import React, { useMemo, useState, useRef, useEffect } from 'react';
import { DEBUG_MODE } from '../../constants';
import { KGMidiRegion } from '../../core/region/KGMidiRegion';
import { KGMidiNote } from '../../core/midi/KGMidiNote';
import { KGTrack } from '../../core/track/KGTrack';
import { KGCore } from '../../core/KGCore';
import PianoNote from './PianoNote';
import PianoKeys from './PianoKeys';
import PianoGridHeader from './PianoGridHeader';
import PianoGrid from './PianoGrid';
import { useNoteOperations } from '../../hooks/useNoteOperations';
import { useNoteSelection } from '../../hooks/useNoteSelection';
import type { KeySignature } from '../../core/KGProject';

interface PianoRollContentProps {
  contentRef: React.MutableRefObject<HTMLDivElement | null>;
  pianoGridRef: React.MutableRefObject<HTMLDivElement | null>;
  maxBars: number;
  timeSignature: { numerator: number; denominator: number };
  activeRegion: KGMidiRegion | null;
  updateTrack: (track: KGTrack) => void;
  tracks: KGTrack[];
  onSetNoteUpdateTrigger?: (setNoteFn: React.Dispatch<React.SetStateAction<number>>) => void;
  onSetDeleteNotesTrigger?: (deleteFn: () => boolean) => void;
  selectedMode: string;
  keySignature: KeySignature;
}

const PianoRollContent: React.FC<PianoRollContentProps> = ({
  contentRef,
  pianoGridRef,
  maxBars,
  timeSignature,
  activeRegion,
  updateTrack,
  tracks,
  onSetNoteUpdateTrigger,
  onSetDeleteNotesTrigger,
  selectedMode,
  keySignature
}) => {
  // Get KGCore instance
  const core = KGCore.instance();
  
  // Use the note operations hook for resize and drag functionality
  const {
    resizingNoteId,
    draggingNoteId,
    tempNoteStyles,
    noteUpdateCounter,
    setNoteUpdateCounter,
    handleGridDoubleClick,
    handleGridClick,
    handleNoteResizeStart,
    handleNoteResize,
    handleNoteResizeEnd,
    handleNoteDragStart,
    handleNoteDrag,
    handleNoteDragEnd,
    deleteSelectedNotes
  } = useNoteOperations({
    activeRegion,
    timeSignature,
    updateTrack,
    tracks,
    pianoGridRef
  });
  
  // Expose setNoteUpdateCounter to parent component
  useEffect(() => {
    if (onSetNoteUpdateTrigger) {
      onSetNoteUpdateTrigger(setNoteUpdateCounter);
    }
  }, [onSetNoteUpdateTrigger, setNoteUpdateCounter]);

  // Expose deleteSelectedNotes to parent component
  useEffect(() => {
    if (onSetDeleteNotesTrigger) {
      onSetDeleteNotesTrigger(deleteSelectedNotes);
    }
  }, [onSetDeleteNotesTrigger, deleteSelectedNotes]);
  
  // Use the note selection hook for selection functionality
  const {
    selectedNoteIds,
    isBoxSelectingRef,
    selectionBoxRef,
    selectionBoxRender,
    handleNoteClick,
    handleBackgroundClick,
    handleBackgroundMouseDown,
    cleanupSelectionListeners
  } = useNoteSelection({
    activeRegion,
    updateTrack,
    tracks
  });

  // Combined click handler for both pointer and pencil modes
  const handleCombinedClick = (e: React.MouseEvent) => {
    // Handle selection click (pointer mode)
    handleBackgroundClick(e);
    // Handle pencil mode note creation
    handleGridClick(e);
  };

  // Sync selected notes with KGCore on mount and when selection changes
  useEffect(() => {
    if (!activeRegion) return;
    
    // Get currently selected items from KGCore
    const selectedItems = core.getSelectedItems();
    
    // Filter for KGMidiNote items that belong to this region
    const selectedNotes = selectedItems.filter(item => 
      item instanceof KGMidiNote && 
      activeRegion.getNotes().some(note => note.getId() === item.getId())
    ) as KGMidiNote[];
    
    // Make sure the note objects have the correct selection state
    activeRegion.getNotes().forEach(note => {
      const isSelected = selectedNotes.some(selectedNote => selectedNote.getId() === note.getId());
      if (isSelected && !note.isSelected()) {
        note.select();
      } else if (!isSelected && note.isSelected()) {
        note.deselect();
      }
    });
  }, [activeRegion]);

