[PRMP-594] Get Document by ID (#858)

FoxMaltas-NHS · adamwhitingnhs · web-flow · commit 89cd2ca1d3c6 · 2025-11-27T16:38:45.000Z
Co-authored-by: adamwhitingnhs &lt;adam.whiting3@nhs.net&gt;
diff --git a/.github/workflows/base-lambdas-reusable-deploy-all.yml b/.github/workflows/base-lambdas-reusable-deploy-all.yml
@@ -682,3 +682,17 @@ jobs:
       lambda_layer_names: "core_lambda_layer"
     secrets:
       AWS_ASSUME_ROLE: ${{ secrets.AWS_ASSUME_ROLE }}
+    
+  deploy_get_document_reference_by_id_lambda:
+    name: Deploy get_document_reference_lambda
+    uses: ./.github/workflows/base-lambdas-reusable-deploy.yml
+    with:
+      environment: ${{ inputs.environment}}
+      python_version: ${{ inputs.python_version }}
+      build_branch: ${{ inputs.build_branch}}
+      sandbox: ${{ inputs.sandbox }}
+      lambda_handler_name: get_document_reference_handler
+      lambda_aws_name: GetDocRefLambda
+      lambda_layer_names: "core_lambda_layer"
+    secrets:
+      AWS_ASSUME_ROLE: ${{ secrets.AWS_ASSUME_ROLE }}
diff --git a/lambdas/handlers/get_document_reference_handler.py b/lambdas/handlers/get_document_reference_handler.py
@@ -0,0 +1,55 @@
+from utils.decorators.handle_lambda_exceptions import handle_lambda_exceptions
+from utils.decorators.override_error_check import override_error_check
+from services.feature_flags_service import FeatureFlagService
+from enums.feature_flags import FeatureFlags
+from services.get_document_reference_service import GetDocumentReferenceService
+from utils.decorators.validate_patient_id import validate_patient_id
+from utils.lambda_exceptions import FeatureFlagsException
+from enums.lambda_error import LambdaError
+from utils.lambda_exceptions import GetDocumentRefException
+from utils.lambda_response import ApiGatewayResponse
+from utils.decorators.ensure_env_var import ensure_environment_variables
+from utils.decorators.set_audit_arg import set_request_context_for_logging
+from enums.logging_app_interaction import LoggingAppInteraction
+from utils.audit_logging_setup import LoggingService
+from utils.request_context import request_context
+import json
+
+logger = LoggingService(__name__)
+
+@validate_patient_id
+@handle_lambda_exceptions
+@set_request_context_for_logging
+@ensure_environment_variables(
+    names=[
+        "LLOYD_GEORGE_DYNAMODB_NAME",
+        "PRESIGNED_ASSUME_ROLE",
+        "APPCONFIG_APPLICATION",
+        "APPCONFIG_ENVIRONMENT",
+        "APPCONFIG_CONFIGURATION",
+        "EDGE_REFERENCE_TABLE",
+        "CLOUDFRONT_URL",
+    ]
+)
+@override_error_check
+def lambda_handler(event: dict[str, any], context):
+    request_context.app_interaction = LoggingAppInteraction.VIEW_LG_RECORD.value
+
+    feature_flag_service = FeatureFlagService()
+    feature_flag_service.validate_feature_flag(FeatureFlags.UPLOAD_DOCUMENT_ITERATION_3_ENABLED)
+    
+    logger.info("Starting document fetch by ID process")
+
+    try:
+        document_id = event["pathParameters"]["id"]
+        nhs_number = event["queryStringParameters"]["patientId"]
+    except KeyError:
+        raise GetDocumentRefException(400, LambdaError.DocumentReferenceMissingParameters)
+    
+    service = GetDocumentReferenceService()
+
+    document_info = service.get_document_url_by_id(document_id, nhs_number)
+
+    return ApiGatewayResponse(
+        status_code=200, body=json.dumps(document_info), methods="GET"
+    ).create_api_gateway_response()
diff --git a/lambdas/services/feature_flags_service.py b/lambdas/services/feature_flags_service.py
@@ -155,4 +155,4 @@ def validate_feature_flag(self, flag_name: str):
 
         if not flag_object.get(flag_name, False):
             logger.info(f"Feature flag '{flag_name}' not enabled, event will not be processed")
-            raise FeatureFlagsException(404, LambdaError.FeatureFlagDisabled)
+            raise FeatureFlagsException(404, LambdaError.FeatureFlagDisabled)
diff --git a/lambdas/services/get_document_reference_service.py b/lambdas/services/get_document_reference_service.py
@@ -0,0 +1,83 @@
+import os
+import uuid
+from datetime import datetime, timezone
+from services.get_fhir_document_reference_service import (
+    GetFhirDocumentReferenceService,
+)
+from utils.audit_logging_setup import LoggingService
+from utils.lambda_exceptions import GetDocumentRefException
+from enums.lambda_error import LambdaError
+from utils.utilities import format_cloudfront_url
+from models.document_reference import DocumentReference
+from utils.dynamo_query_filter_builder import DynamoQueryFilterBuilder
+from enums.dynamo_filter import AttributeOperator
