<?php
/**
 * Add Embed to Posts
 *
 * Functions to add embed code to posts.
 *
 * @package  simple-embed-code
 */

// Exit if accessed directly.

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Add filter to add embed code
 *
 * Filter to add embed to any posts.
 *
 * @uses     ce_get_embed_code    Get embed code from other posts.
 * @uses     ce_quick_replace     Perform a quick/replace of content.
 * @uses.    ce_generate_code     Create the appropriate embed code.
 *
 * @param    string $content      Post content without embedded code.
 * @return   string               Post content with embedded code.
 */
function ce_filter( $content ) {

	global $post;

	if ( ! isset( $post->ID ) ) {
		return $content;
	}

	// Set initial values.
	static $options = null;
	if ( null === $options ) {
		$options = get_option( 'artiss_code_embed' );
	}

	if ( ! is_array( $options ) ) {
		return $content;
	}

	$found_pos  = strpos( $content, $options['opening_ident'] . $options['keyword_ident'], 0 );
	$prefix_len = strlen( $options['opening_ident'] . $options['keyword_ident'] );

	// Loop around the post content looking for all requests for code embeds.

	while ( false !== $found_pos ) {

		// Get the position of the closing identifier - ignore if one is not found!

		$end_pos = strpos( $content, $options['closing_ident'], $found_pos + $prefix_len );
		if ( false !== $end_pos ) {

			// Extract the suffix.

			$suffix_len = $end_pos - ( $found_pos + $prefix_len );
			if ( 0 === $suffix_len ) {
				$suffix = '';
			} else {
				$suffix = substr( $content, $found_pos + $prefix_len, $suffix_len );
			}
			$full_suffix = $suffix;

			// Check for responsive part of suffix.

			$responsive = false;
			$max_width  = false;
			$res_pos    = false;
			if ( 1 < strlen( $suffix ) ) {
				$res_pos = strpos( $suffix, '_RES', 1 );
			}

			if ( false !== $res_pos ) {

				// If responsive section found, check it's at the end or has an underscore afterwards.
				// Otherwise it may be part of something else.

				if ( strlen( $suffix ) - 4 === $res_pos ) {
					$responsive = true;
				} elseif ( '_' === substr( $suffix, $res_pos + 4, 1 ) ) {
					$responsive = true;
					$max_width  = substr( $suffix, $res_pos + 5 );
					if ( ! is_numeric( $max_width ) ) {
						$max_width = '';
					}
				}

				if ( $responsive ) {
					$suffix = substr( $suffix, 0, $res_pos );
				}
			}

			// Get the meta for the current post.

			$post_meta = get_post_meta( $post->ID, $options['keyword_ident'] . $suffix, false );
			if ( isset( $post_meta[0] ) ) {
				$html = $post_meta[0];
			} else {
				// No meta found, so look for it elsewhere.
				$html = ce_get_embed_code( $options['keyword_ident'], $suffix );
			}

			// Build the string to search for.

			$search = $options['opening_ident'] . $options['keyword_ident'] . $full_suffix . $options['closing_ident'];

			// Build the string of code to replace with.

			$replace = ce_generate_code( $html, $responsive, $max_width );

			// Now modify all references.

			$content = str_replace( $search, $replace, $content );

		}
		$found_pos = strpos( $content, $options['opening_ident'] . $options['keyword_ident'], $found_pos + 1 );
	}

	// Loop around the post content looking for HTTP addresses.

	if ( '1' === get_post_meta( $post->ID, '_ce_allow_url_embeds', true ) ) {
		$content = ce_quick_replace( $content, $options, 'http://' );

		// Loop around the post content looking for HTTPS addresses.

		$content = ce_quick_replace( $content, $options, 'https://' );
	}

	return $content;
}

add_filter( 'the_content', 'ce_filter' );
add_filter( 'widget_text_content', 'ce_filter' );
add_action( 'save_post', 'ce_save_url_embed_permission' );

/**
 * Save URL Embed Permission
 *
 * On post save, records whether the post author has the unfiltered_html
 * capability, so that URL embed tokens are only expanded at render time
 * for content authored by trusted users.
 *
 * @param    string $post_id    The post ID.
 */
function ce_save_url_embed_permission( $post_id ) {

	if ( wp_is_post_revision( $post_id ) ) {
		return;
	}

	$post    = get_post( $post_id );
	$allowed = user_can( $post->post_author, 'unfiltered_html' ) ? '1' : '0';
	update_post_meta( $post_id, '_ce_allow_url_embeds', $allowed );
}

/**
 * Quick Replace
 *
 * Function to do a quick search/replace of the content.
 *
 * @param    string $content    The content.
 * @param    array  $options    The options array.
 * @param    string $search     The string to search for.
 * @return   string             The updated content.
 */
function ce_quick_replace( $content = '', $options = '', $search = '' ) {

