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

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

-- ====================================================================================================
-- MENU (game state)
-- ====================================================================================================
blink=0

menu={
    init = function()
        update=menu.update
    end,

    update = function()
        color(15,0) cls()
        ink(1)  print("\x20\x20\x20\x87\x81\x87\x85\x85\x85\x87\x85\x87\x85\x87\x85\x87\x84\x20\x20\x20",0,2)
        ink(9)  print("\x20\x20\x20\x83\x85\x85\x85\x8D\x81\x85\x85\x87\x84\x8D\x85\x85\x85\x20\x20\x20",0,3)
        ink(11) print("\x20\x20\x20\x83\x81\x83\x81\x81\x81\x83\x81\x83\x81\x81\x81\x81\x81\x20\x20\x20",0,4)
        ink(15*flr((blink%60)/30)) print("PRESS SPACE TO PLAY",1,9)
        blink=blink+1

        if btnp(KEY_SPACE) then
            level=1
            game.init()
        end
    end
}

-- ====================================================================================================
-- GAME (game state)
-- ====================================================================================================
game={
    init = function()
        update=game.update
        level.load_from_string("####|# .#|#  ###|#*@  #|#  $ #|#  ###|####")
    end,
    
    update = function()
        border(0)
        color(1,0)
        cls()
        level.draw()
    
        if btnp(KEY_UP) then level.try_move(0,-1)
        elseif btnp(KEY_DOWN) then level.try_move(0,1)
        elseif btnp(KEY_LEFT) then level.try_move(-1,0)
        elseif btnp(KEY_RIGHT) then level.try_move(1,0)
        end
    end
}

-- ====================================================================================================
-- LOADING (game state)
-- ====================================================================================================
loading = {
    init = function()
        border(15)
        update=loading.update
        wait=120
    end
    
    function inbetween_update()
        color(15,0)
        cls()
        print("LEVEL "..level,6,6)
        print("GOOD JOB!",4,8)
        wait=wait-1
        if wait==0 then
            level=level+1
            game_init()
        end
    end
}

function level_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 level_draw()
    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 then color(0,6) print("\016",ox+x-1,oy+y-1)
            elseif map[y][x] == BOX+GOAL then color(0,4) 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)
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
    inbetween_init()
end