<?php
/**
 * AF Translate - Unified AI & Cloud Translation Engine Bridge
 *
 * Implements external API processing loops for OpenAI, DeepL, Google, 
 * Microsoft, Lecto AI, Anthropic (Claude), xAI (Grok), and Google Gemini.
 *
 * @package    AF_Translate
 * @subpackage AF_Translate/includes
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Prevent direct access
}

class AF_Translate_AI_Bridge {

	/**
	 * Route translation request to the active cloud engine configuration.
	 *
	 * @param string $text           The source string extracted by your tokenizer.
	 * @param string $target_locale  The destination ISO code / language tag (e.g., 'es', 'fr', 'ne').
	 * @return string|WP_Error       The localized text translation line or WordPress Error object.
	 */
	public static function translate_string( $text, $target_locale ) {
		// Clean up common system locale extensions for cloud engines (e.g., 'es_ES' to 'es')
		$target_lang = strtolower( substr( $target_locale, 0, 2 ) );
		$settings    = get_option( 'af_translate_api_settings', array() );
		$provider    = isset( $settings['active_provider'] ) ? sanitize_key( $settings['active_provider'] ) : '';

		if ( empty( $provider ) || 'none' === $provider ) {
			return new WP_Error( 'no_api_configured', __( 'No translation APIs configured.', 'af-translate' ) );
		}

		switch ( $provider ) {
			case 'deepl':
				return self::call_deepl( $text, $target_lang, $settings );
			case 'google':
				return self::call_google( $text, $target_lang, $settings );
			case 'lecto':
				return self::call_lecto( $text, $target_lang, $settings );
			case 'microsoft':
				return self::call_microsoft( $text, $target_lang, $settings );
			case 'openai':
				return self::call_openai( $text, $target_locale, $settings );
			case 'anthropic':
				return self::call_anthropic( $text, $target_locale, $settings );
			case 'grok':
				return self::call_grok( $text, $target_locale, $settings );
			case 'gemini':
				return self::call_gemini( $text, $target_locale, $settings );
			default:
				return new WP_Error( 'invalid_provider', __( 'Selected automatic translation provider is invalid.', 'af-translate' ) );
		}
	}

	/**
	 * 1. DEEPL TRANSLATOR API LOOP
	 */
	private static function call_deepl( $text, $target_lang, $settings ) {
		$api_key = isset( $settings['deepl_key'] ) ? trim( $settings['deepl_key'] ) : '';
		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'DeepL API key is empty.', 'af-translate' ) );
		}

		$is_free  = ( 'fx' === substr( strtolower( $api_key ), -2 ) );
		$endpoint = $is_free ? 'https://api-free.deepl.com/v2/translate' : 'https://api.deepl.com/v2/translate';

		$response = wp_remote_post( $endpoint, array(
			'timeout' => 15,
			'headers' => array(
				'Authorization' => 'DeepL-Auth-Key ' . $api_key,
				'Content-Type'  => 'application/json',
			),
			'body'    => json_encode( array(
				'text'        => array( $text ),
				'target_lang' => strtoupper( $target_lang ),
			) ),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body['translations'][0]['text'] ) ) {
			return $body['translations'][0]['text'];
		}

		return new WP_Error( 'api_error', isset( $body['message'] ) ? $body['message'] : __( 'DeepL compilation failed.', 'af-translate' ) );
	}

	/**
	 * 2. GOOGLE TRANSLATE v2 API LOOP
	 */
	private static function call_google( $text, $target_lang, $settings ) {
		$api_key = isset( $settings['google_key'] ) ? trim( $settings['google_key'] ) : '';
		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'Google Translate API key is empty.', 'af-translate' ) );
		}

		$url      = 'https://translation.googleapis.com/language/translate/v2?key=' . $api_key;
		$response = wp_remote_post( $url, array(
			'timeout' => 15,
			'body'    => array(
				'q'      => $text,
				'target' => $target_lang,
				'format' => 'text',
			),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body['data']['translations'][0]['translatedText'] ) ) {
			return html_entity_decode( $body['data']['translations'][0]['translatedText'], ENT_QUOTES, 'UTF-8' );
		}

		return new WP_Error( 'api_error', isset( $body['error']['message'] ) ? $body['error']['message'] : __( 'Google Translate request failed.', 'af-translate' ) );
	}

	/**
	 * 3. LECTO AI API LOOP
	 */
	private static function call_lecto( $text, $target_lang, $settings ) {
		$api_key = isset( $settings['lecto_key'] ) ? trim( $settings['lecto_key'] ) : '';
		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'Lecto AI API key is empty.', 'af-translate' ) );
		}

