import React, { useState, useEffect } from 'react';
import { SCENARIOS } from './constants';
import { Scenario, SessionMode } from './types';
import ScenarioCard from './components/ScenarioCard';
import ChatSession from './components/ChatSession';
import VoiceSession from './components/VoiceSession';
import ScenarioGenerator from './components/ScenarioGenerator';
import CBTReference from './components/CBTReference';
import { Brain, Info, ShieldCheck, Filter, Plus, Sparkles, BookOpen, Loader2, Activity, Zap } from 'lucide-react';

const App: React.FC = () => {
  const [activeScenario, setActiveScenario] = useState<Scenario | null>(null);
  const [sessionMode, setSessionMode] = useState<SessionMode>('text');
  const [selectedDifficulty, setSelectedDifficulty] = useState<string>('All');
  const [isPreparing, setIsPreparing] = useState(false);
  
  // Custom Scenarios State
  const [customScenarios, setCustomScenarios] = useState<Scenario[]>([]);
  const [showGenerator, setShowGenerator] = useState(false);
  const [showReference, setShowReference] = useState(false);

  const handleSelectScenario = (scenario: Scenario, mode: SessionMode) => {
    setIsPreparing(true);
    // Simulate "Clinical Environment Calibration"
    // This provides a clearer boundary between dashboard and the specialized session environment
    setTimeout(() => {
      setActiveScenario(scenario);
      setSessionMode(mode);
      setIsPreparing(false);
    }, 1400);
  };

  const handleExitSession = () => {
    setActiveScenario(null);
  };

  const handleScenarioGenerated = (newScenario: Scenario) => {
    setCustomScenarios(prev => [newScenario, ...prev]);
    setShowGenerator(false);
  };

  const allScenarios = [...customScenarios, ...SCENARIOS];

  const filteredScenarios = allScenarios.filter(scenario => 
    selectedDifficulty === 'All' || scenario.difficulty === selectedDifficulty
  );

  const difficulties = ['All', 'Beginner', 'Intermediate', 'Advanced'];

  // Robust Session Preparation UI
  if (isPreparing) {
    return (
      <div className="min-h-screen bg-slate-900 flex flex-col items-center justify-center p-6 text-white overflow-hidden relative">
        <div className="absolute inset-0 overflow-hidden pointer-events-none opacity-20">
          <div className="absolute top-[-10%] left-[-10%] w-[40%] h-[40%] bg-teal-500 rounded-full blur-[120px] animate-pulse"></div>
          <div className="absolute bottom-[-10%] right-[-10%] w-[40%] h-[40%] bg-blue-500 rounded-full blur-[120px] animate-pulse" style={{ animationDelay: '1s' }}></div>
        </div>

        <div className="relative z-10 flex flex-col items-center max-w-md text-center">
          <div className="w-24 h-24 bg-white/5 rounded-3xl border border-white/10 flex items-center justify-center mb-8 relative">
            <Brain size={48} className="text-teal-400" />
            <div className="absolute inset-0 border-2 border-teal-500/30 rounded-3xl animate-ping opacity-20"></div>
          </div>
          
          <h2 className="text-2xl font-bold mb-3 tracking-tight">Initializing Session</h2>
          <div className="flex items-center gap-2 mb-8">
            <span className="h-1.5 w-1.5 bg-teal-400 rounded-full animate-bounce" style={{ animationDelay: '0ms' }}></span>
            <span className="h-1.5 w-1.5 bg-teal-400 rounded-full animate-bounce" style={{ animationDelay: '150ms' }}></span>
            <span className="h-1.5 w-1.5 bg-teal-400 rounded-full animate-bounce" style={{ animationDelay: '300ms' }}></span>
            <p className="text-xs font-bold text-slate-400 uppercase tracking-widest ml-2">Calibrating AI Parameters</p>
          </div>

          <div className="w-full bg-white/5 h-1.5 rounded-full overflow-hidden mb-4 border border-white/5">
            <div className="h-full bg-teal-500 rounded-full w-0 animate-[loading_1.4s_ease-in-out_forwards]"></div>
          </div>

          <div className="space-y-2 opacity-60">
            <p className="text-[10px] uppercase font-black tracking-tighter flex items-center justify-center gap-2">
              <Zap size={10} className="text-teal-400" />
              Configuring {sessionMode === 'voice' ? 'Voice Link' : 'Neural Chat Bridge'}
            </p>
            <p className="text-[10px] uppercase font-black tracking-tighter flex items-center justify-center gap-2">
              <Activity size={10} className="text-blue-400" />
              Injecting {activeScenario?.cbtFocus[0] || 'Clinical'} Logic
            </p>
          </div>
        </div>

        <style>{`
          @keyframes loading {
            0% { width: 0%; }
            20% { width: 15%; }
            50% { width: 70%; }
            100% { width: 100%; }
          }
        `}</style>
      </div>
    );
  }

  if (activeScenario) {
    return (
      <div className="min-h-screen bg-slate-50 flex flex-col items-center pt-8 px-4 pb-8 animate-in fade-in duration-700">
        {sessionMode === 'text' ? (
          <ChatSession scenario={activeScenario} onExit={handleExitSession} />
        ) : (
          <div className="w-full max-w-4xl h-[80vh]">
             <VoiceSession scenario={activeScenario} onExit={handleExitSession} />
          </div>
        )}
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-[#FDFDFF] text-slate-900 font-sans relative animate-in fade-in duration-500">
      {/* Generator Modal */}
      {showGenerator && (
        <ScenarioGenerator 
          onGenerate={handleScenarioGenerated} 
          onCancel={() => setShowGenerator(false)} 
        />
      )}

