import Chat from "./Chat.ts";

interface FetchOptions extends RequestInit {
  client?: Deno.HttpClient;
}

interface Category {
  name: string;
  description: string;
}

interface Featured {
  characters: string[];
  name: string;
}

interface CharacterInfo {
  external_id: string;
  title: string;
  name: string;
  visibility: string;
  copyable: false;
  greeting: string;
  description: string;
  identifier: string;
  avatar_file_name: string;
  songs: unknown[];
  img_gen_enabled: false;
  base_img_prompt: string;
  img_prompt_regex: string;
  strip_img_prompt_from_msg: boolean;
  user__username: string;
  participant__name: string;
  participant__num_interactions: number;
  participant__user__username: string;
  voice_id: number;
  usage: string;
}

interface SearchResult {
  external_id: string;
  title: string;
  greeting: string;
  description: string;
  avatar_file_name: string;
  visibility: string;
  copyable: boolean;
  participant__name: string;
  participant__num_interactions: number;
  user__id: number;
  user__username: string;
  img_gen_enabled: boolean;
  priority: number;
  search_score: number;
}

export default class Client {
  public token?: string;
  #client?: Deno.HttpClient;

  /**
   * Initalizes a HTTP(S) proxy for each request (Requires --unstable)
   * @param proxyUrl URL of the proxy
   * @param certPath Path to a certificate file
   */
  public async intitalizeProxy(proxyUrl: string, certPath: string | URL) {
    this.#client = Deno.createHttpClient({
      caCerts: [await Deno.readTextFile(certPath)],
      proxy: { url: proxyUrl },
    });
  }

  async fetch(
    input: string | URL | Request,
    options?: FetchOptions | undefined
  ) {
    if (this.#client)
      options = {
        client: this.#client,
        ...options,
      };
    return await fetch(input, options);
  }

  /**
   * Authenticates with character.ai
   * @param authToken The authorization token
   */
  public async authenticate(authToken: string) {
    const res = await this.fetch(
      "https://beta.character.ai/dj-rest-auth/auth0/",
      {
        body: JSON.stringify({
          access_token: authToken,
        }),
        method: "POST",
        headers: {
          Accept: "application/json",
          "Content-Type": "application/json",
        },
      }
    );
    const json = await res.json();

    this.token = json.key;
    if (!this.token)
      throw new Error("Authentication failed, your token might be invalid");
  }

  /**
   * Fetches a list of categories
   * @returns List of categories
   */
  public async fetchCategories(): Promise<Category[]> {
    const res = await this.fetch(
      "https://beta.character.ai/chat/character/categories/"
    );
    const { categories } = await res.json();

    if (!Array.isArray(categories))
      throw new Error("API provided invalid category data");

    return categories;
  }

  /**
   * Fetches a list of featured characters
   * @returns List of featured characters
   */
  public async fetchFeaturedCharacters(): Promise<Featured[]> {
    const res = await this.fetch(
      "https://beta.character.ai/chat/characters/featured/",
      {
        headers: {
          Authorization: `Token ${this.token}`,
          Accept: "application/json",
          "Content-Type": "application/json",
        },
      }
    );
    const { featured_characters } = await res.json();

    if (!Array.isArray(featured_characters))
      throw new Error("API provided invalid featured characters data");

    return featured_characters;
  }

  /**
   * Fetches information for a character
   * @param id Id of the character
   * @returns Character information
   */
  public async fetchCharacterInfo(id: string): Promise<CharacterInfo> {
    const res = await this.fetch(
      "https://beta.character.ai/chat/character/info/",
      {
        body: JSON.stringify({
          external_id: id,
        }),
        method: "POST",
        headers: {
          Authorization: `Token ${this.token}`,
          Accept: "application/json",
          "Content-Type": "application/json",
        },
      }
    );
    const { character } = await res.json();

    return character;
  }

  /**
   * Search for characters
   * @param query Search query
   * @returns Array of characters
   */
  public async search(query: string): Promise<SearchResult[]> {
    const url = new URL(
      "https://beta.character.ai/chat/characters/search/"
    );
    url.searchParams.set("query", query);

    const res = await this.fetch(url, {
      headers: {
        Authorization: `Token ${this.token}`,
        Accept: "application/json",
        "Content-Type": "application/json",
      },
    });
    const { characters } = await res.json();

    if (!Array.isArray(characters))
      throw new Error("API provided invalid search response");

    return characters;
  }

  /**
   * Creates a new chat history
   * @param id Character id
   * @returns The raw history to be used with the Chat class
   */
  public async createChat(id: string) {
    const res = await this.fetch(
      "https://beta.character.ai/chat/history/create/",
      {
        body: JSON.stringify({
          character_external_id: id,
          history_external_id: null,
        }),
        method: "POST",
        headers: {
          Authorization: `Token ${this.token}`,
          Accept: "application/json",
          "Content-Type": "application/json",
        },
      }
    );
    const history = await res.json();

    return history;
  }

  /**
   * Continues a chat
   * @param id Character id
   * @returns The raw history to be used with the Chat class or false if the chat doesn't exist
   */
  public async continueChat(id: string): Promise<Chat | false> {
    const res = await this.fetch(
      "https://beta.character.ai/chat/history/continue/",
      {
        body: JSON.stringify({
          character_external_id: id,
          history_external_id: null,
        }),
        method: "POST",
        headers: {
          Authorization: `Token ${this.token}`,
          Accept: "application/json",
          "Content-Type": "application/json",
        },
      }
    );
    
    const history = await res.json();

    if (history.status === "No Such History") return false;
    
    return history;
  }

  /**
   * Continues a chat or creates a new one if it doesn't exist
   * @param id Character id
   * @returns The Chat class
   */
  public async continueOrCreateChat(id: string): Promise<Chat> {
    let history = await this.continueChat(id);

    if (!history) history = await this.createChat(id);

    return new Chat(this, id, history);
  }
}