#  Hydrogram - Telegram MTProto API Client Library for Python
#  Copyright (C) 2017-2023 Dan <https://github.com/delivrance>
#  Copyright (C) 2023-present Hydrogram <https://hydrogram.org>
#
#  This file is part of Hydrogram.
#
#  Hydrogram is free software: you can redistribute it and/or modify
#  it under the terms of the GNU Lesser General Public License as published
#  by the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  Hydrogram is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU Lesser General Public License for more details.
#
#  You should have received a copy of the GNU Lesser General Public License
#  along with Hydrogram.  If not, see <http://www.gnu.org/licenses/>.

from __future__ import annotations

import base64
import logging
import struct
import time
from pathlib import Path
from typing import Any

import aiosqlite

from hydrogram import raw, utils

from .base import BaseStorage, InputPeer

SCHEMA = """
CREATE TABLE sessions
(
    dc_id     INTEGER PRIMARY KEY,
    api_id    INTEGER,
    test_mode INTEGER,
    auth_key  BLOB,
    date      INTEGER NOT NULL,
    user_id   INTEGER,
    is_bot    INTEGER
);

CREATE TABLE peers
(
    id             INTEGER PRIMARY KEY,
    access_hash    INTEGER,
    type           INTEGER NOT NULL,
    username       TEXT,
    phone_number   TEXT,
    last_update_on INTEGER NOT NULL DEFAULT (CAST(STRFTIME('%s', 'now') AS INTEGER))
);

CREATE TABLE version
(
    number INTEGER PRIMARY KEY
);

CREATE INDEX idx_peers_id ON peers (id);
CREATE INDEX idx_peers_username ON peers (username);
CREATE INDEX idx_peers_phone_number ON peers (phone_number);

CREATE TRIGGER trg_peers_last_update_on
    AFTER UPDATE
    ON peers
BEGIN
    UPDATE peers
    SET last_update_on = CAST(STRFTIME('%s', 'now') AS INTEGER)
    WHERE id = NEW.id;
END;
"""


def get_input_peer(peer_id: int, access_hash: int, peer_type: str) -> InputPeer:
    if peer_type in {"user", "bot"}:
        return raw.types.InputPeerUser(user_id=peer_id, access_hash=access_hash)
    if peer_type == "group":
        return raw.types.InputPeerChat(chat_id=-peer_id)
    if peer_type in {"channel", "supergroup"}:
        return raw.types.InputPeerChannel(
            channel_id=utils.get_channel_id(peer_id), access_hash=access_hash
        )
    raise ValueError(f"Invalid peer type: {peer_type}")


class SQLiteStorage(BaseStorage):
    VERSION = 3
    USERNAME_TTL = 8 * 60 * 60
    FILE_EXTENSION = ".session"

    def __init__(
        self,
        name: str,
        workdir: Path | None = None,
        session_string: str | None = None,
        use_memory: bool = False,
    ):
        super().__init__(name)
        self.database: str | Path = (
            ":memory:"
            if use_memory
            else (workdir / (self.name + self.FILE_EXTENSION) if workdir else ":memory:")
        )
        self.session_string: str | None = session_string
        self.conn: aiosqlite.Connection | None = None

    async def update(self) -> None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return

        version: int | None = await self.version()

        if version == 1:
            await self.conn.execute("DELETE FROM peers")
            version += 1

        if version == 2:
            await self.conn.execute("ALTER TABLE sessions ADD api_id INTEGER")
            version += 1

        await self.version(version)
        await self.conn.commit()

    async def create(self) -> None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return

        await self.conn.executescript(SCHEMA)
        await self.conn.execute(
            "INSERT INTO version VALUES (?)",
            (self.VERSION,),
        )
        await self.conn.execute(
            "INSERT INTO sessions VALUES (?, ?, ?, ?, ?, ?, ?)",
            (2, None, None, None, 0, None, None),
        )
        await self.conn.commit()

    async def open(self) -> None:
        path = self.database
        file_exists = isinstance(path, Path) and path.is_file()

        self.conn = await aiosqlite.connect(self.database)

        await self.conn.execute("PRAGMA journal_mode=WAL")

        if file_exists:
            await self.update()
            await self.conn.execute("VACUUM")
        else:
            await self.create()

