function generateMap(width, height, monsters)
    map = {}                    -- map content
    map_visibility = {}         -- map visibility
    for y=1, height do
        table.insert(map, {})
        table.insert(map_visibility, {})
        for x=1, width do
            table.insert(map[#map], 0)
            table.insert(map_visibility[#map_visibility], 0)
        end
    end
    for id=1, 2 do              -- for player id 1 and 2
        for n=1, monsters do    -- for n monsters
            while true do       -- find random position
                x = math.random(width)
                y = math.random(height)
                if map[y][x] == 0 then break end
            end
            map[y][x] = id      -- set it
        end
    end
end

function love.load()
    generateMap(5, 5, 2)        -- 5x5 map with 2 monsters per player
    turn = math.random(2)       -- random start
    nextTurn()                  -- for message
end

function nextTurn()
    turn = turn + 1
    if turn > 2 then
        turn = 1
    end
    selection = { x = -1, y = -1 }
    print("PLAYER " .. tostring(turn) .. "'s TURN NOW")
end

function love.draw()
    for y=1, #map do
        for x=1, #map[y] do
            if map_visibility[y][x] == 0 then
                love.graphics.setColor(255, 255, 255, 255)
                love.graphics.rectangle("line", x * 32, y * 32, 32, 32)
            else
                love.graphics.setColor(255, 255, 255, 255)  -- empty field (white)
                if map[y][x] == 1 then      -- player 1 monster (red)
                    love.graphics.setColor(255, 0, 0, 255)
                elseif map[y][x] == 2 then  -- player 2 monster (blue)
                    love.graphics.setColor(0, 0, 255, 255)
                end
                love.graphics.rectangle("fill", x * 32, y * 32, 32, 32)
            end
        end
    end
end

function love.mousepressed(x, y, button)
    x = math.floor(x / 32)  -- round down to get "real" coordinates
    y = math.floor(y / 32)
    if y >= 1 and y <= #map and x >= 1 and x <= #map[y] then    -- check if valid
        if button == "l" then   -- left mouse button
            if selection.x ~= -1 and map[y][x] ~= turn and map_visibility[y][x] == 1 then
                if x >= selection.x - 1 and x <= selection.x + 1 and y >= selection.y - 1 and y <= selection.y + 1 then
                    map[y][x] = map[selection.y][selection.x]   -- moved if a monster was selected
                    map[selection.y][selection.x] = 0
                    nextTurn()
                else
                    print("Illegal move!")
                end
            elseif map_visibility[y][x] == 0 then
                map_visibility[y][x] = 1    -- set visibile if hidden
                nextTurn()
            elseif map[y][x] ~= 0 then
                if map[y][x] == turn then
                    selection.x = x
                    selection.y = y
                else
                    print("You cannot move another player's monster")
                end
            end
        elseif button == "r" then   -- right mouse button
            if map_visibility[y][x] == 0 then
                if map[y][x] == 0 then
                    print("Field: EMPTY")
                else
                    print("Field: PLAYER " + tostring(map[y][x]) + " MONSTER")
                end
                nextTurn()
            end
        end
    else
        selection = { x = -1, y = -1 }
    end
end