function love.load()
    images = {}

    for imageIndex, image in ipairs({
        1, 2, 3, 4, 5, 6, 7, 8,
        'uncovered', 'covered_highlighted', 'covered',
        'flower', 'flag', 'question',
    }) do
        images[image] = love.graphics.newImage('images/'..image..'.png')
    end

    cellSize = 18

    gridXCount = 19
    gridYCount = 14

    grid = {}

    for y = 1, gridYCount do
        grid[y] = {}
        for x = 1, gridXCount do
            grid[y][x] = {
                flower = false,
                state = 'covered', -- 'covered', 'uncovered', 'flag', 'question'
            }
        end
    end

    -- Temporary
    grid[1][1].state = 'flag'
    grid[1][2].state = 'question'

    local possibleFlowerPositions = {}

    for y = 1, gridYCount do
        for x = 1, gridXCount do
            table.insert(possibleFlowerPositions, {x = x, y = y})
        end
    end

    for flowerIndex = 1, 40 do
        local position = table.remove(
            possibleFlowerPositions,
            love.math.random(#possibleFlowerPositions)
        )
        grid[position.y][position.x].flower = true
    end

    function getSurroundingFlowerCount(x, y)
        local surroundingFlowerCount = 0

        for dy = -1, 1 do
            for dx = -1, 1 do
                if not (dy == 0 and dx == 0)
                and grid[y + dy]
                and grid[y + dy][x + dx]
                and grid[y + dy][x + dx].flower
                then
                    surroundingFlowerCount = surroundingFlowerCount + 1
                end
            end
        end

        return surroundingFlowerCount
    end
end

function love.update()
    selectedX = math.floor(love.mouse.getX() / cellSize) + 1
    selectedY = math.floor(love.mouse.getY() / cellSize) + 1

    if selectedX > gridXCount then
        selectedX = gridXCount
    end

    if selectedY > gridYCount then
        selectedY = gridYCount
    end
end

function love.mousereleased(mouseX, mouseY, button)
    if button == 1 then
        local stack = {
            {
                x = selectedX,
                y = selectedY,
            }
        }

        while #stack > 0 do
            local current = table.remove(stack)
            local x = current.x
            local y = current.y

            grid[y][x].state = 'uncovered'

            if getSurroundingFlowerCount(x, y) == 0 then
                for dy = -1, 1 do
                    for dx = -1, 1 do
                        if not (dx == 0 and dy == 0)
                        and grid[y + dy]
                        and grid[y + dy][x + dx]
                        and grid[y + dy][x + dx].state == 'covered' then
                            table.insert(stack, {
                                x = x + dx,
                                y = y + dy,
                            })
                        end
                    end
                end
            end
        end
    end
end

function love.draw()
    for y = 1, gridYCount do
        for x = 1, gridXCount do
            local function drawCell(image, x, y)
                love.graphics.draw(
                    image,
                    (x - 1) * cellSize, (y - 1) * cellSize
                )
            end

            if grid[y][x].state == 'uncovered' then
                drawCell(images.uncovered, x, y)
            else
                if x == selectedX and y == selectedY then
                    if love.mouse.isDown(1) then
                        drawCell(images.uncovered, x, y)
                    else
                        drawCell(images.covered_highlighted, x, y)
                    end
                else
                    drawCell(images.covered, x, y)
                end
            end

            if grid[y][x].flower then
                drawCell(images.flower, x, y)
            elseif getSurroundingFlowerCount(x, y) > 0 then
                drawCell(images[getSurroundingFlowerCount(x, y)], x, y)
            end

            if grid[y][x].state == 'flag' then
                drawCell(images.flag, x, y)
            elseif grid[y][x].state == 'question' then
                drawCell(images.question, x, y)
            end
        end
    end
end