import {
    User,
    LoginResponse,
    RegisterResponse,
    SendMessageResponse,
    Message,
} from "./types.js";

export class APIService {
    private static readonly baseUrl = "http://webp-ilv-backend.cs.technikum-wien.at/messenger";

    async register ( name: string, email: string, password: string, groupId: string): Promise<RegisterResponse> {
        const formData = new FormData();
        formData.append( "name", name );
        formData.append( "email", email );
        formData.append( "password", password );
        formData.append( "group_id", groupId );

        const response = await fetch( `${APIService.baseUrl}/registrieren.php`, {method: "POST", body: formData} );
        if ( !response.ok ) {
            throw new Error ( 'Registration failed: ' + response.statusText );
        }

        const text = await response.text();
        let data: RegisterResponse;
        try {
            data = JSON.parse( text );
        } catch {
            console.error( "Non-JSON response from registrieren.php:", text );
            throw new Error( "Registration failed: unexpected server response." );
        }
        return data;
    }

    async login ( usernameOrEmail: string, password: string): Promise <LoginResponse> {
        const formData = new FormData();
        formData.append( "username_or_email", usernameOrEmail );
        formData.append( "password", password );

        const response = await fetch( `${APIService.baseUrl}/login.php`, {method: "POST", body: formData} );

        if ( !response.ok ) {
            throw new Error ( 'Login failed: ' + response.statusText );
        }

        return await response.json();
    }

    async getUsers ( token: string, userId: string): Promise<User[]> {
        const url = new URL( `${APIService.baseUrl}/get_users.php` );
        url.searchParams.set( "token", token );
        url.searchParams.set( "id", userId );

        const response = await fetch ( url, {method: "GET"} );

        if ( !response.ok ) {
            throw new Error ( 'Failed to fetch users: ' + response.statusText );
        }

        return await response.json();
    }

    async sendMessage ( token: string, senderId: string, receiverId: string, message: string ): Promise <SendMessageResponse> {
        const formData = new FormData();
        formData.append( "token", token );
        formData.append( "sender_id", senderId );
        formData.append( "receiver_id", receiverId );
        formData.append( "message", message );

        const response = await fetch( `${APIService.baseUrl}/send_message.php`, {method: "POST", body: formData} );

        if ( !response.ok ) {
            throw new Error ( 'Failed to send message: ' + response.statusText );
        }

        return await response.json();
    }
    async getConversation( token: string, user1Id: string, user2Id:string ): Promise<Message[]> {
        const url = new URL( `${APIService.baseUrl}/get_conversation.php` );
        url.searchParams.set( "token", token );
        url.searchParams.set( "user1_id", user1Id );
        url.searchParams.set( "user2_id", user2Id );

        const response = await fetch( url, {method: "GET"} );;
        if ( !response.ok ) {
            throw new Error ( 'Failed to fetch conversation: ' + response.statusText );
        }
        return await response.json();
    }
}