let apiUrl: string = `${location.protocol}//${location.hostname}:8856/`;

class Favorites {
  private data: string[] = [];

  constructor() {
    this.data = JSON.parse(localStorage.getItem("settings.favorites")) || [];
    this.sync();
  }

  public async sync(): Promise<void> {
    localStorage.setItem("settings.favorites", JSON.stringify(this.data));
  }
  
  public async clear(): Promise<void> {
    this.data = [];
    this.sync();
  }
  
  public async pop(): Promise<string> {
    let item: any = this.data.pop();
    this.sync();
    return item;
  }
  
  public async push(toadd): Promise<void> {
    this.data.push(toadd);
    this.sync();
  }
  
  public async delete(d): Promise<void> {
    this.data = this.data.filter((v) => { return v != d });
    this.sync();
  }
  
  public async at(d): Promise<string> {
    return this.data.at(d);
  }
  
  public async contains(d): Promise<boolean> {
    return this.data.includes(d);
  }

  public async shuffle(): Promise<string[]> {
    let data: string[] = this.data;

    for (let i = 0; i < await this.data.length; i++) {
      data.sort(() => { return Math.random() - 0.5 });
    }

    return data;
  }
}

class Blacklist {
  private data: string[] = [];

  constructor() {
    this.data = JSON.parse(localStorage.getItem("settings.blacklist")) || [];
    this.sync();
  }

  public async sync(): Promise<void> {
    localStorage.setItem("settings.blacklist", JSON.stringify(this.data));
  }
  
  public async clear(): Promise<void> {
    this.data = [];
    this.sync();
  }
  
  public async pop(): Promise<string> {
    let item: any = this.data.pop();
    this.sync();
    return item;
  }
  
  public async push(toadd): Promise<void> {
    this.data.push(toadd);
    this.sync();
  }
  
  public async delete(d): Promise<void> {
    this.data = this.data.filter((v) => { return v != d });
    this.sync();
  }
  
  public async at(d): Promise<string> {
    return this.data.at(d);
  }
  public async contains(d): Promise<boolean> {
    return this.data.includes(d);
  }
}

class Cache {
  private cache: string[];
  private checksum: string;

  constructor() {}

  async load(): Promise<void> {
    if (!localStorage.getItem("cache") || !localStorage.getItem("cache.checksum")) {
      await this.sync();
    } else {
      if (!await this.validate()) {
        await this.sync();
      } else {
        this.cache = JSON.parse(localStorage.getItem("cache"));
        this.checksum = localStorage.getItem("cache.checksum");
      }
    }
  }

  async sync(): Promise<void> {
    try {
      let sync = await fetch(apiUrl + "sync");
      let data = await sync.json();

      if (!sync.ok)
        throw Error(sync.statusText);

      this.checksum = data.checksum;
      this.cache = data.files;

      await this.update();
    } catch (e) {
      throw e;
    }
  }

  private async update(): Promise<void> {
    localStorage.setItem("cache", JSON.stringify(this.cache));
    localStorage.setItem("cache.checksum", this.checksum);
  }

  private async validate(): Promise<boolean> {
    try {
      let sync = await fetch(apiUrl + "sync", {
        body: this.checksum,
        method: "POST",
      });

      if (!sync.ok)
        throw Error(sync.statusText);
      
      return (await sync.json()).valid;
    } catch(e) {
      throw e;
    }
  }

  public async at(d): Promise<string> {
    return this.cache.at(d);
  }

  public async shuffle(): Promise<string[]> {
    let data: string[] = this.cache;

    for (let i = 0; i < await this.length(); i++) {
      data.sort(() => { return Math.random() - 0.5 });
    }

    return data;
  }

  public async length(): Promise<Number> {
    return this.cache.length;
  }
}

class Config {
  private data = {};
  private defaultConfig = {
    "test": 123,
  }
  
  constructor() {
    if (!localStorage.getItem("config"))
      localStorage.setItem("config", JSON.stringify(this.defaultConfig));
    
    this.data = JSON.parse(localStorage.getItem("config"));

    this.verify();
    this.sync();
  }

  private verify() {
    let keys = this.keys();
    
    for (let k in this.defaultConfig)
      if (!keys[k])
        this.data[k] = this.defaultConfig[k];
  }

  public sync() {
    localStorage.setItem("config", JSON.stringify(this.data));
  }

  public set(vr, vl) {
    this.data[vr] = vl;
  }

  public get(vr) {
    return this.data[vr];
  }

  public keys() {
    return Object.keys(this.data);
  }
}

export default class Settings {
  favorites: Favorites;
  blacklist: Blacklist;
  cache: Cache;
  config: Config;

  constructor() {
    this.favorites = new Favorites();
    this.blacklist = new Blacklist();
    this.cache = new Cache();
    this.config = new Config();
  }
}

export { apiUrl };