import sqlite3
from .exceptions import UsernameTakenError


class Users:
    """A table of users, including admins.

    A user must register through the interface provided by JImbrella to be one
    of the users in this table. Those who borrow umbrellas via jForm are not
    stored here.

    Columns:
    - username      | identifier Unicode string. must be unique.
    - password      | salted and hashed password.
    - role          | one of ("admin", "user"). expect additions.
    - status        | one of ("normal", "denied"). expect additions.
    - language      | one of ("en-US", 'zh-CN").
    - realname      | (optional) legal name of user.
    - id            | (optional) student/faculty ID.
    - phone         | (optional) phone number.
    - email         | (optional) email address.

    Schema:
    CREATE TABLE Users(
        username TEXT PRIMARY KEY,
        password TEXT,
        role TEXT,
        status TEXT,
        language TEXT,
        realname TEXT,
        id TEXT,
        phone TEXT,
        email TEXT
    );
    """

    def __init__(self, path):
        self.path = path

    def register(self, username, password, language):
        """Create a new user.

        If username is already taken, raise UsernameTakenError.
        """
        db = sqlite3.connect(self.path)
        try:
            db.execute(
                "INSERT INTO Users (username, password, role, status, language) "
                + "VALUES (?, ?, ?, ?, ?)",
                (username, password, "user", "normal", "en-US"),
            )
        except sqlite3.IntegrityError:
            raise UsernameTakenError(username)

        db.commit()
        db.close()

    def find(self, username) -> dict:
        """Find a user and return it in its `dict` structure. If user is not found, return None."""
        db = sqlite3.connect(self.path)
        db.row_factory = sqlite3.Row

        user = db.execute(
            "SELECT * FROM Users WHERE username = ?", (username,)
        ).fetchone()
        return user