from tuikit.core.window import WindowManager, Window

from tuikit.core.theme import default_theme

from tuikit.core.timer import Timer

from tuikit.core.buffer import ProxyBuffer

from tuikit.core.events import ResizeEvent

import logging

class Application:

    """Tuikit application helper.

    Joins all required pieces to build complete application

    using TUI widgets and event loop.

    """

    def __init__(self, driver='cursesw'):

        self.log = logging.getLogger(__name__)

        self.driver = None

        self.timer = Timer()

        self.window_manager = WindowManager(timer=self.timer)

        self.root_window = Window()

        # flags

        self._started = False

        self._quit = False

        # find and initialize driver

        self.set_driver(driver)

        self.set_theme(default_theme)

        self.window_manager.add(self.root_window)

    def set_driver(self, driver_name):

        """Select driver to be used for rendering and input.

        `driver_name` should be one of: 'base', 'curses', 'sdl'

        """

        if self._started:

            raise Exception('Cannot change driver after starting the application.')

        module = __import__('tuikit.driver.' + driver_name, fromlist=['driver_class'])

        self.driver = module.driver_class()

    def set_theme(self, theme):

        self.window_manager.set_theme(theme)

    def start(self):

        """Start application. Runs main loop."""

        self.log.info('=== Start ===')

        with self.driver:

            self.main_loop()

    def stop(self):

        """Terminate application."""

        self._quit = True

    def main_loop(self):

        """The main loop."""

        self._started = True

        self.window_manager.handle_event(ResizeEvent(*self.driver.size))

        screen = ProxyBuffer(self.driver)

        while not self._quit:

            self.window_manager.draw(screen)

            self.driver.flush()

            timeout = self.timer.nearest_timeout()

            events = self.driver.getevents(timeout)

            self.timer.process_timeouts()

            for event in events:

                self.window_manager.handle_event(event)

        self._started = False

        self.log.info('=== End ===')