audio-ui/components/tracks/Track.tsx

'use client';

import * as React from 'react';
import { Volume2, VolumeX, Headphones, Trash2, ChevronDown, ChevronRight, UnfoldHorizontal, Upload, Mic, Gauge, Circle } from 'lucide-react';
import type { Track as TrackType } from '@/types/track';
import { COLLAPSED_TRACK_HEIGHT, MIN_TRACK_HEIGHT, MAX_TRACK_HEIGHT } from '@/types/track';
import { Button } from '@/components/ui/Button';
import { Slider } from '@/components/ui/Slider';
import { cn } from '@/lib/utils/cn';
import type { EffectType } from '@/lib/audio/effects/chain';
import { VerticalFader } from '@/components/ui/VerticalFader';
import { CircularKnob } from '@/components/ui/CircularKnob';
import { AutomationLane } from '@/components/automation/AutomationLane';
import type { AutomationLane as AutomationLaneType, AutomationPoint as AutomationPointType } from '@/types/automation';
import { createAutomationPoint } from '@/lib/audio/automation/utils';

export interface TrackProps {
  track: TrackType;
  zoom: number;
  currentTime: number;
  duration: number;
  isSelected?: boolean;
  onSelect?: () => void;
  onToggleMute: () => void;
  onToggleSolo: () => void;
  onToggleCollapse: () => void;
  onVolumeChange: (volume: number) => void;
  onPanChange: (pan: number) => void;
  onRemove: () => void;
  onNameChange: (name: string) => void;
  onUpdateTrack: (trackId: string, updates: Partial<TrackType>) => void;
  onSeek?: (time: number) => void;
  onLoadAudio?: (buffer: AudioBuffer) => void;
  onToggleEffect?: (effectId: string) => void;
  onRemoveEffect?: (effectId: string) => void;
  onUpdateEffect?: (effectId: string, parameters: any) => void;
  onAddEffect?: (effectType: EffectType) => void;
  onSelectionChange?: (selection: { start: number; end: number } | null) => void;
  onToggleRecordEnable?: () => void;
  isRecording?: boolean;
  recordingLevel?: number;
  playbackLevel?: number;
}

export function Track({
  track,
  zoom,
  currentTime,
  duration,
  isSelected,
  onSelect,
  onToggleMute,
  onToggleSolo,
  onToggleCollapse,
  onVolumeChange,
  onPanChange,
  onRemove,
  onNameChange,
  onUpdateTrack,
  onSeek,
  onLoadAudio,
  onToggleEffect,
  onRemoveEffect,
  onUpdateEffect,
  onAddEffect,
  onSelectionChange,
  onToggleRecordEnable,
  isRecording = false,
  recordingLevel = 0,
  playbackLevel = 0,
}: TrackProps) {
  const canvasRef = React.useRef<HTMLCanvasElement>(null);
  const containerRef = React.useRef<HTMLDivElement>(null);
  const fileInputRef = React.useRef<HTMLInputElement>(null);
  const [isEditingName, setIsEditingName] = React.useState(false);
  const [nameInput, setNameInput] = React.useState(String(track.name || 'Untitled Track'));
  const [themeKey, setThemeKey] = React.useState(0);
  const inputRef = React.useRef<HTMLInputElement>(null);
  const [isResizing, setIsResizing] = React.useState(false);
  const resizeStartRef = React.useRef({ y: 0, height: 0 });

  // Selection state
  const [isSelecting, setIsSelecting] = React.useState(false);
  const [selectionStart, setSelectionStart] = React.useState<number | null>(null);
  const [isSelectingByDrag, setIsSelectingByDrag] = React.useState(false);
  const [dragStartPos, setDragStartPos] = React.useState<{ x: number; y: number } | null>(null);

  const handleNameClick = () => {
    setIsEditingName(true);
    setNameInput(String(track.name || 'Untitled Track'));
  };

  const handleNameBlur = () => {
    setIsEditingName(false);
    if (nameInput.trim()) {
      onNameChange(nameInput.trim());
    } else {
      setNameInput(String(track.name || 'Untitled Track'));
    }
  };

  const handleNameKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === 'Enter') {
      inputRef.current?.blur();
    } else if (e.key === 'Escape') {
      setNameInput(String(track.name || 'Untitled Track'));
      setIsEditingName(false);
    }
  };

