from __future__ import annotations

import hashlib
import hmac
import secrets
import sqlite3
import time
from pathlib import Path


class UserStore:
    def __init__(self, db_path: str) -> None:
        self._db_path = db_path
        p = Path(db_path)
        if p.parent and not p.parent.exists():
            p.parent.mkdir(parents=True, exist_ok=True)
        self._init_db()

    def _conn(self) -> sqlite3.Connection:
        c = sqlite3.connect(self._db_path)
        c.row_factory = sqlite3.Row
        return c

    def _init_db(self) -> None:
        with self._conn() as c:
            self._ensure_users_table(c)
            self._ensure_sessions_table(c)
            c.execute(
                """
                CREATE TABLE IF NOT EXISTS wechat_bindings (
                    user_id INTEGER PRIMARY KEY,
                    appid TEXT NOT NULL,
                    secret TEXT NOT NULL,
                    author TEXT NOT NULL DEFAULT '',
                    thumb_media_id TEXT NOT NULL DEFAULT '',
                    thumb_image_path TEXT NOT NULL DEFAULT '',
                    updated_at INTEGER NOT NULL,
                    FOREIGN KEY(user_id) REFERENCES users(id)
                )
                """
            )
            c.execute(
                """
                CREATE TABLE IF NOT EXISTS wechat_accounts (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    user_id INTEGER NOT NULL,
                    account_name TEXT NOT NULL,
                    appid TEXT NOT NULL,
                    secret TEXT NOT NULL,
                    author TEXT NOT NULL DEFAULT '',
                    thumb_media_id TEXT NOT NULL DEFAULT '',
                    thumb_image_path TEXT NOT NULL DEFAULT '',
                    updated_at INTEGER NOT NULL,
                    UNIQUE(user_id, account_name),
                    FOREIGN KEY(user_id) REFERENCES users(id)
                )
                """
            )
            c.execute(
                """
                CREATE TABLE IF NOT EXISTS user_prefs (
                    user_id INTEGER PRIMARY KEY,
                    active_wechat_account_id INTEGER,
                    updated_at INTEGER NOT NULL,
                    FOREIGN KEY(user_id) REFERENCES users(id)
                )
                """
            )
            # 兼容历史单绑定结构，自动迁移为默认账号
            rows = c.execute(
                "SELECT user_id, appid, secret, author, thumb_media_id, thumb_image_path, updated_at FROM wechat_bindings"
            ).fetchall()
            for r in rows:
                now = int(time.time())
                cur = c.execute(
                    """
                    INSERT OR IGNORE INTO wechat_accounts
                    (user_id, account_name, appid, secret, author, thumb_media_id, thumb_image_path, updated_at)
                    VALUES (?, '默认公众号', ?, ?, ?, ?, ?, ?)
                    """,
                    (
                        int(r["user_id"]),
                        r["appid"] or "",
                        r["secret"] or "",
                        r["author"] or "",
                        r["thumb_media_id"] or "",
                        r["thumb_image_path"] or "",
                        int(r["updated_at"] or now),
                    ),
                )
                if cur.rowcount:
                    aid = int(
                        c.execute(
                            "SELECT id FROM wechat_accounts WHERE user_id=? AND account_name='默认公众号'",
                            (int(r["user_id"]),),
                        ).fetchone()["id"]
                    )
                    c.execute(
                        """
                        INSERT INTO user_prefs(user_id, active_wechat_account_id, updated_at)
                        VALUES (?, ?, ?)
                        ON CONFLICT(user_id) DO UPDATE SET
                            active_wechat_account_id=COALESCE(user_prefs.active_wechat_account_id, excluded.active_wechat_account_id),
                            updated_at=excluded.updated_at
                        """,
                        (int(r["user_id"]), aid, now),
                    )

    def _table_columns(self, c: sqlite3.Connection, table_name: str) -> set[str]:
        rows = c.execute(f"PRAGMA table_info({table_name})").fetchall()
        return {str(r["name"]) for r in rows}

    def _ensure_users_table(self, c: sqlite3.Connection) -> None:
        required = {"id", "username", "password_hash", "password_salt", "created_at"}
        c.execute(
            """
            CREATE TABLE IF NOT EXISTS users (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                username TEXT NOT NULL UNIQUE,
                password_hash TEXT NOT NULL,
                password_salt TEXT NOT NULL,
                created_at INTEGER NOT NULL
            )
            """
        )
        cols = self._table_columns(c, "users")
        if required.issubset(cols):
            return

