package documentupload

import (
	"context"
	"io"
	"mime"
	"path/filepath"
	"time"

	"queryorchestration/internal/database/repository"
	"queryorchestration/internal/serviceconfig/objectstore"

	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5/pgtype"
)

type File struct {
	ClientID string
	Content  io.Reader
	BatchID  *uuid.UUID // Optional batch ID for batch processing
	Filename string     // Original filename for MIME type detection
}

// detectContentType determines the MIME type based on file extension
func detectContentType(filename string) string {
	// Use Go's standard library to detect MIME type from extension
	contentType := mime.TypeByExtension(filepath.Ext(filename))
	if contentType == "" {
		// Default to binary if extension is unknown
		return "application/octet-stream"
	}
	return contentType
}

func (s *Service) Upload(ctx context.Context, file File) error {
	_, err := s.UploadAndReturnKey(ctx, file)
	return err
}

// UploadAndReturnKey uploads a file and returns the BucketKey used
func (s *Service) UploadAndReturnKey(ctx context.Context, file File) (objectstore.BucketKey, error) {
	var key objectstore.BucketKey
	err := s.cfg.ExecuteDBTransaction(ctx, func(ctx context.Context, q *repository.Queries) error {
		now := time.Now().UTC()
		part, err := s.cfg.GetDBQueries().GetDocumentUploadCurrentPart(ctx, &repository.GetDocumentUploadCurrentPartParams{
			Clientid: &file.ClientID,
			Querydate: pgtype.Timestamptz{
				Valid: true,
				Time:  now,
			},
		})
		if err != nil {
			return err
		}

		uploadId := uuid.New()
		newPart := s.cfg.GetDirectoryPart(part.Part, part.Count)
		key = objectstore.BucketKey{
			ClientID:  file.ClientID,
			Location:  objectstore.Import,
			CreatedAt: now,
			EntityID:  uploadId,
			Part:      &newPart,
			BatchID:   file.BatchID,
		}
		keyStr := key.String()
		bucket := s.cfg.GetBucket()

		err = q.AddDocumentUpload(ctx, &repository.AddDocumentUploadParams{
			ID:       uploadId,
			Clientid: file.ClientID,
			Bucket:   bucket,
			Key:      keyStr,
			Part:     newPart,
			Createdat: pgtype.Timestamp{
				Valid: true,
				Time:  now,
			},
			Filename: &file.Filename,
			BatchID:  file.BatchID,
		})
		if err != nil {
			return err
		}

		// Detect content type from original filename
		contentType := detectContentType(file.Filename)

		// Prepare metadata for S3 object
		metadata := make(map[string]string)
		if file.Filename != "" {
			metadata["original-filename"] = file.Filename
		}

		_, err = s.cfg.GetStoreClient().PutObject(ctx, &s3.PutObjectInput{
			Bucket:      &bucket,
			Key:         &keyStr,
			Body:        file.Content,
			ContentType: &contentType,
			Metadata:    metadata,
		})
		if err != nil {
			return err
		}

		return nil
	})

	return key, err
}