import { useEffect, useState } from 'react';

interface Props {
  segmentsCount: number;
  currentSegmentIndex?: number;  // Optional for streaming mode
  realProgress?: number;  // Optional for streaming mode
  generatedSegments?: any[];  // Optional for streaming mode
  onCancel?: () => void;
  isStreaming?: boolean;  // If true, use real progress; if false, simulate
}

const GENERATION_TIPS = [
  "💡 AI is analyzing your reference image for character details...",
  "🎬 Creating detailed camera movements for cinematic quality...",
  "👤 Generating character descriptions with exact physical features...",
  "🎭 Crafting micro-expressions and natural gestures...",
  "🎨 Designing scene continuity for seamless video flow...",
  "🎯 Ensuring dialogue syncs perfectly with actions...",
  "✨ Adding production-quality details to each segment...",
  "🔍 Cross-checking consistency across all segments...",
  "💾 Auto-saving your prompts for recovery...",
  "🎪 Almost done! Finalizing segment specifications..."
];

export function SegmentGenerationProgress({ segmentsCount, onCancel }: Props) {
  const [progress, setProgress] = useState(0);
  const [currentTip, setCurrentTip] = useState(0);
  const [elapsedTime, setElapsedTime] = useState(0);
  const [estimatedTime] = useState(
    segmentsCount <= 2 ? 20 : segmentsCount <= 5 ? 50 : 90
  );

  // Progress simulation (realistic timing based on actual API performance)
  useEffect(() => {
    const interval = setInterval(() => {
      setProgress(prev => {
        // Slow start (first 30%), medium middle (30-80%), slow end (80-100%)
        if (prev < 30) return prev + 0.5; // Slow start
        if (prev < 80) return prev + 0.8; // Medium speed
        if (prev < 95) return prev + 0.2; // Slow down near end
        return prev; // Stop at 95% until actual completion
      });
    }, 1000);

    return () => clearInterval(interval);
  }, []);

  // Tip rotation
  useEffect(() => {
    const interval = setInterval(() => {
      setCurrentTip(prev => (prev + 1) % GENERATION_TIPS.length);
    }, 4000); // Change tip every 4 seconds

    return () => clearInterval(interval);
  }, []);

  // Elapsed time counter
  useEffect(() => {
    const interval = setInterval(() => {
      setElapsedTime(prev => prev + 1);
    }, 1000);

    return () => clearInterval(interval);
  }, []);

  const formatTime = (seconds: number) => {
    const mins = Math.floor(seconds / 60);
    const secs = seconds % 60;
    return mins > 0 ? `${mins}m ${secs}s` : `${secs}s`;
  };

  return (
    <div className="max-w-2xl mx-auto p-8 glass-dark rounded-2xl shadow-2xl border-2 border-void-700/50">
      {/* Header */}
      <div className="flex justify-between items-center mb-6">
        <div className="flex items-center gap-2 bg-coral-500/20 px-4 py-2 rounded-full border border-coral-500/30">
          <div className="w-2 h-2 bg-coral-400 rounded-full animate-pulse" />
          <span className="text-sm font-medium text-void-100">Generating {segmentsCount} segments</span>
        </div>
        
        <div className="font-mono text-lg font-bold text-void-100">
          <span className="text-coral-400">{formatTime(elapsedTime)}</span>
          <span className="text-void-600 mx-1">/</span>
          <span className="text-void-400">~{formatTime(estimatedTime)}</span>
        </div>
      </div>

      {/* Progress Bar */}
      <div className="relative h-10 bg-void-900/80 border border-void-700 rounded-full overflow-hidden mb-8">
        <div 
          className="h-full bg-gradient-to-r from-coral-500 to-electric-500 rounded-full transition-all duration-500 ease-out relative"
          style={{ width: `${progress}%` }}
        >
          <div className="absolute inset-0 bg-gradient-to-r from-transparent via-white/20 to-transparent animate-shimmer" />
        </div>
        <span className="absolute inset-0 flex items-center justify-center font-bold text-void-100 drop-shadow-lg">
          {Math.round(progress)}%
        </span>
      </div>

      {/* Generation Steps */}
      <div className="grid grid-cols-4 gap-4 mb-8">
        <GenerationStep 
          icon="🔍"
          label="Analyzing"
          status={progress < 20 ? 'active' : 'complete'}
        />
        <GenerationStep 
          icon="🎬"
          label="Creating"
          status={progress < 20 ? 'pending' : progress < 80 ? 'active' : 'complete'}
        />
        <GenerationStep 
          icon="✅"
          label="Validating"
          status={progress < 80 ? 'pending' : progress < 95 ? 'active' : 'complete'}
        />
        <GenerationStep 
          icon="💾"
          label="Saving"
          status={progress < 95 ? 'pending' : 'active'}
        />
      </div>

