[hw-8] add: repo layer

comments/infra/repository/sqlc/repository.go

@@ -0,0 +1,148 @@
+package sqlc
+
+import (
+	"context"
+	"errors"
+	"sort"
+
+	"route256/comments/internal/domain/entity"
+	"route256/comments/internal/domain/model"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/rs/zerolog/log"
+)
+
+type commentsRepo struct {
+	shard1 *pgxpool.Pool
+	shard2 *pgxpool.Pool
+}
+
+func NewCommentsRepository(shard1, shard2 *pgxpool.Pool) *commentsRepo {
+	return &commentsRepo{
+		shard1: shard1,
+		shard2: shard2,
+	}
+}
+
+func (r *commentsRepo) pickShard(sku int64) *pgxpool.Pool {
+	if sku%2 == 0 {
+		return r.shard1
+	}
+
+	return r.shard2
+}
+
+func (r *commentsRepo) GetCommentByID(ctx context.Context, id int64) (*Comment, error) {
+	q1 := New(r.shard1)
+	c, err := q1.GetCommentByID(ctx, id)
+	switch {
+	case err == nil:
+		return c, nil
+	case errors.Is(err, pgx.ErrNoRows):
+		log.Trace().Msgf("comment with id %d not found in shard 1", id)
+	default:
+		return nil, err
+	}
+
+	q2 := New(r.shard2)
+	c2, err2 := q2.GetCommentByID(ctx, id)
+	switch {
+	case err2 == nil:
+		return c2, nil
+	case errors.Is(err2, pgx.ErrNoRows):
+		return nil, model.ErrCommentNotFound
+	default:
+		return nil, err2
+	}
+}
+
+func (r *commentsRepo) InsertComment(ctx context.Context, comment *entity.Comment) (*Comment, error) {
+	shard := r.pickShard(comment.SKU)
+	q := New(shard)
+
+	req := &InsertCommentParams{
+		UserID: comment.UserID,
+		Sku:    comment.SKU,
+		Text:   comment.Text,
+	}
+
+	c, err := q.InsertComment(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	return c, nil
+}
+
+func (r *commentsRepo) ListCommentsBySku(ctx context.Context, sku int64) ([]*Comment, error) {
+	shard := r.pickShard(sku)
+	q := New(shard)
+
+	list, err := q.ListCommentsBySku(ctx, sku)
+	if err != nil {
+		return nil, err
+	}
+
+	out := make([]*Comment, len(list))
+	copy(out, list)
+
+	return out, nil
+}
+
+func (r *commentsRepo) ListCommentsByUser(ctx context.Context, userID int64) ([]*Comment, error) {
+	q1 := New(r.shard1)
+	l1, err1 := q1.ListCommentsByUser(ctx, userID)
+	if err1 != nil {
+		return nil, err1
+	}
+
+	q2 := New(r.shard2)
+	l2, err2 := q2.ListCommentsByUser(ctx, userID)
+	if err2 != nil {
+		return nil, err2
+	}
+
+	merged := make([]*Comment, 0, len(l1)+len(l2))
+	merged = append(merged, l1...)
+	merged = append(merged, l2...)
+
+	sort.Slice(merged, func(i, j int) bool {
+		if merged[i].CreatedAt.Time.Equal(merged[j].CreatedAt.Time) {
+			return merged[i].UserID < merged[j].UserID
+		}
+
+		return merged[i].CreatedAt.Time.After(merged[j].CreatedAt.Time)
+	})
+
+	return merged, nil
+}
+
+func (r *commentsRepo) UpdateComment(ctx context.Context, comment *entity.Comment) (*Comment, error) {
+	req := &UpdateCommentParams{
+		ID:   comment.ID,
+		Text: comment.Text,
+	}
+
+	q1 := New(r.shard1)
+	c, err := q1.UpdateComment(ctx, req)
+	switch {
+	case err == nil:
+		return c, nil
+	case errors.Is(err, pgx.ErrNoRows):
+		log.Trace().Msgf("comment with id %d not found in shard 1", req.ID)
+	default:
+		return nil, err
+	}
+
+	q2 := New(r.shard2)
+	c2, err2 := q2.UpdateComment(ctx, req)
+	switch {
+	case err2 == nil:
+		return c2, nil
+	case errors.Is(err2, pgx.ErrNoRows):
+		return nil, model.ErrCommentNotFound
+	default:
+		return nil, err2
+	}
+}