import * as Tone from 'tone';
import {
  PatternKeyframe,
  ChordKeyframe,
  MuteKeyframe,
  AutomationPoint,
  LayerName,
} from '@/types/audio';
import { DrumMachine } from './drumMachine';
import { ChordEngine } from './chordEngine';
import { drumPatterns, chordProgressions } from './patterns';

type ScheduledEventId = number;

interface ScheduledEvents {
  drumPatterns: ScheduledEventId[];
  chordProgressions: ScheduledEventId[];
  muteEvents: Record<LayerName, ScheduledEventId[]>;
  automationEvents: Record<LayerName, ScheduledEventId[]>;
}

export class TimelineScheduler {
  private transport = Tone.getTransport();
  private events: ScheduledEvents = {
    drumPatterns: [],
    chordProgressions: [],
    muteEvents: { drums: [], chords: [], ambient: [] },
    automationEvents: { drums: [], chords: [], ambient: [] },
  };

  private drumMachine: DrumMachine | null = null;
  private chordEngine: ChordEngine | null = null;
  private volumeCallback: ((layer: LayerName, value: number) => void) | null = null;
  private muteCallback: ((layer: LayerName, muted: boolean) => void) | null = null;

  setDrumMachine(dm: DrumMachine | null): void {
    this.drumMachine = dm;
  }

  setChordEngine(ce: ChordEngine | null): void {
    this.chordEngine = ce;
  }

  setVolumeCallback(cb: (layer: LayerName, value: number) => void): void {
    this.volumeCallback = cb;
  }

  setMuteCallback(cb: (layer: LayerName, muted: boolean) => void): void {
    this.muteCallback = cb;
  }

  scheduleDrumKeyframes(keyframes: PatternKeyframe[]): void {
    this.clearDrumEvents();

    const sorted = [...keyframes].sort((a, b) => a.bar - b.bar);

    sorted.forEach((kf) => {
      const eventId = this.transport.schedule((time) => {
        if (this.drumMachine && drumPatterns[kf.patternIndex]) {
          this.drumMachine.setPattern(drumPatterns[kf.patternIndex]);
        }
      }, `${kf.bar}:0:0`);

      this.events.drumPatterns.push(eventId);
    });
  }

  scheduleChordKeyframes(keyframes: ChordKeyframe[]): void {
    this.clearChordEvents();

    const sorted = [...keyframes].sort((a, b) => a.bar - b.bar);

    sorted.forEach((kf) => {
      const eventId = this.transport.schedule((time) => {
        if (this.chordEngine && chordProgressions[kf.progressionIndex]) {
          this.chordEngine.setProgression(chordProgressions[kf.progressionIndex]);
        }
      }, `${kf.bar}:0:0`);

      this.events.chordProgressions.push(eventId);
    });
  }

  scheduleMuteKeyframes(layer: LayerName, keyframes: MuteKeyframe[]): void {
    this.clearMuteEvents(layer);

    const sorted = [...keyframes].sort((a, b) => a.bar - b.bar);

    sorted.forEach((kf) => {
      const eventId = this.transport.schedule((time) => {
        this.muteCallback?.(layer, kf.muted);
      }, `${kf.bar}:0:0`);

      this.events.muteEvents[layer].push(eventId);
    });
  }

  scheduleVolumeAutomation(layer: LayerName, points: AutomationPoint[]): void {
    this.clearAutomationEvents(layer);

    if (points.length === 0) return;

    const sorted = [...points].sort((a, b) => {
      if (a.bar !== b.bar) return a.bar - b.bar;
      return a.beat - b.beat;
    });

    for (let i = 0; i < sorted.length; i++) {
      const current = sorted[i];
      const next = sorted[i + 1];

      if (!next) {
        const eventId = this.transport.schedule((time) => {
          this.volumeCallback?.(layer, current.value);
        }, `${current.bar}:${current.beat}:0`);
        this.events.automationEvents[layer].push(eventId);
        continue;
      }

      const startTime = this.transport.toSeconds(`${current.bar}:${current.beat}:0`);
      const endTime = this.transport.toSeconds(`${next.bar}:${next.beat}:0`);
      const duration = endTime - startTime;
      const steps = Math.max(1, Math.floor(duration * 16));
      const stepDuration = duration / steps;

      for (let step = 0; step <= steps; step++) {
        const t = step / steps;
        const value = current.value + (next.value - current.value) * t;
        const scheduleTime = startTime + step * stepDuration;

        const eventId = this.transport.schedule((time) => {
          this.volumeCallback?.(layer, value);
        }, scheduleTime);
        this.events.automationEvents[layer].push(eventId);
      }
    }
  }

  private clearDrumEvents(): void {
    this.events.drumPatterns.forEach((id) => this.transport.clear(id));
    this.events.drumPatterns = [];
  }

  private clearChordEvents(): void {
    this.events.chordProgressions.forEach((id) => this.transport.clear(id));
    this.events.chordProgressions = [];
  }

  private clearMuteEvents(layer: LayerName): void {
    this.events.muteEvents[layer].forEach((id) => this.transport.clear(id));
    this.events.muteEvents[layer] = [];
  }

  private clearAutomationEvents(layer: LayerName): void {
    this.events.automationEvents[layer].forEach((id) => this.transport.clear(id));
    this.events.automationEvents[layer] = [];
  }

  clearAll(): void {
    this.clearDrumEvents();
    this.clearChordEvents();
    const layers: LayerName[] = ['drums', 'chords', 'ambient'];
    layers.forEach((l) => {
      this.clearMuteEvents(l);
      this.clearAutomationEvents(l);
    });
  }

  dispose(): void {
    this.clearAll();
    this.drumMachine = null;
    this.chordEngine = null;
    this.volumeCallback = null;
    this.muteCallback = null;
  }
}