  React.useEffect(() => {
    if (isEditingName && inputRef.current) {
      inputRef.current.focus();
      inputRef.current.select();
    }
  }, [isEditingName]);

  // Listen for theme changes
  React.useEffect(() => {
    const observer = new MutationObserver(() => {
      // Increment key to force waveform redraw
      setThemeKey((prev) => prev + 1);
    });

    // Watch for class changes on document element (dark mode toggle)
    observer.observe(document.documentElement, {
      attributes: true,
      attributeFilter: ['class'],
    });

    return () => observer.disconnect();
  }, []);

  // Draw waveform
  React.useEffect(() => {
    if (!track.audioBuffer || !canvasRef.current) return;

    const canvas = canvasRef.current;
    const ctx = canvas.getContext('2d');
    if (!ctx) return;

    // Use parent container's size since canvas is absolute positioned
    const parent = canvas.parentElement;
    if (!parent) return;

    const dpr = window.devicePixelRatio || 1;
    const rect = parent.getBoundingClientRect();

    canvas.width = rect.width * dpr;
    canvas.height = rect.height * dpr;
    ctx.scale(dpr, dpr);

    const width = rect.width;
    const height = rect.height;

    // Clear canvas with theme color
    const bgColor = getComputedStyle(canvas).getPropertyValue('--color-waveform-bg') || 'rgb(15, 23, 42)';
    ctx.fillStyle = bgColor;
    ctx.fillRect(0, 0, width, height);

    const buffer = track.audioBuffer;
    const channelData = buffer.getChannelData(0);
    const samplesPerPixel = Math.floor(buffer.length / (width * zoom));

    // Draw waveform
    ctx.fillStyle = track.color;
    ctx.strokeStyle = track.color;
    ctx.lineWidth = 1;

    for (let x = 0; x < width; x++) {
      const startSample = Math.floor(x * samplesPerPixel);
      const endSample = Math.floor((x + 1) * samplesPerPixel);

      let min = 1.0;
      let max = -1.0;

      for (let i = startSample; i < endSample && i < channelData.length; i++) {
        const sample = channelData[i];
        if (sample < min) min = sample;
        if (sample > max) max = sample;
      }

      const y1 = (height / 2) * (1 - max);
      const y2 = (height / 2) * (1 - min);

      ctx.beginPath();
      ctx.moveTo(x, y1);
      ctx.lineTo(x, y2);
      ctx.stroke();
    }

    // Draw center line
    ctx.strokeStyle = 'rgba(148, 163, 184, 0.2)';
    ctx.lineWidth = 1;
    ctx.beginPath();
    ctx.moveTo(0, height / 2);
    ctx.lineTo(width, height / 2);
    ctx.stroke();

    // Draw selection overlay
    if (track.selection && duration > 0) {
      const selStartX = (track.selection.start / duration) * width;
      const selEndX = (track.selection.end / duration) * width;

      // Draw selection background
      ctx.fillStyle = 'rgba(59, 130, 246, 0.2)';
      ctx.fillRect(selStartX, 0, selEndX - selStartX, height);

      // Draw selection borders
      ctx.strokeStyle = 'rgba(59, 130, 246, 0.8)';
      ctx.lineWidth = 2;

      // Start border
      ctx.beginPath();
      ctx.moveTo(selStartX, 0);
      ctx.lineTo(selStartX, height);
      ctx.stroke();

      // End border
      ctx.beginPath();
      ctx.moveTo(selEndX, 0);
      ctx.lineTo(selEndX, height);
      ctx.stroke();
    }

    // Draw playhead
    if (duration > 0) {
      const playheadX = (currentTime / duration) * width;
      ctx.strokeStyle = 'rgba(239, 68, 68, 0.8)';
      ctx.lineWidth = 2;
      ctx.beginPath();
      ctx.moveTo(playheadX, 0);
      ctx.lineTo(playheadX, height);
      ctx.stroke();
    }
  }, [track.audioBuffer, track.color, track.collapsed, track.height, zoom, currentTime, duration, themeKey, track.selection]);

  const handleCanvasMouseDown = (e: React.MouseEvent<HTMLCanvasElement>) => {
    if (!duration) return;

    const rect = e.currentTarget.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const y = e.clientY - rect.top;
    const clickTime = (x / rect.width) * duration;

