DJBALL

local b_RUNNING = true
local n_UPDATE_INTERVAL = 1 / 20  -- seconds / frames

local Term = {}
Term.W, Term.H = term.getSize()

Board = {
    X = 1,
    Y = 1,
    W = Term.W - 1,
    H = Term.H - 1,
    XMID = Term.W / 2 + 1,
    BLUE_SCORE = 0,
    RED_SCORE = 0
}

Player = {}
Ball = {}
Player.__index = Player
Ball.__index = Ball

local function oppositeDirection(dir1,dir2)
    if (dir1 == 1 and dir2 == 3) or (dir2 == 1 and dir1 == 3) then
        return true
    elseif (dir1 == 2 and dir2 == 4) or (dir2 == 2 and dir1 == 4) then
        return true
    end
    return false
end

-- Create a new player
function Player:new(_n_NUMBER)
    local self =  {
        NUMBER = _n_NUMBER,
        DIRECTION = 4,
        HOLDING = nil,
        CATCHING = false,
        CATCHING_CD = false,
    }
    if _n_NUMBER == 1 then
        self.LEFT = keys.a
        self.UP = keys.w
        self.RIGHT = keys.d
        self.DOWN = keys.s
        self.ACTION = keys.leftShift
        self.TEAM = colors.blue
        self.X = 3
        self.Y = 3
    elseif _n_NUMBER == 2 then
        self.LEFT = keys.left
        self.UP = keys.up
        self.RIGHT = keys.right
        self.DOWN = keys.down
        self.ACTION = keys.m
        self.TEAM = colors.red
        self.X = Term.W - 3
        self.Y = Term.H - 3
    end
    self.XSTART = self.X
    self.YSTART = self.Y
    setmetatable(self,Player)
    return self
end

-- Move the player left (1)
function Player:moveLeft()
    self.DIRECTION = 1
    if self.X > (Board.X + 1) then
        self.X = self.X - 1
    end
end

-- Move the player up (2)
function Player:moveUp()
    self.DIRECTION = 2
    if self.Y > (Board.Y + 1) then
        self.Y = self.Y - 1
    end
end

-- Move the player right (3)
function Player:moveRight()
    self.DIRECTION = 3
    if self.X < (Board.X + Board.W - 1) then
        self.X = self.X + 1
    end
end

-- Move the player down (4)
function Player:moveDown()
    self.DIRECTION = 4
    if self.Y < (Board.Y + Board.H - 1) then
        self.Y = self.Y + 1
    end
end

-- Reset player position
function Player:reset()
    self.X = self.XSTART
    self.Y = self.YSTART
    self.HOLDING = nil
    self.DIRECTION = 4
    self.CATCHING = false
    self.CATCHING_CD = false
end

-- Draw the player
function Player:draw()
    if self.HOLDING ~= nil then
        self.HOLDING.X = self.X
        self.HOLDING.Y = self.Y
    end
    term.setCursorPos(self.X, self.Y)
    term.setTextColor(colors.white)
    term.setBackgroundColor(self.TEAM)
    if not self.CATCHING then
        if self.HOLDING == nil then
            write(self.NUMBER)
        else
            write("o")
        end
    else
        if self.DIRECTION == 1 then
            write("<")
        elseif self.DIRECTION == 2 then
            write("^")
        elseif self.DIRECTION == 3 then
            write(">")
        elseif self.DIRECTION == 4 then
            write("v")
        end
    end
end

-- Collision detection
function Player:collidedWith(object)
    if self.X == object.X and self.Y == object.Y then
        return true
    end
    return false
end

-- Throw a ball
function Player:throw()
    if self.HOLDING ~= nil then
        self.HOLDING.DIRECTION = self.DIRECTION
        self.HOLDING.IS_THROWN = true
        self.HOLDING.IS_CAUGHT = false
        self.HOLDING = nil
    end
end

