
              <span>Last active: {new Date(streak.last_active_date).toLocaleDateString()}</span>
            )}
          </div>
        </div>

        {/* Sync Google Drive */}
        <div className="space-y-2">
          <button
            onClick={handleSync}
            disabled={syncing}
            className="w-full bg-slate-950 hover:bg-slate-900 text-slate-300 font-semibold py-3 px-4 rounded-xl flex items-center justify-center gap-2 border border-slate-800 transition-all text-sm cursor-pointer disabled:opacity-50"
          >
            <RefreshCw className={`w-4 h-4 text-accent-cyan ${syncing ? 'animate-spin' : ''}`} />
            {syncing ? 'Syncing...' : 'Sync Google Drive'}
          </button>
          {syncResult && (
            <p className="text-[11px] text-center text-accent-cyan leading-normal max-h-16 overflow-y-auto px-2">
              {syncResult}
            </p>
          )}
        </div>
      </div>

      {/* User Session Info / Sign Out */}
      <div className="border-t border-slate-900 pt-5 space-y-4">
        <div className="flex items-center gap-3 px-2">
          <div className="w-8 h-8 rounded-full bg-slate-900 border border-slate-800 flex items-center justify-center text-slate-400">
            <User className="w-4 h-4" />
          </div>
          <div className="overflow-hidden">
            <p className="text-xs font-semibold text-white truncate m-0">{user.email}</p>
            <p className="text-[10px] text-slate-500 truncate m-0">Verified User</p>
          </div>
        </div>
        <button
          onClick={handleSignOut}
          className="w-full flex items-center justify-center gap-2 py-2.5 rounded-lg text-xs font-semibold text-rose-400 hover:text-rose-300 bg-rose-500/5 hover:bg-rose-500/10 transition-all cursor-pointer"
        >
          <LogOut className="w-4 h-4" />
          Sign Out
        </button>
      </div>
    </aside>
  );
}