    // Store drag start position
    setDragStartPos({ x: e.clientX, y: e.clientY });
    setIsSelectingByDrag(false);

    // Start selection immediately (will be used if user drags)
    setIsSelecting(true);
    setSelectionStart(clickTime);
  };

  const handleCanvasMouseMove = (e: React.MouseEvent<HTMLCanvasElement>) => {
    if (!isSelecting || selectionStart === null || !duration || !dragStartPos) return;

    const rect = e.currentTarget.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const currentTime = (x / rect.width) * duration;

    // Check if user has moved enough to be considered dragging (threshold: 3 pixels)
    const dragDistance = Math.sqrt(
      Math.pow(e.clientX - dragStartPos.x, 2) + Math.pow(e.clientY - dragStartPos.y, 2)
    );

    if (dragDistance > 3) {
      setIsSelectingByDrag(true);
    }

    // If dragging, update selection
    if (isSelectingByDrag || dragDistance > 3) {
      // Clamp to valid time range
      const clampedTime = Math.max(0, Math.min(duration, currentTime));

      // Update selection (ensure start < end)
      const start = Math.min(selectionStart, clampedTime);
      const end = Math.max(selectionStart, clampedTime);

      onSelectionChange?.({ start, end });
    }
  };

  const handleCanvasMouseUp = (e: React.MouseEvent<HTMLCanvasElement>) => {
    if (!duration) return;

    const rect = e.currentTarget.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const clickTime = (x / rect.width) * duration;

    // Check if user actually dragged (check distance directly, not state)
    const didDrag = dragStartPos
      ? Math.sqrt(
          Math.pow(e.clientX - dragStartPos.x, 2) + Math.pow(e.clientY - dragStartPos.y, 2)
        ) > 3
      : false;

    // If user didn't drag (just clicked), clear selection and seek
    if (!didDrag) {
      onSelectionChange?.(null);
      if (onSeek) {
        onSeek(clickTime);
      }
    }

    // Reset drag state
    setIsSelecting(false);
    setIsSelectingByDrag(false);
    setDragStartPos(null);
  };

  // Handle mouse leaving canvas during selection
  React.useEffect(() => {
    const handleGlobalMouseUp = () => {
      if (isSelecting) {
        setIsSelecting(false);
        setIsSelectingByDrag(false);
        setDragStartPos(null);
      }
    };

    window.addEventListener('mouseup', handleGlobalMouseUp);
    return () => window.removeEventListener('mouseup', handleGlobalMouseUp);
  }, [isSelecting]);

  const handleFileChange = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file || !onLoadAudio) return;

    try {
      const arrayBuffer = await file.arrayBuffer();
      const audioContext = new AudioContext();
      const audioBuffer = await audioContext.decodeAudioData(arrayBuffer);
      onLoadAudio(audioBuffer);

      // Update track name to filename if it's still default
      if (track.name === 'New Track' || track.name === 'Untitled Track') {
        const fileName = file.name.replace(/\.[^/.]+$/, '');
        onNameChange(fileName);
      }
    } catch (error) {
      console.error('Failed to load audio file:', error);
    }

    // Reset input
    e.target.value = '';
  };

  const handleLoadAudioClick = () => {
    fileInputRef.current?.click();
  };

  const [isDragging, setIsDragging] = React.useState(false);

  const handleDragOver = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    setIsDragging(true);
  };

  const handleDragLeave = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    setIsDragging(false);
  };

  const handleDrop = async (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    setIsDragging(false);

    const file = e.dataTransfer.files?.[0];
    if (!file || !onLoadAudio) return;

    // Check if it's an audio file
    if (!file.type.startsWith('audio/')) {
      console.warn('Dropped file is not an audio file');
      return;
    }

    try {
      const arrayBuffer = await file.arrayBuffer();
      const audioContext = new AudioContext();
      const audioBuffer = await audioContext.decodeAudioData(arrayBuffer);
      onLoadAudio(audioBuffer);

