<?php

namespace AIContentWriter;

defined( 'ABSPATH' ) || exit; // Exit if accessed directly.

/**
 * The main plugin class.
 *
 * @since 1.0.0
 * @package AIContentWriter
 */
class Plugin {

	/**
	 * Plugin file path.
	 *
	 * @var string
	 */
	protected $file;

	/**
	 * Plugin version.
	 *
	 * @var string
	 */
	protected $version = '1.0.0';

	/**
	 * The single instance of the class.
	 *
	 * @since 1.0.0
	 * @var self
	 */
	public static $instance;

	/**
	 * Gets the single instance of the class.
	 * This method is used to create a new instance of the class.
	 *
	 * @param string $file The plugin file path.
	 * @param string $version The plugin version.
	 *
	 * @since 1.0.0
	 * @return static
	 */
	final public static function create( $file, $version = '1.0.0' ) {
		if ( null === self::$instance ) {
			self::$instance = new static( $file, $version );
		}

		return self::$instance;
	}

	/**
	 * Constructor.
	 *
	 * @param string $file The plugin file path.
	 * @param string $version The plugin version.
	 *
	 * @since 1.0.0
	 */
	public function __construct( $file, $version ) {
		$this->file    = $file;
		$this->version = $version;
		$this->define_constants();
		$this->includes();
		$this->init_hooks();
	}

	/**
	 * Define the plugin constants.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	private function define_constants() {
		define( 'AICW_VERSION', $this->version );
		define( 'AICW_FILE', $this->file );
		define( 'AICW_PATH', plugin_dir_path( $this->file ) );
		define( 'AICW_URL', plugin_dir_url( $this->file ) );
		define( 'AICW_ASSETS_URL', AICW_URL . 'assets/' );
	}

	/**
	 * Include the required files.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	private function includes() {
		require_once __DIR__ . '/functions.php';
		require_once __DIR__ . '/deprecated.php';
	}

	/**
	 * Initialize the plugin hooks.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	private function init_hooks() {
		register_activation_hook( AICW_FILE, array( Installer::class, 'install' ) );
		register_deactivation_hook( AICW_FILE, array( $this, 'deactivate' ) );
		add_filter( 'plugin_action_links_' . plugin_basename( AICW_FILE ), array( $this, 'action_links' ) );
		add_action( 'admin_notices', array( $this, 'display_flash_notices' ), 12 );
		add_action( 'init', array( $this, 'init' ), 0 );
	}

	/**
	 * Get the plugin version.
	 *
	 * @since 1.0.0
	 * @return string The plugin version.
	 */
	public function get_version() {
		return $this->version;
	}

	/**
	 * Deactivate the plugin.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	public function deactivate() {
		flush_rewrite_rules();
	}

	/**
	 * Add action links to the plugin.
	 *
	 * @param array $links The plugin action links.
	 *
	 * @since 1.0.0
	 * @return array The modified plugin action links.
	 */
	public function action_links( $links ) {
		$action_links = array(
			'settings' => sprintf(
				/* translators: %1$s: Settings URL, %2$s: Settings text */
				'<a href="%1$s">%2$s</a>',
				esc_url( admin_url( 'admin.php?page=aicw-settings' ) ),
				esc_html__( 'Settings', 'ai-content-writer' )
			),
		);

		$action_links = array_merge( $action_links, $links );

		if ( ! defined( 'AICW_PRO_VERSION' ) ) {
			$action_links['go_pro'] = '<a href="https://beautifulplugins.com/plugins/ai-content-writer-pro/?utm_source=plugin&utm_medium=pro-badge&utm_campaign=plugin-action" target="_blank" style="color: #39b54a; font-weight: bold;">' . esc_html__( 'Go Pro', 'ai-content-writer' ) . '</a>';
		}

		return $action_links;
	}

	/**
	 * Add a flash notice.
	 *
	 * @param string  $notice Notice message.
	 * @param string  $type This can be "info", "warning", "error" or "success", "success" as default.
	 * @param boolean $dismissible Whether the notice is-dismissible or not.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	public function flash_notice( $notice = '', $type = 'success', $dismissible = true ) {
		$notices          = get_option( 'aicw_flash_notices', array() );
		$dismissible_text = ( $dismissible ) ? 'is-dismissible' : '';

