From eec73862a29ec7ba913fb62240bd94e891b5ddc4 Mon Sep 17 00:00:00 2001
From: Siddhartha Basu <siddhartha-basu@northwestern.edu>
Date: Thu, 15 Aug 2024 14:39:57 -0500
Subject: [PATCH] feat(service.go): add ListContents method to ContentService
 for content retrieval based on filters

The new `ListContents` method in `ContentService` allows fetching a list
of content entries based on provided filters and pagination parameters.
This method supports dynamic query generation based on the
`ListParameters` input, which includes a limit and a filter string.
---
 internal/app/service/service.go | 53 ++++++++++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 1 deletion(-)

diff --git a/internal/app/service/service.go b/internal/app/service/service.go
index 4a8c3bd..c9e2ec1 100644
--- a/internal/app/service/service.go
+++ b/internal/app/service/service.go
@@ -132,7 +132,8 @@ func (srv *ContentService) buildContent(
 				UpdatedAt: aphgrpc.TimestampProto(mcont.UpdatedOn),
 				Content:   mcont.Content,
 			},
-		}}
+		},
+	}
 }
 
 func (srv *ContentService) StoreContent(
@@ -190,6 +191,56 @@ func (srv *ContentService) DeleteContent(
 	return &empty.Empty{}, nil
 }
 
+func (srv *ContentService) ListContents(
+	ctx context.Context,
+	req *content.ListParameters,
+) (*content.ContentCollection, error) {
+	limit := int64(10)
+	if req.Limit > 0 {
+		limit = req.Limit
+	}
+	astmt, err := filterStrToQuery(req.Filter)
+	if err != nil {
+		return nil, aphgrpc.HandleInvalidParamError(ctx, err)
+	}
+	cntModel, err := srv.repo.ListContents(req.Cursor, limit, astmt)
+	if err != nil {
+		if repository.IsContentListNotFound(err) {
+			return nil, aphgrpc.HandleNotFoundError(ctx, err)
+		}
+	}
+	cntDataSlice := make([]*content.ContentCollection_Data, 0)
+	for _, cntD := range cntModel {
+		cntDataSlice = append(cntDataSlice, &content.ContentCollection_Data{
+			Id: cntD.Key,
+			Attributes: &content.ContentAttributes{
+				Name:      cntD.Name,
+				Namespace: cntD.Namespace,
+				Slug:      cntD.Slug,
+				CreatedBy: cntD.CreatedBy,
+				UpdatedBy: cntD.UpdatedBy,
+				Content:   cntD.Content,
+				CreatedAt: aphgrpc.TimestampProto(cntD.CreatedOn),
+				UpdatedAt: aphgrpc.TimestampProto(cntD.UpdatedOn),
+			},
+		})
+	}
+
+	cnt := &content.ContentCollection{}
+	if len(cntDataSlice) < int(limit)-2 { // fewer result than limit
+		cnt.Data = cntDataSlice
+		cnt.Meta = &content.Meta{Limit: req.Limit}
+		return cnt, nil
+	}
+	cnt.Data = cntDataSlice[:len(cntDataSlice)-1]
+	cnt.Meta = &content.Meta{
+		Limit:      limit,
+		NextCursor: cntModel[len(cntModel)-1].CreatedOn.UnixMilli(),
+	}
+
+	return cnt, nil
+}
+
 func filterStrToQuery(filter string) (string, error) {
 	var empty string
 	if len(filter) == 0 {