'use client';

import * as React from 'react';
import { cn } from '@/lib/utils/cn';
import type { Track } from '@/types/track';

export interface AudioStatisticsProps {
  tracks: Track[];
  className?: string;
}

export function AudioStatistics({ tracks, className }: AudioStatisticsProps) {
  const stats = React.useMemo(() => {
    if (tracks.length === 0) {
      return {
        totalDuration: 0,
        longestTrack: 0,
        sampleRate: 0,
        channels: 0,
        bitDepth: 32,
        peakAmplitude: 0,
        rmsLevel: 0,
        dynamicRange: 0,
        trackCount: 0,
      };
    }

    let maxDuration = 0;
    let maxPeak = 0;
    let sumRms = 0;
    let minPeak = 1;
    let sampleRate = 0;
    let channels = 0;

    tracks.forEach(track => {
      if (!track.audioBuffer) return;

      const duration = track.audioBuffer.duration;
      maxDuration = Math.max(maxDuration, duration);

      // Get sample rate and channels from first track
      if (sampleRate === 0) {
        sampleRate = track.audioBuffer.sampleRate;
        channels = track.audioBuffer.numberOfChannels;
      }

      // Calculate peak and RMS from buffer
      for (let ch = 0; ch < track.audioBuffer.numberOfChannels; ch++) {
        const channelData = track.audioBuffer.getChannelData(ch);
        let chPeak = 0;
        let chRmsSum = 0;

        for (let i = 0; i < channelData.length; i++) {
          const abs = Math.abs(channelData[i]);
          chPeak = Math.max(chPeak, abs);
          chRmsSum += channelData[i] * channelData[i];
        }

        maxPeak = Math.max(maxPeak, chPeak);
        minPeak = Math.min(minPeak, chPeak);
        sumRms += Math.sqrt(chRmsSum / channelData.length);
      }
    });

    const avgRms = sumRms / (tracks.length * Math.max(1, channels));
    const peakDb = maxPeak > 0 ? 20 * Math.log10(maxPeak) : -Infinity;
    const rmsDb = avgRms > 0 ? 20 * Math.log10(avgRms) : -Infinity;
    const dynamicRange = peakDb - rmsDb;

    return {
      totalDuration: maxDuration,
      longestTrack: maxDuration,
      sampleRate,
      channels,
      bitDepth: 32, // Web Audio API uses 32-bit float
      peakAmplitude: maxPeak,
      rmsLevel: avgRms,
      dynamicRange: dynamicRange > 0 ? dynamicRange : 0,
      trackCount: tracks.length,
    };
  }, [tracks]);

  const formatDuration = (seconds: number) => {
    const mins = Math.floor(seconds / 60);
    const secs = Math.floor(seconds % 60);
    const ms = Math.floor((seconds % 1) * 1000);
    return `${mins}:${secs.toString().padStart(2, '0')}.${ms.toString().padStart(3, '0')}`;
  };

  const formatDb = (linear: number) => {
    if (linear === 0) return '-∞ dB';
    const db = 20 * Math.log10(linear);
    return db > -60 ? `${db.toFixed(1)} dB` : '-∞ dB';
  };

  return (
    <div className={cn('w-full h-full bg-card/50 border-2 border-accent/50 rounded-lg p-3', className)}>
      <div className="text-[10px] font-bold text-accent uppercase tracking-wider mb-3">
        Audio Statistics
      </div>
      <div className="space-y-2 text-[10px]">
        {/* File Info */}
        <div className="space-y-1">
          <div className="text-[9px] text-muted-foreground uppercase tracking-wide">Project Info</div>
          <div className="grid grid-cols-2 gap-x-2 gap-y-1">
            <div className="text-muted-foreground">Tracks:</div>
            <div className="font-mono text-right">{stats.trackCount}</div>

            <div className="text-muted-foreground">Duration:</div>
            <div className="font-mono text-right">{formatDuration(stats.totalDuration)}</div>

            <div className="text-muted-foreground">Sample Rate:</div>
            <div className="font-mono text-right">{stats.sampleRate > 0 ? `${(stats.sampleRate / 1000).toFixed(1)} kHz` : 'N/A'}</div>

            <div className="text-muted-foreground">Channels:</div>
            <div className="font-mono text-right">{stats.channels > 0 ? (stats.channels === 1 ? 'Mono' : 'Stereo') : 'N/A'}</div>

            <div className="text-muted-foreground">Bit Depth:</div>
            <div className="font-mono text-right">{stats.bitDepth}-bit float</div>
          </div>
        </div>

        {/* Divider */}
        <div className="border-t border-border/30" />

        {/* Audio Levels */}
        <div className="space-y-1">
          <div className="text-[9px] text-muted-foreground uppercase tracking-wide">Levels</div>
          <div className="grid grid-cols-2 gap-x-2 gap-y-1">
            <div className="text-muted-foreground">Peak:</div>
            <div className={cn(
              'font-mono text-right',
              stats.peakAmplitude > 0.99 ? 'text-red-500 font-bold' : ''
            )}>
              {formatDb(stats.peakAmplitude)}
            </div>

            <div className="text-muted-foreground">RMS:</div>
            <div className="font-mono text-right">{formatDb(stats.rmsLevel)}</div>

            <div className="text-muted-foreground">Dynamic Range:</div>
            <div className="font-mono text-right">
              {stats.dynamicRange > 0 ? `${stats.dynamicRange.toFixed(1)} dB` : 'N/A'}
            </div>

            <div className="text-muted-foreground">Headroom:</div>
            <div className={cn(
              'font-mono text-right',
              stats.peakAmplitude > 0.99 ? 'text-red-500' :
              stats.peakAmplitude > 0.9 ? 'text-yellow-500' : 'text-green-500'
            )}>
              {stats.peakAmplitude > 0 ? `${(20 * Math.log10(1 / stats.peakAmplitude)).toFixed(1)} dB` : 'N/A'}
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}