"""混合检索集成：真实 PostgreSQL + pgvector，嵌入用 DeterministicEmbedder（不联网）.

证明三件单测证明不了的事（任务文档 §4）：
1. 硬过滤零漏 —— 禁忌/draft 实体即使向量最近也绝不出现（T-P2-04 红线）；
2. 关键词路径在 tsv 'simple' 分词下真实命中；
3. 无结果 query 落 kb_gap 且 hit_count 递增（T-P2-06）。
外加：向量化重跑整组替换且逐行带版本（T-P2-03）、kb_asset partial 索引可用。

Run: MEIDA_RUN_INTEGRATION=1 .venv/bin/pytest -m integration -q --no-cov
"""

from __future__ import annotations

import os
import uuid
from collections.abc import AsyncIterator
from typing import Any

import pytest
from sqlalchemy import delete, select, text

from packages.domain.ids import next_id
from packages.retrieval.embedding import DeterministicEmbedder
from packages.retrieval.repo import ChunkInput, hybrid_search, upsert_chunks
from packages.retrieval.service import RetrievalService, UserContext
from packages.shared.db import dispose_engine, session_scope
from packages.shared.models import KbAsset, KbChunk, KbEntity, KbGap


def _infra_available() -> bool:
    return bool(os.getenv("MEIDA_RUN_INTEGRATION"))


pytestmark = [
    pytest.mark.integration,
    pytest.mark.skipif(
        not _infra_available(),
        reason="set MEIDA_RUN_INTEGRATION=1 with PostgreSQL and Redis running",
    ),
]


def _unique(name: str) -> str:
    return f"it-t8-{name}-{uuid.uuid4().hex[:10]}"


@pytest.fixture(autouse=True)
async def _hermetic_engine() -> AsyncIterator[None]:
    """每个用例前后重建全局 engine：asyncpg 连接绑定创建它的事件循环，
    pytest-asyncio 给每个用例一个新 loop，复用池里旧连接会报
    "attached to a different loop"。app 系用例由 lifespan 的 dispose_engine
    兜底；直接用 session_scope 的本文件必须自己管。"""
    await dispose_engine()
    yield
    await dispose_engine()


@pytest.fixture
async def clean_kb() -> AsyncIterator[dict[str, list[Any]]]:
    """登记本用例造的脏数据并在结束时清掉：集成库长活，不能留假实体."""
    registry: dict[str, list[Any]] = {"entities": [], "gaps": []}
    yield registry
    async with session_scope() as session:
        if registry["entities"]:
            ids = registry["entities"]
            await session.execute(delete(KbChunk).where(KbChunk.entity_id.in_(ids)))
            await session.execute(delete(KbAsset).where(KbAsset.entity_id.in_(ids)))
            await session.execute(delete(KbEntity).where(KbEntity.entity_id.in_(ids)))
        for query_text in registry["gaps"]:
            await session.execute(delete(KbGap).where(KbGap.query_text == query_text))


async def _add_entity(
    registry: dict[str, list[Any]],
    *,
    entity_type: str = "item",
    status: str = "published",
    attrs: dict[str, Any] | None = None,
) -> int:
    entity_id = next_id()
    registry["entities"].append(entity_id)
    async with session_scope() as session:
        session.add(
            KbEntity(
                entity_id=entity_id,
                entity_type=entity_type,
                name=_unique(entity_type),
                attrs=attrs or {},
                status=status,
            )
        )
    return entity_id


class RenamedEmbedder:
    """换名复用确定性向量：验证 model/version 逐行落库与整组替换（T-P2-03）."""

    def __init__(self, model_name: str, version: str) -> None:
        self._inner = DeterministicEmbedder(dimensions=1024)
        self.model_name = model_name
        self.version = version
        self.dimensions = 1024

    async def embed(self, texts: list[str]) -> list[list[float]]:
        return await self._inner.embed(texts)


# --- 1. 硬过滤零漏（T-P2-04 红线）--------------------------------------------
async def test_hard_filter_never_leaks_taboo_or_draft(clean_kb: dict[str, list[Any]]) -> None:
    embedder = DeterministicEmbedder(dimensions=1024)
    query_text = "pear shape body dress advice"
    # 防御性登记：若回归导致空结果被记进 kb_gap，用例结束也能清干净。
    clean_kb["gaps"].append(query_text)

    taboo_id = await _add_entity(
        clean_kb, attrs={"occasions": ["wedding"], "avoid_body_shapes": ["apple"]}
    )
    draft_id = await _add_entity(clean_kb, status="draft")
    good_id = await _add_entity(clean_kb, attrs={"occasions": ["wedding"]})

    async with session_scope() as session:
        # 禁忌与 draft 的 chunk 和 query 完全同文：不过滤的话它们必然霸占
        # 向量第一名（距离 0）—— 这样断言"零出现"才有说服力。
        await upsert_chunks(session, taboo_id, [ChunkInput(text=query_text)], embedder)
        await upsert_chunks(session, draft_id, [ChunkInput(text=query_text)], embedder)
        await upsert_chunks(
            session,
            good_id,
            [ChunkInput(text="soft knit sweater paired with a high waist skirt")],
            embedder,
        )

    async with session_scope() as session:
        svc = RetrievalService(session, embedding=embedder)
        outcome = await svc.search(
            query_text,
            user_ctx=UserContext(body_shape="apple", occasion="wedding", entity_types=("item",)),
        )

    assert outcome.degraded is False
    assert outcome.results, "正常 published 实体应被召回"
    assert {r.entity_id for r in outcome.results} == {good_id}

