import sqlite3
import os

def connect_db():
    db_file = 'time_tracker.db'
    if not os.path.exists(db_file):
        print(f"Error: Database file '{db_file}' not found.")
        return None
    return sqlite3.connect(db_file)

def display_entry_details(entry):
    print("\n--- Current Entry Details ---")
    print(f"ID: {entry[0]} | Project: {entry[1]} | Date: {entry[4]}")
    print(f"Description: {entry[2]}")
    print(f"Hours: {entry[5]}")
    print("-" * 30)

def edit_time_entry():
    conn = connect_db()
    if not conn: return
    cursor = conn.cursor()

    try:
        # 1. Select Client
        cursor.execute('SELECT client_id, client_name FROM clients ORDER BY client_name')
        clients = cursor.fetchall()
        
        print("\n--- Select Client to Edit Time ---")
        for cid, name in clients:
            print(f"{cid}: {name}")
        
        client_id = input("\nEnter Client ID (or 0 to go back): ")
        if client_id == '0' or not client_id: return

        while True:
            # 2. List Uninvoiced Entries for Client
            cursor.execute('''SELECT entry_id, project, description, invoiced, date, hours 
                            FROM time_tracking WHERE client_id = ? AND invoiced = 0 
                            ORDER BY date DESC''', (client_id,))
            entries = cursor.fetchall()

            if not entries:
                print("No uninvoiced entries found for this client.")
                break

            print(f"\n--- Time Entries for Client {client_id} ---")
            for e in entries:
                print(f"ID {e[0]}: [{e[4]}] {e[1]} - {e[5]} hrs")
            print("0: Back to Main Menu")

            entry_choice = input("\nSelect Entry ID to edit: ")
            if entry_choice == '0': break

            # Find the specific entry
            selected_entry = next((e for e in entries if str(e[0]) == entry_choice), None)
            if not selected_entry:
                print("Invalid Entry ID.")
                continue

            # 3. Edit Fields one by one
            display_entry_details(selected_entry)
            
            # Project
            new_project = input(f"Project [{selected_entry[1]}]: ") or selected_entry[1]
            # Description
            new_desc = input(f"Description [{selected_entry[2]}]: ") or selected_entry[2]
            # Date
            new_date = input(f"Date [{selected_entry[4]}]: ") or selected_entry[4]
            # Hours
            new_hours_raw = input(f"Hours [{selected_entry[5]}]: ")
            new_hours = float(new_hours_raw) if new_hours_raw else selected_entry[5]

            # 4. Update Database
            cursor.execute('''UPDATE time_tracking 
                            SET project = ?, description = ?, date = ?, hours = ? 
                            WHERE entry_id = ?''', 
                            (new_project, new_desc, new_date, new_hours, entry_choice))
            conn.commit()

            print("\nUpdate Successful! New Values:")
            print(f"Project: {new_project}\nDescription: {new_desc}\nDate: {new_date}\nHours: {new_hours}")
            print("="*30)

    except Exception as e:
        print(f"An error occurred: {e}")
    finally:
        conn.close()

if __name__ == "__main__":
    edit_time_entry()