# Created by: Alex Ubuntu
# Date: 01.01.2026
# Purpose: A personal flashcard trainer to help with learning

# Import the random module
import random
# Import json module
import json

### LOAD FLASHCARDS
# Set flashcards list from file
# Initialize empty list
flashcards_list = []
file_separator = ','

# Open and read the file
flashcard_file = "flashcards.txt"
try:
    with open(flashcard_file, 'r') as file:
        lines = file.readlines()
except:
    # Handle scenario where file is not found 
    # and display comprehensible message to user.
    print(f"The file {flashcard_file} is missing. Please add it to initialise your flashcards.")
    exit()

# Process each line
# Each line has: question,answer
for line in lines:
    # Remove whitespace/newlines
    line = line.strip()
    
    # Extract question and answer 
    # with pattern matching assuming two comma
    # separated values in a row:
    question, answer = line.split(file_separator)
    
    # Add to list
    flashcards_list.append((question, answer))

# Confirm loaded
print(f"{len(flashcards_list)} flashcards loaded!")

# Set flashcards dictionary from file
# Initialize empty dictionary
flashcards = {}
file_separator = ','

### INITIAL INTERACTION WITH USER
# Welcome message
print("Welcome to your personal flashcard trainer!")

# Absolute maximum number of cards so that the user can't ask for too many
ABSOLUTE_MAX_CARDS = 100
DEFAULT_MAX_CARDS = 20

# Fetch from user and save to variable
name = input("What is your name? ")
max_cards = DEFAULT_MAX_CARDS # Set a default value for max_cards

# Confirm name
print(f"\nMy name is {name}")

# Card and score variables
num_cards_completed = 0
num_cards_correct = 0
score = 0

## FUNCTIONS
# Function to calculate and display score information
def display_score_info():

    # Handle case where no cards have been completed yet.
    if num_cards_completed <=0:
        print("You need to practice before you can get a score.")
    else:
        # Calculate score
        score = (num_cards_correct/num_cards_completed) * 100
        print(f"\nYou have answered {num_cards_correct} out of {num_cards_completed} correctly. Your score is {score}%.")

# Function to write score information to file
def write_score_info():
    # Calculate score
    score = (num_cards_correct/num_cards_completed) * 100
    data_to_append = {
        "num_cards_practiced": num_cards_completed,
        "score": score,
    }
    # Initialise user_data as empty dictionary
    user_data = {}
    # Initialise score_data as empty dictionary
    score_data = []
    # Try opening the json file
    try:
        with open('progress.json', 'r') as file:
            # Load file contents if found
            score_data = json.load(file)
    except FileNotFoundError:
        # Otherwise do nothing so score_data remains an empty list
        pass

    # Append latest session data
    score_data.append(data_to_append)

    # Write out score_data with the latest session data appended
    # to json file
    with open('progress.json', 'w') as file:
        json.dump(score_data, file, indent=4)

# Fetches progress history from json file
# Empty list returned if history or file not found
def get_progress_history():
    score_data = []
    # Open and read the file
    try:
        with open(user_filename, 'r') as file:
            # Load file contents if found
            user_data = json.load(file)
            # Use safe extraction to get the progress_history 
            # containing the list of score data for different sessions. 
            # If it isn't there, set to empty list.
            return user_data.get("progress_history", [])
        
    except FileNotFoundError:
        return []

### APP MENU LOOP
while True:
    print("\nSelect an option by entering a number")
    print("1: Set the number of cards you wish to practice")
    print("2: Start flashcards")
    print("3: Show the current score")
    print("4: View progress history") # Option to view progress history
    print("5: Exit")
    
    
    choice = input("\nChoose an option: ")
    
    if choice == "1":

        while True:
            # More stringent validation for input for maximum number of cards
            
            # Fetch input from user but don't attempt to convert the input string 
            # to int until certain it will work 
            entered_max_cards = input("\nHow many cards would you like to practice each session? ")

            # Check if input string represents an integer
            if entered_max_cards.isdigit():

                # Convert to integer data type
                entered_max_cards = int(entered_max_cards)
            
                # Check if value is within the value range 
                # (between 1 and the absolute maximum number of cards)
                if entered_max_cards > 0 and entered_max_cards < ABSOLUTE_MAX_CARDS:
                    