		// Add new notice.
		$notices[] = array(
			'notice' => $notice,
			'type' => $type,
			'dismissible' => $dismissible_text,
		);

		// Update the notices array.
		update_option( 'aicw_flash_notices', $notices );
	}

	/**
	 * Display flash notices after that, remove the option to prevent notices being displayed forever.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	public function display_flash_notices() {
		$notices = get_option( 'aicw_flash_notices', array() );

		foreach ( $notices as $notice ) {
			printf(
				'<div class="notice notice-%1$s %2$s"><p>%3$s</p></div>',
				esc_attr( $notice['type'] ),
				esc_attr( $notice['dismissible'] ),
				esc_html( $notice['notice'] ),
			);
		}

		// Reset options to prevent notices being displayed forever.
		if ( ! empty( $notices ) ) {
			delete_option( 'aicw_flash_notices', array() );
		}
	}

	/**
	 * Initialize the plugin.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	public function init() {
		// Load common classes.
		new Installer();
		new PostTypes();
		new Cron();
		new RestAPI();
		new Frontend();

		// Load admin classes.
		if ( is_admin() ) {
			new Admin\Admin();
			new Admin\Dashboard();
			new Admin\Actions();
			new Admin\Settings();
			new Admin\Notices();
			new Admin\BlockEditor();
			new Admin\ClassicEditor();
		}
	}

	/**
	 * Fetch stock images from the configured image source.
	 *
	 * All sources return the same (Pexels-shaped) photo structure:
	 * `src.original`, `alt`, `photographer`, `url` — so downstream consumers
	 * (thumbnail cron, featured-image picker) work with any source.
	 *
	 * @param string $query The query to search images.
	 * @param int    $per_page The number of images to fetch.
	 *
	 * @since 1.0.0
	 * @return array|\WP_Error The images array.
	 */
	public function generate_images( $query, $per_page = 20 ) {
		$source = get_option( 'aicw_image_source', 'pexels' );

		return $this->fetch_images( $source, $query, $per_page );
	}

	/**
	 * Fetch stock images from a specific source.
	 *
	 * @param string $source The image source: pexels, unsplash, or pixabay.
	 * @param string $query The query to search images.
	 * @param int    $per_page The number of images to fetch.
	 *
	 * @since 2.3.0
	 * @return array|\WP_Error Normalized images array.
	 */
	public function fetch_images( $source, $query, $per_page = 20 ) {
		/**
		 * Short-circuit image fetching for add-on sources.
		 *
		 * Return a non-null value (normalized photos array or WP_Error) to
		 * serve the request. Sources registered via `aicw_image_sources`
		 * implement their fetching here.
		 *
		 * @param array|\WP_Error|null $images   The images, or null to continue.
		 * @param string               $source   The image source slug.
		 * @param string               $query    The search query.
		 * @param int                  $per_page The number of images requested.
		 *
		 * @since 2.4.0
		 */
		$images = apply_filters( 'aicw_pre_fetch_images', null, $source, $query, $per_page );

		if ( null !== $images ) {
			return $images;
		}

		switch ( $source ) {
			case 'unsplash':
				return $this->fetch_unsplash_images( $query, $per_page );
			case 'pixabay':
				return $this->fetch_pixabay_images( $query, $per_page );
			case 'pexels':
			default:
				return $this->fetch_pexels_images( $query, $per_page );
		}
	}

	/**
	 * Fetch images from Pexels.
	 *
	 * @param string $query The search query.
	 * @param int    $per_page The number of images to fetch.
	 *
	 * @since 2.3.0
	 * @return array|\WP_Error
	 */
	protected function fetch_pexels_images( $query, $per_page ) {
		$api_key = get_option( 'aicw_pexels_api_key' );

		if ( empty( $api_key ) ) {
			return new \WP_Error( 'aicw_api_key_not_set', esc_html__( 'Please configure the API settings. A valid Pexels API key is required to generate the images.', 'ai-content-writer' ) );
		}

		$url  = 'https://api.pexels.com/v1/search?query=' . rawurlencode( $query ) . '&per_page=' . absint( $per_page );
		$data = $this->fetch_image_api( $url, array( 'Authorization' => $api_key ) );