      // Update track name to filename if it's still default
      if (track.name === 'New Track' || track.name === 'Untitled Track') {
        const fileName = file.name.replace(/\.[^/.]+$/, '');
        onNameChange(fileName);
      }
    } catch (error) {
      console.error('Failed to load audio file:', error);
    }
  };

  const trackHeight = track.collapsed ? COLLAPSED_TRACK_HEIGHT : track.height;

  // Track height resize handlers
  const handleResizeStart = React.useCallback(
    (e: React.MouseEvent) => {
      if (track.collapsed) return;
      e.preventDefault();
      e.stopPropagation();
      setIsResizing(true);
      resizeStartRef.current = { y: e.clientY, height: track.height };
    },
    [track.collapsed, track.height]
  );

  React.useEffect(() => {
    if (!isResizing) return;

    const handleMouseMove = (e: MouseEvent) => {
      const delta = e.clientY - resizeStartRef.current.y;
      const newHeight = Math.max(
        MIN_TRACK_HEIGHT,
        Math.min(MAX_TRACK_HEIGHT, resizeStartRef.current.height + delta)
      );
      onUpdateTrack(track.id, { height: newHeight });
    };

    const handleMouseUp = () => {
      setIsResizing(false);
    };

    window.addEventListener('mousemove', handleMouseMove);
    window.addEventListener('mouseup', handleMouseUp);

    return () => {
      window.removeEventListener('mousemove', handleMouseMove);
      window.removeEventListener('mouseup', handleMouseUp);
    };
  }, [isResizing, onUpdateTrack, track.id]);

  return (
    <div
      ref={containerRef}
      className={cn(
        'flex flex-col transition-all duration-200 relative',
        isSelected && 'bg-primary/5'
      )}
    >
      {/* Top: Track Row (Control Panel + Waveform) */}
      <div className="flex" style={{ height: trackHeight }}>
        {/* Left: Track Control Panel (Fixed Width) - Ableton Style */}
        <div
          className={cn(
            "w-48 flex-shrink-0 border-b border-r-4 p-2 flex flex-col gap-2 min-h-0 transition-all duration-200 cursor-pointer border-border",
            isSelected
              ? "bg-primary/10 border-r-primary"
              : "bg-card border-r-transparent hover:bg-accent/30"
          )}
          onClick={(e) => {
            e.stopPropagation();
            if (onSelect) onSelect();
          }}
        >
          {/* Track Name Row - Integrated collapse (DAW style) */}
          <div
            className={cn(
              "group flex items-center gap-1.5 px-1 py-0.5 rounded cursor-pointer transition-colors",
              isSelected ? "bg-primary/10" : "hover:bg-accent/50"
            )}
            onClick={(e) => {
              if (!isEditingName) {
                e.stopPropagation();
                onToggleCollapse();
              }
            }}
            title={track.collapsed ? 'Expand track' : 'Collapse track'}
          >
            {/* Small triangle indicator */}
            <div className={cn(
              "flex-shrink-0 transition-colors",
              isSelected ? "text-primary" : "text-muted-foreground group-hover:text-foreground"
            )}>
              {track.collapsed ? (
                <ChevronRight className="h-3 w-3" />
              ) : (
                <ChevronDown className="h-3 w-3" />
              )}
            </div>

            {/* Color stripe (thicker when selected) */}
            <div
              className={cn(
                "h-5 rounded-full flex-shrink-0 transition-all",
                isSelected ? "w-1" : "w-0.5"
              )}
              style={{ backgroundColor: track.color }}
            />

            {/* Track name (editable) */}
            <div className="flex-1 min-w-0">
              {isEditingName ? (
                <input
                  ref={inputRef}
                  type="text"
                  value={nameInput}
                  onChange={(e) => setNameInput(e.target.value)}
                  onBlur={handleNameBlur}
                  onKeyDown={handleNameKeyDown}
                  onClick={(e) => e.stopPropagation()}
                  className="w-full px-1 py-0.5 text-xs font-semibold bg-background border border-border rounded"
                />
              ) : (
                <div
                  onClick={(e) => {
                    e.stopPropagation();
                    handleNameClick();
                  }}
                  className="px-1 py-0.5 text-xs font-semibold text-foreground truncate"
                  title={String(track.name || 'Untitled Track')}
                >
                  {String(track.name || 'Untitled Track')}
                </div>
              )}
            </div>
          </div>

