from models import User
from settings import settings
from fastapi import HTTPException, status, Request
import sqlite3
import jwt
import datetime
import security

connection = sqlite3.connect('database.db')
connection.row_factory = sqlite3.Row
cursor = connection.cursor()


def init() -> None:
    """Initializes the database."""

    # Create users table
    cursor.execute('''
    CREATE TABLE IF NOT EXISTS users (
        id INTEGER PRIMARY KEY,
        name TEXT NOT NULL UNIQUE,
        password TEXT NOT NULL
    )
    ''')

    # Create logs table
    cursor.execute('''
    CREATE TABLE IF NOT EXISTS logs (
        id INTEGER PRIMARY KEY,
        user_id INTEGER NOT NULL,
        calories DOUBLE NOT NULL,
        description TEXT,
        timestamp DATETIME DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (user_id) REFERENCES users (id)
    )
    ''')


def close() -> None:
    """Closes the database connection."""
    connection.close()


def register(user: User) -> None:
    """Registers a new user in the database."""
    cursor.execute(
        "INSERT INTO users (name, password) VALUES (?, ?)",
        (user.name,
         security.hash_password(user.password))
    connection.commit()


def get_user_by_token(request: Request) -> User:
    """Retrieves a user from the database using a JWT token."""
    token=request.headers.get("Authorization")
    if not token or not token.startswith("Bearer "):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Not authenticated"
        )
    token=token.split(" ")[1]
    payload=jwt.decode(
        token,
        key=settings.jwt_secret,
        algorithms=[
            settings.jwt_algorithm])

    connection=sqlite3.connect('database.db')
    connection.row_factory=sqlite3.Row
    cursor=connection.cursor()
    cursor.execute(
        "SELECT id, name, password FROM users WHERE id = ?", (payload["id"],))
    row=cursor.fetchone()
    connection.close()

    if not row:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Not authenticated"
        )

    return User(**row)


def login(user: User) -> str:
    """Logs in a user and returns a JWT token."""
    cursor.execute(
        "SELECT id, name, password FROM users WHERE name = ?", (user.name,))
    row=cursor.fetchone()

    if not row or not security.verify_password(user.password, row["password"]):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid credentials"
        )

    exp=datetime.datetime.now(
        datetime.timezone.utc) + datetime.timedelta(hours=1)
    payload={
        "id": row["id"],
        "exp": exp
    }

    return jwt.encode(
        payload=payload,
        key=settings.jwt_secret,
        algorithm=settings.jwt_algorithm)