	$start_pos = strpos( $content, $options['opening_ident'] . $search, 0 );

	while ( false !== $start_pos ) {

		$end_pos = strpos( $content, $options['closing_ident'], $start_pos + 1 );

		if ( false !== $end_pos ) {
			$url  = substr( $content, $start_pos + strlen( $options['opening_ident'] ), $end_pos - ( $start_pos + strlen( $options['opening_ident'] ) ) );
			$file = ce_get_file( $url );
			if ( false === $file ) {
				$file = ce_report_error( __( 'File could not be fetched', 'simple-embed-code' ), 'Code Embed', false );
			}
			$content   = str_replace( $options['opening_ident'] . $url . $options['closing_ident'], wp_kses_post( $file ), $content );
			$start_pos = strpos( $content, $options['opening_ident'] . $search, 0 );
		} else {
			$start_pos = strpos( $content, $options['opening_ident'] . $search, $start_pos + 1 );
		}
	}

	return $content;
}

/**
 * Generate Embed Code
 *
 * Function to generate the embed code that will be output.
 *
 * @param    string      $html           The embed code (required).
 * @param    bool        $responsive     Responsive output required? (optional).
 * @param    string|bool $max_width      Maximum width of responsive output (optional).
 * @return   string                      The embed code.
 */
function ce_generate_code( $html, $responsive = false, $max_width = false ) {

	$code = '';

	if ( false !== $max_width && '' !== $max_width ) {
		$code .= '<div style="width: ' . $max_width . 'px; max-width: 100%">';
	}

	if ( $responsive ) {
		$code .= '<div class="ce-video-container">';
	}

	$code .= $html;

	if ( $responsive ) {
		$code .= '</div>';
	}

	if ( false !== $max_width && '' !== $max_width ) {
		$code .= '</div>';
	}

	return $code;
}

/**
 * Get the Global Embed Code
 *
 * Function to look for and, if available, return the global embed code.
 *
 * @uses   ce_report_error     Generate an error message
 *
 * @param  string $ident       The embed code opening identifier.
 * @param  string $suffix      The embed code suffix.
 * @return string              The embed code (or error).
 */
function ce_get_embed_code( $ident, $suffix ) {

	// Meta was not found in the current post, so look across the meta table.

	$meta_name = $ident . $suffix;
	global $wpdb;
	$meta = $wpdb->get_results( $wpdb->prepare( "SELECT meta_value, post_title, ID FROM $wpdb->postmeta INNER JOIN $wpdb->posts ON post_id = ID WHERE meta_key = %s AND post_status NOT IN ('trash', 'auto-draft', 'inherit')", $meta_name ) ); // @codingStandardsIgnoreLine -- requires the latest data when called, so caching is inappropriate

	$total_records = count( $meta );

	if ( 0 < $total_records ) {

		// Results were found - count how many distinct embed code values exist.

		$records = count( array_unique( wp_list_pluck( $meta, 'meta_value' ) ) );

		if ( 1 === $records ) {

			// Only one unique code result returned, so assume this is the global embed.

			$html = $meta[0]->meta_value;

		} else {

			// More than one unique code result returned, so output the list of posts.

			/* translators: %1$s: the embed code name, %2$d: the number of pieces of embed code being stored with that name, %3$d: the number of posts using that embed name */
			$error = sprintf( __( 'Cannot use %1$s as a global code as it is being used to store %2$d unique pieces of code in %3$d posts', 'simple-embed-code' ), $meta_name, $records, $total_records );
			$html  = ce_report_error( $error, 'Code Embed', false );
		}
	} else {

		// No meta code was found, so write out an error.

		/* translators: %s: the name of the embed */
		$html = ce_report_error( sprintf( __( 'No embed code was found for %s', 'simple-embed-code' ), $meta_name ), 'Code Embed', false );

	}
	return $html;
}

/**
 * Fetch a file
 *
 * Use WordPress API to fetch a file and check the results.
 *
 * @param  string $filein      File name to fetch.
 * @return string|false        File contents as a string, or false on failure.
 */
function ce_get_file( $filein ) {

	if ( function_exists( 'vip_safe_wp_remote_get' ) ) {

		$response = vip_safe_wp_remote_get( $filein, '', 3, 3 );

	} else {

		$response = wp_safe_remote_get( $filein, array( 'timeout' => 3 ) ); // @codingStandardsIgnoreLine -- for non-VIP environments

	}

	if ( is_array( $response ) ) {

		return $response['body'];

	} else {

		return false;

	}
}

/**
 * Report an error
 *
 * Function to report an error.
 *
 * @param  string $error            Error message.
 * @param  string $plugin_name      The name of the plugin.
 * @param  bool   $echo_out         True or false, depending on whether you wish to return or echo the results.
 * @return bool|string              Returns the error message or true when echoing or if not a user with edit capabilities.
 */
function ce_report_error( $error, $plugin_name, $echo_out = true ) {

	$output = '<p role="alert" style="color: #b91c1c; font-weight: bold;">' . esc_html( $plugin_name ) . ': ' . esc_html( $error ) . "</p>\n";

	if ( $echo_out || ! current_user_can( 'edit_posts' ) ) {
		if ( current_user_can( 'edit_posts' ) ) {
			echo $output; // @codingStandardsIgnoreLine -- being escaped above so this is a false positive
		}
		return true;
	} else {
		return $output;
	}
}