from __future__ import annotations

import os
import random
from pathlib import Path
from typing import Generator, List
import sys

import pytest
from fastapi.testclient import TestClient
from sqlalchemy import text
from sqlalchemy.exc import SQLAlchemyError

# Ensure the project root is importable when running directly via python.
ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from app import db
from app.main import create_app


TEST_USER_ID = 872341
SCHEMA_PATH = Path("file/tableschema/chat.sql")
DEFAULT_MYSQL_URL = "mysql+pymysql://root:12345678@127.0.0.1:3306/data-ge?charset=utf8mb4"


@pytest.fixture(scope="module")
def client() -> Generator[TestClient, None, None]:
    mysql_url = os.getenv("TEST_DATABASE_URL", DEFAULT_MYSQL_URL)
    os.environ["DATABASE_URL"] = mysql_url
    db.get_engine.cache_clear()
    engine = db.get_engine()
    try:
        # Quick connectivity check
        with engine.connect() as conn:
            conn.execute(text("SELECT 1"))
    except SQLAlchemyError:
        pytest.skip(f"Cannot connect to MySQL at {mysql_url}")

    #_ensure_chat_schema(engine)

    app = create_app()
    with TestClient(app) as test_client:
        yield test_client

    # cleanup test artifacts
    with engine.begin() as conn:
        # remove retrievals and turns tied to test sessions
        conn.execute(
            text(
                """
                DELETE FROM chat_turn_retrieval
                WHERE turn_id IN (
                    SELECT id FROM chat_turn WHERE session_id IN (SELECT id FROM chat_session WHERE user_id=:uid)
                )
                """
            ),
            {"uid": TEST_USER_ID},
        )
        conn.execute(
            text("DELETE FROM chat_turn WHERE session_id IN (SELECT id FROM chat_session WHERE user_id=:uid)"),
            {"uid": TEST_USER_ID},
        )
        conn.execute(text("DELETE FROM chat_session WHERE user_id=:uid"), {"uid": TEST_USER_ID})
    db.get_engine.cache_clear()


def test_session_lifecycle_mysql(client: TestClient) -> None:
    # Create a session
    resp = client.post("/api/v1/chat/sessions", json={"user_id": TEST_USER_ID})
    assert resp.status_code == 200, resp.text
    session = resp.json()
    session_id = session["id"]
    assert session["status"] == "OPEN"

    # Get session
    assert client.get(f"/api/v1/chat/sessions/{session_id}").status_code == 200

    # List sessions (filter by user)
    resp = client.get(f"/api/v1/chat/sessions", params={"user_id": TEST_USER_ID})
    assert resp.status_code == 200
    assert any(item["id"] == session_id for item in resp.json())

    # Update status
    resp = client.post(f"/api/v1/chat/sessions/{session_id}/update", json={"status": "PAUSED"})
    assert resp.status_code == 200
    assert resp.json()["status"] == "PAUSED"

    # Close session
    resp = client.post(f"/api/v1/chat/sessions/{session_id}/close")
    assert resp.status_code == 200
    assert resp.json()["status"] == "CLOSED"


def test_turns_and_retrievals_mysql(client: TestClient) -> None:
    session_id = client.post("/api/v1/chat/sessions", json={"user_id": TEST_USER_ID}).json()["id"]
    turn_payload = {
        "user_id": TEST_USER_ID,
        "user_query": "展示昨天订单GMV",
        "intent": "METRIC_QUERY",
        "ast_json": {"select": ["gmv"], "where": {"dt": "yesterday"}},
        "main_metric_ids": [random.randint(1000, 9999)],
        "created_metric_ids": [],
    }
    resp = client.post(f"/api/v1/chat/sessions/{session_id}/turns", json=turn_payload)
    assert resp.status_code == 200, resp.text
    turn = resp.json()
    turn_id = turn["id"]
    assert turn["turn_no"] == 1

    # Fetch turn
    assert client.get(f"/api/v1/chat/turns/{turn_id}").status_code == 200

    # List turns under session
    resp = client.get(f"/api/v1/chat/sessions/{session_id}/turns")
    assert resp.status_code == 200
    assert any(t["id"] == turn_id for t in resp.json())

    # Insert retrievals
    retrievals_payload = {
        "retrievals": [
            {"item_type": "METRIC", "item_id": "metric_foo", "used_in_sql": True, "rank_no": 1},
            {"item_type": "SNIPPET", "item_id": "snpt_bar", "similarity_score": 0.77, "rank_no": 2},
        ]
    }
    resp = client.post(f"/api/v1/chat/turns/{turn_id}/retrievals", json=retrievals_payload)
    assert resp.status_code == 200
    assert resp.json()["inserted"] == 2

    # List retrievals
    resp = client.get(f"/api/v1/chat/turns/{turn_id}/retrievals")
    assert resp.status_code == 200
    items = resp.json()
    assert len(items) == 2
    assert {item["item_type"] for item in items} == {"METRIC", "SNIPPET"}


if __name__ == "__main__":
    import pytest as _pytest

    raise SystemExit(_pytest.main([__file__]))