"""一次性迁移：把 2026-09-16/17 期间 MySQL 里的数据搬到 PostgreSQL。

用法（两个库都在跑：docker compose --profile legacy up -d mysql；docker compose up -d postgres）：
    .venv\\Scripts\\python.exe scripts\\migrate_mysql_to_pg.py [--mysql-port 13307]

幂等：目标端用 ON CONFLICT DO NOTHING；knowledge 不迁移（启动时由 YAML 重新灌入）。
"""

import argparse
import json
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(ROOT))

from dotenv import load_dotenv  # noqa: E402

load_dotenv(ROOT / ".env")

import pymysql  # noqa: E402
from pymysql.cursors import DictCursor  # noqa: E402
from psycopg.types.json import Jsonb  # noqa: E402

from backend.db import database as db  # noqa: E402


def _json(value):
    if value is None:
        return None
    if isinstance(value, (dict, list)):
        return Jsonb(value)
    try:
        return Jsonb(json.loads(value))
    except (TypeError, ValueError):
        return None


def main() -> int:
    ap = argparse.ArgumentParser()
    ap.add_argument("--mysql-host", default="127.0.0.1")
    ap.add_argument("--mysql-port", type=int, default=13307)
    ap.add_argument("--mysql-user", default="assistant")
    ap.add_argument("--mysql-password", default="assistant_dev_123")
    ap.add_argument("--mysql-db", default="school_assistant")
    args = ap.parse_args()

    src = pymysql.connect(
        host=args.mysql_host, port=args.mysql_port, user=args.mysql_user, password=args.mysql_password,
        database=args.mysql_db, charset="utf8mb4", cursorclass=DictCursor,
    )
    db.init_db()
    counts: dict[str, int] = {}

    def rows(sql: str) -> list[dict]:
        with src.cursor() as cur:
            cur.execute(sql)
            return list(cur.fetchall())

    with db.get_conn() as pg:
        for r in rows("SELECT * FROM settings"):
            counts["settings"] = counts.get("settings", 0) + db._execute(
                pg, 'INSERT INTO settings ("key", "value") VALUES (%s, %s) ON CONFLICT DO NOTHING', (r["key"], r["value"]))

        for r in rows("SELECT * FROM tasks"):
            counts["tasks"] = counts.get("tasks", 0) + db._execute(
                pg,
                """INSERT INTO tasks (id, school_id, student_id, knowledge_id, status, current_step, inputs, artifacts,
                       skill_version, browser_profile_path, pause_reason, next_check_at, created_at, updated_at)
                   VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s) ON CONFLICT DO NOTHING""",
                (r["id"], r.get("school_id") or "default", r["student_id"], r["knowledge_id"], r["status"], r["current_step"],
                 _json(r["inputs"]) or Jsonb({}), _json(r["artifacts"]) or Jsonb({}), r["skill_version"],
                 r["browser_profile_path"], r["pause_reason"], r["next_check_at"], r["created_at"], r["updated_at"]),
            )

        for r in rows("SELECT * FROM run_logs ORDER BY id"):
            counts["run_logs"] = counts.get("run_logs", 0) + db._execute(
                pg,
                """INSERT INTO run_logs (id, task_id, step_id, agent_history, screenshots, verdict, started_at, finished_at)
                   VALUES (%s, %s, %s, %s, %s, %s, %s, %s) ON CONFLICT DO NOTHING""",
                (r["id"], r["task_id"], r["step_id"], _json(r["agent_history"]), _json(r["screenshots"]) or Jsonb([]),
                 r["verdict"], r["started_at"], r["finished_at"]),
            )

        for r in rows("SELECT * FROM system_accounts ORDER BY id"):
            counts["system_accounts"] = counts.get("system_accounts", 0) + db._execute(
                pg,
                """INSERT INTO system_accounts (id, school_id, student_id, system_id, role, username, password_enc, created_at, updated_at)
                   VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s) ON CONFLICT DO NOTHING""",
                (r["id"], r.get("school_id") or "default", r["student_id"], r["system_id"], r.get("role") or "",
                 r["username"], r["password_enc"], r["created_at"], r["updated_at"]),
            )

        for r in rows("SELECT * FROM learned_entries ORDER BY id"):
            counts["learned_entries"] = counts.get("learned_entries", 0) + db._execute(
                pg,
                """INSERT INTO learned_entries (id, school_id, knowledge_id, business_id, "key", "value", status, category,
                       observations, source_task_id, created_at, updated_at, verified_at, verified_by)
                   VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s) ON CONFLICT DO NOTHING""",
                (r["id"], r.get("school_id") or "default", r["knowledge_id"], r["business_id"], r["key"], r["value"],
                 r["status"], r.get("category") or "note", r.get("observations") or 1, r["source_task_id"],
                 r["created_at"], r["updated_at"], r["verified_at"], r.get("verified_by")),
            )

        for table in ("run_logs", "system_accounts", "learned_entries"):
            db._execute(pg, f"SELECT setval(pg_get_serial_sequence('{table}', 'id'), COALESCE((SELECT MAX(id) FROM {table}), 0) + 1, false)")

    src.close()
    print("migrated rows:", counts)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())