//go:build !dev

package s3

import (
	"context"
	"fmt"
	"io"
	"log"
	"os"
)

var Client Uploader

// FallbackToInMemory mirrors the dev-build flag so main.go can reference it
// in non-dev builds. It is always false here: the production/R2 build never
// uses the in-memory fallback client.
var FallbackToInMemory bool

// ClientIsStub reports whether the active client is the production stub that
// cannot perform real S3 operations. It is always true in the !dev build:
// every operation (Upload, Download, Delete) returns "not implemented" because
// the AWS SDK v2 is not compiled in. main.go uses it to warn at startup so the
// operator knows that profile-picture deletion will never succeed in this build.
var ClientIsStub = true

type Uploader interface {
	Upload(ctx context.Context, bucket, key string, body io.Reader, contentType string) error
	Download(ctx context.Context, bucket, key string, w io.Writer) error
	Delete(ctx context.Context, bucket, key string) error
	GetURL(ctx context.Context, bucket, key string) (string, error)
	HealthCheck(ctx context.Context) error
}

type S3Client struct {
	bucket    string
	endpoint  string
	region    string
	accessKey string
	secretKey string
	publicURL string
}

func Connect() error {
	endpoint := os.Getenv("R2_ENDPOINT")
	if endpoint == "" {
		log.Println("WARNING: R2_ENDPOINT not set, S3 client not initialized")
		return nil
	}

	Client = &S3Client{
		endpoint:  endpoint,
		bucket:    getEnv("R2_BUCKET", ""),
		region:    getEnv("AWS_REGION", "auto"),
		accessKey: getEnv("R2_ACCESS_KEY", ""),
		secretKey: getEnv("R2_SECRET_KEY", ""),
		publicURL: getEnv("R2_PUBLIC_URL", ""),
	}

	log.Printf("Connected to R2: bucket=%s, endpoint=%s", Client.(*S3Client).bucket, endpoint)
	return nil
}

func (s *S3Client) Upload(ctx context.Context, bucket, key string, body io.Reader, contentType string) error {
	return fmt.Errorf("not implemented: production S3 upload requires AWS SDK v2 (use RUSTFS in dev)")
}

func (s *S3Client) Download(ctx context.Context, bucket, key string, w io.Writer) error {
	return fmt.Errorf("not implemented: production S3 download requires AWS SDK v2 (use RUSTFS in dev)")
}

func (s *S3Client) Delete(ctx context.Context, bucket, key string) error {
	return fmt.Errorf("not implemented: production S3 delete requires AWS SDK v2 (use RUSTFS in dev)")
}

func (s *S3Client) GetURL(ctx context.Context, bucket, key string) (string, error) {
	return fmt.Sprintf("%s/%s/%s", s.publicURL, bucket, key), nil
}

func (s *S3Client) HealthCheck(_ context.Context) error {
	if s.endpoint == "" {
		return fmt.Errorf("S3 client not initialized: R2_ENDPOINT not set")
	}
	// Production stub — can't perform a real check without the SDK.
	// Actual operations (Upload, Download, Delete) will return errors.
	return nil
}

func getEnv(key, fallback string) string {
	if val := os.Getenv(key); val != "" {
		return val
	}
	if fallback != "" {
		return fallback
	}
	panic("Environment variable not set: " + key)
}