food-ai/backend/internal/adapters/pexels/client.go

package pexels

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"time"
)

const (
	pexelsSearchURL    = "https://api.pexels.com/v1/search"
	defaultPlaceholder = "https://images.pexels.com/photos/1640777/pexels-photo-1640777.jpeg?auto=compress&cs=tinysrgb&w=1260&h=750"
)

// PhotoSearcher can search for a photo by text query.
type PhotoSearcher interface {
	SearchPhoto(ctx context.Context, query string) (string, error)
}

// Client is an HTTP client for the Pexels Photos API.
type Client struct {
	apiKey     string
	httpClient *http.Client
}

// NewClient creates a new Pexels client.
func NewClient(apiKey string) *Client {
	return &Client{
		apiKey: apiKey,
		httpClient: &http.Client{
			Timeout: 10 * time.Second,
		},
	}
}

// SearchPhoto searches for a landscape photo matching query.
// Returns a default placeholder URL if no photo is found or on error.
func (c *Client) SearchPhoto(ctx context.Context, query string) (string, error) {
	params := url.Values{}
	params.Set("query", query)
	params.Set("per_page", "1")
	params.Set("orientation", "landscape")

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, pexelsSearchURL+"?"+params.Encode(), nil)
	if err != nil {
		return defaultPlaceholder, fmt.Errorf("create request: %w", err)
	}
	req.Header.Set("Authorization", c.apiKey)

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return defaultPlaceholder, fmt.Errorf("send request: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return defaultPlaceholder, fmt.Errorf("pexels API error: status %d", resp.StatusCode)
	}

	var result struct {
		Photos []struct {
			Src struct {
				Medium string `json:"medium"`
			} `json:"src"`
		} `json:"photos"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return defaultPlaceholder, fmt.Errorf("decode response: %w", err)
	}

	if len(result.Photos) == 0 || result.Photos[0].Src.Medium == "" {
		return defaultPlaceholder, nil
	}
	return result.Photos[0].Src.Medium, nil
}