import {
    Direction,
    MazeMap,
    MazeTile,
} from "./MazeMap";

class GameState
{
    public userID: string;
    public mapID: string;
    public tileID: string;

    constructor(userID: string, mapID: string, tileID: string)
    {
        this.userID = userID;
        this.mapID = mapID;
        this.tileID = tileID;
    }
}

export class GameServer
{
    private mapList: MazeMap[];
    private states: GameState[];

    constructor()
    {
        this.mapList = [];
        this.states = [];
    }

    public addMap(newMap: MazeMap): boolean
    {
        const validationResult = newMap.validate();
        if(validationResult.length > 0){
            let message = "Cannot add invalid map:";
            for (const e of validationResult) {
                message += "\n\t" + e;
            }
            throw new Error(message);
        }

        if(-1 === this.mapList.findIndex(m => m.id === newMap.id))
        {
            this.mapList.push(newMap);
            return true;
        }
        else {
            return false;
        }
    }

    public startGame(userID: string, mapID: string): MazeTile
    {
        const map = this.mapList.find(m => m.id === mapID);
        if(map == null){
            throw new Error(`Map "${mapID}" does not exist.`);
        }
        const start = map.getStartTile();

        let state = this.states.find(s => s.userID === userID);
        if(state == null)
        {
            state = new GameState(userID, map.id, start.id);
            this.states.push(state);
        }
        else
        {
            state.mapID = map.id;
            state.tileID = start.id;
        }

        return start;
    }

    public navigate(userID: string, currentTile:string, direction:Direction): MazeTile
    {
        const newPosition = new MazeTile("");
        newPosition.paths.push(Direction.left);
        return newPosition;
    }

    public currentPosition(userID: string): MazeTile
    {
        const state = this.states.find(s => s.userID === userID);
        if(state == null){
            return null;
        }

        const map = this.mapList.find(m => m.id === state.mapID);
        const tile = map.getTile(state.tileID);
        return tile;
    }
}