"""field_matcher.py 测试 — OCR 字段 → KB 字段匹配, embedding + LLM。"""

import sys
from pathlib import Path
from unittest.mock import patch, MagicMock

import pytest

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

from backend.field_matcher import (
    _cosine_similarity, match_ocr_to_kb, _match_via_llm,
    format_field_mapping_context,
)


# ── 余弦相似度 ──────────────────────────────────────────────────

class TestCosineSimilarity:
    def test_identical_vectors(self):
        assert _cosine_similarity([1, 0, 0], [1, 0, 0]) == 1.0

    def test_orthogonal_vectors(self):
        assert _cosine_similarity([1, 0, 0], [0, 1, 0]) == 0.0

    def test_opposite_vectors(self):
        assert _cosine_similarity([1, 0], [-1, 0]) == -1.0

    def test_normalized_vectors_range(self):
        sim = _cosine_similarity([0.6, 0.8], [0.8, 0.6])
        assert -1.0 <= sim <= 1.0


# ── LLM 匹配 ────────────────────────────────────────────────────

class TestMatchViaLlm:
    def test_returns_json_mapping(self):
        mock_llm = MagicMock()
        mock_response = MagicMock()
        mock_response.content = '{"工单号": "billNo", "客户": "customerName"}'
        mock_llm.invoke.return_value = mock_response

        kb_fields = [
            {"name": "billNo", "description": "工单号", "type": "String"},
            {"name": "customerName", "description": "客户名称", "type": "String"},
        ]
        result = _match_via_llm(["工单号", "客户"], kb_fields, mock_llm)
        assert result == {"工单号": "billNo", "客户": "customerName"}

    def test_includes_candidates_hint_when_provided(self):
        mock_llm = MagicMock()
        mock_response = MagicMock()
        mock_response.content = '{"工单号": "billNo"}'
        mock_llm.invoke.return_value = mock_response
        candidates = {"工单号": [("billNo", 0.85), ("orderId", 0.62)]}
        result = _match_via_llm(
            ["工单号"],
            [{"name": "billNo", "description": "工单号", "type": "String"}],
            mock_llm, candidates=candidates)
        call_args = mock_llm.invoke.call_args[0][0]
        assert "候选" in call_args
        assert "billNo" in call_args

    def test_llm_error_returns_empty_dict(self):
        mock_llm = MagicMock()
        mock_llm.invoke.side_effect = RuntimeError("LLM crash")
        result = _match_via_llm(["x"], [{"name": "y", "description": "", "type": "String"}], mock_llm)
        assert result == {}

    def test_llm_returns_invalid_json_returns_empty(self):
        mock_llm = MagicMock()
        mock_response = MagicMock()
        mock_response.content = "not json at all"
        mock_llm.invoke.return_value = mock_response
        result = _match_via_llm(["x"], [{"name": "y", "description": "", "type": "String"}], mock_llm)
        assert result == {}


# ── 完整匹配流程 ────────────────────────────────────────────────

class TestMatchOcrToKb:
    @pytest.fixture(autouse=True)
    def mock_embed(self):
        with patch("backend.field_matcher._embed") as mock_embed:
            def _fake_embed(text):
                if "billNo" in text or "工单" in text:
                    return [1.0, 0.0, 0.0]
                if "customerName" in text or "客户" in text:
                    return [0.0, 1.0, 0.0]
                if "amount" in text or "金额" in text:
                    return [0.0, 0.0, 1.0]
                return [0.0, 0.0, 0.0]
            mock_embed.side_effect = _fake_embed
            yield mock_embed

    def test_matches_without_llm(self):
        kb_fields = [
            {"name": "billNo", "description": "工单号", "type": "String"},
            {"name": "customerName", "description": "客户名称", "type": "String"},
            {"name": "amount", "description": "金额", "type": "BigDecimal"},
        ]
        mapping = match_ocr_to_kb(
            ["工单号", "客户名称", "金额"], kb_fields, llm=None)
        assert mapping["工单号"] == "billNo"
        assert mapping["客户名称"] == "customerName"
        assert mapping["金额"] == "amount"

    def test_empty_inputs_return_empty(self):
        assert match_ocr_to_kb([], [], llm=None) == {}
        assert match_ocr_to_kb(["x"], [], llm=None) == {}
        assert match_ocr_to_kb([], [{"name": "y", "description": "", "type": "String"}], llm=None) == {}

    def test_low_similarity_not_matched(self):
        kb_fields = [{"name": "far", "description": "不相关字段", "type": "String"}]
        mapping = match_ocr_to_kb(["无关"], kb_fields, llm=None)
        assert "无关" not in mapping or mapping == {}

    def test_uses_llm_when_provided(self):
        mock_llm = MagicMock()
        mock_response = MagicMock()
        mock_response.content = '{"工单号": "billNo", "客户名称": "customerName"}'
        mock_llm.invoke.return_value = mock_response
        kb_fields = [
            {"name": "billNo", "description": "工单号", "type": "String"},
            {"name": "customerName", "description": "客户", "type": "String"},
        ]
        mapping = match_ocr_to_kb(["工单号", "客户名称"], kb_fields, llm=mock_llm)
        assert mapping["工单号"] == "billNo"

    def test_embedding_failure_falls_back_to_llm(self):
        mock_llm = MagicMock()
        mock_response = MagicMock()
        mock_response.content = '{"工单号": "billNo"}'
        mock_llm.invoke.return_value = mock_response
        with patch("backend.field_matcher._embed", side_effect=RuntimeError("model error")):
            kb_fields = [{"name": "billNo", "description": "工单号", "type": "String"}]
            mapping = match_ocr_to_kb(["工单号"], kb_fields, llm=mock_llm)
            assert mapping["工单号"] == "billNo"


# ── 格式化上下文 ────────────────────────────────────────────────

class TestFormatFieldMappingContext:
    def test_formats_mapping_as_table(self):
        ctx = format_field_mapping_context({"工单号": "billNo", "客户": "customerName"})
        assert "[字段映射" in ctx
        assert "$P{billNo}" in ctx
        assert "$P{customerName}" in ctx
        assert "工单号" in ctx
        assert "客户" in ctx

    def test_empty_mapping_returns_empty_string(self):
        assert format_field_mapping_context({}) == ""

    def test_single_entry(self):
        ctx = format_field_mapping_context({"发票号码": "invoiceNo"})
        assert "$P{invoiceNo}" in ctx