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

		if ( empty( $data['photos'] ) ) {
			return new \WP_Error( 'unexpected_api_response', esc_html__( 'An unexpected error occurred while generating the images.', 'ai-content-writer' ) );
		}

		// Pexels is already the canonical shape.
		return $data['photos'];
	}

	/**
	 * Fetch images from Unsplash, normalized to the Pexels shape.
	 *
	 * @param string $query The search query.
	 * @param int    $per_page The number of images to fetch.
	 *
	 * @since 2.3.0
	 * @return array|\WP_Error
	 */
	protected function fetch_unsplash_images( $query, $per_page ) {
		$api_key = get_option( 'aicw_unsplash_api_key' );

		if ( empty( $api_key ) ) {
			return new \WP_Error( 'aicw_api_key_not_set', esc_html__( 'Please configure the API settings. A valid Unsplash access key is required to generate the images.', 'ai-content-writer' ) );
		}

		$url  = 'https://api.unsplash.com/search/photos?query=' . rawurlencode( $query ) . '&per_page=' . absint( $per_page );
		$data = $this->fetch_image_api( $url, array( 'Authorization' => 'Client-ID ' . $api_key ) );

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

		if ( empty( $data['results'] ) ) {
			return new \WP_Error( 'unexpected_api_response', esc_html__( 'An unexpected error occurred while generating the images.', 'ai-content-writer' ) );
		}

		$photos = array();
		foreach ( $data['results'] as $photo ) {
			if ( empty( $photo['urls']['regular'] ) ) {
				continue;
			}

			$photos[] = array(
				'src'          => array(
					'original' => $photo['urls']['regular'],
					'large'    => $photo['urls']['regular'],
					'medium'   => isset( $photo['urls']['small'] ) ? $photo['urls']['small'] : $photo['urls']['regular'],
				),
				'alt'          => isset( $photo['alt_description'] ) ? (string) $photo['alt_description'] : '',
				'photographer' => isset( $photo['user']['name'] ) ? (string) $photo['user']['name'] : '',
				'url'          => isset( $photo['links']['html'] ) ? (string) $photo['links']['html'] : '',
			);
		}

		return $photos;
	}

	/**
	 * Fetch images from Pixabay, normalized to the Pexels shape.
	 *
	 * @param string $query The search query.
	 * @param int    $per_page The number of images to fetch.
	 *
	 * @since 2.3.0
	 * @return array|\WP_Error
	 */
	protected function fetch_pixabay_images( $query, $per_page ) {
		$api_key = get_option( 'aicw_pixabay_api_key' );

		if ( empty( $api_key ) ) {
			return new \WP_Error( 'aicw_api_key_not_set', esc_html__( 'Please configure the API settings. A valid Pixabay API key is required to generate the images.', 'ai-content-writer' ) );
		}

		// Pixabay rejects a q longer than 100 characters, so trim at a word boundary.
		if ( mb_strlen( $query ) > 100 ) {
			$query = mb_substr( $query, 0, 100 );
			$space = mb_strrpos( $query, ' ' );
			$query = false !== $space ? mb_substr( $query, 0, $space ) : $query;
		}

		// Pixabay matches every word, so full titles often find nothing. Fall back to fewer keywords.
		$keywords = $this->get_search_keywords( $query );
		$queries  = array_unique( array_filter( array( $query, implode( ' ', array_slice( $keywords, 0, 4 ) ), implode( ' ', array_slice( $keywords, 0, 2 ) ) ) ) );

		// Pixabay requires per_page between 3 and 200.
		$per_page = max( 3, absint( $per_page ) );

		foreach ( $queries as $search ) {
			$url  = 'https://pixabay.com/api/?key=' . rawurlencode( $api_key ) . '&q=' . rawurlencode( $search ) . '&image_type=photo&per_page=' . $per_page;
			$data = $this->fetch_image_api( $url, array() );

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

			if ( ! empty( $data['hits'] ) ) {
				break;
			}
		}

		if ( empty( $data['hits'] ) ) {
			return new \WP_Error( 'aicw_no_images_found', esc_html__( 'No matching images were found for this title.', 'ai-content-writer' ) );
		}