    # 对照组：去掉禁忌/场景过滤后禁忌实体确实在库里且可被召回 ——
    # 证明上面拦截它的是硬过滤，而不是数据没写进去。draft 永远不出现。
    query_vec = (await embedder.embed([query_text]))[0]
    async with session_scope() as session:
        control = await hybrid_search(session, query_vec, query_text)
    control_entities = {r.entity_id for r in control}
    assert taboo_id in control_entities
    assert draft_id not in control_entities


# --- 2. 关键词路径（tsv 'simple' 分词）----------------------------------------
async def test_keyword_recall_ranks_matching_chunk_first(
    clean_kb: dict[str, list[Any]],
) -> None:
    embedder = DeterministicEmbedder(dimensions=1024)
    entity_id = await _add_entity(clean_kb)
    matching = "breathable linen shirt keeps you cool in summer"
    unrelated = "heavy wool coat for freezing winter nights"

    async with session_scope() as session:
        await upsert_chunks(
            session,
            entity_id,
            [ChunkInput(text=matching), ChunkInput(text=unrelated)],
            embedder,
        )

    # 查询文本与两个 chunk 都不同文 → 向量路分不出高下（近似正交），
    # 排序由关键词路（0.2 权重、归一后差距 1.0）决定。
    async with session_scope() as session:
        results = await hybrid_search(
            session, (await embedder.embed(["linen shirt summer"]))[0], "linen shirt summer"
        )

    assert [r.text for r in results] == [matching, unrelated]
    assert results[0].kw_score == pytest.approx(1.0)
    assert results[1].kw_score == 0.0


# --- 3. 向量化可重跑（T-P2-03）------------------------------------------------
async def test_upsert_chunks_is_versioned_and_rerunnable(
    clean_kb: dict[str, list[Any]],
) -> None:
    entity_id = await _add_entity(clean_kb)

    async with session_scope() as session:
        first = await upsert_chunks(
            session,
            entity_id,
            [ChunkInput(text="rule one"), ChunkInput(text="rule two")],
            RenamedEmbedder("bge-m3", "v1"),
        )
        assert {c.embedding_model for c in first} == {"bge-m3"}
        assert {c.embedding_version for c in first} == {"v1"}

    # 换模型名（= 换版本）重跑：整组替换，不残留旧版本向量
    async with session_scope() as session:
        await upsert_chunks(
            session,
            entity_id,
            [ChunkInput(text="rule one"), ChunkInput(text="rule two"), ChunkInput(text="rule new")],
            RenamedEmbedder("bge-m4", "v2"),
        )

    async with session_scope() as session:
        rows = (
            (await session.execute(select(KbChunk).where(KbChunk.entity_id == entity_id)))
            .scalars()
            .all()
        )
    assert len(rows) == 3
    assert {r.embedding_model for r in rows} == {"bge-m4"}
    assert {r.embedding_version for r in rows} == {"v2"}


# --- 4. 无结果 query 落 kb_gap（T-P2-06）--------------------------------------
async def test_no_result_query_lands_in_kb_gap_with_counter(
    clean_kb: dict[str, list[Any]],
) -> None:
    query_text = _unique("missing")
    clean_kb["gaps"].append(query_text)
    svc_embedder = DeterministicEmbedder(dimensions=1024)

    async with session_scope() as session:
        svc = RetrievalService(session, embedding=svc_embedder)
        first = await svc.search(query_text, user_ctx=UserContext(entity_types=("nonexistent",)))
        second = await svc.search(query_text, user_ctx=UserContext(entity_types=("nonexistent",)))

    assert first.degraded and first.results == []
    assert second.degraded and second.results == []

    async with session_scope() as session:
        gaps = (
            (await session.execute(select(KbGap).where(KbGap.query_text == query_text)))
            .scalars()
            .all()
        )
    assert len(gaps) == 1  # 同 query + 同 filter_ctx 只有一行
    assert gaps[0].hit_count == 2
    assert gaps[0].filter_ctx["entity_types"] == ["nonexistent"]


# --- 5. kb_asset 按 entity 查询 + partial 索引可用 -----------------------------
async def test_tryon_ready_assets_query_uses_partial_index(
    clean_kb: dict[str, list[Any]],
) -> None:
    entity_id = await _add_entity(clean_kb)
    async with session_scope() as session:
        session.add_all(
            [
                KbAsset(
                    asset_id=next_id(),
                    entity_id=entity_id,
                    asset_type="front",
                    cos_key=_unique("front"),
                    tryon_ready=True,
                    review_status="approved",
                ),
                KbAsset(
                    asset_id=next_id(),
                    entity_id=entity_id,
                    asset_type="side",
                    cos_key=_unique("side"),
                    tryon_ready=False,
                    review_status="pending",
                ),
            ]
        )

    async with session_scope() as session:
        ready = (
            (
                await session.execute(
                    select(KbAsset).where(
                        KbAsset.entity_id == entity_id, KbAsset.tryon_ready.is_(True)
                    )
                )
            )
            .scalars()
            .all()
        )
        assert len(ready) == 1
        assert ready[0].tryon_ready is True

        # 关闭顺序扫描逼 planner 走索引，证明 partial 索引真的可用
        # （SET LOCAL 只影响当前事务，随 session_scope 提交即失效）。
        await session.execute(text("SET LOCAL enable_seqscan = off"))
        plan_lines = (
            (await session.execute(text("EXPLAIN SELECT asset_id FROM kb_asset WHERE tryon_ready")))
            .scalars()
            .all()
        )
    plan_text = "\n".join(str(line) for line in plan_lines)
    assert "ix_kb_asset_tryon_ready" in plan_text