        now = int(time.time())
        c.execute("PRAGMA foreign_keys=OFF")
        c.execute("DROP TABLE IF EXISTS users_new")
        c.execute(
            """
            CREATE TABLE users_new (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                username TEXT NOT NULL UNIQUE,
                password_hash TEXT NOT NULL,
                password_salt TEXT NOT NULL,
                created_at INTEGER NOT NULL
            )
            """
        )

        if {"username", "password_hash", "password_salt"}.issubset(cols):
            if "created_at" in cols:
                c.execute(
                    """
                    INSERT OR IGNORE INTO users_new(id, username, password_hash, password_salt, created_at)
                    SELECT id, username, password_hash, password_salt, COALESCE(created_at, ?)
                    FROM users
                    """,
                    (now,),
                )
            else:
                c.execute(
                    """
                    INSERT OR IGNORE INTO users_new(id, username, password_hash, password_salt, created_at)
                    SELECT id, username, password_hash, password_salt, ?
                    FROM users
                    """,
                    (now,),
                )
        elif {"username", "password"}.issubset(cols):
            if "created_at" in cols:
                rows = c.execute("SELECT id, username, password, created_at FROM users").fetchall()
            else:
                rows = c.execute("SELECT id, username, password FROM users").fetchall()
            for r in rows:
                username = (r["username"] or "").strip()
                raw_pwd = str(r["password"] or "")
                if not username or not raw_pwd:
                    continue
                salt = secrets.token_hex(16)
                pwd_hash = self._hash_password(raw_pwd, salt)
                created_at = int(r["created_at"]) if "created_at" in r.keys() and r["created_at"] else now
                c.execute(
                    """
                    INSERT OR IGNORE INTO users_new(id, username, password_hash, password_salt, created_at)
                    VALUES (?, ?, ?, ?, ?)
                    """,
                    (int(r["id"]), username, pwd_hash, salt, created_at),
                )

        c.execute("DROP TABLE users")
        c.execute("ALTER TABLE users_new RENAME TO users")
        c.execute("PRAGMA foreign_keys=ON")

    def _ensure_sessions_table(self, c: sqlite3.Connection) -> None:
        required = {"token_hash", "user_id", "expires_at", "created_at"}
        c.execute(
            """
            CREATE TABLE IF NOT EXISTS sessions (
                token_hash TEXT PRIMARY KEY,
                user_id INTEGER NOT NULL,
                expires_at INTEGER NOT NULL,
                created_at INTEGER NOT NULL,
                FOREIGN KEY(user_id) REFERENCES users(id)
            )
            """
        )
        cols = self._table_columns(c, "sessions")
        if required.issubset(cols):
            return
        c.execute("DROP TABLE IF EXISTS sessions")
        c.execute(
            """
            CREATE TABLE sessions (
                token_hash TEXT PRIMARY KEY,
                user_id INTEGER NOT NULL,
                expires_at INTEGER NOT NULL,
                created_at INTEGER NOT NULL,
                FOREIGN KEY(user_id) REFERENCES users(id)
            )
            """
        )

    def _hash_password(self, password: str, salt: str) -> str:
        data = hashlib.pbkdf2_hmac("sha256", password.encode("utf-8"), salt.encode("utf-8"), 120_000)
        return data.hex()

    def _hash_token(self, token: str) -> str:
        return hashlib.sha256(token.encode("utf-8")).hexdigest()

    def create_user(self, username: str, password: str) -> dict | None:
        now = int(time.time())
        salt = secrets.token_hex(16)
        pwd_hash = self._hash_password(password, salt)
        try:
            with self._conn() as c:
                cur = c.execute(
                    "INSERT INTO users(username, password_hash, password_salt, created_at) VALUES (?, ?, ?, ?)",
                    (username, pwd_hash, salt, now),
                )
                uid = int(cur.lastrowid)
                return {"id": uid, "username": username}
        except sqlite3.IntegrityError:
            return None
        except sqlite3.Error as exc:
            raise RuntimeError(f"create_user_db_error: {exc}") from exc

    def verify_user(self, username: str, password: str) -> dict | None:
        try:
            with self._conn() as c:
                row = c.execute(
                    "SELECT id, username, password_hash, password_salt FROM users WHERE username=?",
                    (username,),
                ).fetchone()
        except sqlite3.Error as exc:
            raise RuntimeError(f"verify_user_db_error: {exc}") from exc
        if not row:
            return None
        calc = self._hash_password(password, row["password_salt"])
        if not hmac.compare_digest(calc, row["password_hash"]):
            return None
        return {"id": int(row["id"]), "username": row["username"]}

