feat: complete API-driven projects with infrastructure and business acceptance

examples/userService/internal/service/user/exportUser.go

@@ -0,0 +1,40 @@
+package user
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"example.com/userService/internal/types"
+	"fmt"
+	"strings"
+	"time"
+)
+
+func (s *Service) ExportUser(ctx context.Context, req *types.UserIDReq) (*types.ExportResp, error) {
+	u, err := s.GetUser(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	payload, err := json.Marshal(u)
+	if err != nil {
+		return nil, s.failure(ctx, err)
+	}
+	var nonce [16]byte
+	if _, err = rand.Read(nonce[:]); err != nil {
+		return nil, s.failure(ctx, err)
+	}
+	key := fmt.Sprintf("exports/users/%d/%s.txt", u.ID, hex.EncodeToString(nonce[:]))
+	if _, err = s.deps.Uploads.Put(ctx, key, strings.NewReader(string(payload)), int64(len(payload)), "text/plain"); err != nil {
+		return nil, s.failure(ctx, err)
+	}
+	url, err := s.deps.Downloads.PresignGet(ctx, key, 5*time.Minute)
+	if err != nil {
+		cleanup, cancel := context.WithTimeout(context.WithoutCancel(ctx), 2*time.Second)
+		defer cancel()
+		_ = s.deps.Files.Delete(cleanup, key)
+		return nil, s.failure(ctx, err)
+	}
+	s.deps.Logger.InfoContext(ctx, "user.exported", "userId", u.ID)
+	return &types.ExportResp{DownloadURL: url.String()}, nil
+}