Implemented Vote pg repo

cmd/server/main.go

@@ -51,7 +51,7 @@ func main() {
 
 	articles := article.NewUsecase(repo)
 	comments := comment.NewUsecase(repo)
-	votes := vote.NewUsecase(nil)
+	votes := vote.NewUsecase(repo)
 	users := user.NewUsecase()
 
 	res := resolver.NewRootResolvers(log, articles, comments, users, votes)

internal/repository/pg/vote.go

@@ -0,0 +1,55 @@
+package pg
+
+import (
+	"context"
+	"fmt"
+	"github.com/darleet/blog-graphql/internal/model"
+	"github.com/darleet/blog-graphql/pkg/errors"
+)
+
+func parseValue(value model.VoteValue) int {
+	switch value {
+	case model.VoteValueUp:
+		return 1
+	case model.VoteValueDown:
+		return -1
+	default:
+		return 0
+	}
+}
+
+func (r *Repository) SetArticleVote(ctx context.Context, userID string, input model.VoteArticle) (int, error) {
+	q := `
+		INSERT INTO articles_votes (article_id, author_id, value) VALUES ($1, $2, $3)  
+		ON CONFLICT (article_id, author_id) DO UPDATE SET value = $3 
+		RETURNING (SELECT COALESCE(SUM(value), 0) FROM articles_votes WHERE article_id = $1)
+	`
+
+	value := parseValue(input.Value)
+
+	var votes int
+	err := r.pool.QueryRow(ctx, q, input.ArticleID, userID, value).Scan(&votes)
+
+	if err != nil {
+		return 0, errors.NewInternalServerError(fmt.Errorf("VoteRepository.SetArticleVote: %w", err))
+	}
+	return votes, nil
+}
+
+func (r *Repository) SetCommentVote(ctx context.Context, userID string, input model.VoteComment) (int, error) {
+	q := `
+		INSERT INTO comments_votes (comment_id, author_id, value) VALUES ($1, $2, $3)  
+		ON CONFLICT (comment_id, author_id) DO UPDATE SET value = $3 
+		RETURNING (SELECT COALESCE(SUM(value), 0) FROM comments_votes WHERE comment_id = $1)
+	`
+
+	value := parseValue(input.Value)
+
+	var votes int
+	err := r.pool.QueryRow(ctx, q, input.CommentID, userID, value).Scan(&votes)
+
+	if err != nil {
+		return 0, errors.NewInternalServerError(fmt.Errorf("VoteRepository.SetCommentVote: %w", err))
+	}
+	return votes, nil
+}