                    # Set the max_cards variable with the user's preference
                    max_cards = entered_max_cards
                    # Confirm number maximum number of cards per session
                    print(f"\nI want to practice at most {max_cards} cards per session")
                    break
                else:
                    ## Let the user know what the range should be (Bonus task).
                    print(f"\nPlease enter a valid number bewteen 1 and {ABSOLUTE_MAX_CARDS}.")    
            else:
                print(f"\nPlease enter a whole number number over 0.")  

    elif choice == "2":
        
        # Reset the number of cards completed for each session
        num_cards_completed = 0
        num_cards_correct = 0

        # Iterate through flashcards list of tuples
        # Each tuple element of the list contains a question, answer pair
        # Using a for loop means that the number of flashcards displayed
        # is limited by the number of items in flashcards so the user
        # may end up practicing fewer cards than they specified  
        for q, a in flashcards_list:
            # Ask user question and save response into variable
            user_answer = input(f"\nQuestion: {q}\n")
            
            # Increment the count of cards completed
            num_cards_completed += 1
            
            # Display user's answer and correct answer
            print(f"Your answer: {user_answer}, Correct answer: {a}")

            # Response deemed to be correct even if given in different case
            if user_answer.lower() == a.lower():
                
                # Increment count of cards answered correctly
                num_cards_correct += 1
                print("Correct")
            else:
                print("Incorrect")
        
            # Check if number of cards completed has hit the user's
            # preferred maximum number of cards
            if num_cards_completed >= max_cards:
                break
        
        print("\nWell done on completing your practice session!")
        # Write score info out with each session completed
        write_score_info()
        # Display score info at the end of a session
        display_score_info()

    elif choice == "3":

        display_score_info()

    elif choice == "4":
        #Session 4: 10 cards completed, score 60% 
        # Open and read the file
        with open('progress.txt', 'r') as file:
            lines = file.readlines()

        print("How many sessions would you like to view?")
        num_sessions = int(input("Enter the number or 0 to show all: "))
        print("What order would you like to see them in?")
        print("1: Oldest")
        print("2: Most recent")
        order = input("Choose an option by entering 1 or 2: ")

        # If the user wants to see all sessions, set num_sessions
        # to the number of sessions available
        if num_sessions==0:
            num_sessions = len(lines) 

        selected_lines = lines
        if order =="2":
            # Need to reverse order of list if 
            # most recent first is selected
            selected_lines = selected_lines[::-1]
        selected_lines = selected_lines[:num_sessions]
        
        #TODO: Add handling of invalid inputs

        # Process each line
        # Each line has: num_cards_completed,num_cards_correct,score
        # Enumerate to get the session number - assumes the 
        # row number corresponds to the session number
        for i, line in enumerate(selected_lines):
            # Remove whitespace/newlines
            line = line.strip()
    
            # Split by ',' separator
            parts = line.split(file_separator)

            # Extract num_cards_completed,num_cards_correct,score
            # Name these variables something different 
            # (e.g. saved_cards_completed, saved_cards_correct, saved_score) 
            # so they don't write over those being used by the rest of the program
            saved_cards_completed = parts[0]
            saved_cards_correct = parts[1]
            saved_score = parts[2]

            print(f"Session {i}: {saved_cards_completed} cards completed, score {saved_score}%")

    elif choice == "5":
        print(f"We hope you enjoyed your practice session today, {name}.")
        
        display_score_info()

        # Display feedback message based on score
        if score > 90 and score <= 100:
            print("Excellent work!")
        elif score > 70 and score <= 90:
            print("Good job!")
        elif score > 50 and score <= 70:
            print("Keep practicing!")
        elif score > 0 and score <= 50: 
            print("Need more study time!")
        
        print("Look forward to seeing you again soon!")
        break
    
    else:
        # Clarify instruction to get valid input
        print("\nInvalid value entered. Please make sure you enter just a single digit (no other words): 1, 2, 3 or 4, to select an option.")