-- Pong Game for SimpleOS
-- CC: Tweaked compatible

local w, h = term.getSize()
h = h - 1 -- Leave room for score

-- Game state
local paddle1Y, paddle2Y = math.floor(h/2) - 1, math.floor(h/2) - 1
local paddleHeight = 4
local ballX, ballY = math.floor(w/2), math.floor(h/2)
local ballDX, ballDY = 1, 0
local score1, score2 = 0, 0
local gameOver = false
local speed = 0.08
local aiMode = true -- Single player by default

-- Reset ball
local function resetBall(direction)
    ballX = math.floor(w/2)
    ballY = math.floor(h/2)
    ballDX = direction or (math.random(2) == 1 and 1 or -1)
    ballDY = (math.random(3) - 2) * 0.5
end

-- Draw game
local function draw()
    term.setBackgroundColor(colors.black)
    term.clear()
    
    -- Draw center line
    term.setTextColor(colors.gray)
    for y = 1, h do
        if y % 2 == 0 then
            term.setCursorPos(math.floor(w/2), y)
            term.write("|")
        end
    end
    
    -- Draw paddles
    term.setBackgroundColor(colors.white)
    for i = 0, paddleHeight - 1 do
        term.setCursorPos(2, paddle1Y + i)
        term.write(" ")
        term.setCursorPos(w - 1, paddle2Y + i)
        term.write(" ")
    end
    
    -- Draw ball
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.yellow)
    term.setCursorPos(math.floor(ballX), math.floor(ballY))
    term.write("O")
    
    -- Draw score bar
    term.setBackgroundColor(colors.gray)
    for x = 1, w do
        term.setCursorPos(x, h + 1)
        term.write(" ")
    end
    term.setTextColor(colors.white)
    term.setCursorPos(2, h + 1)
    term.write("P1: " .. score1)
    term.setCursorPos(w - 7, h + 1)
    term.write("P2: " .. score2)
    term.setCursorPos(math.floor(w/2) - 3, h + 1)
    term.write("[Q]uit")
end

-- AI movement
local function moveAI()
    local targetY = ballY - paddleHeight / 2
    if paddle2Y < targetY - 1 then
        paddle2Y = math.min(paddle2Y + 1, h - paddleHeight + 1)
    elseif paddle2Y > targetY + 1 then
        paddle2Y = math.max(paddle2Y - 1, 1)
    end
end

-- Update ball
local function update()
    ballX = ballX + ballDX
    ballY = ballY + ballDY
    
    -- Top/bottom bounce
    if ballY <= 1 then
        ballY = 1
        ballDY = -ballDY
    elseif ballY >= h then
        ballY = h
        ballDY = -ballDY
    end
    
    -- Paddle 1 collision
    if ballX <= 3 and ballX >= 2 then
        if ballY >= paddle1Y and ballY < paddle1Y + paddleHeight then
            ballDX = math.abs(ballDX)
            local hitPos = (ballY - paddle1Y) / paddleHeight
            ballDY = (hitPos - 0.5) * 2
        end
    end
    
    -- Paddle 2 collision
    if ballX >= w - 2 and ballX <= w - 1 then
        if ballY >= paddle2Y and ballY < paddle2Y + paddleHeight then
            ballDX = -math.abs(ballDX)
            local hitPos = (ballY - paddle2Y) / paddleHeight
            ballDY = (hitPos - 0.5) * 2
        end
    end
    
    -- Scoring
    if ballX < 1 then
        score2 = score2 + 1
        resetBall(-1)
    elseif ballX > w then
        score1 = score1 + 1
        resetBall(1)
    end
    
    -- Win condition
    if score1 >= 10 or score2 >= 10 then
        gameOver = true
    end
end

-- Game over screen
local function showGameOver()
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.yellow)
    term.setCursorPos(math.floor(w/2) - 5, math.floor(h/2) - 1)
    if score1 >= 10 then
        term.write("PLAYER 1 WINS!")
    else
        term.write("PLAYER 2 WINS!")
    end
    term.setTextColor(colors.white)
    term.setCursorPos(math.floor(w/2) - 10, math.floor(h/2) + 1)
    term.write("Press ENTER to restart")
    term.setCursorPos(math.floor(w/2) - 7, math.floor(h/2) + 2)
    term.write("Press Q to quit")
end

-- Main game loop
local function run()
    resetBall()
    score1, score2 = 0, 0
    gameOver = false
    paddle1Y = math.floor(h/2) - paddleHeight/2
    paddle2Y = math.floor(h/2) - paddleHeight/2
    
    -- Mode selection
    term.setBackgroundColor(colors.black)
    term.clear()
    term.setTextColor(colors.yellow)
    term.setCursorPos(math.floor(w/2) - 3, math.floor(h/2) - 2)
    term.write("PONG")
    term.setTextColor(colors.white)
    term.setCursorPos(math.floor(w/2) - 10, math.floor(h/2))
    term.write("[1] Single Player (vs AI)")
    term.setCursorPos(math.floor(w/2) - 8, math.floor(h/2) + 1)
    term.write("[2] Two Players")
    
    while true do
        local event, key = os.pullEvent("key")
        if key == keys.one then
            aiMode = true
            break
        elseif key == keys.two then
            aiMode = false
            break
        elseif key == keys.q then
            return
        end
    end
    
    while true do
        draw()
        
        if gameOver then
            showGameOver()
            while true do
                local event, key = os.pullEvent("key")
                if key == keys.enter then
                    resetBall()
                    score1, score2 = 0, 0
                    gameOver = false
                    paddle1Y = math.floor(h/2) - paddleHeight/2
                    paddle2Y = math.floor(h/2) - paddleHeight/2
                    break
                elseif key == keys.q then
                    return
                end
            end
        end
        
        local timer = os.startTimer(speed)
        
        while true do
            local event, p1 = os.pullEvent()
            
            if event == "key" then
                -- Player 1 controls (W/S)
                if p1 == keys.w then
                    paddle1Y = math.max(1, paddle1Y - 1)
                elseif p1 == keys.s then
                    paddle1Y = math.min(h - paddleHeight + 1, paddle1Y + 1)
                end
                
                -- Player 2 controls (Up/Down) - only in 2P mode
                if not aiMode then
                    if p1 == keys.up then
                        paddle2Y = math.max(1, paddle2Y - 1)
                    elseif p1 == keys.down then
                        paddle2Y = math.min(h - paddleHeight + 1, paddle2Y + 1)
                    end
                end
                
                if p1 == keys.q then
                    return
                end
                draw()
            elseif event == "timer" and p1 == timer then
                break
            end
        end
        
        if aiMode then
            moveAI()
        end
        update()
    end
end

run()