class Game

# File lib/ruby-snake/game.rb, line 12
def initialize
        Curses.init_screen

        Curses.noecho # Don't show typed key.
        Curses.stdscr.keypad(true)

        # colors
        Curses.start_color
        Curses.init_pair(COLOR_BLUE, COLOR_BLUE, COLOR_BLUE) # Color of boders
        Curses.init_pair(COLOR_RED, COLOR_RED, COLOR_RED)
        Curses.init_pair(COLOR_BLACK, COLOR_BLACK, COLOR_BLACK)
        Curses.init_pair(COLOR_YELLOW, COLOR_YELLOW, COLOR_YELLOW)
        
        setup         
end

# File lib/ruby-snake/game.rb, line 28
def start
        # Create a thread to montior key events
        key_listener = Thread.new do
                loop {Thread.current[:key] = Curses.getch}
        end

        while true
                handle_key key_listener[:key]
                if !@pause

                        if @dead_snake # erase dead snake
                                @dead_snake.body.each {|pos| erase pos}
                                erase @dead_snake.food
                                @dead_snake = false
                        end

                        tail = @snake.goto @direction

                        if @snake.alive?
                                draw_snake
                                draw_food
                                erase tail
                                @speed += 1 if @snake.score / 100 > @speed - 1
                        else
                                @dead_snake = @snake.dup
                                setup
                                @message = "You die! Press 'S' to restart the game."
                                @pause = true
                        end

                        draw_ui
                        Curses.refresh
                        sleep(0.2 * (0.8 ** (@speed - 1)))
                end
                
        end

end

# File lib/ruby-snake/game.rb, line 104
def draw_food
        Curses.setpos(@snake.food.y, (@snake.food.x - 1) * 2)
        Curses.attron(color_pair(COLOR_YELLOW)|A_NORMAL) {Curses.addstr "  "}
end

# File lib/ruby-snake/game.rb, line 97
def draw_snake
        @snake.body.each do |pos|
                Curses.setpos(pos.y, (pos.x - 1) * 2)
                Curses.attron(color_pair(COLOR_RED)|A_NORMAL) {Curses.addstr "  "}
        end
end

# File lib/ruby-snake/game.rb, line 78
def draw_ui
        # top border
        Curses.setpos(TOP, LEFT)
        Curses.attron(color_pair(COLOR_BLUE)|A_NORMAL) {Curses.addstr(' ' * RIGHT)}
        # bottom border
        Curses.setpos(BOTTOM, LEFT)
        Curses.attron(color_pair(COLOR_BLUE)|A_NORMAL) {Curses.addstr(' ' * RIGHT)}
        Curses.addstr(' ' * RIGHT)
        # left boder & right boder
        Curses.attron(color_pair(COLOR_BLUE)|A_NORMAL) do
                TOP.upto(BOTTOM) do |i|
                        Curses.setpos(i, LEFT); Curses.addstr "  "
                        Curses.setpos(i, RIGHT); Curses.addstr "  "
                end
        end
        Curses.setpos(BOTTOM + 1, LEFT)
        Curses.addstr("Score: #{@snake.score} Speed: #{@speed}, #{@message}")
end

# File lib/ruby-snake/game.rb, line 109
def erase pos
        Curses.setpos(pos.y, (pos.x - 1) * 2)
        Curses.attron(color_pair(COLOR_BLACK)|A_NORMAL) {Curses.addstr "  "}
end

# File lib/ruby-snake/game.rb, line 114
def handle_key key
        case key
        when 'q', 'Q'
                exit
        when 'p', 'P'
                @message = "Press 'S' to start, Press 'Q' to quit."
                @pause = true
                draw_ui
                Curses.refresh
        when 's', 'S'
                @message = "Press 'P' to pause, Press 'Q' to quit."
                @pause = false
        when Curses::Key::UP
                @direction = Snake::UP
        when Curses::Key::DOWN
                @direction = Snake::DOWN
        when Curses::Key::LEFT
                @direction = Snake::LEFT
        when Curses::Key::RIGHT
                @direction = Snake::RIGHT
        end
end

# File lib/ruby-snake/game.rb, line 69
def setup
        @snake = Snake.new(RIGHT / 2 - 1, BOTTOM - 1)
        @score = 0
        @speed = 1
        @pause = false
        @direction = Snake::RIGHT
        @message = "Press 'P' to pause, Press 'Q' to quit."
end