-- Load all the sprites here. It's long so I wont paste it 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
sprites_player = {sprite_player_1, -- Up
                  sprite_player_2, -- Down
                  sprite_player_3, -- Left
                  sprite_player_4} -- Right
player = {x = 2, y = 2, facing = 2}
map_width = 20
map_height = 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}}
obj_attr = {{walkable = false},
            {walkable = true},
            {walkable = true},
            {walkable = true},
            {walkable = false},
            {walkable = false},
            {walkable = false},
            {walkable = true}}
on_title_screen = true;

function is_valid(x, y)
    return x >= 1 and y >= 1 and x <= map_width and y <= map_height
end

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

function is_valid_walkable(x, y)
    return is_valid(x, y) and is_walkable(x, y)
end

function on.paint(gc)
    if on_title_screen then
        gc:drawImage(title_screen, 0, 0)
    else
        for i = 1, map_height do
            for j = 1, map_width do
                if map[i][j] ~= 0 then
                    gc:drawImage(sprites[map[i][j]], (j - 1) * 16, (i - 1) * 16)
                end
            end
        end
        gc:drawImage(sprites_player[player.facing], (player.x - 1) * 16, (player.y - 1) * 16)
        gc:fillRect(0, 209, 318, 3)
    end
end

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

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