-- Load all the sprites here
-- sprite_1 = image.new("...")
-- [...]
sprites = {sprite_1, -- Tree
           sprite_2, -- Ground
           sprite_3, -- Short grass
           sprite_4, -- Long grass
           sprite_5, -- Fence
           sprite_6, -- Wood fence
           sprite_7, -- Sign
           sprite_8} -- Ground 2
spritesPlayer = {spritePlayer_1, -- Up
                 spritePlayer_2, -- Down
                 spritePlayer_3, -- Left
                 spritePlayer_4} -- Right
player = {x = 2, y = 2, facing = 2}
mapWidth = 20
mapHeight = 13
map = {{5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5},
       {5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4, 5},
       {5, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 1, 4, 4, 4, 4, 5},
       {5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 4, 4, 4, 4, 5},
       {5, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 4, 4, 4, 4, 5},
       {5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 5},
       {5, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 5},
       {5, 0, 0, 6, 6, 7, 6, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 5},
       {5, 0, 0, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5},
       {5, 0, 0, 3, 3, 3, 3, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5},
       {5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 5},
       {5, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5},
       {5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5}}
objAttr = {{walkable = false},
           {walkable = true},
           {walkable = true},
           {walkable = true},
           {walkable = false},
           {walkable = false},
           {walkable = false},
           {walkable = true}}
onTitleScreen = true;

function isValid(x, y)
    return x >= 1 and y >= 1 and x <= mapWidth and y <= mapHeight
end

function isWalkable(x, y)
    if map[y][x] ~= 0 then
        return objAttr[map[y][x]].walkable
    end
    return true
end

function on.paint(gc)
    if onTitleScreen then
        gc:drawImage(titleScreen, 0, 0)
    else
        for y = 1, mapHeight do
            for x = 1, mapWidth do
                if map[y][x] ~= 0 then
                    gc:drawImage(sprites[map[y][x]], (x - 1) * 16, (y - 1) * 16)
                end
            end
        end
        gc:drawImage(spritesPlayer[player.facing], (player.x - 1) * 16, (player.y - 1) * 16)
        gc:fillRect(0, 209, 318, 3)
    end
end

function on.enterKey()
    if onTitleScreen then
        onTitleScreen = false
        platform.window:invalidate()
    end
end

function on.arrowKey(key)
    local x = player.x
    local y = player.y
    if key == "up" then
        if player.facing == 1 then y = y - 1 end
        player.facing = 1
    elseif key == "down" then
        if player.facing == 2 then y = y + 1 end
        player.facing = 2
    elseif key == "left" then
        if player.facing == 3 then x = x - 1 end
        player.facing = 3
    elseif key == "right" then
        if player.facing == 4 then x = x + 1 end
        player.facing = 4
    end
    if isValid(x, y) and isWalkable(x, y) then
        player.x = x
        player.y = y
    end
    platform.window:invalidate((player.x - 2) * 16, (player.y - 2) * 16, 48, 48)
end