		$photos = array();
		foreach ( $data['hits'] as $photo ) {
			if ( empty( $photo['largeImageURL'] ) ) {
				continue;
			}

			$photos[] = array(
				'src'          => array(
					'original' => $photo['largeImageURL'],
					'large'    => $photo['largeImageURL'],
					'medium'   => isset( $photo['webformatURL'] ) ? $photo['webformatURL'] : $photo['largeImageURL'],
				),
				'alt'          => isset( $photo['tags'] ) ? (string) $photo['tags'] : '',
				'photographer' => isset( $photo['user'] ) ? (string) $photo['user'] : '',
				'url'          => isset( $photo['pageURL'] ) ? (string) $photo['pageURL'] : '',
			);
		}

		return $photos;
	}

	/**
	 * Extract the meaningful search keywords from a title, in order.
	 *
	 * @param string $query The search query.
	 *
	 * @since 2.5.1
	 * @return array Keywords without stop words, numbers, or punctuation.
	 */
	protected function get_search_keywords( $query ) {
		$stop_words = array( 'about', 'add', 'and', 'are', 'best', 'can', 'create', 'does', 'easier', 'easy', 'fix', 'for', 'from', 'get', 'guide', 'how', 'improve', 'into', 'its', 'make', 'new', 'not', 'set', 'the', 'this', 'tips', 'top', 'two', 'use', 'ways', 'what', 'when', 'why', 'with', 'without', 'you', 'your' );
		$words      = preg_split( '/[^\p{L}\p{N}]+/u', mb_strtolower( $query ), -1, PREG_SPLIT_NO_EMPTY );

		return array_values(
			array_unique(
				array_filter(
					$words,
					function ( $word ) use ( $stop_words ) {
						return mb_strlen( $word ) > 2 && ! is_numeric( $word ) && ! in_array( $word, $stop_words, true );
					}
				)
			)
		);
	}

	/**
	 * Perform an image API GET request and decode the JSON response.
	 *
	 * @param string $url The request URL.
	 * @param array  $headers Request headers.
	 *
	 * @since 2.3.0
	 * @return array|\WP_Error Decoded response.
	 */
	protected function fetch_image_api( $url, $headers ) {
		$response = wp_remote_get(
			$url,
			array(
				'timeout' => 30,
				'headers' => $headers,
			)
		);

		if ( is_wp_error( $response ) ) {
			return new \WP_Error( 'api_error', $response->get_error_message() );
		}

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

		// Some APIs (e.g. Pixabay) return errors as plain text; surface that message.
		if ( ! is_array( $data ) && wp_remote_retrieve_response_code( $response ) >= 400 && '' !== trim( $body ) ) {
			return new \WP_Error( 'api_error', sanitize_text_field( mb_substr( wp_strip_all_tags( $body ), 0, 300 ) ) );
		}

		if ( ! is_array( $data ) ) {
			return new \WP_Error( 'unexpected_api_response', esc_html__( 'An unexpected error occurred while generating the images.', 'ai-content-writer' ) );
		}

		return $data;
	}

	/**
	 * Create a log entry
	 *
	 * @param string $message The log message.
	 * @param string $type    The log type (e.g., 'success', 'info', 'error', 'warning').
	 * @param int    $campaign_id Optional. The campaign ID associated with the log. Default is empty.
	 *
	 * @since 2.0.6
	 * @return int|\WP_Error The ID of the created log post or WP_Error on failure.
	 */
	public function create_log( $message, $type = 'info', $campaign_id = '' ) {
		if ( empty( $message ) ) {
			return new \WP_Error( 'aicw_log_message_empty', esc_html__( 'Log message cannot be empty.', 'ai-content-writer' ) );
		}

		$log_data = array(
			'post_title'   => sanitize_title( $type ),
			'post_content' => wp_kses_post( $message ),
			'post_status'  => 'publish',
			'post_type'    => 'aicw_log',
		);

		// If campaign ID is provided, add it as post meta.
		if ( ! empty( $campaign_id ) ) {
			$log_data['meta_input']['_aicw_related_campaign'] = absint( $campaign_id );
		}

		return wp_insert_post( $log_data );
	}
}