<?php
/**
 * Placeholder rendering and truncation.
 *
 * @package PingPush
 */

defined( 'ABSPATH' ) || exit;

/**
 * Renders {placeholder} templates.
 */
class PingPush_Templates {

	/**
	 * Placeholders available to every event.
	 *
	 * @return string[]
	 */
	public static function global_placeholders() {
		return array( 'site_name', 'site_url', 'admin_url', 'event', 'date', 'time' );
	}

	/**
	 * Render a template.
	 *
	 * Supports {key} for scalar values in $data, {field:name} for form fields,
	 * and {fields} for all form fields as "Label: value" lines.
	 *
	 * @param string $template Template.
	 * @param array  $data     Data.
	 * @return string
	 */
	public static function render( $template, array $data ) {
		$data = array_merge( self::global_data(), $data );

		$fields = ( isset( $data['fields'] ) && is_array( $data['fields'] ) ) ? $data['fields'] : array();

		$out = preg_replace_callback(
			'/\{([a-z0-9_]+)(?::([^}]+))?\}/i',
			static function ( $m ) use ( $data, $fields ) {
				$key = strtolower( $m[1] );

				if ( 'field' === $key && isset( $m[2] ) ) {
					$name = trim( $m[2] );
					if ( array_key_exists( $name, $fields ) ) {
						return self::stringify( $fields[ $name ]['value'] ?? $fields[ $name ] );
					}
					foreach ( $fields as $field_key => $field ) {
						$label = is_array( $field ) ? ( $field['label'] ?? '' ) : '';
						if ( 0 === strcasecmp( (string) $field_key, $name ) || ( '' !== $label && 0 === strcasecmp( $label, $name ) ) ) {
							return self::stringify( is_array( $field ) ? ( $field['value'] ?? '' ) : $field );
						}
					}
					return '';
				}

				if ( 'fields' === $key ) {
					return self::fields_to_text( $fields );
				}

				if ( array_key_exists( $key, $data ) && ! is_array( $data[ $key ] ) && ! is_object( $data[ $key ] ) ) {
					return (string) $data[ $key ];
				}

				return $m[0];
			},
			(string) $template
		);

		// Collapse 3+ newlines left by empty placeholders.
		$out = preg_replace( "/\n{3,}/", "\n\n", (string) $out );
		return trim( (string) $out );
	}

	/**
	 * Fields as "Label: value" lines, skipping empties.
	 *
	 * @param array $fields Fields [key => ['label'=>..., 'value'=>...]].
	 * @return string
	 */
	public static function fields_to_text( array $fields ) {
		$lines = array();
		foreach ( $fields as $key => $field ) {
			$label = is_array( $field ) && ! empty( $field['label'] ) ? $field['label'] : (string) $key;
			$value = self::stringify( is_array( $field ) ? ( $field['value'] ?? '' ) : $field );
			if ( '' === trim( $value ) ) {
				continue;
			}
			$lines[] = $label . ': ' . $value;
		}
		return implode( "\n", $lines );
	}

	/**
	 * Turn a value into a single string.
	 *
	 * @param mixed $value Value.
	 * @return string
	 */
	public static function stringify( $value ) {
		if ( is_array( $value ) ) {
			$flat = array();
			array_walk_recursive(
				$value,
				static function ( $v ) use ( &$flat ) {
					if ( is_scalar( $v ) && '' !== trim( (string) $v ) ) {
						$flat[] = (string) $v;
					}
				}
			);
			return implode( ', ', $flat );
		}
		if ( is_bool( $value ) ) {
			return $value ? __( 'Yes', 'pingpush' ) : __( 'No', 'pingpush' );
		}
		if ( is_scalar( $value ) ) {
			return trim( wp_strip_all_tags( html_entity_decode( (string) $value, ENT_QUOTES, 'UTF-8' ) ) );
		}
		return '';
	}

	/**
	 * Plain text, safe length.
	 *
	 * @param string $text Text.
	 * @param int    $max  Max characters.
	 * @return string
	 */
	public static function truncate( $text, $max ) {
		$text = wp_strip_all_tags( html_entity_decode( (string) $text, ENT_QUOTES, 'UTF-8' ) );
		$len  = function_exists( 'mb_strlen' ) ? mb_strlen( $text, 'UTF-8' ) : strlen( $text );
		if ( $len <= $max ) {
			return $text;
		}
		$cut = function_exists( 'mb_substr' ) ? mb_substr( $text, 0, $max - 1, 'UTF-8' ) : substr( $text, 0, $max - 1 );
		return rtrim( $cut ) . '…';
	}

	/**
	 * Data available to every template.
	 *
	 * @return array<string,string>
	 */
	private static function global_data() {
		return array(
			'site_name' => wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ),
			'site_url'  => home_url( '/' ),
			'admin_url' => admin_url(),
			'date'      => wp_date( get_option( 'date_format' ) ),
			'time'      => wp_date( get_option( 'time_format' ) ),
		);
	}
}