package storage

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"path/filepath"
	"time"

	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/google/uuid"

	"queryorchestration/internal/serviceconfig/objectstore"
)

type Service struct {
	cfg objectstore.ConfigProvider
}

type StorageResult struct {
	Bucket    string
	Key       string
	SizeBytes int64
}

func New(cfg objectstore.ConfigProvider) *Service {
	return &Service{cfg: cfg}
}

// StoreZIPFile uploads ZIP file to S3 and returns storage metadata
func (s *Service) StoreZIPFile(ctx context.Context, clientID string, filename string, content io.Reader) (*StorageResult, error) {
	// Create unique S3 key with timestamp and UUID
	timestamp := time.Now().Format("2006/01/02/15")
	batchID := uuid.New()
	key := fmt.Sprintf("batches/%s/%s/%s-%s", clientID, timestamp, batchID.String(), filename)

	// Get bucket from existing configuration
	bucketName := s.cfg.GetBucket()

	// Read content to get size (required for S3 PutObject)
	buf := &bytes.Buffer{}
	size, err := io.Copy(buf, content)
	if err != nil {
		return nil, fmt.Errorf("failed to read file content: %w", err)
	}

	// Upload to S3 using the store client
	_, err = s.cfg.GetStoreClient().PutObject(ctx, &s3.PutObjectInput{
		Bucket: &bucketName,
		Key:    &key,
		Body:   bytes.NewReader(buf.Bytes()),
	})
	if err != nil {
		return nil, fmt.Errorf("failed to upload ZIP to S3: %w", err)
	}

	return &StorageResult{
		Bucket:    bucketName,
		Key:       key,
		SizeBytes: size,
	}, nil
}

// ValidateZIPFile performs basic ZIP file validation
func (s *Service) ValidateZIPFile(filename string, sizeBytes int64) error {
	// Check file extension
	ext := filepath.Ext(filename)
	if ext != ".zip" {
		return fmt.Errorf("invalid file type: expected .zip, got %s", ext)
	}

	// Check file size (100MB limit for Part 1)
	const maxSizeBytes = 100 * 1024 * 1024 // 100MB
	if sizeBytes > maxSizeBytes {
		return fmt.Errorf("file too large: %d bytes exceeds limit of %d bytes", sizeBytes, maxSizeBytes)
	}

	if sizeBytes == 0 {
		return fmt.Errorf("empty file not allowed")
	}

	return nil
}