<?php
/**
 * Helper functions for the AI plugin.
 *
 * @package WordPress\AI
 */

declare( strict_types=1 );

namespace WordPress\AI;

use Throwable;
use WordPress\AI_Client\AI_Client;

/**
 * Purposely using return instead of exit here.
 *
 * This file is loaded via the composer files directive.
 * When tools like PHPCS and PHPStan run, they include
 * our composer autoloader and that will then load this file,
 * causing the script to exit and not function properly.
 */
if ( ! defined( 'ABSPATH' ) ) {
	return;
}

/**
 * Normalizes the content by cleaning it and removing unwanted HTML tags.
 *
 * @since 0.1.0
 *
 * @param string $content The content to normalize.
 * @return string The normalized content.
 */
function normalize_content( string $content ): string {
	/**
	 * Hook to filter content before cleaning it.
	 *
	 * @since 0.1.0
	 *
	 * @param string $post_content The post content.
	 *
	 * @return string The filtered Post content.
	 */
	$content = (string) apply_filters( 'ai_experiments_pre_normalize_content', $content );

	// Strip HTML entities.
	$content = preg_replace( '/&#?[a-z0-9]{2,8};/i', '', $content );

	// Replace HTML linebreaks with newlines.
	$content = preg_replace( '#<br\s?/?>#', "\n\n", (string) $content );

	// Strip all HTML tags.
	$content = wp_strip_all_tags( (string) $content );

	// Remove unrendered shortcode tags.
	$content = preg_replace( '#\[.+\](.+)\[/.+\]#', '$1', $content );

	/**
	 * Filters the normalized content to allow for additional cleanup.
	 *
	 * @since 0.1.0
	 *
	 * @param string $content The normalized content.
	 *
	 * @return string The filtered normalized content.
	 */
	$content = (string) apply_filters( 'ai_experiments_normalize_content', (string) $content );

	return trim( $content );
}

/**
 * Returns the context for the given post ID.
 *
 * @since 0.1.0
 *
 * @param int $post_id The ID of the post to get the context for.
 * @return array<string, string> The context for the given post ID.
 */
function get_post_context( int $post_id ): array {
	$context = array();

	// Get the post details using the get-post-details ability.
	$details_ability = wp_get_ability( 'ai/get-post-details' );
	if ( $details_ability ) {
		$details = $details_ability->execute( array( 'post_id' => $post_id ) );

		if ( is_array( $details ) ) {
			$context = array_merge( $context, $details );

			if ( isset( $context['content'] ) ) {
				// phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
				$context['content'] = normalize_content( (string) apply_filters( 'the_content', $context['content'] ) );
			}

			if ( isset( $context['type'] ) ) {
				$context['content_type'] = $context['type'];
				unset( $context['type'] );
			}

			// Remove any empty context values.
			$context = array_filter( $context );
		}
	}

	// Get the post terms using the get-terms ability.
	$terms_ability = wp_get_ability( 'ai/get-post-terms' );
	if ( $terms_ability ) {
		$terms = $terms_ability->execute( array( 'post_id' => $post_id ) );

		if ( $terms && ! is_wp_error( $terms ) ) {
			$grouped_terms = array();

			foreach ( $terms as $term ) {
				$grouped_terms[ $term->taxonomy ][] = $term->name;
			}

			$context = array_merge(
				$context,
				array_map(
					static fn( array $term_names ): string => implode( ', ', $term_names ),
					$grouped_terms
				)
			);
		}
	}

	return $context;
}

/**
 * Returns the preferred models.
 *
 * @since 0.1.0
 *
 * @return array<int, array{string, string}> The preferred models.
 */
function get_preferred_models(): array {
	$preferred_models = array(
		array(
			'anthropic',
			'claude-haiku-4-5',
		),
		array(
			'google',
			'gemini-2.5-flash',
		),
		array(
			'openai',
			'gpt-4o-mini',
		),
		array(
			'openai',
			'gpt-4.1',
		),
	);

	/**
	 * Filters the preferred models.
	 *
	 * @since 0.1.0
	 *
	 * @param array<int, array{string, string}> $preferred_models The preferred models.
	 * @return array<int, array{string, string}> The filtered preferred models.
	 */
	return (array) apply_filters( 'ai_experiments_preferred_models', $preferred_models );
}

/**
 * Returns the preferred image models.
 *
 * @since 0.2.0
 *
 * @return array<int, array{string, string}> The preferred image models.
 */
function get_preferred_image_models(): array {
	$preferred_models = array(
		array(
			'google',
			'gemini-3-pro-image-preview',
		),
		array(
			'google',
			'gemini-2.5-flash-image',
		),
		array(
			'google',
			'imagen-4.0-generate-001',
		),
		array(
			'openai',
			'gpt-image-1',
		),
		array(
			'openai',
			'dall-e-3',
		),
	);

	/**
	 * Filters the preferred image models.
	 *
	 * @since 0.2.0
	 *
	 * @param array<int, array{string, string}> $preferred_models The preferred image models.
	 * @return array<int, array{string, string}> The filtered preferred image models.
	 */
	return (array) apply_filters( 'ai_experiments_preferred_image_models', $preferred_models );
}

/**
 * Checks if we have AI credentials set.
 *
 * @since 0.1.0
 *
 * @return bool True if we have AI credentials, false otherwise.
 */
function has_ai_credentials(): bool {
	$credentials = get_option( 'wp_ai_client_provider_credentials', array() );

	// If there are no credentials, return false.
	if ( ! is_array( $credentials ) || empty( $credentials ) ) {
		return false;
	}

	// If all of the AI keys are empty, return false; otherwise, return true.
	return ! empty(
		array_filter(
			$credentials,
			static function ( $api_key ): bool {
				return is_string( $api_key ) && '' !== $api_key;
			}
		)
	);
}

/**
 * Checks if we have valid AI credentials.
 *
 * @since 0.1.0
 *
 * @return bool True if we have valid AI credentials, false otherwise.
 */
function has_valid_ai_credentials(): bool {
	// If we have no AI credentials, return false.
	if ( ! has_ai_credentials() ) {
		return false;
	}

	/**
	 * Filters whether valid AI credentials are available.
	 *
	 * Allows overriding the credentials check, useful for testing.
	 *
	 * @since 0.1.0
	 *
	 * @param bool|null $has_valid_credentials Whether valid credentials are available. Return null to use default check.
	 * @return bool|null True if valid credentials are available, false otherwise, or null to use default check.
	 */
	$valid = apply_filters( 'ai_experiments_pre_has_valid_credentials_check', null );
	if ( null !== $valid ) {
		return (bool) $valid;
	}

	// See if we have credentials that give us access to generate text.
	try {
		return AI_Client::prompt( 'Test' )->is_supported_for_text_generation();
	} catch ( Throwable $t ) {
		return false;
	}
}