#!/usr/bin/env python3

import math
import argparse
import json
from enum import Enum, auto
from time import sleep
from threading import Thread
from queue import Queue, Empty
from typing import Tuple, Callable, TypedDict, List

import pygame
import pygame.freetype
import requests

from iboard import IBoard
from screensavers import ClockScreensaver


class ButtonDef(TypedDict):
    text: str
    cbk: Callable[[], None]


class ActionType(Enum):
    MSG = auto()  # Shows a message for about 5 seconds
    GET = auto()  # Performs a HTTP GET


class Action(TypedDict):
    label: str
    action_type: ActionType
    action_param: str
    action_message: str


class Button:
    PRESS_OFFSET = 2

    def __init__(self, position: pygame.Rect, text: str, cbk: Callable[[], None]):
        self.position: pygame.Rect
        self.set_position(position)
        self.text = text
        self.cbk = cbk
        self.font = pygame.freetype.SysFont(name="Sans", size=20)
        text_rect = self.font.get_rect(self.text)
        self.text_pos = pygame.Rect((self.position.left + (self.position.width - text_rect.width)/2),
                                    (self.position.top + (self.position.height - text_rect.height)/2),
                                    text_rect.width, text_rect.height)

    def set_position(self, position: pygame.Rect):
        self.position = position

    def get_position(self) -> pygame.Rect:
        if pygame.mouse.get_pressed(3)[0] and self.pos_is_inside(pygame.mouse.get_pos()):
            return pygame.Rect(self.position.left + self.PRESS_OFFSET, self.position.top + self.PRESS_OFFSET,
                               self.position.width, self.position.height)
        return self.position

    def get_text_pos(self) -> pygame.Rect:
        if pygame.mouse.get_pressed(3)[0] and self.pos_is_inside(pygame.mouse.get_pos()):
            return pygame.Rect(self.text_pos.left + self.PRESS_OFFSET, self.text_pos.top + self.PRESS_OFFSET,
                               self.text_pos.width, self.text_pos.height)
        return self.text_pos

    def draw(self, screen: pygame.Surface):
        pygame.draw.rect(screen, "black", self.get_position(), 0)
        self.font.render_to(screen, self.get_text_pos(), self.text, fgcolor="pink")

    def pos_is_inside(self, pos: Tuple) -> bool:
        return (self.position.left < pos[0] and (self.position.left + self.position.width) > pos[0]) and \
            (self.position.top < pos[1] and (self.position.top + self.position.height) > pos[1])

    def handle_event(self, event: pygame.event.Event):
        if event.type == pygame.MOUSEBUTTONUP:
            if event.button == 1 and self.pos_is_inside(event.pos):
                self.cbk()


class MessageBoard(IBoard):
    def __init__(self, screen_rect: pygame.Rect, text: str, bg_color: str):
        self.text = text
        self.font = pygame.freetype.SysFont(name="Sans", size=30)
        text_rect = self.font.get_rect(self.text)
        self.text_pos = pygame.Rect((screen_rect.left + (screen_rect.width - text_rect.width)/2),
                                    (screen_rect.top + (screen_rect.height - text_rect.height)/2),
                                    text_rect.width, text_rect.height)
        self.bg_color = bg_color
        self.was_drawn_already = False

    def handle_event(self, _):
        pass

    def draw(self, screen: pygame.Surface, force_redraw: bool):
        if not self.was_drawn_already or force_redraw:
            screen.fill(self.bg_color)
            self.font.render_to(screen, self.text_pos, self.text, fgcolor="black")
            self.was_drawn_already = True


class MenuBoard(IBoard):
    BUTTON_MARGINS = 10

    def __init__(self, screen_rect: pygame.Rect, buttons: List[ButtonDef], bg_color: str):
        self.rows = math.floor(math.sqrt(len(buttons)))
        self.cols = math.ceil(math.sqrt(len(buttons)))
        if (self.rows * self.cols) < len(buttons):
            # extra row if buttons don't fit
            self.rows += 1
        button_positions = self.generate_button_positions(screen_rect)
        self.buttons = list(map(lambda d: Button(next(button_positions), d['text'], d['cbk']), buttons))
        self.bg_color = bg_color

    def generate_button_positions(self, screen_rect: pygame.Rect):
        current_button_row = 0
        current_button_col = 0
        button_width = math.floor((screen_rect.width - (self.cols + 1) * self.BUTTON_MARGINS) / self.cols)
        button_height = math.floor((screen_rect.height - (self.rows + 1) * self.BUTTON_MARGINS) / self.rows)
        while (current_button_row * current_button_col) < (self.cols * self.rows):
            top = self.BUTTON_MARGINS + (current_button_row * (button_height + self.BUTTON_MARGINS))
            left = self.BUTTON_MARGINS + (current_button_col * (button_width + self.BUTTON_MARGINS))
            current_button_col += 1
            if current_button_col >= self.cols:
                current_button_col = 0
                current_button_row += 1
            yield pygame.Rect(left, top, button_width, button_height)

