# Copyright (c) 2025-2026 马建军. All rights reserved.
# 专有软件 — 未经授权禁止复制、传播、转售。
# 严禁用于：带单/代客理财、向他人推荐期货品种或买卖建议、融资配资等业务。
# 详见 LICENSE.zh-CN.txt 与 docs/软件购买与使用协议.md

"""数据库连接：SQLite futures.db。"""
from __future__ import annotations

import sqlite3
import time
from typing import Any, Sequence

from modules.core.paths import DB_PATH as _ROOT_DB_PATH, KLINE_DB_PATH as _KLINE_DB_PATH

DB_PATH = _ROOT_DB_PATH
KLINE_DB_PATH = _KLINE_DB_PATH

OperationalError = sqlite3.OperationalError
IntegrityError = sqlite3.IntegrityError


def db_backend() -> str:
    return "sqlite"


def is_postgres() -> bool:
    return False


def database_label() -> str:
    return f"SQLite ({DB_PATH})"


def adapt_sql(sql: str) -> str:
    return sql


def is_benign_migration_error(exc: BaseException) -> bool:
    """ALTER TABLE 重复列等初始化迁移可忽略的错误。"""
    return is_schema_migration_error(exc)


def is_schema_migration_error(exc: BaseException) -> bool:
    """init_db 增量迁移：缺表/缺列/重复列均可忽略。"""
    msg = str(exc).lower()
    if any(
        x in msg
        for x in (
            "duplicate column",
            "already exists",
            "duplicate key",
            "no such table",
            "does not exist",
        )
    ):
        return True
    if isinstance(exc, sqlite3.OperationalError) and (
        "duplicate column" in msg or "no such table" in msg
    ):
        return True
    return False


def is_missing_relation_error(exc: BaseException) -> bool:
    """表/视图不存在。"""
    if is_schema_migration_error(exc):
        msg = str(exc).lower()
        return any(x in msg for x in ("no such table", "does not exist"))
    return False


def rollback_if_postgres(conn: "DbConnection") -> None:
    """兼容旧调用；当前仅使用 SQLite。"""
    return


class DbCursor:
    """统一 cursor：兼容 sqlite3 的 execute / fetchone / lastrowid。"""

    def __init__(self, raw_cursor: Any, raw_conn: Any) -> None:
        self._cur = raw_cursor
        self._conn = raw_conn
        self.lastrowid: int | None = None
        self.rowcount: int = 0

    def execute(self, sql: str, params: Sequence[Any] | None = None) -> "DbCursor":
        params = params or ()
        self._cur.execute(sql, params)
        self.rowcount = int(getattr(self._cur, "rowcount", 0) or 0)
        self.lastrowid = getattr(self._cur, "lastrowid", None)
        return self

    def fetchone(self) -> Any:
        return self._cur.fetchone()

    def fetchall(self) -> list[Any]:
        return self._cur.fetchall()

    def close(self) -> None:
        try:
            self._cur.close()
        except Exception:
            pass


class DbConnection:
    """统一连接：execute / commit / close，接口对齐 sqlite3.Connection。"""

    def __init__(self, raw_conn: Any) -> None:
        self._conn = raw_conn
        self.row_factory = None

    def execute(self, sql: str, params: Sequence[Any] | None = None) -> DbCursor:
        cur = self.cursor()
        try:
            return cur.execute(sql, params)
        except Exception:
            raise

    def cursor(self) -> DbCursor:
        return DbCursor(self._conn.cursor(), self._conn)

    def commit(self) -> None:
        self._conn.commit()

    def rollback(self) -> None:
        self._conn.rollback()

    def close(self) -> None:
        try:
            self._conn.close()
        except Exception:
            pass

    def __enter__(self) -> "DbConnection":
        return self

    def __exit__(self, exc_type, exc, tb) -> None:
        if exc:
            try:
                self.rollback()
            except Exception:
                pass
        else:
            try:
                self.commit()
            except Exception:
                pass
        self.close()


def connect_db(path: str | None = None) -> DbConnection:
    """获取 SQLite 数据库连接（用毕 close）。"""
    db_path = path or DB_PATH
    raw = sqlite3.connect(db_path, timeout=30, check_same_thread=False)
    raw.row_factory = sqlite3.Row
    raw.execute("PRAGMA busy_timeout=30000")
    try:
        raw.execute("PRAGMA journal_mode=WAL")
    except sqlite3.OperationalError:
        pass
    return DbConnection(raw)


def close_pg_pool() -> None:
    """兼容旧调用。"""
    return


def execute_retry(
    conn: DbConnection,
    sql: str,
    params: tuple = (),
    *,
    retries: int = 6,
    base_delay: float = 0.05,
) -> DbCursor:
    """遇锁冲突时短暂退避重试（SQLite locked）。"""
    last_exc: Exception | None = None
    for attempt in range(retries):
        try:
            return conn.execute(sql, params)
        except OperationalError as exc:
            msg = str(exc).lower()
            if "locked" not in msg:
                raise
            last_exc = exc
            if attempt < retries - 1:
                time.sleep(base_delay * (attempt + 1))
    if last_exc:
        raise last_exc
    raise OperationalError("database is locked")


def commit_retry(
    conn: DbConnection,
    *,
    retries: int = 6,
    base_delay: float = 0.05,
) -> None:
    """遇锁冲突时短暂退避重试 commit。"""
    last_exc: Exception | None = None
    for attempt in range(retries):
        try:
            conn.commit()
            return
        except OperationalError as exc:
            msg = str(exc).lower()
            if "locked" not in msg:
                raise
            last_exc = exc
            if attempt < retries - 1:
                time.sleep(base_delay * (attempt + 1))
    if last_exc:
        raise last_exc
    raise OperationalError("database is locked")


def is_db_contention_error(exc: BaseException) -> bool:
    """SQLite locked。"""
    if isinstance(exc, sqlite3.OperationalError):
        return "locked" in str(exc).lower()
    return False


def reset_backend_for_tests(backend: str | None = None) -> None:
    """兼容旧测试调用。"""
    return