    def change_password(self, user_id: int, old_password: str, new_password: str) -> bool:
        with self._conn() as c:
            row = c.execute(
                "SELECT password_hash, password_salt FROM users WHERE id=?",
                (user_id,),
            ).fetchone()
            if not row:
                return False
            calc_old = self._hash_password(old_password, row["password_salt"])
            if not hmac.compare_digest(calc_old, row["password_hash"]):
                return False
            new_salt = secrets.token_hex(16)
            new_hash = self._hash_password(new_password, new_salt)
            c.execute(
                "UPDATE users SET password_hash=?, password_salt=? WHERE id=?",
                (new_hash, new_salt, user_id),
            )
            return True

    def reset_password_by_username(self, username: str, new_password: str) -> bool:
        uname = (username or "").strip()
        if not uname:
            return False
        with self._conn() as c:
            row = c.execute("SELECT id FROM users WHERE username=?", (uname,)).fetchone()
            if not row:
                return False
            new_salt = secrets.token_hex(16)
            new_hash = self._hash_password(new_password, new_salt)
            c.execute(
                "UPDATE users SET password_hash=?, password_salt=? WHERE id=?",
                (new_hash, new_salt, int(row["id"])),
            )
            return True

    def create_session(self, user_id: int, ttl_seconds: int = 7 * 24 * 3600) -> str:
        token = secrets.token_urlsafe(32)
        token_hash = self._hash_token(token)
        now = int(time.time())
        exp = now + max(600, int(ttl_seconds))
        with self._conn() as c:
            c.execute(
                "INSERT OR REPLACE INTO sessions(token_hash, user_id, expires_at, created_at) VALUES (?, ?, ?, ?)",
                (token_hash, user_id, exp, now),
            )
        return token

    def delete_session(self, token: str) -> None:
        if not token:
            return
        with self._conn() as c:
            c.execute("DELETE FROM sessions WHERE token_hash=?", (self._hash_token(token),))

    def delete_sessions_by_user(self, user_id: int) -> None:
        with self._conn() as c:
            c.execute("DELETE FROM sessions WHERE user_id=?", (user_id,))

    def get_user_by_session(self, token: str) -> dict | None:
        if not token:
            return None
        now = int(time.time())
        th = self._hash_token(token)
        with self._conn() as c:
            c.execute("DELETE FROM sessions WHERE expires_at < ?", (now,))
            row = c.execute(
                """
                SELECT u.id, u.username
                FROM sessions s
                JOIN users u ON u.id=s.user_id
                WHERE s.token_hash=? AND s.expires_at>=?
                """,
                (th, now),
            ).fetchone()
        if not row:
            return None
        return {"id": int(row["id"]), "username": row["username"]}

    def save_wechat_binding(
        self,
        user_id: int,
        appid: str,
        secret: str,
        author: str = "",
        thumb_media_id: str = "",
        thumb_image_path: str = "",
    ) -> None:
        now = int(time.time())
        with self._conn() as c:
            c.execute(
                """
                INSERT INTO wechat_bindings(user_id, appid, secret, author, thumb_media_id, thumb_image_path, updated_at)
                VALUES (?, ?, ?, ?, ?, ?, ?)
                ON CONFLICT(user_id) DO UPDATE SET
                    appid=excluded.appid,
                    secret=excluded.secret,
                    author=excluded.author,
                    thumb_media_id=excluded.thumb_media_id,
                    thumb_image_path=excluded.thumb_image_path,
                    updated_at=excluded.updated_at
                """,
                (user_id, appid, secret, author, thumb_media_id, thumb_image_path, now),
            )

    def get_wechat_binding(self, user_id: int) -> dict | None:
        return self.get_active_wechat_binding(user_id)

    def list_wechat_bindings(self, user_id: int) -> list[dict]:
        with self._conn() as c:
            rows = c.execute(
                """
                SELECT id, account_name, appid, author, thumb_media_id, thumb_image_path, updated_at
                FROM wechat_accounts
                WHERE user_id=?
                ORDER BY updated_at DESC, id DESC
                """,
                (user_id,),
            ).fetchall()
            pref = c.execute(
                "SELECT active_wechat_account_id FROM user_prefs WHERE user_id=?",
                (user_id,),
            ).fetchone()
        active_id = int(pref["active_wechat_account_id"]) if pref and pref["active_wechat_account_id"] else None
        out: list[dict] = []
        for r in rows:
            out.append(
                {
                    "id": int(r["id"]),
                    "account_name": r["account_name"] or "",
                    "appid": r["appid"] or "",
                    "author": r["author"] or "",
                    "thumb_media_id": r["thumb_media_id"] or "",
                    "thumb_image_path": r["thumb_image_path"] or "",
                    "updated_at": int(r["updated_at"] or 0),
                    "active": int(r["id"]) == active_id,
                }
            )
        return out

