"""用户管理服务 - 基础单元测试模块。

使用 pytest 和 httpx 对 API 接口进行测试。
"""

import pytest
from fastapi.testclient import TestClient

from app.main import app
from app.database import db


# ──────────────────────────────────────────────
# 测试客户端
# ──────────────────────────────────────────────

@pytest.fixture(autouse=True)
def reset_database():
    """每个测试用例执行前重置数据库状态。

    保存原始数据并在测试后恢复，避免测试间的数据污染。
    """
    # 清空数据库并重新初始化种子数据
    db._users.clear()
    db._username_index.clear()
    db._init_seed_data()
    yield


client = TestClient(app)


# ──────────────────────────────────────────────
# 健康检查测试
# ──────────────────────────────────────────────


class TestHealthCheck:
    """健康检查接口测试类。"""

    def test_health_check_returns_ok(self):
        """测试健康检查接口返回状态 ok。"""
        response = client.get("/health")
        assert response.status_code == 200
        data = response.json()
        assert data["status"] == "ok"
        assert data["service"] == "user-management-service"
        assert data["total_users"] >= 3


# ──────────────────────────────────────────────
# 用户创建测试
# ──────────────────────────────────────────────


class TestCreateUser:
    """用户注册接口测试类。"""

    def test_create_user_success(self):
        """测试成功创建用户。"""
        response = client.post(
            "/api/users",
            json={
                "username": "newuser",
                "email": "newuser@example.com",
                "password": "password123",
            },
        )
        assert response.status_code == 201
        data = response.json()
        assert data["username"] == "newuser"
        assert data["email"] == "newuser@example.com"
        assert data["is_active"] is True
        assert "id" in data
        assert "created_at" in data

    def test_create_user_duplicate_username(self):
        """测试创建重复用户名应返回 409。"""
        response = client.post(
            "/api/users",
            json={
                "username": "alice",
                "email": "alice2@example.com",
                "password": "password123",
            },
        )
        assert response.status_code == 409
        assert "已被占用" in response.json()["detail"]

    def test_create_user_duplicate_email(self):
        """测试创建重复邮箱应返回 409。"""
        response = client.post(
            "/api/users",
            json={
                "username": "alice2",
                "email": "alice@example.com",
                "password": "password123",
            },
        )
        assert response.status_code == 409
        assert "已被注册" in response.json()["detail"]

    def test_create_user_validation_error(self):
        """测试用户名太短应返回 422。"""
        response = client.post(
            "/api/users",
            json={
                "username": "ab",
                "email": "test@example.com",
                "password": "password123",
            },
        )
        assert response.status_code == 422


# ──────────────────────────────────────────────
# 用户查询测试
# ──────────────────────────────────────────────


class TestGetUsers:
    """用户查询接口测试类。"""

    def test_get_all_users(self):
        """测试获取所有用户（分页）。"""
        response = client.get("/api/users?skip=0&limit=10")
        assert response.status_code == 200
        data = response.json()
        assert len(data) >= 3
        # 验证返回的字段不包含密码
        for user in data:
            assert "password" not in user
            assert "hashed_password" not in user

    def test_get_user_by_id_success(self):
        """测试通过 ID 获取用户成功。"""
        response = client.get("/api/users/user-001")
        assert response.status_code == 200
        data = response.json()
        assert data["username"] == "alice"
        assert data["email"] == "alice@example.com"

    def test_get_user_by_id_not_found(self):
        """测试获取不存在的用户返回 404。"""
        response = client.get("/api/users/user-999")
        assert response.status_code == 404

    def test_get_users_pagination(self):
        """测试分页参数生效。"""
        response = client.get("/api/users?skip=0&limit=1")
        assert response.status_code == 200
        data = response.json()
        assert len(data) == 1


# ──────────────────────────────────────────────
# 用户更新测试
# ──────────────────────────────────────────────


class TestUpdateUser:
    """用户更新接口测试类。"""

    def test_update_username_success(self):
        """测试成功更新用户名。"""
        response = client.put(
            "/api/users/user-001",
            json={"username": "alice_updated"},
        )
        assert response.status_code == 200
        data = response.json()
        assert data["username"] == "alice_updated"

    def test_update_user_not_found(self):
        """测试更新不存在的用户返回 404。"""
        response = client.put(
            "/api/users/user-999",
            json={"username": "new_name"},
        )
        assert response.status_code == 404

    def test_update_username_conflict(self):
        """测试更新为已存在的用户名返回 409。"""
        response = client.put(
            "/api/users/user-001",
            json={"username": "bob"},
        )
        assert response.status_code == 409


# ──────────────────────────────────────────────
# 用户删除测试
# ──────────────────────────────────────────────


class TestDeleteUser:
    """用户删除接口测试类。"""

    def test_delete_user_success(self):
        """测试成功删除用户。"""
        response = client.delete("/api/users/user-001")
        assert response.status_code == 200
        data = response.json()
        assert "成功删除" in data["message"]

        # 验证用户确实被删除
        get_response = client.get("/api/users/user-001")
        assert get_response.status_code == 404

    def test_delete_user_not_found(self):
        """测试删除不存在的用户返回 404。"""
        response = client.delete("/api/users/user-999")
        assert response.status_code == 404


# ──────────────────────────────────────────────
# 用户登录测试
# ──────────────────────────────────────────────


class TestLogin:
    """用户登录接口测试类。"""

    def test_login_success(self):
        """测试使用正确的用户名和密码登录成功。"""
        response = client.post(
            "/api/users/login",
            json={"username": "alice", "password": "abc123"},
        )
        assert response.status_code == 200
        data = response.json()
        assert data["username"] == "alice"

    def test_login_wrong_password(self):
        """测试使用错误密码登录返回 401。"""
        response = client.post(
            "/api/users/login",
            json={"username": "alice", "password": "wrong_password"},
        )
        assert response.status_code == 401

    def test_login_user_not_found(self):
        """测试使用不存在的用户名登录返回 401。"""
        response = client.post(
            "/api/users/login",
            json={"username": "nonexistent", "password": "password123"},
        )
        assert response.status_code == 401