#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
把本地 SQLite 聊天记录迁移到 MySQL:
  source: db/chat_log_db/chats.db -> table chat_logs

用法示例:
  python scripts/migrate_chat_logs_to_mysql.py --host xinhui.cloud --port 3306 \
    --user ai_cs_user --password xxx --database ai_cs --batch-size 2000 --truncate-target
"""

from __future__ import annotations

import argparse
import os
import sqlite3
import time
from pathlib import Path

import pymysql


def ensure_mysql_table(conn):
    with conn.cursor() as cur:
        cur.execute(
            """
            CREATE TABLE IF NOT EXISTS chat_logs (
                id            INTEGER PRIMARY KEY AUTO_INCREMENT,
                customer_id   VARCHAR(128) NOT NULL,
                customer_name VARCHAR(255) DEFAULT '',
                acc_id        VARCHAR(128) DEFAULT '',
                platform      VARCHAR(64) DEFAULT '',
                direction     VARCHAR(8) NOT NULL,
                message       TEXT NOT NULL,
                msg_type      INTEGER DEFAULT 0,
                timestamp     DATETIME NOT NULL
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
            """
        )
        cur.execute("SHOW INDEX FROM chat_logs")
        exists = {str(r.get("Key_name", "")) for r in cur.fetchall()}
        if "idx_customer" not in exists:
            cur.execute("CREATE INDEX idx_customer ON chat_logs(customer_id)")
        if "idx_ts" not in exists:
            cur.execute("CREATE INDEX idx_ts ON chat_logs(timestamp)")
        if "idx_acc" not in exists:
            cur.execute("CREATE INDEX idx_acc ON chat_logs(acc_id)")
    conn.commit()


def get_sqlite_conn(path: Path):
    conn = sqlite3.connect(str(path))
    conn.row_factory = sqlite3.Row
    return conn


def get_mysql_conn(host: str, port: int, user: str, password: str, database: str):
    return pymysql.connect(
        host=host,
        port=port,
        user=user,
        password=password,
        database=database,
        charset="utf8mb4",
        autocommit=False,
        cursorclass=pymysql.cursors.DictCursor,
    )


def migrate(sqlite_path: Path, host: str, port: int, user: str, password: str, database: str, batch_size: int, truncate_target: bool):
    if not sqlite_path.exists():
        raise FileNotFoundError(f"SQLite 文件不存在: {sqlite_path}")

    s_conn = get_sqlite_conn(sqlite_path)
    m_conn = get_mysql_conn(host, port, user, password, database)
    try:
        ensure_mysql_table(m_conn)
        if truncate_target:
            with m_conn.cursor() as cur:
                cur.execute("TRUNCATE TABLE chat_logs")
            m_conn.commit()

        total = s_conn.execute("SELECT COUNT(*) AS c FROM chat_logs").fetchone()["c"]
        print(f"[MIGRATE] SQLite 源总行数: {total}")
        if total == 0:
            return 0

        migrated = 0
        last_id = 0
        started = time.time()

        insert_sql = (
            "INSERT INTO chat_logs "
            "(customer_id, customer_name, acc_id, platform, direction, message, msg_type, timestamp) "
            "VALUES (%s,%s,%s,%s,%s,%s,%s,%s)"
        )

        while True:
            rows = s_conn.execute(
                """
                SELECT id, customer_id, customer_name, acc_id, platform, direction, message, msg_type, timestamp
                FROM chat_logs
                WHERE id > ?
                ORDER BY id ASC
                LIMIT ?
                """,
                (last_id, batch_size),
            ).fetchall()
            if not rows:
                break

            vals = []
            for r in rows:
                vals.append(
                    (
                        r["customer_id"] or "",
                        r["customer_name"] or "",
                        r["acc_id"] or "",
                        r["platform"] or "",
                        r["direction"] or "in",
                        r["message"] or "",
                        int(r["msg_type"] or 0),
                        r["timestamp"],
                    )
                )
                last_id = r["id"]

            with m_conn.cursor() as cur:
                cur.executemany(insert_sql, vals)
            m_conn.commit()

            migrated += len(vals)
            elapsed = time.time() - started
            print(f"[MIGRATE] {migrated}/{total} ({(migrated/total)*100:.1f}%) elapsed={elapsed:.1f}s")

        return migrated
    finally:
        try:
            s_conn.close()
        except Exception:
            pass
        try:
            m_conn.close()
        except Exception:
            pass


def main():
    parser = argparse.ArgumentParser(description="迁移 chat_logs: SQLite -> MySQL")
    parser.add_argument("--sqlite-path", default=str(Path("db") / "chat_log_db" / "chats.db"))
    parser.add_argument("--host", required=True)
    parser.add_argument("--port", type=int, default=3306)
    parser.add_argument("--user", required=True)
    parser.add_argument("--password", required=True)
    parser.add_argument("--database", required=True)
    parser.add_argument("--batch-size", type=int, default=2000)
    parser.add_argument("--truncate-target", action="store_true")
    args = parser.parse_args()

    sqlite_path = Path(args.sqlite_path)
    migrated = migrate(
        sqlite_path=sqlite_path,
        host=args.host,
        port=args.port,
        user=args.user,
        password=args.password,
        database=args.database,
        batch_size=max(100, int(args.batch_size)),
        truncate_target=bool(args.truncate_target),
    )
    print(f"[DONE] 迁移完成，写入 {migrated} 条")


if __name__ == "__main__":
    main()