  // Clean up event listeners on unmount
  useEffect(() => {
    return () => {
      cleanupSelectionListeners();
    };
  }, []);

  // Memoize the notes rendering to prevent unnecessary recalculations
  const memoizedNotes = useMemo(() => {
    if (!activeRegion) return null;
    
    if (DEBUG_MODE.PIANO_ROLL) {
      console.log(`Rendering notes for region: ${activeRegion.getId()}`);
      console.log(`Number of notes: ${activeRegion.getNotes().length}`);
      console.log(`Note update counter: ${noteUpdateCounter}`);
      console.log(`Selected notes: ${Array.from(selectedNoteIds).join(', ')}`);
    }
    
    const notes = activeRegion.getNotes();
    const beatWidth = parseInt(getComputedStyle(document.documentElement).getPropertyValue('--region-grid-beat-width')) || 40;
    const noteHeight = parseInt(getComputedStyle(document.documentElement).getPropertyValue('--region-piano-key-height')) || 20;
    const regionStartBeat = activeRegion.getStartFromBeat();
    
    return notes.map((note, index) => {
      // Calculate position and size
      const startBeat = note.getStartBeat() + regionStartBeat; // Absolute beat position
      const endBeat = note.getEndBeat() + regionStartBeat; // Absolute beat position
      const pitch = note.getPitch();
      
      // Convert pitch to y position (higher notes have lower y values)
      // We need to find the index of the pitch in our piano roll
      const pitchIndex = 107 - pitch; // Reverse the pitch to get the index (B7 is 107)
      
      // Calculate position and dimensions
      const left = startBeat * beatWidth;
      const top = pitchIndex * noteHeight;
      const width = (endBeat - startBeat) * beatWidth;
      
      const noteId = note.getId();
      
      // Check if this note is being resized or dragged and has a temporary style
      if ((resizingNoteId === noteId || draggingNoteId === noteId) && tempNoteStyles[noteId]) {
        // Use the temporary style for position and size
        const tempStyle = tempNoteStyles[noteId];
        
        return (
          <PianoNote
            key={`note-${noteId}`}
            id={noteId}
            index={index}
            left={parseFloat(tempStyle.left as string)}
            top={parseFloat(tempStyle.top as string)}
            width={parseFloat(tempStyle.width as string)}
            height={noteHeight}
            onResizeStart={handleNoteResizeStart}
            onResize={handleNoteResize}
            onResizeEnd={handleNoteResizeEnd}
            onDragStart={handleNoteDragStart}
            onDrag={handleNoteDrag}
            onDragEnd={handleNoteDragEnd}
            onClick={handleNoteClick}
          />
        );
      }
      
      return (
        <PianoNote
          key={`note-${noteId}`}
          id={noteId}
          index={index}
          left={left}
          top={top}
          width={width}
          height={noteHeight}
          onResizeStart={handleNoteResizeStart}
          onResize={handleNoteResize}
          onResizeEnd={handleNoteResizeEnd}
          onDragStart={handleNoteDragStart}
          onDrag={handleNoteDrag}
          onDragEnd={handleNoteDragEnd}
          onClick={handleNoteClick}
        />
      );
    });
  }, [activeRegion, noteUpdateCounter, resizingNoteId, draggingNoteId, tempNoteStyles, selectedNoteIds, selectionBoxRender, tracks]);

  return (
    <div 
      className="piano-roll-content"
      ref={contentRef}
    >
      <PianoGridHeader maxBars={maxBars} timeSignature={timeSignature} />
      
      <div className="piano-roll-body">
        <PianoKeys activeRegion={activeRegion} />
        
        <PianoGrid
          gridRef={pianoGridRef}
          onDoubleClick={handleGridDoubleClick}
          onClick={handleCombinedClick}
          onMouseDown={handleBackgroundMouseDown}
          isBoxSelecting={isBoxSelectingRef.current}
          selectionBox={selectionBoxRef.current}
          regionStartBeat={activeRegion?.getStartFromBeat() || 0}
          selectedMode={selectedMode}
          keySignature={keySignature}
        >
          {memoizedNotes}
        </PianoGrid>
      </div>
    </div>
  );
};

export default PianoRollContent;