"""Tests for pdf-generate Lambda handler.

QA-C6 (partial): Verifies SQS batch processing, error handling, and
batch failure reporting for the PDF generation pipeline.
"""

import importlib
import sys
import os
from unittest.mock import MagicMock, patch


from helpers import make_sqs_event

# Import pdf-generate app under a unique module name to avoid collision with
# suggestions/app.py (both are named 'app').
_pdf_gen_dir = os.path.join(os.path.dirname(__file__), "..", "pdf-generate")
_spec = importlib.util.spec_from_file_location(
    "pdf_generate_app", os.path.join(_pdf_gen_dir, "app.py")
)
pdf_generate_app = importlib.util.module_from_spec(_spec)
sys.modules["pdf_generate_app"] = pdf_generate_app
_spec.loader.exec_module(pdf_generate_app)


class TestPdfGenerateHandler:
    """Test the SQS handler entry point for pdf-generate Lambda."""

    @patch.object(pdf_generate_app, "generate_pdf")
    def test_handler_processes_sqs_record_successfully(self, mock_generate_pdf):
        """QA-C6: Handler extracts proposalId from SQS body and calls generate_pdf."""
        mock_generate_pdf.return_value = None

        event = make_sqs_event({"payload": {"proposalId": "abc-123"}})
        result = pdf_generate_app.handler(event, None)

        mock_generate_pdf.assert_called_once_with("abc-123")
        assert result["batchItemFailures"] == []

    @patch.object(pdf_generate_app, "generate_pdf")
    def test_handler_processes_multiple_records(self, mock_generate_pdf):
        """QA-C6: Handler processes all records in an SQS batch."""
        mock_generate_pdf.return_value = None

        event = make_sqs_event(
            {"payload": {"proposalId": "id-1"}},
            {"payload": {"proposalId": "id-2"}},
            {"payload": {"proposalId": "id-3"}},
        )
        result = pdf_generate_app.handler(event, None)

        assert mock_generate_pdf.call_count == 3
        assert result["batchItemFailures"] == []

    @patch.object(pdf_generate_app, "generate_pdf")
    def test_handler_returns_batch_failures_on_error(self, mock_generate_pdf):
        """QA-C6: Handler returns failed message IDs for partial batch failure."""
        mock_generate_pdf.side_effect = [None, Exception("PDF generation failed"), None]

        event = make_sqs_event(
            {"payload": {"proposalId": "id-1"}},
            {"payload": {"proposalId": "id-2"}},
            {"payload": {"proposalId": "id-3"}},
        )
        result = pdf_generate_app.handler(event, None)

        assert len(result["batchItemFailures"]) == 1
        assert result["batchItemFailures"][0]["itemIdentifier"] == "msg-1"

    @patch.object(pdf_generate_app, "generate_pdf")
    def test_handler_handles_malformed_body(self, mock_generate_pdf):
        """QA-C6: Handler reports failure for records with invalid JSON body."""
        event = {
            "Records": [
                {
                    "messageId": "msg-bad",
                    "body": "not-valid-json",
                    "receiptHandle": "handle-0",
                }
            ]
        }
        result = pdf_generate_app.handler(event, None)

        assert len(result["batchItemFailures"]) == 1
        assert result["batchItemFailures"][0]["itemIdentifier"] == "msg-bad"
        mock_generate_pdf.assert_not_called()

    @patch.object(pdf_generate_app, "generate_pdf")
    def test_handler_handles_missing_proposal_id(self, mock_generate_pdf):
        """QA-C6: Handler reports failure when proposalId is missing from payload."""
        event = make_sqs_event({"payload": {}})
        result = pdf_generate_app.handler(event, None)

        assert len(result["batchItemFailures"]) == 1
        mock_generate_pdf.assert_not_called()

    @patch.object(pdf_generate_app, "generate_pdf")
    def test_handler_handles_empty_records(self, mock_generate_pdf):
        """QA-C6: Handler handles empty Records array gracefully."""
        result = pdf_generate_app.handler({"Records": []}, None)

        assert result["batchItemFailures"] == []
        mock_generate_pdf.assert_not_called()

    @patch.object(pdf_generate_app, "generate_pdf")
    def test_handler_handles_body_without_payload_wrapper(self, mock_generate_pdf):
        """QA-C6: Handler supports body with proposalId at top level (no payload wrapper)."""
        mock_generate_pdf.return_value = None

        event = make_sqs_event({"proposalId": "direct-id"})
        result = pdf_generate_app.handler(event, None)

        mock_generate_pdf.assert_called_once_with("direct-id")
        assert result["batchItemFailures"] == []


class TestPdfGenerateHelpers:
    """Test helper functions in the pdf-generate Lambda."""

    @patch.object(pdf_generate_app, "_retry_request")
    def test_fetch_proposal_returns_dict_on_200(self, mock_retry):
        """QA-C6: fetch_proposal returns proposal dict on 200 response."""
        mock_response = MagicMock()
        mock_response.status_code = 200
        mock_response.json.return_value = {"id": "abc", "proposalNumber": "P-001"}
        mock_retry.return_value = mock_response

        result = pdf_generate_app.fetch_proposal("abc")

        assert result is not None
        assert result["proposalNumber"] == "P-001"

    @patch.object(pdf_generate_app, "_retry_request")
    def test_fetch_proposal_returns_none_on_404(self, mock_retry):
        """QA-C6: fetch_proposal returns None when API returns 404."""
        mock_response = MagicMock()
        mock_response.status_code = 404
        mock_retry.return_value = mock_response

        result = pdf_generate_app.fetch_proposal("nonexistent")

        assert result is None

    @patch.object(pdf_generate_app, "_retry_request")
    def test_fetch_proposal_returns_none_on_exception(self, mock_retry):
        """QA-C6: fetch_proposal returns None on network error."""
        mock_retry.side_effect = Exception("Connection refused")

        result = pdf_generate_app.fetch_proposal("abc")

        assert result is None