import {watch, FSWatcher} from 'chokidar';
import { EventEmitter } from 'events';
import { join } from 'path';
import { DocumentAccessor } from '../../model/doc';
import { DiffWatcherEvent, IDiffWatcher } from '../watcher';
import { setupHelp, setupRecursive } from './util';

type RecursiveWatcherOption={
    /** @default true */
    watchFile?:boolean,
    /** @default false */
    watchDir?:boolean,
}

export class RecursiveWatcher extends EventEmitter implements IDiffWatcher  {
    on<U extends keyof DiffWatcherEvent>(event:U,listener:DiffWatcherEvent[U]): this{
        return super.on(event,listener);
    }
    emit<U extends keyof DiffWatcherEvent>(event:U,...arg:Parameters<DiffWatcherEvent[U]>): boolean{
        return super.emit(event,...arg);
    }
    readonly path: string;
    private watcher: FSWatcher

    constructor(path:string, option:RecursiveWatcherOption = {
        watchDir:false,
        watchFile:true,
    }){
        super();
        this.path = path;
        this.watcher = watch(path,{
            persistent:true,
            ignoreInitial:true,
            depth:100,
        });
        option.watchFile ??= true;
        if(option.watchFile){
            this.watcher.on("add",path=>{
                const cpath = join(this.path,path);
                this.emit("create",cpath);
            }).on("unlink",path=>{
                const cpath = join(this.path,path);
                this.emit("delete",cpath);
            });
        }
        if(option.watchDir){
            this.watcher.on("addDir",path=>{
                const cpath = join(this.path,path);
                this.emit("create",cpath);
            }).on("unlinkDir",path=>{
                const cpath = join(this.path,path);
                this.emit("delete",cpath);
            })
        }
    }
    async setup(cntr: DocumentAccessor): Promise<void> {
        await setupRecursive(this,this.path,cntr);
    }
}