from __future__ import annotations

import sys
import types
from io import BytesIO

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import StaticPool

from app.auth.deps import get_current_user
from app.api.routes.documents import router as documents_router
from app.db.base import Base, get_db
from app.db.models import Document, DocumentChunk
from app.db.models import User
from app.rag.chunker import chunk_blocks
from app.rag.extractors import ExtractedBlock, extract_document
from app.rag.ingest import _chunk_payload


def test_extract_text_document_blocks() -> None:
    extracted = extract_document("1. Общие положения\n\nТекст пункта".encode(), "gost.txt")

    assert extracted.mime_type == "text/plain"
    assert extracted.text.startswith("1. Общие положения")
    assert [block.paragraph_index for block in extracted.blocks] == [0, 2]


def test_extract_docx_document_sections() -> None:
    docx = pytest.importorskip("docx")
    document = docx.Document()
    document.add_heading("1. Термины", level=1)
    document.add_paragraph("Определение из ГОСТ.")
    buffer = BytesIO()
    document.save(buffer)

    extracted = extract_document(buffer.getvalue(), "terms.docx")

    assert extracted.mime_type.endswith("wordprocessingml.document")
    assert any(block.section_path == "1. Термины" for block in extracted.blocks)
    assert "Определение из ГОСТ." in extracted.text


def test_extract_pdf_document_pages(monkeypatch: pytest.MonkeyPatch) -> None:
    class FakePage:
        def __init__(self, text: str) -> None:
            self._text = text

        def extract_text(self) -> str:
            return self._text

    class FakePdfReader:
        def __init__(self, _: BytesIO) -> None:
            self.pages = [FakePage("Страница 1"), FakePage("Страница 2")]

    fake_pypdf = types.SimpleNamespace(PdfReader=FakePdfReader)
    monkeypatch.setitem(sys.modules, "pypdf", fake_pypdf)

    extracted = extract_document(b"%PDF fake", "doc.pdf")

    assert extracted.mime_type == "application/pdf"
    assert [block.page_start for block in extracted.blocks] == [1, 2]
    assert "Страница 2" in extracted.text


def test_chunk_blocks_keeps_source_metadata() -> None:
    chunks = chunk_blocks(
        [
            ExtractedBlock(text="1. Область применения", page_start=3, page_end=3),
            ExtractedBlock(text="Требование к оформлению.", page_start=3, page_end=3),
        ],
        chunk_size=200,
    )

    assert len(chunks) == 1
    assert chunks[0].page_start == 3
    assert chunks[0].source_ref == "стр. 3"
    assert "Требование" in chunks[0].content


def test_qdrant_payload_contains_citation_fields() -> None:
    doc = Document(id=7, user_id=2, title="ГОСТ", filename="gost.pdf", mime_type="application/pdf")
    row = DocumentChunk(
        id=11,
        document_id=7,
        chunk_index=4,
        content="Пункт 5.3",
        source_filename="gost.pdf",
        mime_type="application/pdf",
        page_start=12,
        page_end=13,
        section_title="5. Требования",
        section_path="5. Требования > 5.3 Оформление",
        paragraph_index=9,
        source_ref="стр. 12-13, 5. Требования > 5.3 Оформление",
    )

    payload = _chunk_payload(doc, row)

    assert payload["document_id"] == 7
    assert payload["chunk_id"] == 11
    assert payload["page_start"] == 12
    assert payload["source_ref"].startswith("стр. 12-13")


def test_upload_document_endpoint_stores_chunks(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("RAG_ENABLED", "false")
    from app.config import get_settings

    get_settings.cache_clear()
    engine = create_engine(
        "sqlite://",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    TestingSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
    Base.metadata.create_all(bind=engine)

    db = TestingSessionLocal()
    user = User(username="owner", display_name="Owner", api_token_hash="hash", is_active=True)
    db.add(user)
    db.commit()
    db.refresh(user)
    user_id = user.id
    db.close()

    app = FastAPI()
    app.include_router(documents_router, prefix="/api/v1")

    def override_get_db():
        session = TestingSessionLocal()
        try:
            yield session
        finally:
            session.close()

    def override_current_user():
        session = TestingSessionLocal()
        try:
            return session.get(User, user_id)
        finally:
            session.close()

    app.dependency_overrides[get_db] = override_get_db
    app.dependency_overrides[get_current_user] = override_current_user

    with TestClient(app) as client:
        response = client.post(
            "/api/v1/documents/upload",
            files={"file": ("tz.txt", b"1. Scope\n\nRequirement text", "text/plain")},
        )

    assert response.status_code == 200
    payload = response.json()["document"]
    assert payload["filename"] == "tz.txt"
    assert payload["chunk_count"] == 1
    assert payload["index_status"] == "stored"