-- Create a new ball
function Ball:new(_n_NUMBER)
    local self = {
        NUMBER = _n_NUMBER,
        IS_THROWN = false,
        IS_CAUGHT = false,
        COLOUR = colors.white,
        DIRECTION = 0,
        TEAM = colors.white
    }
    if _n_NUMBER == 1 or _n_NUMBER == 3 or _n_NUMBER == 5 then
        self.X = 5
        self.Y = math.floor((Term.H - (Term.H / 2) + 0.5))
    else
        self.X = Term.W - 5
        self.Y = math.floor((Term.H - (Term.H / 2) + 1))
    end
    self.XSTART = self.X
    self.YSTART = self.Y
    setmetatable(self,Ball)
    return self
end

-- Reset the ball
function Ball:reset()
    self.X = self.XSTART
    self.Y = self.YSTART
    self.IS_THROWN = false
    self.IS_CAUGHT = false
    self.DIRECTION = 0
    self.TEAM = colors.white
end

-- Move the ball's position if it is thrown
function Ball:move()
    if not self.IS_CAUGHT then
        if self.IS_THROWN then
            if self.DIRECTION == 1 then
                if self.X > (Board.X + 1) then
                    self.X = self.X - 1
                else
                    self.DIRECTION = 3
                end
            elseif self.DIRECTION == 2 then
                if self.Y > (Board.Y + 1) then
                    self.Y = self.Y - 1
                else
                    self.DIRECTION = 4
                end
            elseif self.DIRECTION == 3 then
                if self.X < (Board.X + Board.W - 1) then
                    self.X = self.X + 1
                else
                    self.DIRECTION = 1
                end
            elseif self.DIRECTION == 4 then
                if self.Y < (Board.Y + Board.H - 1) then
                    self.Y = self.Y + 1
                else
                    self.DIRECTION = 2
                end
            end
        end
    end
end

-- Draw the ball
function Ball:draw()
    term.setCursorPos(self.X,self.Y)
    if self.IS_CAUGHT then
        term.setTextColor(self.COLOUR)
        term.setBackgroundColor(self.TEAM)
    else
        term.setTextColor(self.TEAM)
        term.setBackgroundColor(colors.black)
    end
    write("o")
end

-- Initiation
local UPDATE_TIMER = os.startTimer(1)
local PLAYER_1_CATCH_TIMER = nil
local PLAYER_1_CD_CATCH_TIMER = nil
local PLAYER_2_CATCH_TIMER = nil
local PLAYER_2_CD_CATCH_TIMER = nil
local PLAYER_1 = Player:new(1)
local PLAYER_2 = Player:new(2)
local BALL_1 = Ball:new(1)
local BALL_2 = Ball:new(2)

-- Draw the board
function updateBoard()
    term.setBackgroundColor(colors.black)
    term.clear()
    paintutils.drawBox(Board.X,Board.Y,Board.X+Board.W,Board.Y+Board.H,colors.gray)
    BALL_1:draw()
    BALL_2:draw()
    PLAYER_1:draw()
    PLAYER_2:draw()
    term.setBackgroundColor(colors.gray)
    term.setTextColor(colors.blue)
    term.setCursorPos((Term.W / 2),1)
    write(Board.BLUE_SCORE)
    term.setTextColor(colors.red)
    term.setCursorPos((Term.W / 2 + 2),1)
    write(Board.RED_SCORE)
end

