"""
Unit Tests — PDFService

Tests:
- Returns None for a visit that doesn't exist
- Returns bytes for a valid visit
- Output starts with PDF magic bytes (%PDF)
- PDF size is reasonable (>1KB)
- Works correctly with no checklists / no photos
- Works with checklists and photos present
"""

import pytest
from sqlalchemy.ext.asyncio import AsyncSession

from models.visit_model import Visit
from models.checklist_model import Checklist
from models.photo_model import Photo
from services.pdf_service import PDFService


PDF_MAGIC = b"%PDF"


@pytest.mark.asyncio
class TestPDFService:

    async def test_returns_none_for_missing_visit(
        self, async_session: AsyncSession
    ):
        import uuid
        svc = PDFService()
        result = await svc.generate_visit_report(async_session, uuid.uuid4())
        assert result is None

    async def test_returns_bytes_for_valid_visit(
        self, async_session: AsyncSession, sample_visit: Visit
    ):
        svc = PDFService()
        result = await svc.generate_visit_report(async_session, sample_visit.id)
        assert result is not None
        assert isinstance(result, bytes)

    async def test_output_is_valid_pdf(
        self, async_session: AsyncSession, sample_visit: Visit
    ):
        """PDF must start with the %PDF magic header."""
        svc = PDFService()
        result = await svc.generate_visit_report(async_session, sample_visit.id)
        assert result is not None
        assert result[:4] == PDF_MAGIC

    async def test_pdf_has_reasonable_size(
        self, async_session: AsyncSession, sample_visit: Visit
    ):
        """PDF should be at least 1KB (basic structure is there)."""
        svc = PDFService()
        result = await svc.generate_visit_report(async_session, sample_visit.id)
        assert result is not None
        assert len(result) > 1024  # > 1 KB

    async def test_pdf_with_no_checklists_no_photos(
        self, async_session: AsyncSession, sample_visit: Visit
    ):
        """Visit with no related data should still produce a valid PDF."""
        svc = PDFService()
        result = await svc.generate_visit_report(async_session, sample_visit.id)
        assert result is not None
        assert result[:4] == PDF_MAGIC

    async def test_pdf_with_checklists(
        self,
        async_session: AsyncSession,
        sample_visit: Visit,
        sample_checklist: Checklist,
    ):
        """Checklist data should be included — PDF size increases."""
        svc = PDFService()
        result = await svc.generate_visit_report(async_session, sample_visit.id)
        assert result is not None
        assert len(result) > 1024

    async def test_pdf_with_photos(
        self,
        async_session: AsyncSession,
        sample_visit: Visit,
        sample_photo: Photo,
    ):
        """Photo metadata table should be included — PDF still valid."""
        svc = PDFService()
        result = await svc.generate_visit_report(async_session, sample_visit.id)
        assert result is not None
        assert result[:4] == PDF_MAGIC

    async def test_pdf_with_all_data(
        self,
        async_session: AsyncSession,
        sample_visit: Visit,
    ):
        """Full visit with multiple checklists and photos."""
        # Add 3 checklists
        for i, checked in enumerate([True, False, True]):
            async_session.add(Checklist(
                visit_id=sample_visit.id,
                item_name=f"Step {i+1}",
                is_checked=checked,
                notes=f"Note for step {i+1}" if checked else None,
            ))
        # Add 2 photos
        for j in range(2):
            async_session.add(Photo(
                visit_id=sample_visit.id,
                file_path=f"/uploads/photo_{j}.jpg",
                file_name=f"photo_{j}.jpg",
                file_size=51200,
                mime_type="image/jpeg",
            ))
        await async_session.flush()

        svc = PDFService()
        result = await svc.generate_visit_report(async_session, sample_visit.id)
        assert result is not None
        assert result[:4] == PDF_MAGIC
        assert len(result) > 2048  # Richer content = larger PDF