          {/* Track Controls - Only show when not collapsed */}
          {!track.collapsed && (
            <div className="flex-1 flex flex-col items-center justify-between min-h-0 overflow-hidden">
              {/* Pan Knob */}
              <div className="flex-shrink-0">
                <CircularKnob
                  value={track.pan}
                  onChange={onPanChange}
                  min={-1}
                  max={1}
                  step={0.01}
                  size={48}
                  label="PAN"
                />
              </div>

              {/* Vertical Volume Fader with integrated meter */}
              <div className="flex-1 flex items-center justify-center min-h-0">
                <VerticalFader
                  value={track.volume}
                  level={track.recordEnabled || isRecording ? recordingLevel : playbackLevel}
                  onChange={onVolumeChange}
                  min={0}
                  max={1}
                  step={0.01}
                  showDb={true}
                />
              </div>

              {/* Inline Button Row - Below fader */}
              <div className="flex-shrink-0 w-full">
                {/* R/S/M inline row with icons */}
                <div className="flex items-center gap-1 justify-center">
                  {/* Record Arm */}
                  {onToggleRecordEnable && (
                    <button
                      onClick={onToggleRecordEnable}
                      className={cn(
                        'h-6 w-6 rounded flex items-center justify-center transition-all',
                        track.recordEnabled
                          ? 'bg-red-500 text-white shadow-md shadow-red-500/30'
                          : 'bg-card hover:bg-accent text-muted-foreground border border-border/50',
                        isRecording && 'animate-pulse'
                      )}
                      title="Arm track for recording"
                    >
                      <Circle className="h-3 w-3 fill-current" />
                    </button>
                  )}

                  {/* Solo Button */}
                  <button
                    onClick={onToggleSolo}
                    className={cn(
                      'h-6 w-6 rounded flex items-center justify-center transition-all',
                      track.solo
                        ? 'bg-yellow-500 text-black shadow-md shadow-yellow-500/30'
                        : 'bg-card hover:bg-accent text-muted-foreground border border-border/50'
                    )}
                    title="Solo track"
                  >
                    <Headphones className="h-3 w-3" />
                  </button>

                  {/* Mute Button */}
                  <button
                    onClick={onToggleMute}
                    className={cn(
                      'h-6 w-6 rounded flex items-center justify-center transition-all',
                      track.mute
                        ? 'bg-blue-500 text-white shadow-md shadow-blue-500/30'
                        : 'bg-card hover:bg-accent text-muted-foreground border border-border/50'
                    )}
                    title="Mute track"
                  >
                    {track.mute ? <VolumeX className="h-3 w-3" /> : <Volume2 className="h-3 w-3" />}
                  </button>

                  {/* Automation Toggle */}
                  <button
                    onClick={() => {
                      onUpdateTrack(track.id, {
                        automation: {
                          ...track.automation,
                          showAutomation: !track.automation?.showAutomation,
                        },
                      });
                    }}
                    className={cn(
                      'h-6 w-6 rounded flex items-center justify-center transition-all text-[10px] font-bold',
                      track.automation?.showAutomation
                        ? 'bg-primary text-primary-foreground shadow-md shadow-primary/30'
                        : 'bg-card hover:bg-accent text-muted-foreground border border-border/50'
                    )}
                    title={track.automation?.showAutomation ? 'Hide automation' : 'Show automation'}
                  >
                    A
                  </button>
                </div>
              </div>
            </div>
          )}
        </div>

      {/* Right: Waveform Area (Flexible Width) */}
      <div
        className="flex-1 relative bg-waveform-bg border-b border-l border-border"
      >
        {/* Delete Button - Top Right Overlay */}
        <button
          onClick={(e) => {
            e.stopPropagation();
            onRemove();
          }}
          className={cn(
            'absolute top-2 right-2 z-20 h-6 w-6 rounded flex items-center justify-center transition-all',
            'bg-card/80 hover:bg-destructive/90 text-muted-foreground hover:text-white',
            'border border-border/50 hover:border-destructive',
            'backdrop-blur-sm shadow-sm hover:shadow-md'
          )}
          title="Remove track"
        >
          <Trash2 className="h-3 w-3" />
        </button>