+from utils.common_query_filters import NotDeleted
+
+logger = LoggingService(__name__)
+
+class GetDocumentReferenceService:
+    def __init__(self):
+        self.fhir_doc_service = GetFhirDocumentReferenceService()
+        self.document_service = self.fhir_doc_service.document_service
+        self.dynamo_service = self.document_service.dynamo_service
+        self.s3_service = self.fhir_doc_service.s3_service
+        self.lg_table = os.environ.get("LLOYD_GEORGE_DYNAMODB_NAME")
+        self.cloudfront_table_name = os.environ.get("EDGE_REFERENCE_TABLE")
+        self.cloudfront_url = os.environ.get("CLOUDFRONT_URL")
+
+    def get_document_url_by_id(self, document_id: str, nhs_number: str):
+        document_reference = self.get_document_reference(document_id, nhs_number)
+        
+        presigned_s3_url = self.create_document_presigned_url(
+            document_reference.s3_bucket_name,
+            document_reference.s3_file_key
+            )
+        
+        return {
+            "url": presigned_s3_url,
+            "contentType": document_reference.content_type
+        }
+    
+    def create_document_presigned_url(self, bucket_name, file_location):
+        presigned_url_response = self.s3_service.create_download_presigned_url(
+            s3_bucket_name=bucket_name,
+            file_key=file_location,
+        )
+
+        presigned_id = str(uuid.uuid4())
+        deletion_date = datetime.now(timezone.utc)
+
+        ttl_half_an_hour_in_seconds = self.s3_service.presigned_url_expiry
+        dynamo_item_ttl = int(deletion_date.timestamp() + ttl_half_an_hour_in_seconds)
+        self.dynamo_service.create_item(
+            self.cloudfront_table_name,
+            {
+                "ID": presigned_id,
+                "presignedUrl": presigned_url_response,
+                "TTL": dynamo_item_ttl,
+            },
+        )
+        return format_cloudfront_url(presigned_id, self.cloudfront_url)
+    
+    def get_document_reference(self, document_id: str, nhs_number: str) -> DocumentReference:
+        filter_builder = DynamoQueryFilterBuilder()
+        filter_builder.add_condition("DocStatus", AttributeOperator.EQUAL, "final")
+        filter_builder.add_condition("NhsNumber", AttributeOperator.EQUAL, nhs_number)
+
+        table_filter = filter_builder.build()
+
+        table_filter = table_filter & NotDeleted
+
+        documents = self.document_service.fetch_documents_from_table(
+            table_name=self.lg_table,
+            search_condition=document_id,
+            search_key="ID",
+            query_filter=table_filter,
+        )
+        if len(documents) > 0:
+            logger.info("Document found for given id")
+            return documents[0]
+        else:
+            raise GetDocumentRefException(
+                404, LambdaError.DocumentReferenceNotFound
+            )
diff --git a/lambdas/tests/unit/conftest.py b/lambdas/tests/unit/conftest.py
@@ -140,6 +140,8 @@
 MOCK_DOCUMENT_REVIEW_BUCKET = "test_document_review_bucket"
 MOCK_EDGE_TABLE = "test_edge_reference_table"
 
+MOCK_EDGE_REFERENCE_TABLE = "test_edge_reference_table"
+
 @pytest.fixture
 def set_env(monkeypatch):
     monkeypatch.setenv("AWS_DEFAULT_REGION", REGION_NAME)
@@ -232,6 +234,7 @@ def set_env(monkeypatch):
     monkeypatch.setenv("EDGE_REFERENCE_TABLE", MOCK_EDGE_TABLE)
     monkeypatch.setenv("STAGING_STORE_BUCKET_NAME", MOCK_STAGING_STORE_BUCKET)
     monkeypatch.setenv("METADATA_SQS_QUEUE_URL", MOCK_LG_METADATA_SQS_QUEUE)
+    monkeypatch.setenv("EDGE_REFERENCE_TABLE", MOCK_EDGE_REFERENCE_TABLE)
 
 EXPECTED_PARSED_PATIENT_BASE_CASE = PatientDetails(
     givenName=["Jane"],
diff --git a/lambdas/tests/unit/handlers/test_get_document_reference_handler.py b/lambdas/tests/unit/handlers/test_get_document_reference_handler.py
@@ -0,0 +1,154 @@
+import pytest
+import json
+import os
+from unittest.mock import patch
+from handlers.get_document_reference_handler import lambda_handler
+from utils.lambda_exceptions import GetDocumentRefException
+from enums.feature_flags import FeatureFlags
+from utils.lambda_response import ApiGatewayResponse
+from utils.lambda_exceptions import FeatureFlagsException
+from enums.lambda_error import LambdaError
+from utils.error_response import ErrorResponse
+
+
+@pytest.fixture
+def mock_feature_flag_service(mocker):
+    yield mocker.patch("handlers.get_document_reference_handler.FeatureFlagService").return_value
+
+@pytest.fixture
+def mock_get_document_service(mocker):
+    yield mocker.patch(
