package mrktplaats

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"mime/multipart"
)

// SaleabilityService handles image recognition for listings.
type SaleabilityService struct {
	t *transport
}

// Prediction is an image recognition result.
type Prediction struct {
	CategoryID   int     `json:"categoryId"`
	CategoryName string  `json:"categoryName"`
	Confidence   float64 `json:"confidence"`
	Attributes   []any   `json:"attributes"`
}

// RecognizeResponse contains image recognition predictions.
type RecognizeResponse struct {
	Predictions []Prediction `json:"predictions"`
}

// Recognize uploads an image and returns category/attribute predictions.
// Large images are automatically compressed to stay within the API size limit.
func (s *SaleabilityService) Recognize(ctx context.Context, img io.Reader, filename string) (*RecognizeResponse, error) {
	data, err := autoCompressImage(img)
	if err != nil {
		return nil, fmt.Errorf("mrktplaats: reading image: %w", err)
	}

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	part, err := w.CreateFormFile("picture", filename)
	if err != nil {
		return nil, fmt.Errorf("mrktplaats: creating form file: %w", err)
	}
	if _, err := io.Copy(part, bytes.NewReader(data)); err != nil {
		return nil, fmt.Errorf("mrktplaats: copying image: %w", err)
	}
	w.Close()

	var resp RecognizeResponse
	if err := s.t.postMultipart(ctx, "/app/saleability/v4/recognize", nil, nil, w.FormDataContentType(), &buf, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}