FLOOR = 0
GOAL = 1
BOX = 2
PLAYER = 4
WALL = 7

function init()
    mode(2)
    level=1
    player={}
    init_level()
end

function init_level()
    update=update_level
    load_from_string("####|# .#|#  ###|#*@  #|#  $ #|#  ###|####")
end

function load_from_string(str)
    map={}
    local pos=0
    local y,x=1,1
    local maxx=0
    map[y] = {}
    while pos<#str do
        local chr = ascii(str,pos)
        if chr == 35 then map[y][x] = WALL end
        if chr == 64 then player.x,player.y=x,y map[y][x] = FLOOR end
        if chr == 43 then player.x,player.y=x,y map[y][x] = GOAL end
        if chr == 36 then map[y][x] = BOX end
        if chr == 42 then map[y][x] = GOAL+BOX end
        if chr == 46 then map[y][x] = GOAL end
        if chr == 32 then map[y][x] = FLOOR end
        if chr == 124 then
            y=y+1
            map[y] = {}
            if maxx < x then maxx=x end
            x=0
        end
        pos=pos+1
        x=x+1
    end
    ox = flr((20-maxx)/2)
    oy = flr((15-y)/2)
end

function update_level()
    border(0)
    color(1,0)
    cls()
    for y=1,#map do
        for x=1,#map[y] do
            if map[y][x] == WALL then color(4,15) print("\127",ox+x-1,oy+y-1)
            elseif map[y][x]&BOX == BOX then color(0,6) print("\016",ox+x-1,oy+y-1)
            elseif map[y][x] == GOAL then color(4,0) print("\144",ox+x-1,oy+y-1)
            end
        end
    end
    color(15,0) print("\248",ox+player.x-1,oy+player.y-1)

    if btnp(KEY_UP) then try_move(0,-1)
    elseif btnp(KEY_DOWN) then try_move(0,1)
    elseif btnp(KEY_LEFT) then try_move(-1,0)
    elseif btnp(KEY_RIGHT) then try_move(1,0)
    end
end

function try_move(x,y)
    if is_empty(x,y) then
        move_player(x,y)
    elseif is_box(x,y) and is_empty(x*2,y*2) then
        move_box(x,y)
    end
end

function is_empty(x,y)
    return map[player.y+y][player.x+x] < 2
end

function is_box(x,y)
    return map[player.y+y][player.x+x] < 4
end

function move_player(x,y)
    player.x=player.x+x
    player.y=player.y+y 
end

function move_box(x,y)
    map[player.y+y*2][player.x+x*2] = map[player.y+y*2][player.x+x*2] + BOX
    map[player.y+y][player.x+x] = map[player.y+y][player.x+x] - BOX
    move_player(x,y)
    check_finished()
end

function check_finished()
    for y=1,#map do
        for x=1,#map[y] do
            if map[y][x] == GOAL then return end
        end
    end
    init_goodjob()
end

function init_goodjob()
    border(15)
    update=update_goodjob
    wait=120
end

function update_goodjob()
    color(15,0)
    cls()
    print("LEVEL "..level,6,6)
    print("GOOD JOB!",4,8)
    wait=wait-1
    if wait==0 then
        level=level+1
        init_level()
    end
end