-- The loop
updateBoard()
while b_RUNNING do
    updateBoard()
    local event, button, X, Y = os.pullEvent()
    if event == "key" then
        if button == PLAYER_1.UP then
            PLAYER_1:moveUp()
        elseif button == PLAYER_1.LEFT then
            PLAYER_1:moveLeft()
        elseif button == PLAYER_1.DOWN then
            PLAYER_1:moveDown()
        elseif button == PLAYER_1.RIGHT then
            PLAYER_1:moveRight()
        elseif button == PLAYER_1.ACTION then
            if PLAYER_1.HOLDING ~= nil then
                PLAYER_1:throw()
            else
                if not PLAYER_1.CATCHING and not PLAYER_1.CATCHING_CD then
                    PLAYER_1.CATCHING = true
                    PLAYER_1_CATCH_TIMER = os.startTimer(0.5)
                end
            end
        elseif button == PLAYER_2.UP then
            PLAYER_2:moveUp()
        elseif button == PLAYER_2.LEFT then
            PLAYER_2:moveLeft()
        elseif button == PLAYER_2.DOWN then
            PLAYER_2:moveDown()
        elseif button == PLAYER_2.RIGHT then
            PLAYER_2:moveRight()
        elseif button == PLAYER_2.ACTION then
            if PLAYER_2.HOLDING ~= nil then
                PLAYER_2:throw()
            else
                if not PLAYER_2.CATCHING and not PLAYER_2.CATCHING_CD then
                    PLAYER_2.CATCHING = true
                    PLAYER_2_CATCH_TIMER = os.startTimer(0.5)
                end
            end
        end
    elseif event == "timer" then
        if button == UPDATE_TIMER then
            BALL_1:move()
            BALL_2:move()
            UPDATE_TIMER = os.startTimer(n_UPDATE_INTERVAL)
        elseif button == PLAYER_1_CATCH_TIMER then
            if PLAYER_1.CATCHING then
                PLAYER_1.CATCHING = false
                PLAYER_1.CATCHING_CD = true
                PLAYER_1_CD_CATCH_TIMER = os.startTimer(3)
            end
        elseif button == PLAYER_1_CD_CATCH_TIMER then
            PLAYER_1.CATCHING_CD = false
        elseif button == PLAYER_2_CATCH_TIMER then
            if PLAYER_2.CATCHING then
                PLAYER_2.CATCHING = false
                PLAYER_2.CATCHING_CD = true
                PLAYER_2_CD_CATCH_TIMER = os.startTimer(3)
            end
        elseif button == PLAYER_2_CD_CATCH_TIMER then
            PLAYER_2.CATCHING_CD = false
        end
    elseif event == "key_up" then
        if button == PLAYER_1.ACTION then
            PLAYER_1.CATCHING = false
        elseif button == PLAYER_2.ACTION then
            PLAYER_2.CATCHING = false
        end
    end
    if PLAYER_1:collidedWith(BALL_1) then
        if BALL_1.TEAM ~= PLAYER_1.TEAM then
            if not oppositeDirection(BALL_1.DIRECTION, PLAYER_1.DIRECTION) and BALL_1.TEAM ~= colors.white then
                BALL_1:reset()
                BALL_2:reset()
                PLAYER_1:reset()
                PLAYER_2:reset()
                PLAYER_1_CATCH_TIMER = nil
                PLAYER_1_CD_CATCH_TIMER = nil
                PLAYER_2_CATCH_TIMER = nil
                PLAYER_2_CD_CATCH_TIMER = nil
                Board.RED_SCORE = Board.RED_SCORE + 1
            elseif oppositeDirection(BALL_1.DIRECTION, PLAYER_1.DIRECTION) and BALL_1.TEAM ~= colors.white then
                if PLAYER_1.CATCHING then
                    PLAYER_1.HOLDING = BALL_1
                    BALL_1.DIRECTION = PLAYER_1.DIRECTION
                    BALL_1.TEAM = PLAYER_1.TEAM
                    BALL_1.IS_CAUGHT = true
                else
                    BALL_1:reset()
