"""导出功能测试."""
import csv
import io
import json

import pytest

from src.core.search import Searcher


class FakeExportCollection:
    def count(self):
        return 2

    def get(self, include=None):
        return {
            "ids": ["doc_0", "doc_1"],
            "documents": ["内容A。\n\n段落B。", "内容C。"],
            "metadatas": [
                {"source_file": "a.md", "section_title": "标题A", "heading_level": 1, "chunk_index": 0},
                {"source_file": "b.md", "section_title": "", "heading_level": 0, "chunk_index": 0},
            ],
        }


class FakeExportDB:
    def get_or_create_collection(self, name):
        return FakeExportCollection()

    def list_collections(self):
        return []


class FakeExportEmbedder:
    @property
    def dimension(self):
        return 4

    def embed(self, texts):
        return [[0.1, 0.2, 0.3, 0.4] for _ in texts]


@pytest.fixture
def searcher():
    db = FakeExportDB()
    embedder = FakeExportEmbedder()
    return Searcher(db, embedder, "test_export")


def test_export_json_returns_valid_json(searcher):
    """export_json 返回合法的 JSON 字符串."""
    output = searcher.export_json()
    data = json.loads(output)
    assert isinstance(data, list)
    assert len(data) == 2


def test_export_json_contains_all_fields(searcher):
    """导出包含所有必要字段."""
    output = searcher.export_json()
    data = json.loads(output)
    first = data[0]
    assert "id" in first
    assert "content" in first
    assert "source_file" in first
    assert "section_title" in first


def test_export_csv_returns_valid_csv(searcher):
    """export_csv 返回合法的 CSV 字符串."""
    output = searcher.export_csv()
    reader = csv.DictReader(io.StringIO(output))
    rows = list(reader)
    assert len(rows) == 2


def test_export_csv_has_header(searcher):
    """CSV 包含表头."""
    output = searcher.export_csv()
    reader = csv.DictReader(io.StringIO(output))
    assert reader.fieldnames is not None
    assert "content" in reader.fieldnames
    assert "source_file" in reader.fieldnames


def test_export_empty_collection():
    """空 collection 导出空列表."""

    class EmptyCollection:
        def count(self):
            return 0
        def get(self, include=None):
            return {"ids": [], "documents": [], "metadatas": []}

    class EmptyDB:
        def get_or_create_collection(self, name):
            return EmptyCollection()
        def list_collections(self):
            return []

    s = Searcher(EmptyDB(), FakeExportEmbedder(), "empty")
    json_out = s.export_json()
    assert json.loads(json_out) == []
    csv_out = s.export_csv()
    lines = csv_out.strip().split("\n")
    assert len(lines) == 1  # 仅表头