Mirroar/hivemind

import cache from 'utils/cache';

export type ExitCoords = {
    N: RoomPosition[];
    S: RoomPosition[];
    W: RoomPosition[];
    E: RoomPosition[];
};

function getExitCenters(roomName: string): ExitCoords {
    return cache.inHeap('exitCenters:' + roomName, 10_000, () => {
        const exitCoords = getExitCoordsByDirection(roomName);
        return findExitCenters(roomName, exitCoords);
    });
}

function getExitCoordsByDirection(roomName: string): ExitCoords {
    const terrain = new Room.Terrain(roomName);

    const exitCoords: ExitCoords = {
        N: [],
        S: [],
        W: [],
        E: [],
    };

    for (let i = 1; i < 49; i++) {
        if (terrain.get(0, i) !== TERRAIN_MASK_WALL) exitCoords.W.push(new RoomPosition(0, i, roomName));
        if (terrain.get(49, i) !== TERRAIN_MASK_WALL) exitCoords.E.push(new RoomPosition(49, i, roomName));
        if (terrain.get(i, 0) !== TERRAIN_MASK_WALL) exitCoords.N.push(new RoomPosition(i, 0, roomName));
        if (terrain.get(i, 49) !== TERRAIN_MASK_WALL) exitCoords.S.push(new RoomPosition(i, 49, roomName));
    }

    return exitCoords;
}

/**
 * Finds center positions of all room exits.
 *
 * @return {object}
 *   Array of RoomPosition objects, keyed by exit direction.
 */
function findExitCenters(roomName: string, exitCoords: ExitCoords): ExitCoords {
    const exitCenters: ExitCoords = {
        N: [],
        S: [],
        W: [],
        E: [],
    };

    for (const dir of _.keys(exitCoords)) {
        let startPos = null;
        let previousPos = null;
        for (const pos of exitCoords[dir]) {
            if (!startPos) {
                startPos = pos;
            }

            if (previousPos && pos.getRangeTo(previousPos) > 1) {
                // New exit block started.
                const middlePos = new RoomPosition(Math.ceil((previousPos.x + startPos.x) / 2), Math.ceil((previousPos.y + startPos.y) / 2), roomName);
                exitCenters[dir].push(middlePos);

                startPos = pos;
            }

            previousPos = pos;
        }

        if (startPos) {
            // Finish last wall run.
            const middlePos = new RoomPosition(Math.ceil((previousPos.x + startPos.x) / 2), Math.ceil((previousPos.y + startPos.y) / 2), roomName);
            exitCenters[dir].push(middlePos);
        }
    }

    return exitCenters;
}

export {
    getExitCenters,
};