                    BALL_2:reset()
                    PLAYER_1:reset()
                    PLAYER_2:reset()
                    PLAYER_1_CATCH_TIMER = nil
                    PLAYER_1_CD_CATCH_TIMER = nil
                    PLAYER_2_CATCH_TIMER = nil
                    PLAYER_2_CD_CATCH_TIMER = nil
                    Board.RED_SCORE = Board.RED_SCORE + 1
                end
            elseif BALL_1.TEAM == colors.white then
                if PLAYER_1.CATCHING then
                    PLAYER_1.HOLDING = BALL_1
                    BALL_1.DIRECTION = PLAYER_1.DIRECTION
                    BALL_1.TEAM = PLAYER_1.TEAM
                    BALL_1.IS_CAUGHT = true
                end
            end
        elseif oppositeDirection(BALL_1.DIRECTION, PLAYER_1.DIRECTION) then
            if PLAYER_1.CATCHING then
                PLAYER_1.HOLDING = BALL_1
                BALL_1.DIRECTION = PLAYER_1.DIRECTION
                BALL_1.TEAM = PLAYER_1.TEAM
                BALL_1.IS_CAUGHT = true
            end
        end
    elseif PLAYER_1:collidedWith(BALL_2) then
        if BALL_2.TEAM ~= PLAYER_1.TEAM then
            if not oppositeDirection(BALL_2.DIRECTION, PLAYER_1.DIRECTION) and BALL_2.TEAM ~= colors.white then
                BALL_1:reset()
                BALL_2:reset()
                PLAYER_1:reset()
                PLAYER_2:reset()
                PLAYER_1_CATCH_TIMER = nil
                PLAYER_1_CD_CATCH_TIMER = nil
                PLAYER_2_CATCH_TIMER = nil
                PLAYER_2_CD_CATCH_TIMER = nil
                Board.RED_SCORE = Board.RED_SCORE + 1
            elseif oppositeDirection(BALL_2.DIRECTION, PLAYER_1.DIRECTION) and BALL_2.TEAM ~= colors.white then
                if PLAYER_1.CATCHING then
                    PLAYER_1.HOLDING = BALL_2
                    BALL_2.DIRECTION = PLAYER_1.DIRECTION
                    BALL_2.TEAM = PLAYER_1.TEAM
                    BALL_2.IS_CAUGHT = true
                else
                    BALL_1:reset()
                    BALL_2:reset()
                    PLAYER_1:reset()
                    PLAYER_2:reset()
                    PLAYER_1_CATCH_TIMER = nil
                    PLAYER_1_CD_CATCH_TIMER = nil
                    PLAYER_2_CATCH_TIMER = nil
                    PLAYER_2_CD_CATCH_TIMER = nil
                    Board.RED_SCORE = Board.RED_SCORE + 1
                end
            elseif BALL_2.TEAM == colors.white then
                if PLAYER_1.CATCHING then
                    PLAYER_1.HOLDING = BALL_2
                    BALL_2.DIRECTION = PLAYER_1.DIRECTION
                    BALL_2.TEAM = PLAYER_1.TEAM
                    BALL_2.IS_CAUGHT = true
                end
            end
        elseif oppositeDirection(BALL_2.DIRECTION, PLAYER_1.DIRECTION) then
            if PLAYER_1.CATCHING then
                PLAYER_1.HOLDING = BALL_2
                BALL_2.DIRECTION = PLAYER_1.DIRECTION
                BALL_2.TEAM = PLAYER_1.TEAM
                BALL_2.IS_CAUGHT = true
            end
        end
    end
    if PLAYER_2:collidedWith(BALL_1) then
        if BALL_1.TEAM ~= PLAYER_2.TEAM then
            if not oppositeDirection(BALL_1.DIRECTION, PLAYER_2.DIRECTION) and BALL_1.TEAM ~= colors.white then
                BALL_1:reset()
                BALL_2:reset()
                PLAYER_1:reset()
                PLAYER_2:reset()
                PLAYER_1_CATCH_TIMER = nil
                PLAYER_1_CD_CATCH_TIMER = nil
                PLAYER_2_CATCH_TIMER = nil
                PLAYER_2_CD_CATCH_TIMER = nil
