import decompress from "decompress";
import sharp from 'sharp';
import fs from 'fs';
import path from 'path';

const collection = 'assets';

/**
 * Application layer manager
 */
class GameObjectsManager{
    name = 'gameObject';

    /**
     * Plugin initializer
     * @param {App} app The Application
     */
    init(app){
        const {db, config} = app;

        /**
         * Gets last asset Id from database
         * @returns {Number} Last Asset Id
         */
        this.getLastId = async function(){
            let ag = await db.aggregate(collection, [
                {
                    $group:{
                        _id: null,
                        max: {
                            $max: "$id",
                        },
                    },
                },
            ]);
            return ag.max || 0;
        }

        /**
         * Creates a game object
         * @param {Context} ctx Request context
         * @param {GameObject} data Asset data
         */
        this.create = async function(ctx, data){
            data.id = (await this.getLastId()) + 1;
            await db.create(collection, data);
            if (ctx.files?.file){
                await this.addFile(data, ctx.files.file)
                await fs.promises.unlink(ctx.files.file.path)
                await db.update(collection, {id: data.id}, data);
            }
            return data;
        }

        /**
         * Retrieves game object from database
         * @param {Number} id Game object ID
         * @returns {GameObject} The game object
         */
        this.read = async function(id){
            id = parseInt(id);
            return await db.get(collection, {id});
        }

        /**
         * Updates game object into the database
         * @param {Context} ctx Request context
         * @param {GameObject} data Game object
         */
        this.update = async function(ctx, data){
            data.id = parseInt(data.id);
            let object = await this.read(data.id);
            data = Object.assign(object, data);
            if (ctx.files?.file){
                await this.addFile(data, ctx.files.file)
                await fs.promises.unlink(ctx.files.file.path)
            }if (ctx.files?.thumb){
                await this.addThumb(data, ctx.files.thumb.path);
                await fs.promises.unlink(ctx.files.thumb.path)
            }
            await db.update(collection, {id: data.id}, data);
            return data;
        }

        /**
         * Removes game object from database
         * @param {Number} id Game object ID
         */
        this.remove = async function(id){
            id = parseInt(id);
            await db.remove(collection, {id});
        }

        /**
         * Assigns a file to a game object
         * @param {GameObject} object Game object
         * @param {File} tmpFile A file
         */
        this.addFile = async function(object, tmpFile){
            let i = tmpFile;
            let ofn = i.name;
            let ext = path.extname(ofn).toLowerCase();
            let src = `${config.fs.repo}/source/${object.id}${ext}`;
            let def = `${config.fs.repo}/default/${object.id}`;
            await fs.promises.copyFile(i.path, src);
            object.asset = {
                ofn,
                name: `${object.id}${ext}`
            }
            if (ext == '.zip'){
                let result = await decompress(src, def);
                object.asset.list = result.map(f=>f.path);
                object.asset.type = 'bundle';
            }else{
                object.asset.type = 'single';
                await fs.promises.copyFile(src, def + ext);
                await this.addThumb(object, src);
            }
        }

        /**
         * Assigns a thumbnail to a game object
         * @param {GameObject} object Game object
         * @param {File} thumbSrc A thumbnail
         */
        this.addThumb = async function(object, thumbSrc){
            let dest = `${config.fs.repo}/thumb/${object.id}.webp`;
            await sharp(thumbSrc).resize({height: 250}).toFile(dest);
            object.asset.thumb = `${object.id}.webp`;
        }

        /**
         * Returns list of GameObjects
         * @param {Object} query Query to DB 
         * @returns {GameObject[]} Array of game objects
         */
        this.list = async function(query){
            return await db.list(collection, {
                query: {},
                project: { name:1, id:1, type:1, asset:1}
            });
        }
    }

    /**
     * Class starter
     * @param {App} app The application
     */
    async start(app){

    }
}

/**
 * GameObject entity
 */
class GameObject {
    /**
     * Game object name
     * @type string
     */
    name = null;

    type = null;


    file = null;
}

export { GameObjectsManager }