-- mine.lua
--
-- todo:
-- bomb count shouldn't be random
-- first picked square should always be safe


w=10
h=10
cw=floor(160/w)
ch=floor(160/h)
mcount=0
board={}

function waitclick()
	while(pevent()~=penDown) do
		end
	while(pevent()~=penUp) do
		end
end

-- board cell values:
-- " " empty, covered
-- "." empty, uncovered
-- "B" bomb, covered
-- "b" bomb, uncovered
function initboard()
	mcount=0
	board={}
	for y=0, h-1,1 do
		for x=0,w-1,1 do
			local a=" "
 			if( random() < 0.2 ) then
				a = "B"
			else
				mcount = mcount + 1
			end
			board[x+y*w] = a
		end
	end
end

function drawboard()
    pclear()
    for y=0, h-1,1 do
        for x=0,w-1,1 do
            pbox( x*cw, y*ch, cw-1, ch-1)
        end
    end
end

-- show all hidden bombs
function showbombs()
  for y=0, h-1,1 do
    for x=0,w-1,1 do
      if( board[y*w + x ] == "B" ) then
        pbox( x*cw+3, y*ch+2, cw-7, ch-5,0)
        pmoveto( x*cw+5, y*ch+2 )
        print("B")
      end
    end
  end
end

function valid( x,y )
	if( x<0 ) then
		return 0
	end
	if( x>=w ) then
		return 0
	end
	if( y<0 ) then
		return 0
	end
	if( y>=h ) then
		return 0
	end
	return 1
end

function probe( x,y )
	if( valid(x,y)==1 ) then
		if( board[y*w + x ] == "B" ) then
			return 1
		end
	end
	return 0
end

function count( x,y )
	local c=0
	c=c+probe(x-1,y-1)
	c=c+probe(x,y-1)
	c=c+probe(x+1,y-1)
	c=c+probe(x-1,y)
	c=c+probe(x+1,y)
	c=c+probe(x-1,y+1)
	c=c+probe(x,y+1)
	c=c+probe(x+1,y+1)
	return c
end

-- returns:
-- "" uncovered a safe cell
-- "B" hit a bomb
-- "D" done - all safe squares cleared
function uncover(x,y)
	if( valid(x,y)==0 ) then
		return
	end
	local m = board[x+y*w]
	if(m==".") then
		return ""
	end
	pbox( x*cw, y*ch, cw-1, ch-1,0)
	prect( x*cw, y*ch, cw-1, ch-1)
	pmoveto( x*cw+4, y*ch+3 )
	if( m=="B" ) then
		-- hide from showbombs()
		board[x+y*w] = "b"
		print( "B!" )
		return "B"
	else
		board[x+y*w] = "."
		local c = count(x,y)
		if( c>0 ) then
			print( c )
		else
			uncover(x-1,y-1)
			uncover(x,y-1)
			uncover(x+1,y-1)
			uncover(x-1,y)
			uncover(x+1,y)
			uncover(x-1,y+1)
			uncover(x,y+1)
			uncover(x+1,y+1)
		end
	end
	mcount = mcount - 1
	if( mcount <= 0 ) then
		return "D"
	end
	return ""
end


pmode()
while( 1 ) do

	initboard()
	drawboard()
	done = 0
	while(done==0) do
		e,px,py = pevent()
		if(e==penDown ) then
			x=floor(px/cw)
			y=floor(py/ch)
			if( valid(x,y) ) then
				m=uncover(x,y)
				if(m=="B") then
					done=1
					palert( "Kaboom.\nGame over.")
				end
				if(m=="D") then
					done=1
palert( "Woo hoo!\nNice one!")
				end
			end
		end
	end
	showbombs()
	pmoveto( 42,75 )
	print("tap for new game")
	waitclick()
end