class MapLoader {
    constructor(fileName) {
        this.fileName = fileName;
        this.fileContent = null;
    }

    start() {
        this.readFile();
    }

    readFile() {
        const rawFile = new XMLHttpRequest();
        rawFile.open("GET", this.fileName, false);
        rawFile.addEventListener('readystatechange', () => {
            if(rawFile.readyState === 4) {
                if(rawFile.status === 200 || rawFile.status === 0) {
                    const content = rawFile.responseText;
                    console.log(content);
                    this.fileContent = content;

                    this.loadMap();
                }
            }
        });
        rawFile.send(null);
    }

    loadMap() {
        const tiles = [];
        const mapRaw = this.fileContent;

        const rows = mapRaw.split(/\r?\n/g);

        if(rows.length === 0) {
            throw LoadingException;
        }

        const width = rows[0].length,
            height = rows.length;
        let spawn;

        for(let x = 0; x < width; x++) {
            tiles.push([]);
        }

        rows.forEach((row, y) => {
            if(row.length !== width) {
                throw `Row length not consistent. Expected ${width}, got ${row.length} at row ${y}`;
            }

            for(let x = 0; x < row.length; x++) {
                const tileRaw = row[x];
                let tile;

                switch (tileRaw) {
                    case 'X':
                        tile = new MapTile(x, y, true);
                        break;
                    case '.':
                        tile = new MapTile(x, y, false, true);
                        break;
                    case '-':
                        tile = new MapTile(x, y, false);
                        break;
                    case 'S':
                        tile = new MapTile(x, y, false);
                        spawn = {x, y};
                        break;
                    case 'O':
                        tile = new MapTile(x, y, false);
                        break;
                }

                tiles[x][y] = tile;
            }
        });

        this.map = new GameMap(tiles, spawn);
    }

    getMap() {
        while(!this.map) {

        }
        return this.map;
    }
}