		$endpoint = 'https://api.lecto.ai/v1/translate/text';
		$response = wp_remote_post( $endpoint, array(
			'timeout' => 15,
			'headers' => array(
				'X-API-Key'    => $api_key,
				'Content-Type' => 'application/json',
			),
			'body'    => json_encode( array(
				'texts' => array( $text ),
				'to'    => array( $target_lang ),
			) ),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body['translations'][0]['to'][0]['translated'][0] ) ) {
			return $body['translations'][0]['to'][0]['translated'][0];
		}

		return new WP_Error( 'api_error', isset( $body['message'] ) ? $body['message'] : __( 'Lecto AI execution payload failed.', 'af-translate' ) );
	}

	/**
	 * 4. MICROSOFT TRANSLATOR v3 API LOOP
	 */
	private static function call_microsoft( $text, $target_lang, $settings ) {
		$api_key = isset( $settings['microsoft_key'] ) ? trim( $settings['microsoft_key'] ) : '';
		$region  = isset( $settings['microsoft_region'] ) ? trim( $settings['microsoft_region'] ) : 'global';

		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'Microsoft Translator API key is empty.', 'af-translate' ) );
		}

		$url      = 'https://api.cognitive.microsofttranslator.com/translate?api-version=3.0&to=' . $target_lang;
		$response = wp_remote_post( $url, array(
			'timeout' => 15,
			'headers' => array(
				'Ocp-Apim-Subscription-Key'    => $api_key,
				'Ocp-Apim-Subscription-Region' => $region,
				'Content-Type'                 => 'application/json',
			),
			'body'    => json_encode( array(
				array( 'Text' => $text ),
			) ),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body[0]['translations'][0]['text'] ) ) {
			return $body[0]['translations'][0]['text'];
		}

		return new WP_Error( 'api_error', isset( $body['error']['message'] ) ? $body['error']['message'] : __( 'Microsoft Translator verification failed.', 'af-translate' ) );
	}

	/**
	 * 5. OPENAI CHAT COMPLETIONS API LOOP
	 */
	private static function call_openai( $text, $target_locale, $settings ) {
		$api_key = isset( $settings['openai_key'] ) ? trim( $settings['openai_key'] ) : '';
		$model   = ! empty( $settings['openai_model'] ) ? trim( $settings['openai_model'] ) : 'gpt-4o-mini';
		$prompt  = ! empty( $settings['openai_custom_prompt'] ) ? $settings['openai_custom_prompt'] : 'Translate this WordPress string to {target_language}. Keep code/HTML placeholders identical.';

		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'OpenAI API key is empty.', 'af-translate' ) );
		}

		$resolved_prompt = str_replace( '{target_language}', $target_locale, $prompt );
		$endpoint        = 'https://api.openai.com/v1/chat/completions';

		$response = wp_remote_post( $endpoint, array(
			'timeout' => 20,
			'headers' => array(
				'Authorization' => 'Bearer ' . $api_key,
				'Content-Type'  => 'application/json',
			),
			'body'    => json_encode( array(
				'model'       => sanitize_text_field( $model ),
				'temperature' => 0.2,
				'messages'    => array(
					array( 'role' => 'system', 'content' => $resolved_prompt ),
					array( 'role' => 'user', 'content' => $text ),
				),
			) ),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body['choices'][0]['message']['content'] ) ) {
			return trim( $body['choices'][0]['message']['content'], '"\'' );
		}

		return new WP_Error( 'api_error', isset( $body['error']['message'] ) ? $body['error']['message'] : __( 'OpenAI response compilation failed.', 'af-translate' ) );
	}

	/**
	 * 6. ANTHROPIC (CLAUDE) API LOOP
	 */
	private static function call_anthropic( $text, $target_locale, $settings ) {
		$api_key = isset( $settings['anthropic_key'] ) ? trim( $settings['anthropic_key'] ) : '';
		$model   = ! empty( $settings['anthropic_model'] ) ? trim( $settings['anthropic_model'] ) : 'claude-3-5-sonnet-latest';
		$prompt  = ! empty( $settings['anthropic_custom_prompt'] ) ? $settings['anthropic_custom_prompt'] : 'Translate this WordPress string to {target_language}. Keep code/HTML placeholders identical.';

		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'Anthropic API key is empty.', 'af-translate' ) );
		}