                Board.BLUE_SCORE = Board.BLUE_SCORE + 1
            elseif oppositeDirection(BALL_1.DIRECTION, PLAYER_2.DIRECTION) and BALL_1.TEAM ~= colors.white then
                if PLAYER_2.CATCHING then
                    PLAYER_2.HOLDING = BALL_1
                    BALL_1.DIRECTION = PLAYER_2.DIRECTION
                    BALL_1.TEAM = PLAYER_2.TEAM
                    BALL_1.IS_CAUGHT = true
                else
                    BALL_1:reset()
                    BALL_2:reset()
                    PLAYER_1:reset()
                    PLAYER_2:reset()
                    PLAYER_1_CATCH_TIMER = nil
                    PLAYER_1_CD_CATCH_TIMER = nil
                    PLAYER_2_CATCH_TIMER = nil
                    PLAYER_2_CD_CATCH_TIMER = nil
                    Board.BLUE_SCORE = Board.BLUE_SCORE + 1
                end
            elseif BALL_1.TEAM == colors.white then
                if PLAYER_2.CATCHING then
                    PLAYER_2.HOLDING = BALL_1
                    BALL_1.DIRECTION = PLAYER_2.DIRECTION
                    BALL_1.TEAM = PLAYER_2.TEAM
                    BALL_1.IS_CAUGHT = true
                end
            end
        elseif oppositeDirection(BALL_1.DIRECTION, PLAYER_2.DIRECTION) then
            if PLAYER_2.CATCHING then
                PLAYER_2.HOLDING = BALL_1
                BALL_1.DIRECTION = PLAYER_2.DIRECTION
                BALL_1.TEAM = PLAYER_2.TEAM
                BALL_1.IS_CAUGHT = true
            end
        end
    elseif PLAYER_2:collidedWith(BALL_2) then
        if BALL_2.TEAM ~= PLAYER_2.TEAM then
            if not oppositeDirection(BALL_2.DIRECTION, PLAYER_2.DIRECTION) and BALL_2.TEAM ~= colors.white then
                BALL_1:reset()
                BALL_2:reset()
                PLAYER_1:reset()
                PLAYER_2:reset()
                PLAYER_1_CATCH_TIMER = nil
                PLAYER_1_CD_CATCH_TIMER = nil
                PLAYER_2_CATCH_TIMER = nil
                PLAYER_2_CD_CATCH_TIMER = nil
                Board.BLUE_SCORE = Board.BLUE_SCORE + 1
            elseif oppositeDirection(BALL_2.DIRECTION, PLAYER_2.DIRECTION) and BALL_2.TEAM ~= colors.white then
                if PLAYER_2.CATCHING then
                    PLAYER_2.HOLDING = BALL_2
                    BALL_2.DIRECTION = PLAYER_2.DIRECTION
                    BALL_2.TEAM = PLAYER_2.TEAM
                    BALL_2.IS_CAUGHT = true
                else
                    BALL_1:reset()
                    BALL_2:reset()
                    PLAYER_1:reset()
                    PLAYER_2:reset()
                    PLAYER_1_CATCH_TIMER = nil
                    PLAYER_1_CD_CATCH_TIMER = nil
                    PLAYER_2_CATCH_TIMER = nil
                    PLAYER_2_CD_CATCH_TIMER = nil
                    Board.BLUE_SCORE = Board.BLUE_SCORE + 1
                end
            elseif BALL_2.TEAM == colors.white then
                if PLAYER_2.CATCHING then
                    PLAYER_2.HOLDING = BALL_2
                    BALL_2.DIRECTION = PLAYER_2.DIRECTION
                    BALL_2.TEAM = PLAYER_2.TEAM
                    BALL_2.IS_CAUGHT = true
                end
            end
        elseif oppositeDirection(BALL_2.DIRECTION, PLAYER_2.DIRECTION) then
            if PLAYER_2.CATCHING then
                PLAYER_2.HOLDING = BALL_2
                BALL_2.DIRECTION = PLAYER_2.DIRECTION
                BALL_2.TEAM = PLAYER_2.TEAM
                BALL_2.IS_CAUGHT = true
            end
        end
    end
end