      {/* Rotating Tips */}
      <div 
        key={currentTip}
        className="bg-void-900/60 backdrop-blur-sm p-4 rounded-xl mb-8 flex items-center gap-3 min-h-[60px] animate-fade-in border border-void-700/50"
      >
        <span className="text-2xl">💡</span>
        <p className="text-sm leading-relaxed text-void-200">{GENERATION_TIPS[currentTip]}</p>
      </div>

      {/* Segments Preview */}
      <div className="mb-6">
        <h4 className="text-sm mb-3 text-void-300 font-semibold">Segments Being Generated:</h4>
        <div className="grid grid-cols-4 sm:grid-cols-8 gap-2">
          {Array.from({ length: segmentsCount }).map((_, i) => (
            <SegmentCard
              key={i}
              number={i + 1}
              status={
                progress > (i / segmentsCount) * 100 ? 'complete' : 
                progress > ((i - 0.5) / segmentsCount) * 100 ? 'generating' : 
                'pending'
              }
            />
          ))}
        </div>
      </div>

      {/* Auto-Save Indicator */}
      <div className="flex items-center justify-center gap-2 mb-6 text-sm text-void-300">
        <span className={progress < 95 ? '' : 'animate-spin'}>💾</span>
        <span>Auto-saving prompts for recovery...</span>
      </div>

      {/* Cancel Button */}
      {onCancel && (
        <button 
          onClick={onCancel}
          className="w-full py-3 bg-red-500/20 border border-red-500/50 rounded-lg hover:bg-red-500/30 transition-colors text-void-100 font-medium"
        >
          Cancel Generation
        </button>
      )}
    </div>
  );
}

function GenerationStep({ icon, label, status }: {
  icon: string;
  label: string;
  status: 'pending' | 'active' | 'complete';
}) {
  return (
    <div className="flex flex-col items-center gap-2">
      <div className={`
        w-12 h-12 rounded-full flex items-center justify-center text-xl transition-all border-2
        ${status === 'complete' ? 'bg-electric-500/30 border-electric-400 shadow-lg shadow-electric-500/50' : ''}
        ${status === 'active' ? 'bg-coral-500/30 border-coral-400 shadow-lg shadow-coral-500/50 animate-pulse' : ''}
        ${status === 'pending' ? 'bg-void-900/50 border-void-700' : ''}
      `}>
        <span className={status === 'complete' ? 'text-electric-300' : status === 'active' ? 'text-coral-300' : 'text-void-500'}>
          {status === 'complete' ? '✓' : icon}
        </span>
      </div>
      <span className={`text-xs ${status === 'active' ? 'font-semibold text-coral-300' : status === 'complete' ? 'text-electric-300' : 'text-void-400'}`}>
        {label}
      </span>
    </div>
  );
}

function SegmentCard({ number, status }: {
  number: number;
  status: 'pending' | 'generating' | 'complete';
}) {
  return (
    <div className={`
      p-2 rounded-lg text-center transition-all border-2
      ${status === 'complete' ? 'bg-electric-500/20 border-electric-500/50 shadow-lg shadow-electric-500/20' : ''}
      ${status === 'generating' ? 'bg-coral-500/20 border-coral-500/50 shadow-lg shadow-coral-500/30 animate-pulse' : ''}
      ${status === 'pending' ? 'bg-void-900/50 border-void-700' : ''}
    `}>
      <div className={`font-bold text-xs ${status === 'complete' ? 'text-electric-300' : status === 'generating' ? 'text-coral-300' : 'text-void-400'}`}>
        #{number}
      </div>
      <div className="text-lg">
        {status === 'complete' && <span className="text-electric-400">✓</span>}
        {status === 'generating' && <span className="animate-spin inline-block">⚙️</span>}
        {status === 'pending' && <span className="text-void-500">⏳</span>}
      </div>
      <div className={`text-[10px] font-medium ${status === 'complete' ? 'text-electric-400' : status === 'generating' ? 'text-coral-400' : 'text-void-500'}`}>
        {status === 'complete' && 'Ready'}
        {status === 'generating' && 'Queue'}
        {status === 'pending' && 'Queue'}
      </div>
    </div>
  );
}