		$resolved_prompt = str_replace( '{target_language}', $target_locale, $prompt );
		$endpoint        = 'https://api.anthropic.com/v1/messages';

		$response = wp_remote_post( $endpoint, array(
			'timeout' => 25,
			'headers' => array(
				'x-api-key'         => $api_key,
				'anthropic-version' => '2023-06-01',
				'content-type'      => 'application/json',
			),
			'body'    => json_encode( array(
				'model'       => sanitize_text_field( $model ),
				'max_tokens'  => 2000,
				'temperature' => 0.1,
				'system'      => $resolved_prompt,
				'messages'    => array(
					array( 'role' => 'user', 'content' => array( array( 'type' => 'text', 'text' => $text ) ) )
				),
			) ),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body['content'][0]['text'] ) ) {
			return trim( $body['content'][0]['text'] );
		}

		return new WP_Error( 'api_error', isset( $body['error']['message'] ) ? $body['error']['message'] : __( 'Anthropic payload execution failed.', 'af-translate' ) );
	}

	/**
	 * 7. XAI (GROK) API LOOP
	 */
	private static function call_grok( $text, $target_locale, $settings ) {
		$api_key = isset( $settings['grok_key'] ) ? trim( $settings['grok_key'] ) : '';
		$model   = ! empty( $settings['grok_model'] ) ? trim( $settings['grok_model'] ) : 'grok-4';
		$prompt  = ! empty( $settings['grok_custom_prompt'] ) ? $settings['grok_custom_prompt'] : 'Translate this WordPress string to {target_language}. Keep code/HTML placeholders identical.';

		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'Grok API key is empty.', 'af-translate' ) );
		}

		$resolved_prompt = str_replace( '{target_language}', $target_locale, $prompt );
		$endpoint        = 'https://api.x.ai/v1/chat/completions';

		$response = wp_remote_post( $endpoint, array(
			'timeout' => 25,
			'headers' => array(
				'Authorization' => 'Bearer ' . $api_key,
				'Content-Type'  => 'application/json',
			),
			'body'    => json_encode( array(
				'model'       => sanitize_text_field( $model ),
				'temperature' => 0.2,
				'messages'    => array(
					array( 'role' => 'system', 'content' => $resolved_prompt ),
					array( 'role' => 'user', 'content' => $text ),
				),
			) ),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body['choices'][0]['message']['content'] ) ) {
			return trim( $body['choices'][0]['message']['content'], '"\'' );
		}

		return new WP_Error( 'api_error', isset( $body['error']['message'] ) ? $body['error']['message'] : __( 'Grok response validation failed.', 'af-translate' ) );
	}

	/**
	 * 8. GOOGLE GEMINI API LOOP
	 */
	private static function call_gemini( $text, $target_locale, $settings ) {
		$api_key = isset( $settings['gemini_key'] ) ? trim( $settings['gemini_key'] ) : '';
		$model   = ! empty( $settings['gemini_model'] ) ? trim( $settings['gemini_model'] ) : 'gemini-2.5-flash';
		$prompt  = ! empty( $settings['gemini_custom_prompt'] ) ? $settings['gemini_custom_prompt'] : 'Translate this WordPress string to {target_language}. Keep code/HTML placeholders identical.';

		if ( empty( $api_key ) ) {
			return new WP_Error( 'missing_key', __( 'Gemini API key is empty.', 'af-translate' ) );
		}

		$resolved_prompt = str_replace( '{target_language}', $target_locale, $prompt );
		$endpoint        = 'https://generativelanguage.googleapis.com/v1beta/models/' . sanitize_text_field( $model ) . ':generateContent?key=' . $api_key;

		$response = wp_remote_post( $endpoint, array(
			'timeout' => 20,
			'headers' => array(
				'Content-Type' => 'application/json',
			),
			'body'    => json_encode( array(
				'contents' => array(
					array(
						'parts' => array(
							array( 'text' => $text )
						)
					)
				),
				'systemInstruction' => array(
					'parts' => array(
						array( 'text' => $resolved_prompt )
					)
				),
				'generationConfig' => array(
					'temperature' => 0.2
				)
			) ),
		) );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( isset( $body['candidates'][0]['content']['parts'][0]['text'] ) ) {
			return trim( $body['candidates'][0]['content']['parts'][0]['text'] );
		}

		return new WP_Error( 'api_error', isset( $body['error']['message'] ) ? $body['error']['message'] : __( 'Gemini execution loop failed.', 'af-translate' ) );
	}
}