"""文档管理 API 测试（QdrantService 为 mock，不真实联网）"""

from collections.abc import Iterator
from typing import Any

import pytest
from fastapi.testclient import TestClient

from app.api.v1 import document as document_module
from app.main import app
from app.services.qdrant import QdrantService


class FakeQdrant:
    """假 QdrantService：返回固定数据或抛出固定异常"""

    def __init__(
        self,
        scroll_result: tuple[list[dict[str, Any]], str | None] | None = None,
        detail: dict[str, Any] | None = None,
        deleted: dict[str, int] | None = None,
        error: Exception | None = None,
    ) -> None:
        self.scroll_result = scroll_result if scroll_result is not None else ([], None)
        self.detail = detail
        self.deleted = deleted if deleted is not None else {}
        self.error = error

    async def scroll_l1(self, limit: int = 20, offset: str | None = None) -> tuple[list[dict[str, Any]], str | None]:
        if self.error is not None:
            raise self.error
        return self.scroll_result

    async def get_doc_detail(self, doc_id: str) -> dict[str, Any] | None:
        if self.error is not None:
            raise self.error
        return self.detail

    async def delete_by_doc_id(self, doc_id: str) -> dict[str, int]:
        if self.error is not None:
            raise self.error
        return self.deleted


@pytest.fixture
def client(monkeypatch: pytest.MonkeyPatch) -> Iterator[TestClient]:
    """TestClient，lifespan 中的 Qdrant 集合初始化替换为空操作"""

    async def _noop_ensure_collections(self: QdrantService) -> None:
        return None

    monkeypatch.setattr(QdrantService, "ensure_collections", _noop_ensure_collections)
    with TestClient(app) as test_client:
        yield test_client


def _install_fake(monkeypatch: pytest.MonkeyPatch, fake: FakeQdrant) -> None:
    """将 _get_qdrant 单例替换为假服务"""
    monkeypatch.setattr(document_module, "_get_qdrant", lambda: fake)


def _make_item(doc_id: str = "doc-1") -> dict[str, Any]:
    """构造固定的 L1 列表项"""
    return {
        "doc_id": doc_id,
        "title": "标题",
        "category": "技术文档",
        "tags": ["API"],
        "summary": "一句话总结",
    }


def test_list_documents_success(client: TestClient, monkeypatch: pytest.MonkeyPatch) -> None:
    """列表：正常返回 items 与 next_offset"""
    fake = FakeQdrant(scroll_result=([_make_item()], "cursor-2"))
    _install_fake(monkeypatch, fake)

    resp = client.get("/api/v1/documents", params={"limit": 10, "offset": "cursor-1"})

    assert resp.status_code == 200
    body = resp.json()
    assert body["code"] == 0
    data = body["data"]
    assert data["items"] == [_make_item()]
    assert data["next_offset"] == "cursor-2"


def test_list_documents_empty(client: TestClient, monkeypatch: pytest.MonkeyPatch) -> None:
    """列表：空库返回 items=[]、next_offset=None"""
    fake = FakeQdrant(scroll_result=([], None))
    _install_fake(monkeypatch, fake)

    resp = client.get("/api/v1/documents")

    body = resp.json()
    assert body["code"] == 0
    assert body["data"] == {"items": [], "next_offset": None}


def test_get_document_detail(client: TestClient, monkeypatch: pytest.MonkeyPatch) -> None:
    """详情：存在返回 l1/l2_nodes/l3_nodes/chunks_count"""
    detail = {
        "l1": {"doc_id": "doc-1", "title": "标题", "text": "一句话总结"},
        "l2_nodes": [{"doc_id": "doc-1", "section_path": "1", "text": "大纲节点"}],
        "l3_nodes": [],
        "chunks_count": 3,
    }
    fake = FakeQdrant(detail=detail)
    _install_fake(monkeypatch, fake)

    resp = client.get("/api/v1/documents/doc-1")

    body = resp.json()
    assert body["code"] == 0
    assert body["data"] == detail


def test_get_document_not_found(client: TestClient, monkeypatch: pytest.MonkeyPatch) -> None:
    """详情：不存在返回 code=1004"""
    fake = FakeQdrant(detail=None)
    _install_fake(monkeypatch, fake)

    resp = client.get("/api/v1/documents/missing")

    body = resp.json()
    assert body["code"] == 1004
    assert body["message"] == "文档不存在"
    assert body["data"] is None


def test_delete_document_success(client: TestClient, monkeypatch: pytest.MonkeyPatch) -> None:
    """删除：返回各集合删除数与 deleted_total"""
    deleted = {"doc_l1": 1, "doc_l2": 2, "doc_l3": 4, "chunks": 6}
    fake = FakeQdrant(deleted=deleted)
    _install_fake(monkeypatch, fake)

    resp = client.delete("/api/v1/documents/doc-1")

    body = resp.json()
    assert body["code"] == 0
    data = body["data"]
    assert data["doc_id"] == "doc-1"
    assert data["deleted"] == deleted
    assert data["deleted_total"] == 13


def test_delete_document_not_found_idempotent(client: TestClient, monkeypatch: pytest.MonkeyPatch) -> None:
    """删除：不存在 doc_id 仍 code=0，各集合删除数全 0、deleted_total=0（幂等）"""
    deleted = {"doc_l1": 0, "doc_l2": 0, "doc_l3": 0, "chunks": 0}
    fake = FakeQdrant(deleted=deleted)
    _install_fake(monkeypatch, fake)

    resp = client.delete("/api/v1/documents/missing")

    body = resp.json()
    assert body["code"] == 0
    data = body["data"]
    assert data["deleted"] == deleted
    assert data["deleted_total"] == 0


def test_list_documents_service_error(client: TestClient, monkeypatch: pytest.MonkeyPatch) -> None:
    """列表：scroll 抛错返回 code=2000"""
    fake = FakeQdrant(error=RuntimeError("boom"))
    _install_fake(monkeypatch, fake)

    resp = client.get("/api/v1/documents")

    body = resp.json()
    assert body["code"] == 2000
    assert body["data"] is None