import sqlite3
from os import urandom
from hashlib import sha256

def init_db(path: str) -> None:
    with sqlite3.connect(path) as connection:
        cursor = connection.cursor()
        cursor.execute('''
            CREATE TABLE IF NOT EXISTS Tokens (
                TKHASH TEXT PRIMARY KEY NOT NULL,
                USERID INTEGER NOT NULL,
                NAME TEXT NOT NULL
            )
        ''')

        cursor.execute('''
            CREATE TABLE IF NOT EXISTS Domains (
                DOMAIN TEXT PRIMARY KEY NOT NULL,
                USERID INTEGER NOT NULL
            )
        ''')

        cursor.execute('''
            CREATE TABLE IF NOT EXISTS Users (
                USERID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
                USERNAME TEXT NOT NULL UNIQUE,
                PWHASH TEXT NOT NULL,
                PWSALT TEXT NOT NULL,
                EMAIL TEXT
                IS_ADMIN INTEGER NOT NULL DEFAULT 0
            )
        ''')

        connection.commit()
        cursor.close()

def check_token_domain(db_path: str, token: str, domain: str) -> bool:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        token_hash = sha256(token.encode('utf-8')).hexdigest()

        cursor.execute('''
            SELECT COUNT(*) FROM Tokens
            JOIN Domains ON Tokens.userid = Domains.userid
            WHERE tkhash = ?
                AND domain = ?
        ''', (token_hash, domain))

    return cursor.fetchone()[0] == 1

def user_login(db_path: str, username: str, password: str) -> int | None:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT pwsalt FROM Users
            WHERE username = ?
        ''', (username,))

        password_salt = cursor.fetchone()
        if password_salt is None:
            return None
        password_salt = password_salt[0]

        password_hash = sha256( (password_salt + password).encode('utf-8') ).hexdigest()

        cursor.execute('''
            SELECT userid FROM Users
            WHERE username = ?
                AND pwhash = ?
        ''', (username, password_hash))

        result = cursor.fetchone()
        if result is None:
            return None

        return result[0]

def get_username(db_path: str, userid: int) -> str | None:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT username FROM Users
            WHERE userid = ?
        ''', (userid, ))

        username = cursor.fetchone()
        if username is None:
            return None

        return username[0]

def get_user_domains(db_path: str, userid: int) -> list[str]:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT domain FROM Domains
            WHERE userid = ?
        ''', (userid, ))

        domains = cursor.fetchall()

        domains = map(lambda x: x[0], domains)

        return domains

def get_user_tokens(db_path: str, userid: int) -> list[str]:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT name FROM Tokens
            WHERE userid = ?
        ''', (userid, ))

        tokens = cursor.fetchall()

        tokens = map(lambda x: x[0], tokens)

        return tokens

def generate_user_token(db_path: str, userid: int, token_name: str) -> str | None:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT COUNT(*) FROM Users
            WHERE userid = ?
        ''', (userid, ))

        if cursor.fetchone()[0] != 1:
            return None

        cursor.execute('''
            SELECT COUNT(*) FROM Tokens
            WHERE userid = ?
        ''', (userid, ))

        if cursor.fetchone()[0] >= 5:
            return None

        cursor.execute('''
            SELECT COUNT(*) FROM Tokens
            WHERE userid = ?
                AND name = ?
        ''', (userid, token_name))

        if cursor.fetchone()[0] != 0:
            return None

        if not token_name.isalnum():
            return None

        if len(token_name) >= 16:
            return None

        for _ in range(10):
            try:
                token = urandom(32).hex()
                token_hash = sha256(token.encode("utf-8")).hexdigest()

                cursor.execute('''
                    INSERT INTO Tokens (tkhash, userid, name) VALUES (?, ?, ?)
                ''', (token_hash, userid, token_name))

                return token
            except sqlite3.IntegrityError:
                pass

        return None


def revoke_user_token(db_path: str, userid: int, token_name: str) -> None:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            DELETE FROM Tokens
            WHERE userid = ?
                AND name = ?
        ''', (userid, token_name))

def change_user_password(db_path: str, userid: int, oldpass: str, newpass: str) -> bool:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT COUNT(*) FROM Users
            WHERE userid = ?
        ''', (userid, ))

        if cursor.fetchone()[0] != 1:
            return False

        cursor.execute('''
            SELECT pwsalt FROM Users
            WHERE userid = ?
        ''', (userid, ))

        salt = cursor.fetchone()
        if salt is None:
            return False
        salt = salt[0]


        oldpass_hash = sha256( (salt + oldpass).encode('utf-8')).hexdigest()

        cursor.execute('''
            SELECT COUNT(*) FROM Users
            WHERE userid = ?
                AND pwhash = ?
        ''', (userid, oldpass_hash))

        if cursor.fetchone()[0] != 1:
            return False

    return set_user_password(db_path, userid, newpass)

def set_user_password(db_path: str, userid: int, newpass: str) -> bool:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT COUNT(*) FROM Users
            WHERE userid = ?
        ''', (userid, ))

        if cursor.fetchone()[0] != 1:
            return False

        salt = urandom(16).hex()
        newpass_hash = sha256( (salt + newpass).encode('utf-8')).hexdigest()

        cursor.execute('''
            UPDATE Users
            SET
                pwsalt = ?,
                pwhash = ?
            WHERE userid = ?
        ''', (salt, newpass_hash, userid))

        return True

def is_admin(db_path: str, userid: int) -> bool:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT COUNT(*) FROM Users
            WHERE userid = ?
                AND IS_ADMIN = 1
        ''', (userid, ))

        return cursor.fetchone()[0] == 1

def get_users(db_path: str) -> dict:
    with sqlite3.connect(db_path) as connection:
        cursor = connection.cursor()

        cursor.execute('''
            SELECT userid, username, is_admin FROM Users
        ''')

        users = cursor.fetchall()

        users = list(map(lambda x: {"userid": x[0], "username": x[1], "domains": [], "is_admin": bool(x[2])}, users))

        for user in users:
            cursor.execute('''
                SELECT domain FROM Domains
                WHERE userid = ?
            ''', (user["userid"], ))

            domains = cursor.fetchall()

            domains = list(map(lambda x: x[0], domains))

            user['domains'] = domains

        return users