local wnd = Window("Snake", 1024, 768)
local rnd = Renderer(wnd)
local font = Font("asserts/msyh.ttf", 18)
local musicPlayer = MusicPlayer()

require("code/helper")

math.randomseed(os.time())


function GameBox()
    local box = {}
    box.w = 20
    box.h = 20
    box.size = 25
    box.dots = Point(10, 10)

    box.update = function()
        
    end
    box.draw = function()
        local c = rnd:getColor()
        rnd:setColor(RGBA(127, 127, 127, 0))
        for i=0, box.w-1 do
            for j=0, box.h-1 do
                rnd:fillRect(Rect(i * box.size, j * box.size, box.size, box.size))
            end
        end
        if box.dots then
            rnd:setColor(RGBA(255, 0, 0, 0))
            rnd:fillRect(Rect(box.dots.x * box.size, box.dots.y * box.size, box.size, box.size))
        end
        rnd:setColor(c)
    end
    return box
end

function Snake(box)
    local s = {}
    s.x = 5
    s.y = 0
    s.face = "right"
    s.dead = false
    s.body = {}
    table.insert(s.body, Point(1,0))
    table.insert(s.body, Point(2,0))
    table.insert(s.body, Point(3,0))
    table.insert(s.body, Point(4,0))
    table.insert(s.body, Point(5,0))
    s.queue = {}

    s.box = box
    s.update = function()
        if not s.dead then
            if s.queue[1] then
                local key = table.remove(s.queue, 1)
                if key == string.byte('w') and s.face ~= "down" then
                    s.face = "up"
                elseif key == string.byte('s') and s.face ~= "up" then
                    s.face = "down"
                elseif key == string.byte('a') and s.face ~= "right" then
                    s.face = "left"
                elseif key == string.byte('d') and s.face ~= "left" then
                    s.face = "right"
                end
            end

            local case = {
                up = function()
                    s.y = s.y - 1
                    if s.y < 0 then
                        s.dead = true
                    end
                end,
                down = function()
                    s.y = s.y + 1
                    if s.y >= s.box.h then
                        s.dead = true
                    end
                end,
                left = function()
                    s.x = s.x - 1
                    if s.x < 0 then
                        s.dead = true
                    end
                end,
                right = function()
                    s.x = s.x + 1
                    if s.x >= s.box.w then
                        s.dead = true
                    end
                end
            }
            case[s.face]()
            if not s.dead then
                if box.dots then
                    if box.dots.x == s.x and box.dots.y == s.y then
                        box.dots = Point(math.random(box.w)-1, math.random(box.h)-1)
                    else
                        table.remove(s.body, 1)
                    end
                end
                -- check if collapse
                for _, p in ipairs(s.body) do
                    if p.x == s.x and p.y == s.y then
                        s.dead = true
                        break
                    end
                end
                if not s.dead then
                    table.insert(s.body, Point(s.x, s.y))
                end
            end
        end
    end
    s.draw = function()
        if not s.dead then
            local c = rnd:getColor()
            rnd:setColor(RGBA(0, 0, 255, 0))
            for _, p in ipairs(s.body) do
                rnd:fillRect(Rect(p.x * s.box.size, p.y * s.box.size, s.box.size, s.box.size))
            end
            rnd:setColor(RGBA(255, 255, 0, 0))
            rnd:fillRect(Rect(s.x * s.box.size, s.y * s.box.size, s.box.size, s.box.size))
            rnd:setColor(c)
        end
    end

    return s
end

local world = GameBox()
local player = Snake(world)

wnd:on('keydown', function(key)
    table.insert(player.queue, key)
end)

SetInterval(function()
    world:update()
    player:update()
    rnd:clear()
    world:draw()
    player:draw()
    rnd:update()
end, 200)

wnd:show()