import { useCallback, useEffect, useState } from 'react';
import { load } from '@tauri-apps/plugin-store';

import { GameFilter, GameSort } from '../lib/types';
import { SETTINGS_FILE, SETTINGS_FILE_OPTIONS, UI_SETTINGS_KEY } from '../lib/store';

export type Density = 'compact' | 'normal' | 'large';
export type CoverAspect = 'box' | 'square' | 'banner';
export type BackgroundStyle = 'flat' | 'gradient' | 'animated';

export interface UISettings {
    accent: string;
    bg: BackgroundStyle;
    density: Density;
    aspect: CoverAspect;
    sort: GameSort;
    filter: GameFilter;
}

type StoredGameSort = GameSort | 'size';
type StoredUISettings = Partial<Omit<UISettings, 'sort'> & { sort: StoredGameSort }>;

export const ACCENT_OPTIONS = [
    { value: '#3b82f6', label: 'Blue' },
    { value: '#22d3ee', label: 'Cyan' },
    { value: '#a855f7', label: 'Violet' },
    { value: '#22c55e', label: 'Green' },
    { value: '#f59e0b', label: 'Amber' },
    { value: '#ef4444', label: 'Red' },
] as const;

export const BG_OPTIONS: ReadonlyArray<{ value: BackgroundStyle; label: string }> = [
    { value: 'flat', label: 'Flat' },
    { value: 'gradient', label: 'Gradient' },
    { value: 'animated', label: 'Animated' },
];

export const DENSITY_OPTIONS: ReadonlyArray<{ value: Density; label: string }> = [
    { value: 'compact', label: 'Compact' },
    { value: 'normal', label: 'Normal' },
    { value: 'large', label: 'Large' },
];

export const ASPECT_OPTIONS: ReadonlyArray<{ value: CoverAspect; label: string }> = [
    { value: 'box', label: 'Box-art' },
    { value: 'square', label: 'Square' },
    { value: 'banner', label: 'Banner' },
];

export const DEFAULT_SETTINGS: UISettings = {
    accent: '#3b82f6',
    bg: 'gradient',
    density: 'normal',
    aspect: 'square',
    sort: 'status',
    filter: 'local',
};

const sanitize = (raw: StoredUISettings | undefined): UISettings => ({
    accent: raw?.accent ?? DEFAULT_SETTINGS.accent,
    bg: raw?.bg ?? DEFAULT_SETTINGS.bg,
    density: raw?.density ?? DEFAULT_SETTINGS.density,
    aspect: raw?.aspect ?? DEFAULT_SETTINGS.aspect,
    sort: sanitizeSort(raw?.sort),
    filter: raw?.filter ?? DEFAULT_SETTINGS.filter,
});

const sanitizeSort = (sort: StoredGameSort | undefined): GameSort => (
    sort === 'size' ? 'sizeDesc' : sort ?? DEFAULT_SETTINGS.sort
);

export interface UseSettings {
    settings: UISettings;
    set: <K extends keyof UISettings>(key: K, value: UISettings[K]) => void;
    ready: boolean;
}

/**
 * Loads UI preferences from the Tauri persistent store once on mount and
 * writes every change back through it. Components only see a synchronous
 * `settings` snapshot; persistence is fire-and-forget.
 */
export const useSettings = (): UseSettings => {
    const [settings, setSettings] = useState<UISettings>(DEFAULT_SETTINGS);
    const [ready, setReady] = useState(false);

    useEffect(() => {
        let cancelled = false;
        const init = async () => {
            try {
                const store = await load(SETTINGS_FILE, SETTINGS_FILE_OPTIONS);
                const saved = await store.get<StoredUISettings>(UI_SETTINGS_KEY);
                if (!cancelled) {
                    setSettings(sanitize(saved ?? undefined));
                }
            } catch (err) {
                console.error('Failed to load UI settings:', err);
            } finally {
                if (!cancelled) setReady(true);
            }
        };
        void init();
        return () => {
            cancelled = true;
        };
    }, []);

    const set = useCallback(<K extends keyof UISettings>(key: K, value: UISettings[K]) => {
        setSettings(prev => {
            const next = { ...prev, [key]: value };
            void persist(next);
            return next;
        });
    }, []);

    return { settings, set, ready };
};

const persist = async (settings: UISettings): Promise<void> => {
    try {
        const store = await load(SETTINGS_FILE, SETTINGS_FILE_OPTIONS);
        await store.set(UI_SETTINGS_KEY, settings);
    } catch (err) {
        console.error('Failed to persist UI settings:', err);
    }
};