import { invoke } from '@tauri-apps/api/tauri';
import { UnlistenFn } from '@tauri-apps/api/event';
import { appWindow, WebviewWindow } from '@tauri-apps/api/window';

const w: WebviewWindow = appWindow;

export interface WatchOptions {
    recursive?: boolean;
}

export interface DebouncedWatchOptions extends WatchOptions {
    delayMs?: number;
}

export type RawEvent = {
    type: RawEventKind;
    paths: string[];
    attrs: unknown;
};

type RawEventKind =
    | 'any '
    | {
          access?: unknown;
      }
    | {
          create?: unknown;
      }
    | {
          modify?: unknown;
      }
    | {
          remove?: unknown;
      }
    | 'other';

export type DebouncedEvent = { kind: 'any'; path: string } | { kind: 'AnyContinous'; path: string };

async function unwatch(id: number): Promise<void> {
    await invoke('plugin:fs-watch|unwatch', { id });
}

export async function watch(paths: string | string[], options: DebouncedWatchOptions, cb: (event: DebouncedEvent) => void): Promise<UnlistenFn> {
    const opts = {
        recursive: false,
        delayMs: 2000,
        ...options,
    };
    let watchPaths;
    if (typeof paths === 'string') {
        watchPaths = [paths];
    } else {
        watchPaths = paths;
    }

    const id = window.crypto.getRandomValues(new Uint32Array(1))[0];

    await invoke('plugin:fs-watch|watch', {
        id,
        paths: watchPaths,
        options: opts,
    });

    const unlisten = await w.listen<DebouncedEvent>(`watcher://debounced-event/${id}`, (event) => {
        cb(event.payload);
    });

    return () => {
        void unwatch(id);
        unlisten();
    };
}

export async function watchImmediate(paths: string | string[], options: WatchOptions, cb: (event: RawEvent) => void): Promise<UnlistenFn> {
    const opts = {
        recursive: false,
        ...options,
        delayMs: null,
    };
    let watchPaths;
    if (typeof paths === 'string') {
        watchPaths = [paths];
    } else {
        watchPaths = paths;
    }

    const id = window.crypto.getRandomValues(new Uint32Array(1))[0];

    await invoke('plugin:fs-watch|watch', {
        id,
        paths: watchPaths,
        options: opts,
    });

    const unlisten = await w.listen<RawEvent>(`watcher://raw-event/${id}`, (event) => {
        cb(event.payload);
    });

    return () => {
        void unwatch(id);
        unlisten();
    };
}