import Axios from "axios";

// Base URL for API queries.
const API_BASE_URL = "/api";

// How many chars at most for the description.
const max_description_length = 100;

// Wrapper for channels returned from our server.
export class Channel {
    // Title of the channel according to youtube.
    public Title: string;

    // Description of channel according to youtube.
    public Description: string;

    // Youtube ID
    public ID: string;

    // Tags given to the video.
    public User_Tags: Array<string>;

    // ID's belonging to the channel.
    public Video_IDs: Array<string>;

    // Popuplate this using data from our server.
    constructor(c : any){
        if (c == null) {
            this.Title = "NULL"
            this.Description = "NULL"
            this.ID = "NULL"
            this.User_Tags = ["NULL", "NULL", "NULL"]
            this.Video_IDs = ["NULL", "NULL"]
        } else {
            this.Title = c.title;
            this.Description = c.description;
            this.ID = c.id;
            this.User_Tags = c.user_Tags;
            this.Video_IDs = c.video_IDs;
        }
    }
}

// Wrapper for videos returned from our server.
export class Video {
    // Title of the video according to youtube.
    public Title: string;

    // Description of video according to youtube.
    public Description: string;

    // Youtube ID
    public ID: string;

    // Thumbnail
    public Thumbnail: string;
    
    // What channel made this video.
    public Channel: string;

    // Duration of the video in seconds.
    public Seconds: number;

    // Tags relevant to the video.
    public Tags: Array<string>;
    
    // Youtube URL of the video.
    public URL: string;

    // Popuplate this using data from our server.
    constructor(v: any){
        if (v == null){
            this.Title = "NULL";
            this.Description = "NULL";
            this.ID = "NULL";
            this.Thumbnail = "NULL";
            this.Channel = "NULL";
            this.Seconds = 9999999;
            this.Tags = ["NULL", "NULL"];
            this.URL = "NULL";
        } else {
            this.Title = v.title;
            this.Description = v.description;
            this.ID = v.id;
            this.Thumbnail = v.thumbnail;
            this.Channel = v.channel;
            this.Seconds = v.seconds;
            this.Tags = v.tags;
            this.URL = "https://www.youtube.com/watch?v=" + v.id;
        }
    }
}

// Types of modifications which can be applied to various models.
export enum Modification {
    Add, Delete, Refresh
}

// Change a channel state.
export async function channel_modify(youtubeID : string, modify : Modification): Promise<void | string> {
    switch (modify){
        case Modification.Add: {
            let URL = API_BASE_URL + '/Channels/' + youtubeID;
            let resp = await Axios.post(URL).catch((error) => {
                if (error.response)
                    return error.response.data;
                else if (error.request)
                    return error.request;
                else
                    return "Axios request failed for unkown reason.";
            });
            if (typeof resp == "string") 
                return resp;
            break;
        }
        case Modification.Delete: {
            let URL = API_BASE_URL + '/Channels/' + youtubeID;
            let resp = await Axios.delete(URL).catch(e => console.log(e));
            if (resp != null){
                if (resp.status != 200)
                    return resp.data();
                else
                    return;
            } else {
                return "Response is null";
            }
        }
        case Modification.Refresh: {
            let URL = API_BASE_URL + '/Channels/Update/' + youtubeID;
            let resp = await Axios.post(URL).catch(e => console.log(e));
            if (resp != null){
                if (resp.status != 200)
                    return resp.data();
                else
                    return;
            } else {
                return "Response is null";
            }
        }
        default: {
            console.log("Unknown request type, error ...");
            break;
        }
    }
}

// Delete a video.
export async function video_delete(youtubeID : string) : Promise<void> {
    let URL = API_BASE_URL + '/Videos/' + youtubeID;
    let resp = await Axios.delete(URL).catch(e => console.log(e));
    if ((resp == null) || (resp.data == null)){
        console.log("Video delete via " + URL + " FAIL");
    };
}

// Search for channels based on a search string.
export async function search_channels(searchstr : string): Promise<Array<Channel>> {
    // Temporary holder for data.
    let Channels : Array<Channel> = [];

    // Ask server for data.
    let resp = await Axios.get(API_BASE_URL + '/Channels/' + searchstr).catch(e => console.log(e));

    // Handle all our nulls.
    if (resp == null || resp.data == null)
        console.log("server /api/Channels/" + searchstr +  " return is null");
    else {
        // Parse our videos.
        resp.data.forEach((c: any) => {
            // Trim description if needed.
            if (c.description.length > max_description_length) {
                c.description = c.description.substring(0, max_description_length) + " ...";
            }

            // Add it to our array
            Channels.push(new Channel(c));
        });
    }
    
    // Send back the resulting videos.
    return Promise.resolve(Channels);
}

// Search for videos based on a search string.
export async function search_videos(searchstr : string): Promise<Array<Video>> {
    // Temporary holder for videos.
    let Videos : Array<Video> = [];

    // Ask server for videos.
    let resp = await Axios.get(API_BASE_URL + '/Videos/' + searchstr).catch(e => console.log(e));

    // Handle all our nulls.
    if (resp == null || resp.data == null)
        console.log("server /videos/ return is null");
    else {
        // Parse our videos.
        resp.data.forEach((v: any) => {
            // Trim description if needed.
            if (v.description.length > max_description_length) {
                v.description = v.description.substring(0, max_description_length) + " ...";
            }

            // Add it to our array
            Videos.push(new Video(v));
        });
    }
    
    // Send back the resulting videos.
    return Promise.resolve(Videos);
}