<?php
/**
 * AI Content Signals - TDMRep surface
 *
 * Serves a W3C TDM Reservation Protocol manifest at
 * /.well-known/tdmrep.json, derived from the global AI Train signal.
 * Opt-in via the settings page.
 *
 * The well-known path is discovered by convention, so nothing needs to
 * reference it. The request is matched by URL path on parse_request, which
 * avoids registering rewrite rules and flushing them.
 *
 * @package AIContentSignals
 * @since   1.3.0
 */

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Serve the TDMRep manifest when its well-known path is requested.
 */
function ayudawp_acs_tdmrep_maybe_serve() {
	$request_uri  = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
	$request_path = wp_parse_url( $request_uri, PHP_URL_PATH );

	if ( ! $request_path || false === strpos( $request_path, '/.well-known/tdmrep.json' ) ) {
		return;
	}

	// Match against the home-relative path so it also works on subdirectory installs.
	$target_path = wp_parse_url( home_url( '/.well-known/tdmrep.json' ), PHP_URL_PATH );

	if ( untrailingslashit( $request_path ) !== untrailingslashit( (string) $target_path ) ) {
		return;
	}

	$settings = get_option( 'ayudawp_acs_settings', array() );
	if ( 'yes' !== ( $settings['emit_tdmrep'] ?? 'no' ) ) {
		// Surface disabled: let WordPress handle the request normally.
		return;
	}

	nocache_headers();

	// wp_send_json() sets the JSON Content-Type, prints the encoded body and exits.
	// Using it (instead of echo wp_json_encode()) keeps output escaping inside core,
	// avoiding a WordPress.Security.EscapeOutput flag. JSON_UNESCAPED_SLASHES keeps
	// the public manifest readable (location: "/" instead of "\/").
	wp_send_json( ayudawp_acs_tdmrep_manifest(), 200, JSON_UNESCAPED_SLASHES );
}
add_action( 'parse_request', 'ayudawp_acs_tdmrep_maybe_serve' );

/**
 * Build the TDMRep manifest from the global signals.
 *
 * tdm-reservation: 1 reserves mining rights (ai-train=no), 0 allows them
 * (ai-train=yes). When AI Train is unspecified, no entry is emitted.
 *
 * @return array TDMRep entries.
 */
function ayudawp_acs_tdmrep_manifest() {
	$signals  = ayudawp_acs_get_effective_signals();
	$ai_train = $signals['ai_train'] ?? '';

	if ( 'no' === $ai_train ) {
		return array(
			array(
				'location'        => '/',
				'tdm-reservation' => 1,
			),
		);
	}

	if ( 'yes' === $ai_train ) {
		return array(
			array(
				'location'        => '/',
				'tdm-reservation' => 0,
			),
		);
	}

	return array();
}