      {/* Reference Modal */}
      {showReference && (
        <CBTReference onClose={() => setShowReference(false)} />
      )}

      {/* Hero Section */}
      <div className="bg-white border-b border-slate-200">
        <div className="max-w-5xl mx-auto px-6 py-12">
          <div className="flex flex-col md:flex-row md:items-center justify-between gap-6 mb-8">
            <div className="flex items-center gap-3">
              <div className="bg-teal-600 p-2 rounded-lg text-white shadow-sm shadow-teal-200">
                <Brain size={32} />
              </div>
              <h1 className="text-3xl font-bold tracking-tight text-slate-900">Cognitive Clarity</h1>
            </div>
            
            <button 
              onClick={() => setShowReference(true)}
              className="flex items-center justify-center gap-2 bg-slate-50 text-slate-600 hover:text-teal-700 hover:bg-teal-50 px-5 py-2.5 rounded-xl border border-slate-200 transition-all font-bold text-sm"
            >
              <BookOpen size={18} />
              <span>Reference Guide</span>
            </button>
          </div>
          
          <p className="text-xl text-slate-600 max-w-2xl leading-relaxed font-light">
            A clinical roleplaying platform utilizing CBT principles and AI to help you navigate social complexities and restructure internal dialogues.
          </p>
          
          <div className="flex flex-wrap gap-4 mt-8">
            <div className="flex items-center gap-2 text-sm text-slate-500 bg-slate-50 px-3 py-1.5 rounded-full border border-slate-100">
              <ShieldCheck className="text-teal-600" size={18} />
              <span>Evidence-Based Framework</span>
            </div>
            <div className="flex items-center gap-2 text-sm text-slate-500 bg-slate-50 px-3 py-1.5 rounded-full border border-slate-100">
              <Info className="text-teal-600" size={18} />
              <span>Personalized Adaptive Logic</span>
            </div>
          </div>
        </div>
      </div>

      {/* Main Content */}
      <main className="max-w-5xl mx-auto px-6 py-12">
        <div className="flex flex-col sm:flex-row justify-between items-start sm:items-center gap-4 mb-8">
          <h2 className="text-2xl font-medium text-slate-800">
            Training Scenarios
          </h2>

          <div className="flex flex-col sm:flex-row gap-3 w-full sm:w-auto">
            {/* Filter Controls */}
            <div className="flex items-center bg-white border border-slate-200 rounded-lg p-1 shadow-sm overflow-x-auto">
              <div className="px-3 text-slate-400 flex items-center gap-2 text-sm font-medium border-r border-slate-100 mr-1">
                 <Filter size={14} />
                 <span className="hidden sm:inline">Difficulty</span>
              </div>
              <div className="flex gap-1">
                {difficulties.map((diff) => (
                  <button
                    key={diff}
                    onClick={() => setSelectedDifficulty(diff)}
                    className={`px-3 py-1.5 text-xs rounded-md transition-all whitespace-nowrap ${
                      selectedDifficulty === diff
                        ? 'bg-teal-50 text-teal-700 font-semibold border border-teal-100'
                        : 'text-slate-500 hover:bg-slate-50 border border-transparent'
                    }`}
                  >
                    {diff}
                  </button>
                ))}
              </div>
            </div>

            <button 
              onClick={() => setShowGenerator(true)}
              className="flex items-center justify-center gap-2 bg-teal-600 text-white px-5 py-2.5 rounded-lg hover:bg-teal-700 transition-all font-bold text-sm shadow-md shadow-teal-100"
            >
              <Plus size={18} />
              <span>Create Custom</span>
            </button>
          </div>
        </div>

        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
          {filteredScenarios.map(scenario => (
            <ScenarioCard 
              key={scenario.id} 
              scenario={scenario} 
              onSelect={handleSelectScenario} 
            />
          ))}
          
          <button 
            onClick={() => setShowGenerator(true)}
            className="flex flex-col items-center justify-center gap-4 p-6 rounded-xl border-2 border-dashed border-slate-200 text-slate-400 hover:border-teal-300 hover:text-teal-600 hover:bg-teal-50/50 transition-all h-full min-h-[250px] group"
          >
            <div className="bg-slate-50 p-4 rounded-full group-hover:bg-white transition-colors">
               <Plus size={32} />
            </div>
            <div className="text-center">
              <span className="block font-bold text-sm uppercase tracking-widest mb-1">Custom Scenario</span>
              <span className="text-xs font-light">Generate a specific roleplay session</span>
            </div>
          </button>
        </div>
      </main>
      
      <footer className="bg-white border-t border-slate-200 py-12">
        <div className="max-w-5xl mx-auto px-6 flex flex-col md:flex-row justify-between items-center gap-8">
          <div className="flex items-center gap-2 text-slate-400">
             <Brain size={20} />
             <span className="text-sm font-bold uppercase tracking-widest">Cognitive Clarity v1.0</span>
          </div>
          <div className="flex gap-8 text-xs font-bold text-slate-400 uppercase tracking-widest">
            <a href="#" className="hover:text-teal-600 transition-colors">Privacy Protocol</a>
            <a href="#" className="hover:text-teal-600 transition-colors">Clinical Terms</a>
            <a href="#" className="hover:text-teal-600 transition-colors">Support</a>
          </div>
        </div>
      </footer>
    </div>
  );
};

export default App;