from flask_sqlalchemy import SQLAlchemy
from flask import g
import os
import sqlite3

def get_db():
    db = getattr(g, '_database', None)
    if db is None:
        db = g._database = sqlite3.connect(os.path.join(os.path.dirname(__file__), 'db.sqlite3'))
    return db

def create_leaderboard_table():
    db = get_db()
    cursor = db.cursor()
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS leaderboard (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            username TEXT,
            problem_id INTEGER,
            runtime REAL,
            memory_used INTEGER,
            line_number INTEGER,
            timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
        )
    ''')
    db.commit()

def log_leaderboard(username, problem_id, runtime, memory_used, line_number):
    db = get_db()
    cursor = db.cursor()
    cursor.execute('''
        INSERT INTO leaderboard (username, problem_id, runtime, memory_used, line_number)
        VALUES (?, ?, ?, ?, ?)
    ''', (username, problem_id, runtime, memory_used, line_number))
    db.commit()

def get_leaderboard():
    db = get_db()
    cursor = db.cursor()
    cursor.execute('''
        SELECT username, problem_id, runtime, memory_used, line_number, timestamp
        FROM leaderboard
        ORDER BY runtime ASC, memory_used ASC
        LIMIT 20
    ''')
    return cursor.fetchall()