        {track.audioBuffer ? (
          <>
            {/* Waveform Canvas */}
            <canvas
              ref={canvasRef}
              className="absolute inset-0 w-full h-full cursor-pointer"
              onMouseDown={handleCanvasMouseDown}
              onMouseMove={handleCanvasMouseMove}
              onMouseUp={handleCanvasMouseUp}
            />
          </>
        ) : (
          !track.collapsed && (
            <>
              <div
                className={cn(
                  "absolute inset-0 flex flex-col items-center justify-center text-sm text-muted-foreground hover:text-foreground transition-colors cursor-pointer group",
                  isDragging ? "bg-primary/20 text-primary border-2 border-primary border-dashed" : "hover:bg-accent/50"
                )}
                onClick={(e) => {
                  e.stopPropagation();
                  handleLoadAudioClick();
                }}
                onDragOver={handleDragOver}
                onDragLeave={handleDragLeave}
                onDrop={handleDrop}
              >
                <Upload className="h-6 w-6 mb-2 opacity-50 group-hover:opacity-100" />
                <p>{isDragging ? 'Drop audio file here' : 'Click to load audio file'}</p>
                <p className="text-xs opacity-75 mt-1">or drag & drop</p>
              </div>
              <input
                ref={fileInputRef}
                type="file"
                accept="audio/*"
                onChange={handleFileChange}
                className="hidden"
              />
            </>
          )
        )}
      </div>
      </div>

      {/* Automation Lanes */}
      {!track.collapsed && track.automation?.showAutomation && (
        <div className="bg-background/30">
          {track.automation.lanes.map((lane) => (
            <AutomationLane
              key={lane.id}
              lane={lane}
              duration={duration}
              zoom={zoom}
              currentTime={currentTime}
              onUpdateLane={(updates) => {
                const updatedLanes = track.automation.lanes.map((l) =>
                  l.id === lane.id ? { ...l, ...updates } : l
                );
                onUpdateTrack(track.id, {
                  automation: { ...track.automation, lanes: updatedLanes },
                });
              }}
              onAddPoint={(time, value) => {
                const newPoint = createAutomationPoint({
                  time,
                  value,
                  curve: 'linear',
                });
                const updatedLanes = track.automation.lanes.map((l) =>
                  l.id === lane.id
                    ? { ...l, points: [...l.points, newPoint] }
                    : l
                );
                onUpdateTrack(track.id, {
                  automation: { ...track.automation, lanes: updatedLanes },
                });
              }}
              onUpdatePoint={(pointId, updates) => {
                const updatedLanes = track.automation.lanes.map((l) =>
                  l.id === lane.id
                    ? {
                        ...l,
                        points: l.points.map((p) =>
                          p.id === pointId ? { ...p, ...updates } : p
                        ),
                      }
                    : l
                );
                onUpdateTrack(track.id, {
                  automation: { ...track.automation, lanes: updatedLanes },
                });
              }}
              onRemovePoint={(pointId) => {
                const updatedLanes = track.automation.lanes.map((l) =>
                  l.id === lane.id
                    ? { ...l, points: l.points.filter((p) => p.id !== pointId) }
                    : l
                );
                onUpdateTrack(track.id, {
                  automation: { ...track.automation, lanes: updatedLanes },
                });
              }}
            />
          ))}
        </div>
      )}

      {/* Track Height Resize Handle */}
      {!track.collapsed && (
        <div
          className={cn(
            'absolute bottom-0 left-0 right-0 h-1 cursor-ns-resize hover:bg-primary/50 transition-all duration-200 z-20 group',
            isResizing && 'bg-primary/50 h-1.5'
          )}
          onMouseDown={handleResizeStart}
          title="Drag to resize track height"
        >
          <div className="absolute inset-x-0 bottom-0 h-px bg-border group-hover:bg-primary transition-colors duration-200" />
        </div>
      )}
    </div>
  );
}