    def handle_event(self, event: pygame.event.Event):
        for b in self.buttons:
            b.handle_event(event)

    def draw(self, screen: pygame.Surface, force_redraw: bool):
        if force_redraw:
            screen.fill(self.bg_color)
            for b in self.buttons:
                b.draw(screen)


class App:
    FPS = 30

    def __init__(self, urls: List[Action], bg_color: str, fullscreen: bool, screensaver_delay: int):
        pygame.init()
        info = pygame.display.Info()
        flags = 0
        if fullscreen:
            flags = pygame.FULLSCREEN
        self.screen = pygame.display.set_mode((info.current_w, info.current_h), flags=flags)
        self.clock = pygame.time.Clock()
        self.running = False
        self.bg_color = bg_color
        buttons = list(map(lambda u: ButtonDef(text=u['label'], cbk=self.button_press_handler(u)), urls))
        buttons.append(ButtonDef(text="Exit", cbk=self.quit))
        self.board: IBoard = MenuBoard(self.get_screen_rect(), buttons, bg_color)
        self.task_q = Queue()
        self.screensaver = ClockScreensaver()
        self.TICKS_UNTIL_SCREENSAVER = screensaver_delay * self.FPS
        self.screensaver_ticks = self.TICKS_UNTIL_SCREENSAVER

    def get_screen_rect(self) -> pygame.Rect:
        return pygame.Rect(0, 0, self.screen.get_width(), self.screen.get_height())

    def show_message_handler(self, action: Action) -> Callable[[], None]:
        def impl():
            previous_board = self.board

            def thr_fun():
                def end_thr():
                    self.board = previous_board

                try:
                    sleep_time = int(action['action_param'])
                    sleep(sleep_time)
                except Exception as e:
                    def f(ex):
                        def x():
                            self.board = MessageBoard(self.get_screen_rect(), f"Exception caught: {ex}", bg_color="red")
                        return x
                    self.task_q.put(f(e))
                    sleep(5)
                finally:
                    self.task_q.put(end_thr)

            process_thr = Thread(target=thr_fun)
            process_thr.start()
            self.board = MessageBoard(self.get_screen_rect(), action['action_message'], bg_color=self.bg_color)
        return impl

    def get_handler(self, action: Action) -> Callable[[], None]:
        def impl():
            previous_board = self.board

            def thr_fun():
                def end_thr():
                    self.board = previous_board

                ret = requests.get(action['action_param'])
                print(f"GET {action['action_param']}: {ret}")
                self.task_q.put(end_thr)

            process_thr = Thread(target=thr_fun)
            process_thr.start()
            self.board = MessageBoard(self.get_screen_rect(), action['action_message'], bg_color=self.bg_color)
        return impl

    def button_press_handler(self, action: Action) -> Callable[[], None]:
        if action['action_type'] == ActionType.MSG:
            return self.show_message_handler(action)
        elif action['action_type'] == ActionType.GET:
            return self.get_handler(action)
        raise NotImplementedError(action['action_type'])

    def loop(self):
        self.running = True
        needs_redrawing = True
        while self.running:
            try:
                self.task_q.get_nowait()()
            except Empty:
                pass
            for event in pygame.event.get():
                if event.type == pygame.QUIT:
                    self.running = False
                if self.screensaver_ticks != 0:
                    self.board.handle_event(event)
                self.screensaver_ticks = self.TICKS_UNTIL_SCREENSAVER
                needs_redrawing = True

            if self.screensaver_ticks == 0:
                self.screensaver.draw(self.screen, False)
            else:
                self.board.draw(self.screen, needs_redrawing)
                self.screensaver_ticks -= 1
                needs_redrawing = False

            pygame.display.flip()

            self.clock.tick(self.FPS)
        pygame.quit()

    def quit(self):
        self.board = MessageBoard(self.get_screen_rect(), "Exiting...", bg_color=self.bg_color)
        self.running = False


def get_url_defs(config_data: dict) -> List[Action]:
    url_defs = []
    for d in data['urls']:
        url_defs.append(Action(label=d['label'],
                               action_type=ActionType[d['action_type']],
                               action_param=d['action_param'],
                               action_message=d['action_message']))
    return url_defs


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument("config_path", help="Path to the config file.", type=str)
    parser.add_argument("--no-fullscreen", help="Fullscreen", action='store_true')
    parser.add_argument("--screensaver-delay", help="Screensaver delay, in seconds. Default=30",
                        type=int, default=30)
    args = parser.parse_args()

    url_defs: List[Action] = []
    with open(args.config_path, "rb") as f:
        data = json.load(f)
        url_defs = get_url_defs(data)

    app = App(url_defs, bg_color=data["bg_color"], fullscreen=not args.no_fullscreen,
              screensaver_delay=args.screensaver_delay)
    app.loop()