    def add_wechat_binding(
        self,
        user_id: int,
        account_name: str,
        appid: str,
        secret: str,
        author: str = "",
        thumb_media_id: str = "",
        thumb_image_path: str = "",
    ) -> dict:
        now = int(time.time())
        name = account_name.strip() or f"公众号{now % 10000}"
        with self._conn() as c:
            try:
                cur = c.execute(
                    """
                    INSERT INTO wechat_accounts
                    (user_id, account_name, appid, secret, author, thumb_media_id, thumb_image_path, updated_at)
                    VALUES (?, ?, ?, ?, ?, ?, ?, ?)
                    """,
                    (user_id, name, appid, secret, author, thumb_media_id, thumb_image_path, now),
                )
            except sqlite3.IntegrityError:
                name = f"{name}-{now % 1000}"
                cur = c.execute(
                    """
                    INSERT INTO wechat_accounts
                    (user_id, account_name, appid, secret, author, thumb_media_id, thumb_image_path, updated_at)
                    VALUES (?, ?, ?, ?, ?, ?, ?, ?)
                    """,
                    (user_id, name, appid, secret, author, thumb_media_id, thumb_image_path, now),
                )
            aid = int(cur.lastrowid)
            c.execute(
                """
                INSERT INTO user_prefs(user_id, active_wechat_account_id, updated_at)
                VALUES (?, ?, ?)
                ON CONFLICT(user_id) DO UPDATE SET
                    active_wechat_account_id=excluded.active_wechat_account_id,
                    updated_at=excluded.updated_at
                """,
                (user_id, aid, now),
            )
        return {"id": aid, "account_name": name}

    def switch_active_wechat_binding(self, user_id: int, account_id: int) -> bool:
        now = int(time.time())
        with self._conn() as c:
            row = c.execute(
                "SELECT id FROM wechat_accounts WHERE id=? AND user_id=?",
                (account_id, user_id),
            ).fetchone()
            if not row:
                return False
            c.execute(
                """
                INSERT INTO user_prefs(user_id, active_wechat_account_id, updated_at)
                VALUES (?, ?, ?)
                ON CONFLICT(user_id) DO UPDATE SET
                    active_wechat_account_id=excluded.active_wechat_account_id,
                    updated_at=excluded.updated_at
                """,
                (user_id, account_id, now),
            )
        return True

    def get_active_wechat_binding(self, user_id: int) -> dict | None:
        with self._conn() as c:
            pref = c.execute(
                "SELECT active_wechat_account_id FROM user_prefs WHERE user_id=?",
                (user_id,),
            ).fetchone()
            aid = int(pref["active_wechat_account_id"]) if pref and pref["active_wechat_account_id"] else None
            row = None
            if aid:
                row = c.execute(
                    """
                    SELECT id, account_name, appid, secret, author, thumb_media_id, thumb_image_path, updated_at
                    FROM wechat_accounts
                    WHERE id=? AND user_id=?
                    """,
                    (aid, user_id),
                ).fetchone()
            if not row:
                row = c.execute(
                    """
                    SELECT id, account_name, appid, secret, author, thumb_media_id, thumb_image_path, updated_at
                    FROM wechat_accounts
                    WHERE user_id=?
                    ORDER BY updated_at DESC, id DESC
                    LIMIT 1
                    """,
                    (user_id,),
                ).fetchone()
                if row:
                    c.execute(
                        """
                        INSERT INTO user_prefs(user_id, active_wechat_account_id, updated_at)
                        VALUES (?, ?, ?)
                        ON CONFLICT(user_id) DO UPDATE SET
                            active_wechat_account_id=excluded.active_wechat_account_id,
                            updated_at=excluded.updated_at
                        """,
                        (user_id, int(row["id"]), int(time.time())),
                    )
        if not row:
            return None
        return {
            "id": int(row["id"]),
            "account_name": row["account_name"] or "",
            "appid": row["appid"] or "",
            "secret": row["secret"] or "",
            "author": row["author"] or "",
            "thumb_media_id": row["thumb_media_id"] or "",
            "thumb_image_path": row["thumb_image_path"] or "",
            "updated_at": int(row["updated_at"] or 0),
        }