<?php

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

/**
 * Vite asset loading helper.
 *
 * Decides whether frontend entries load from the Vite dev server or from the
 * built dist/ bundles. The dev server writes dist/.hot while it runs (see the
 * wordpress-hot-file plugin in vite.config.ts); the file's existence is the
 * switch and its contents are the dev server origin.
 *
 * @package Epicformbuilder
 */
class Epicformbuilder_Vite {

	/**
	 * Whether the react-refresh preamble has been scheduled for this request.
	 *
	 * @var bool
	 */
	private static $preamble_printed = false;

	/**
	 * Map of classic handle => ES module src (production), read by enqueue().
	 *
	 * @var array<string,string>
	 */
	private static $module_src = [];

	/**
	 * True when the Vite dev server is running.
	 *
	 * @return bool
	 */
	public static function is_dev(): bool {
		return file_exists( EPICFORMS_PATH . 'dist/.hot' ) && '' !== self::origin();
	}

	/**
	 * The dev server origin, e.g. https://localhost:3000.
	 *
	 * @return string
	 */
	public static function origin(): string {
		$origin = trim( (string) file_get_contents( EPICFORMS_PATH . 'dist/.hot' ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- local file.

		// Only a bare scheme://host[:port] is meaningful here.
		return preg_match( '#^https?://[a-z0-9.-]+(:\d+)?$#i', $origin ) ? $origin : '';
	}

	/**
	 * Register a frontend entry under its classic handles.
	 *
	 * Prod: registers the dist JS/CSS files exactly as before. Dev: registers
	 * the same handles as stubs (no src) so existing dependency references
	 * (e.g. Elementor's get_script_depends()) keep resolving while the actual
	 * code loads from the dev server as ES modules.
	 *
	 * @param string $handle     Script handle, e.g. 'epicforms-admin-client'.
	 * @param string $css_handle Style handle, e.g. 'epicforms-admin-css'.
	 * @param string $dist_js    Plugin-relative dist JS, e.g. 'dist/admin.js'.
	 * @param string $dist_css   Plugin-relative dist CSS, e.g. 'dist/admin.css'.
	 * @param array  $deps       Classic script dependencies.
	 */
	public static function register( string $handle, string $css_handle, string $dist_js, string $dist_css, array $deps = [] ): void {
		wp_deregister_script( $handle );
		wp_deregister_style( $css_handle );

		// The classic handle is a *stub* (no src): it exists so its $deps (wp-element,
		// wp-i18n, …) are enqueued — providing the window.wp.* globals the ESM bundle's
		// build-time shims read — and so dependents like Elementor's get_script_depends()
		// keep resolving. The actual code is an ES module, enqueued in enqueue().
		wp_register_script( $handle, false, $deps, self::is_dev() ? null : EPICFORMS_VERSION, true );

		if ( self::is_dev() ) {
			wp_register_style( $css_handle, false, [], null );
			return;
		}

		wp_register_style( $css_handle, EPICFORMS_URL . $dist_css, [], EPICFORMS_VERSION );
		self::$module_src[ $handle ] = EPICFORMS_URL . $dist_js;
	}

	/**
	 * Enqueue a registered entry, adding the dev-server modules in dev mode.
	 *
	 * @param string $handle     Script handle registered via register().
	 * @param string $css_handle Style handle registered via register().
	 * @param string $entry      Source entry, e.g. 'src/admin/index.jsx'.
	 */
	public static function enqueue( string $handle, string $css_handle, string $entry ): void {
		wp_enqueue_script( $handle );   // classic stub -> enqueues $deps (wp-element, …) first.
		wp_enqueue_style( $css_handle );

		if ( self::is_dev() ) {
			$origin = self::origin();
			self::print_react_refresh_preamble( $origin );
			wp_enqueue_script_module( 'epicforms-vite-client', $origin . '/@vite/client', [], null );
			wp_enqueue_script_module( 'epicforms-dev-' . $handle, $origin . '/' . $entry, [ 'epicforms-vite-client' ], null );
			return;
		}

		// Production: the built code is an ES module. It has no bare imports (shared deps
		// are shim-aliased to window.wp.* at build time), so no import map is needed. The
		// classic stub above (non-deferred) runs first and provides window.wp.*; this
		// deferred module runs after and its shims find those globals.
		if ( isset( self::$module_src[ $handle ] ) ) {
			wp_enqueue_script_module( 'epicforms-mod-' . $handle, self::$module_src[ $handle ], [], EPICFORMS_VERSION );
		}
	}

	/**
	 * Print the @vitejs/plugin-react refresh preamble once per request.
	 *
	 * Must execute before the entry module. Prefers the head; if the head has
	 * already been printed (e.g. Elementor widgets enqueue during content
	 * rendering), falls back to the footer at priority 1 — WordPress prints
	 * enqueued script modules on the footer hook at priority 10, so the
	 * preamble still comes first.
	 *
	 * @param string $origin Dev server origin.
	 */
	private static function print_react_refresh_preamble( string $origin ): void {
		if ( self::$preamble_printed ) {
			return;
		}
		self::$preamble_printed = true;

		$print = function () use ( $origin ) {
			// JSON-encoded, not URL-escaped: the origin lands in a JS string.
			$runtime = wp_json_encode( $origin . '/@react-refresh', JSON_UNESCAPED_SLASHES | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT );

			wp_print_inline_script_tag(
				'import RefreshRuntime from ' . $runtime . ';'
				. 'RefreshRuntime.injectIntoGlobalHook(window);'
				. 'window.$RefreshReg$ = () => {};'
				. 'window.$RefreshSig$ = () => (type) => type;'
				. 'window.__vite_plugin_react_preamble_installed__ = true;',
				[ 'type' => 'module' ]
			);
		};

		if ( is_admin() ) {
			$hook = did_action( 'admin_head' ) ? 'admin_print_footer_scripts' : 'admin_head';
		} else {
			$hook = did_action( 'wp_head' ) ? 'wp_footer' : 'wp_head';
		}
		add_action( $hook, $print, 1 );
	}
}