'use client';

import { useState, useEffect, useCallback } from 'react';

export interface AudioSettings {
  bufferSize: number; // 256, 512, 1024, 2048, 4096
  sampleRate: number; // 44100, 48000, 96000
  autoNormalizeOnImport: boolean;
}

export interface UISettings {
  theme: 'dark' | 'light' | 'auto';
  fontSize: 'small' | 'medium' | 'large';
}

export interface EditorSettings {
  autoSaveInterval: number; // seconds, 0 = disabled
  undoHistoryLimit: number; // 10-200
  snapToGrid: boolean;
  gridResolution: number; // seconds
  defaultZoom: number; // 1-20
}

export interface PerformanceSettings {
  peakCalculationQuality: 'low' | 'medium' | 'high';
  waveformRenderingQuality: 'low' | 'medium' | 'high';
  enableSpectrogram: boolean;
  maxFileSizeMB: number; // 100-1000
}

export interface Settings {
  audio: AudioSettings;
  ui: UISettings;
  editor: EditorSettings;
  performance: PerformanceSettings;
}

const DEFAULT_SETTINGS: Settings = {
  audio: {
    bufferSize: 2048,
    sampleRate: 48000,
    autoNormalizeOnImport: false,
  },
  ui: {
    theme: 'dark',
    fontSize: 'medium',
  },
  editor: {
    autoSaveInterval: 3, // 3 seconds
    undoHistoryLimit: 50,
    snapToGrid: false,
    gridResolution: 1.0, // 1 second
    defaultZoom: 1,
  },
  performance: {
    peakCalculationQuality: 'high',
    waveformRenderingQuality: 'high',
    enableSpectrogram: true,
    maxFileSizeMB: 500,
  },
};

const SETTINGS_STORAGE_KEY = 'audio-editor-settings';

function loadSettings(): Settings {
  if (typeof window === 'undefined') return DEFAULT_SETTINGS;

  try {
    const stored = localStorage.getItem(SETTINGS_STORAGE_KEY);
    if (!stored) return DEFAULT_SETTINGS;

    const parsed = JSON.parse(stored);
    // Merge with defaults to handle new settings added in updates
    return {
      audio: { ...DEFAULT_SETTINGS.audio, ...parsed.audio },
      ui: { ...DEFAULT_SETTINGS.ui, ...parsed.ui },
      editor: { ...DEFAULT_SETTINGS.editor, ...parsed.editor },
      performance: { ...DEFAULT_SETTINGS.performance, ...parsed.performance },
    };
  } catch (error) {
    console.error('Failed to load settings from localStorage:', error);
    return DEFAULT_SETTINGS;
  }
}

function saveSettings(settings: Settings): void {
  if (typeof window === 'undefined') return;

  try {
    localStorage.setItem(SETTINGS_STORAGE_KEY, JSON.stringify(settings));
  } catch (error) {
    console.error('Failed to save settings to localStorage:', error);
  }
}

export function useSettings() {
  const [settings, setSettings] = useState<Settings>(loadSettings);

  // Save to localStorage whenever settings change
  useEffect(() => {
    saveSettings(settings);
  }, [settings]);

  const updateAudioSettings = useCallback((updates: Partial<AudioSettings>) => {
    setSettings((prev) => ({
      ...prev,
      audio: { ...prev.audio, ...updates },
    }));
  }, []);

  const updateUISettings = useCallback((updates: Partial<UISettings>) => {
    setSettings((prev) => ({
      ...prev,
      ui: { ...prev.ui, ...updates },
    }));
  }, []);

  const updateEditorSettings = useCallback((updates: Partial<EditorSettings>) => {
    setSettings((prev) => ({
      ...prev,
      editor: { ...prev.editor, ...updates },
    }));
  }, []);

  const updatePerformanceSettings = useCallback((updates: Partial<PerformanceSettings>) => {
    setSettings((prev) => ({
      ...prev,
      performance: { ...prev.performance, ...updates },
    }));
  }, []);

  const resetSettings = useCallback(() => {
    setSettings(DEFAULT_SETTINGS);
  }, []);

  const resetCategory = useCallback((category: keyof Settings) => {
    setSettings((prev) => ({
      ...prev,
      [category]: DEFAULT_SETTINGS[category],
    }));
  }, []);

  return {
    settings,
    updateAudioSettings,
    updateUISettings,
    updateEditorSettings,
    updatePerformanceSettings,
    resetSettings,
    resetCategory,
  };
}