import csv
from random import shuffle

# 1. Load participants from CSV, now including id and last_match_id
def load_participants(filename):
    participants = []
    with open(filename, 'r') as file:
        reader = csv.DictReader(file)
        for row in reader:
            participants.append({
                'id': int(row['id']),
                'name': row['name'],
                'household': row['household'],
                'email': row['email'],
                'last_match_id': int(row['last_match_id']) if row['last_match_id'] else None
            })
    return participants

# 2. Generate potential matches, ensuring a complete set
def generate_complete_matches(participants):
    max_attempts = 100  # Limit to avoid infinite loops
    attempts = 0

    while attempts < max_attempts:
        # Shuffle both givers and receivers lists
        givers = participants.copy()
        receivers = participants.copy()
        shuffle(givers)
        shuffle(receivers)

        matches = {}
        used_receivers = set()  # Track receivers that have already been matched

        for giver in givers:
            match_found = False
            for receiver in receivers:
                if receiver['id'] not in used_receivers and \
                        giver['id'] != receiver['id'] and \
                        giver['household'] != receiver['household'] and \
                        giver['last_match_id'] != receiver['id'] and \
                        matches.get(receiver['id']) != giver['id']:
                    matches[giver['id']] = receiver
                    used_receivers.add(receiver['id'])  # Mark this receiver as used
                    match_found = True
                    break

            if not match_found:
                # Incomplete match, restart the process
                attempts += 1
                break
        else:
            # Complete match set found
            return matches

    print("Could not find a complete match set after several attempts. Restarting the entire process.")
    return None


# 3. Confirm matches interactively
def confirm_matches(participants, matches):
    print("Proposed Matches:")
    for giver_id, receiver in matches.items():
        giver = next(p for p in participants if p['id'] == giver_id)
        print(f"{giver['name']} ({giver['email']}) will give a gift to {receiver['name']} ({receiver['email']})")
        response = input("Approve this match? (yes/no): ").strip().lower()
        if response != 'yes':
            print("Match not approved. Restarting the matching process...\n")
            return False  # Signal to restart if any match is disapproved
    return True

# 4. Final confirmation to save matches
def final_confirmation(participants, matches):
    print("\nFinal Match List:")
    for giver_id, receiver in matches.items():
        giver = next(p for p in participants if p['id'] == giver_id)
        print(f"{giver['name']} will give a gift to {receiver['name']}")

    # Final save prompt
    response = input("\nDo you want to save this match list? (yes to save, no to restart): ").strip().lower()
    return response == 'yes'

# 5. Update last matches in the CSV file
def update_last_match_in_file(participants, matches, filename):
    for giver_id, receiver in matches.items():
        for participant in participants:
            if participant['id'] == giver_id:
                participant['last_match_id'] = receiver['id']

    with open(filename, 'w', newline='') as file:
        fieldnames = ['id', 'name', 'household', 'email', 'last_match_id']
        writer = csv.DictWriter(file, fieldnames=fieldnames)
        writer.writeheader()
        for participant in participants:
            writer.writerow({
                'id': participant['id'],
                'name': participant['name'],
                'household': participant['household'],
                'email': participant['email'],
                'last_match_id': participant['last_match_id']
            })
    print("Matches saved to 'participants.csv'.")

# 6. Main function to run the match process
def main():
    participants = load_participants('participants.csv')
    while True:
        matches = generate_complete_matches(participants)
        if matches and confirm_matches(participants, matches):
            if final_confirmation(participants, matches):
                update_last_match_in_file(participants, matches, 'participants.csv')
                break
            else:
                print("\nRestarting the matching process...\n")
        else:
            print("No complete match found, restarting...\n")

if __name__ == '__main__':
    main()