import csv
import os
import pickle
import random
import sys
import termios
import tty

from pathlib import Path


class Flashcards:
    def __init__(self):
        self.cards = {}
        self.selected_category = None
        self.current_cards = None
        self.current_card_index = 0
        self.side = 0  # 0 = korean, 1 = eng

        self.difficult_cards = []
        self.difficult_pickle_path = "difficult_cards.pkl"
        self.load_difficult_cards()

    def save_difficult_cards(self):
        with open(self.difficult_pickle_path, "wb") as f:
            pickle.dump(self.difficult_cards, f)

    def load_difficult_cards(self):
        if Path(self.difficult_pickle_path).exists():
            with open(self.difficult_pickle_path, "rb") as f:
                self.difficult_cards = pickle.load(f)

    @staticmethod
    def get_key():
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)

        try:
            tty.setraw(fd)
            return sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)

    @staticmethod
    def clear():
        print("\033[2J\033[H", end="")

    def main(self):
        self.parse_cards()
        self.select_category()
        self.loop()

    def select_category(self):
        self.current_card_index = 0
        self.side = 0
        self.clear()
        print("Categories")
        print('============================')
        for idx, category in enumerate(list(self.cards.keys())):
            print(f"[{idx}] {category}")

        if len(self.difficult_cards) > 0:
            print('[d] Difficult Cards')

        print("\n")
        resp = input("Select a Category: ")

        if resp == 'd':
            self.selected_category = "Difficult Cards"
            self.current_cards = random.sample(self.difficult_cards, len(self.difficult_cards))
        else:
            self.selected_category = list(self.cards.keys())[int(resp)]
            self.current_cards = random.sample(self.cards[self.selected_category], len(self.cards[self.selected_category]))

    def parse_cards(self):
        for root, dirs, files in os.walk("."):
            for file_name in files:
                file_path = os.path.join(root, file_name)
                if '.tsv' in file_path:
                    with open(file_path, 'r') as f:
                        reader = csv.reader(f, delimiter="\t")
                        for idx, row in enumerate(reader):
                            if idx == 0:
                                self.cards[row[0]] = []
                            self.cards[row[0]].append(row[1:])

        self.cards = dict(sorted(self.cards.items()))

    def loop(self):
        while True:
            self.card_screen()

            key = self.get_key()
            if key == "k":
                self.flip_card()
            elif key == "j":
                self.flip_card()
            elif key == "l":
                self.next_card()
            elif key == "h":
                self.prev_card()
            elif key == "d":
                self.add_difficult_card()
            elif key == "x":
                self.rm_difficult_card()
            elif key == "c":
                self.select_category()
            elif key == "q":
                break

    def next_card(self):
        if self.current_card_index < len(self.current_cards) - 1:
            self.current_card_index += 1

    def prev_card(self):
        if self.current_card_index > 0:
            self.current_card_index -= 1

    def add_difficult_card(self):
        if self.current_cards[self.current_card_index] not in self.difficult_cards:
            print("adding card...")
            self.save_difficult_cards()
            self.difficult_cards.append(self.current_cards[self.current_card_index])

    def rm_difficult_card(self):
        print("removing card...")
        self.save_difficult_cards()
        discarded = self.current_cards.pop(self.current_card_index)
        self.difficult_cards.remove(discarded)
        if self.current_card_index > len(self.difficult_cards) - 1:
            self.current_card_index = len(self.difficult_cards) - 1
        if len(self.difficult_cards) == 0:
            self.current_card_index = 0
            self.side = 0
            self.select_category()

    def card_screen(self):
        self.clear()
        print(f"{self.selected_category} | {self.current_card_index + 1}/{len(self.current_cards)} | DC {len(self.difficult_cards)} {'*' if self.current_cards[self.current_card_index] in self.difficult_cards else ''}")
        print('----------------------------------------------\n')
        print(self.current_cards[self.current_card_index][self.side])

        print('\n\n\n\n')
        print('vim keys to move cards | q: quit | c: change category')
        print('d: add to difficult cards | x: remove from difficult cards')

    def flip_card(self):
        if self.side == 0:
            self.side = 1
        else:
            self.side = 0


if __name__ == "__main__":
    f = Flashcards()
    f.main()