        await self.conn.commit()

        if self.session_string:
            await self._load_session_string()

    async def _load_session_string(self) -> None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return

        if self.session_string:
            dc_id, api_id, test_mode, auth_key, user_id, is_bot = struct.unpack(
                self.SESSION_STRING_FORMAT,
                base64.urlsafe_b64decode(
                    self.session_string + "=" * (-len(self.session_string) % 4)
                ),
            )

            await self.dc_id(dc_id)
            await self.api_id(api_id)
            await self.test_mode(test_mode)
            await self.auth_key(auth_key)
            await self.user_id(user_id)
            await self.is_bot(is_bot)
            await self.date(0)

    async def save(self) -> None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return

        await self.date(int(time.time()))
        await self.conn.commit()

    async def close(self) -> None:
        if self.conn:
            await self.conn.close()

    async def delete(self) -> None:
        if self.database != ":memory:":
            Path(self.database).unlink()

    async def update_peers(
        self, peers: list[tuple[int, int, str, str | None, str | None]]
    ) -> None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return

        await self.conn.executemany(
            "REPLACE INTO peers (id, access_hash, type, username, phone_number) "
            "VALUES (?, ?, ?, ?, ?)",
            peers,
        )
        await self.conn.commit()

    async def get_peer_by_id(self, peer_id: int) -> InputPeer | None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return None

        q = await self.conn.execute(
            "SELECT id, access_hash, type FROM peers WHERE id = ?", (peer_id,)
        )
        r = await q.fetchone()
        if not r:
            raise KeyError(f"ID not found: {peer_id}")

        return get_input_peer(*r)

    async def get_peer_by_username(self, username: str) -> InputPeer | None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return None

        q = await self.conn.execute(
            "SELECT id, access_hash, type, last_update_on "
            "FROM peers "
            "WHERE username = ? "
            "ORDER BY last_update_on DESC",
            (username,),
        )
        r = await q.fetchone()
        if not r:
            raise KeyError(f"Username not found: {username}")

        if abs(time.time() - r[3]) > self.USERNAME_TTL:
            raise KeyError(f"Username expired: {username}")

        return get_input_peer(*r[:3])

    async def get_peer_by_phone_number(self, phone_number: str) -> InputPeer | None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return None

        q = await self.conn.execute(
            "SELECT id, access_hash, type FROM peers WHERE phone_number = ?", (phone_number,)
        )
        r = await q.fetchone()
        if not r:
            raise KeyError(f"Phone number not found: {phone_number}")

        return get_input_peer(*r)

    async def _get(self, attr: str) -> Any:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return None

        q = await self.conn.execute(f"SELECT {attr} FROM sessions")
        row = await q.fetchone()
        return row[0] if row else None

    async def _set(self, attr: str, value: Any) -> None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return

        await self.conn.execute(f"UPDATE sessions SET {attr} = ?", (value,))
        await self.conn.commit()

    async def _accessor(self, attr: str, value: Any = object) -> Any | None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return None

        if value is object:
            return await self._get(attr)

        await self._set(attr, value)
        return None

    async def dc_id(self, value: int | object = object) -> int | None:
        return await self._accessor("dc_id", value)

    async def api_id(self, value: int | object = object) -> int | None:
        return await self._accessor("api_id", value)

    async def test_mode(self, value: bool | object = object) -> bool | None:
        return await self._accessor("test_mode", value)

    async def auth_key(self, value: bytes | object = object) -> bytes | None:
        return await self._accessor("auth_key", value)

    async def date(self, value: int | object = object) -> int | None:
        return await self._accessor("date", value)

    async def user_id(self, value: int | object = object) -> int | None:
        return await self._accessor("user_id", value)

    async def is_bot(self, value: bool | object = object) -> bool | None:
        return await self._accessor("is_bot", value)

    async def version(self, value: int | object = object) -> int | None:
        if not self.conn:
            logging.warning("Database connection is not available.")
            return None

        if value is object:
            q = await self.conn.execute("SELECT number FROM version")
            row = await q.fetchone()
            return row[0] if row else None

        await self.conn.execute("UPDATE version SET number = ?", (value,))
        await self.conn.commit()
        return None