wpmind/includes/Providers/Image/GeminiImageProvider.php

<?php
/**
 * Google Gemini Image Provider
 *
 * @package WPMind
 * @since 2.4.0
 */

declare(strict_types=1);

namespace WPMind\Providers\Image;

defined( 'ABSPATH' ) || exit;

/**
 * Google Gemini Image Provider
 */
class GeminiImageProvider extends AbstractImageProvider {

	protected string $id       = 'google_gemini_image';
	protected string $name     = 'Gemini Pro Image';
	protected string $base_url = 'https://generativelanguage.googleapis.com/v1/';
	protected array $models    = [ 'gemini-3-pro-image', 'imagen-3' ];

	/**
	 * {@inheritdoc}
	 */
	protected function getHeaders(): array {
		// Gemini 使用 API Key 作为查询参数，不需要 Authorization header
		return [
			'Content-Type' => 'application/json',
		];
	}

	/**
	 * 获取带 API Key 的 URL
	 */
	private function getUrlWithKey( string $endpoint ): string {
		return $this->base_url . ltrim( $endpoint, '/' ) . '?key=' . $this->api_key;
	}

	/**
	 * {@inheritdoc}
	 */
	public function generate( string $prompt, array $options = [] ): array {
		$model = $options['model'] ?? 'imagen-3';

		$url = $this->getUrlWithKey( 'models/' . $model . ':generateContent' );

		$response = wp_remote_post(
			$url,
			[
				'timeout' => $this->timeout,
				'headers' => $this->getHeaders(),
				'body'    => wp_json_encode(
					[
						'contents'         => [
							[
								'parts' => [
									[ 'text' => $prompt ],
								],
							],
						],
						'generationConfig' => [
							'responseModalities' => [ 'image' ],
						],
					]
				),
			]
		);

		if ( is_wp_error( $response ) ) {
			return [
				'success' => false,
				'error'   => $response->get_error_message(),
			];
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );

		// 提取图像数据
		$images = $body['candidates'][0]['content']['parts'] ?? [];
		$urls   = [];

		foreach ( $images as $part ) {
			if ( isset( $part['inlineData'] ) ) {
				// Base64 编码的图像
				$urls[] = 'data:' . $part['inlineData']['mimeType'] . ';base64,' . $part['inlineData']['data'];
			}
		}

		if ( empty( $urls ) ) {
			return [
				'success' => false,
				'error'   => $body['error']['message'] ?? '生成失败',
			];
		}

		return [
			'success' => true,
			'urls'    => $urls,
			'url'     => $urls[0] ?? '',
		];
	}

	/**
	 * {@inheritdoc}
	 */
	public function testConnection(): array {
		$url = $this->getUrlWithKey( 'models' );

		$response = wp_remote_get(
			$url,
			[
				'timeout' => 30,
				'headers' => $this->getHeaders(),
			]
		);

		if ( is_wp_error( $response ) ) {
			return [
				'success' => false,
				'message' => $response->get_error_message(),
			];
		}

		$status = wp_remote_retrieve_response_code( $response );

		if ( $status === 200 ) {
			return [
				'success' => true,
				'message' => '连接成功',
			];
		}
		if ( $status === 400 || $status === 403 ) {
			return [
				'success' => false,
				'message' => 'API Key 无效',
			];
		}

		return [
			'success' => false,
			'message' => '连接失败 (HTTP ' . $status . ')',
		];
	}
}