import sqlite3
import matplotlib.pyplot as plt
from datetime import datetime

# Inicjalizacja bazy danych
def init_db():
    conn = sqlite3.connect("finance.db")
    cursor = conn.cursor()
    cursor.execute("""
        CREATE TABLE IF NOT EXISTS transactions (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            type TEXT NOT NULL, -- 'income' lub 'expense'
            amount REAL NOT NULL,
            category TEXT,
            date TEXT NOT NULL
        )
    """)
    conn.commit()
    conn.close()

# Dodawanie transakcji
def add_transaction(transaction_type, amount, category):
    conn = sqlite3.connect("finance.db")
    cursor = conn.cursor()
    date = datetime.now().strftime("%Y-%m-%d")
    cursor.execute("""
        INSERT INTO transactions (type, amount, category, date)
        VALUES (?, ?, ?, ?)
    """, (transaction_type, amount, category, date))
    conn.commit()
    conn.close()
    print("Transakcja dodana!")

# Przeglądanie historii transakcji
def view_transactions():
    conn = sqlite3.connect("finance.db")
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM transactions ORDER BY date DESC")
    transactions = cursor.fetchall()
    conn.close()
    print("\nHistoria transakcji:")
    for t in transactions:
        print(f"{t[0]} | {t[1]} | {t[2]:.2f} | {t[3]} | {t[4]}")

# Filtrowanie transakcji
def filter_transactions(category=None, start_date=None, end_date=None):
    conn = sqlite3.connect("finance.db")
    cursor = conn.cursor()
    query = "SELECT * FROM transactions WHERE 1=1"
    params = []
    if category:
        query += " AND category = ?"
        params.append(category)
    if start_date:
        query += " AND date >= ?"
        params.append(start_date)
    if end_date:
        query += " AND date <= ?"
        params.append(end_date)
    cursor.execute(query, params)
    transactions = cursor.fetchall()
    conn.close()
    print("\nFiltrowane transakcje:")
    for t in transactions:
        print(f"{t[0]} | {t[1]} | {t[2]:.2f} | {t[3]} | {t[4]}")

# Wyświetlanie salda
def calculate_balance():
    conn = sqlite3.connect("finance.db")
    cursor = conn.cursor()
    cursor.execute("SELECT SUM(amount) FROM transactions WHERE type = 'income'")
    income = cursor.fetchone()[0] or 0
    cursor.execute("SELECT SUM(amount) FROM transactions WHERE type = 'expense'")
    expense = cursor.fetchone()[0] or 0
    conn.close()
    balance = income - expense
    print(f"Saldo konta: {balance:.2f} zł")

# Wyświetlanie statystyk
def show_statistics():
    conn = sqlite3.connect("finance.db")
    cursor = conn.cursor()
    cursor.execute("SELECT category, SUM(amount) FROM transactions WHERE type = 'expense' GROUP BY category")
    data = cursor.fetchall()
    conn.close()
    if not data:
        print("Brak danych do wyświetlenia statystyk.")
        return

    categories = [d[0] for d in data]
    amounts = [d[1] for d in data]

    plt.bar(categories, amounts)
    plt.title("Wydatki według kategorii")
    plt.xlabel("Kategoria")
    plt.ylabel("Kwota (zł)")
    plt.show()

# Główna pętla programu
def main():
    init_db()
    while True:
        print("\n--- MENU ---")
        print("1. Dodaj transakcję")
        print("2. Wyświetl historię transakcji")
        print("3. Filtruj transakcje")
        print("4. Pokaż saldo konta")
        print("5. Wyświetl statystyki")
        print("6. Wyjście")
        choice = input("Wybierz opcję: ")

        if choice == "1":
            t_type = input("Typ (income/expense): ").strip().lower()
            amount = float(input("Kwota: "))
            category = input("Kategoria: ").strip()
            add_transaction(t_type, amount, category)
        elif choice == "2":
            view_transactions()
        elif choice == "3":
            category = input("Kategoria (lub ENTER aby pominąć): ").strip() or None
            start_date = input("Data początkowa (YYYY-MM-DD, lub ENTER aby pominąć): ").strip() or None
            end_date = input("Data końcowa (YYYY-MM-DD, lub ENTER aby pominąć): ").strip() or None
            filter_transactions(category, start_date, end_date)
        elif choice == "4":
            calculate_balance()
        elif choice == "5":
            show_statistics()
        elif choice == "6":
            print("Do widzenia!")
            break
        else:
            print("Nieprawidłowa opcja. Spróbuj ponownie.")

if __name__ == "__main__":
    main()