import { Wall, ItemType, Map, Maps, Items } from "./types.js"

export const getItemKey = (
    x: number, 
    y: number, 
    w: number
): number => {
    let nx = Math.round(x * 2)
    let ny = Math.round(y * 2)
    let key = ny * w * 2 + nx
    return key
}

const getPoint = (
    width: number, 
    height: number,
    data: number[],
    x: number,
    y: number
): number => {
    if (x < 0 || x >= width || y < 0 || y >= height) {
        return 0
    } else {
        return data[y * width + x]
    }
}

const genWalls = (
    width: number,
    height: number,
    data: number[]
): number[] => {

    let walls = Array(width * height)
    for (let y = 0; y < height; y++) {
        for (let x = 0; x < width; x++) {
            
            let north = getPoint(width, height, data, x, y-1) == 1
            let south = getPoint(width, height, data, x, y+1) == 1
            let east = getPoint(width, height, data, x+1, y) == 1
            let west = getPoint(width, height, data, x-1, y) == 1
            let current = getPoint(width, height, data, x, y) == 1

            let point = Wall.EMPTY
            
            if (!current) {
                walls[y * width + x] = point
                continue
            }

            if (north && south && east && west) {
                point = Wall.CROSS
            } else if (east && west && north) {
                point = Wall.TEE_NORTH
            } else if (east && west && south) {
                point = Wall.TEE_SOUTH
            } else if (north && south && east) {
                point = Wall.TEE_EAST
            } else if (north && south && west) {
                point = Wall.TEE_WEST
            } else if (east && west) {
                point = Wall.WALL_HZ
            } else if (north && south) {
                point = Wall.WALL_VT   
            } else if (west && south) {
                point = Wall.TURN_Q1
            } else if (south && east) {
                point = Wall.TURN_Q2
            } else if (east && north) {
                point = Wall.TURN_Q3
            } else if (north && west) {
                point = Wall.TURN_Q4
            } else if (north) {
                point = Wall.WALL_END_NORTH
            } else if (east) {
                point = Wall.WALL_END_EAST
            } else if (south) {
                point = Wall.WALL_END_SOUTH
            } else if (west) {
                point = Wall.WALL_END_WEST
            } else {
                point = Wall.DOT
            }

            walls[y * width + x] = point

        }
    }

    return walls
}

export const genItems = (map: Map): Items => {

    let width = map.width
    let height = map.height
    let data = map.data
    
    let items: Items = {}

    for (let y = 0; y < height; y++) {
        for (let x = 0; x < width; x++) {
            let tile = getPoint(width, height, data, x, y)
            if (tile != 0) continue

            let item_key = getItemKey(x, y, width)
            items[item_key] = {type: ItemType.DOT, pos: {x, y}}

            let tile_south = getPoint(width, height, data, x, y + 1)
            if (tile_south == 0) {
                item_key = getItemKey(x, y + .5, width)
                items[item_key] = {type: ItemType.DOT, pos: {x, y: y + .5}}
            }

            let tile_east = getPoint(width, height, data, x + 1, y)
            if (tile_east == 0) {
                item_key = getItemKey(x + .5, y, width)
                items[item_key] = {type: ItemType.DOT, pos: {x: x + .5, y}}
            }
        }
    }

    return items
}

let mapData: Maps = {}
let id: number = 0

export const genMap = (
    width: number,
    height: number,
    data: number[],
    mapId: number,
): Map => {

    mapData[mapId] = {
        data: structuredClone(data),
        walls: genWalls(width, height, data),
        width,
        height,
        id: mapId
    }

    return mapData[mapId]
}

export const loadMap = (
    width: number,
    height: number,
    data: number[]
): number => {

    let mapId = id++

    mapData[mapId] = {
        data: structuredClone(data),
        walls: genWalls(width, height, data),
        width,
        height,
        id: mapId
    }

    return mapId
}

export const getMap = (mapId: number): Map | undefined => {
    if (mapId == undefined) return undefined
    return mapData[mapId]
}