+        "handlers.get_document_reference_handler.GetDocumentReferenceService"
+        ).return_value
+    
+@pytest.fixture
+def mock_valid_nhs_number():
+    yield "4407064188"
+
+@pytest.fixture
+def feature_flag():
+    yield FeatureFlags.UPLOAD_DOCUMENT_ITERATION_3_ENABLED
+
+@pytest.fixture
+def mock_interaction_id():
+    yield "88888888-4444-4444-4444-121212121212"
+
+@pytest.fixture
+def mocked_bad_env_vars():
+    env_vars = {
+        #"LLOYD_GEORGE_DYNAMODB_NAME": "mock_dynamodb_name",
+        "PRESIGNED_ASSUME_ROLE": "mock_presigned_role",
+        "APPCONFIG_APPLICATION": "mock_value",
+        "APPCONFIG_ENVIRONMENT": "mock_value",
+        "APPCONFIG_CONFIGURATION": "mock_value",
+        "EDGE_REFERENCE_TABLE": "mock_value",
+        "CLOUDFRONT_URL": "mock_value",
+    }
+
+    with patch.dict(os.environ, env_vars):
+        yield "LLOYD_GEORGE_DYNAMODB_NAME"
+
+
+
+def test_handler_valid_request_returns_200(
+        valid_id_event_with_auth_header,
+        mock_feature_flag_service,
+        mock_get_document_service,
+        mock_valid_nhs_number,
+        context,
+        set_env,
+        feature_flag
+        ):
+    mock_document_id = "1"
+    valid_id_event_with_auth_header["pathParameters"] = {"id": mock_document_id}
+    valid_id_event_with_auth_header["queryStringParameters"]["patientId"] = mock_valid_nhs_number
+    mock_presigned_s3_url = "https://mock.url/"
+    mock_content_type = "application/pdf"
+
+    expected_body = {
+        "url": mock_presigned_s3_url,
+        "contentType": mock_content_type
+    }
+
+    expected_result = ApiGatewayResponse(
+        status_code=200, body=json.dumps(expected_body), methods="GET"
+    ).create_api_gateway_response()
+
+    mock_get_document_service.get_document_url_by_id.return_value = expected_body
+
+    result = lambda_handler(valid_id_event_with_auth_header, context)
+
+    assert result == expected_result
+    assert result["body"] == json.dumps(expected_body)
+
+    mock_feature_flag_service.validate_feature_flag.assert_called_once_with(
+        feature_flag
+        )
+    mock_get_document_service.get_document_url_by_id.assert_called_once_with(
+        mock_document_id,
+        mock_valid_nhs_number)
+
+def test_missing_nhs_number_errors(
+        valid_id_event_with_auth_header,
+        mock_feature_flag_service,
+        context,
+        set_env,
+        feature_flag,
+    ):
+    valid_id_event_with_auth_header["pathParameters"] = {"id": "1"}
+    valid_id_event_with_auth_header["queryStringParameters"].pop("patientId")
+
+    expected_result = ApiGatewayResponse(
+        status_code=400,
+        body=LambdaError.PatientIdNoKey.create_error_body(),
+        methods="GET",
+    ).create_api_gateway_response()
+
+    result = lambda_handler(valid_id_event_with_auth_header, context)
+
+    assert result == expected_result
+
+def test_missing_document_id_errors(
+        valid_id_event_with_auth_header,
+        mock_feature_flag_service,
+        mock_valid_nhs_number,
+        context,
+        set_env,
+        feature_flag,
+        mock_interaction_id
+    ):
+    valid_id_event_with_auth_header["pathParameters"] = {}
+    valid_id_event_with_auth_header["queryStringParameters"]["patientId"] = mock_valid_nhs_number
+
+    expected_error = GetDocumentRefException(400, LambdaError.DocumentReferenceMissingParameters)
+
+    expected_result = ApiGatewayResponse(
+        status_code=400,
+        body=ErrorResponse(
+            err_code=expected_error.err_code,
+            message=expected_error.message,
+            interaction_id=mock_interaction_id
+        ).create(),
+        methods="GET"
+    ).create_api_gateway_response()
+
+    mock_feature_flag_service.get_feature_flags_by_flag.return_value = {feature_flag: True}
+
+    result = lambda_handler(valid_id_event_with_auth_header, context)
+
+    assert result == expected_result
+
+def test_env_vars_not_set_errors(
+        valid_id_event_with_auth_header,
+        context,
+        mocked_bad_env_vars
+    ):
+    expected_result = ApiGatewayResponse(
+        status_code=500,
+        body=LambdaError.EnvMissing.create_error_body({"name": mocked_bad_env_vars}),
+        methods="GET"
+    ).create_api_gateway_response()
+
+    result = lambda_handler(valid_id_event_with_auth_header, context)
+
+    assert result == expected_result
diff --git a/lambdas/tests/unit/services/test_get_document_reference_service.py b/lambdas/tests/unit/services/test_get_document_reference_service.py
diff --git a/lambdas/utils/lambda_exceptions.py b/lambdas/utils/lambda_exceptions.py
