<?php

namespace Jio\WidgetSystem;

defined('ABSPATH') || exit;

/** Admin AJAX endpoints for per-sidebar export, JSON import and template import. */
final class TransferController {
	public const NONCE = 'jio_widgets_transfer';

	public static function register_hooks(): void {
		add_action('wp_ajax_jio_widgets_export_sidebar', [self::class, 'ajax_export']);
		add_action('wp_ajax_jio_widgets_import_sidebar', [self::class, 'ajax_import']);
		add_action('wp_ajax_jio_widgets_list_templates', [self::class, 'ajax_list_templates']);
		add_action('wp_ajax_jio_widgets_import_template', [self::class, 'ajax_import_template']);
	}

	public static function ajax_export(): void {
		self::authorize();
		$sidebar = self::target_sidebar();
		$json = wp_json_encode(WidgetTransfer::export($sidebar), JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
		wp_send_json_success(['json_text' => (string) $json, 'sidebar_id' => $sidebar]);
	}

	public static function ajax_import(): void {
		self::authorize();
		$sidebar = self::target_sidebar();
		$raw = isset($_POST['json']) ? trim((string) wp_unslash($_POST['json'])) : '';
		if ($raw === '') {
			wp_send_json_error(['message' => __('请粘贴 JSON 内容。', 'jio')]);
		}
		if (strlen($raw) > 2 * MB_IN_BYTES) {
			wp_send_json_error(['message' => __('JSON 内容超过 2MB。', 'jio')]);
		}
		$payload = json_decode($raw, true);
		if (!is_array($payload)) {
			wp_send_json_error(['message' => __('JSON 解析失败，请检查格式。', 'jio')]);
		}
		$mode = self::import_mode();
		$result = self::run_import($payload, $sidebar, $mode);
		$message = $mode === 'append'
			/* translators: 1: sidebar name, 2: imported widget count */
			? __('已向侧栏「%1$s」末尾追加 %2$d 个小工具。请刷新页面后查看效果。', 'jio')
			/* translators: 1: sidebar name, 2: imported widget count */
			: __('已覆盖侧栏「%1$s」并导入 %2$d 个小工具。请刷新页面后查看效果。', 'jio');
		self::send_result($sidebar, $mode, $result, $message);
	}

	public static function ajax_list_templates(): void {
		self::authorize();
		$list = [];
		foreach (WidgetTransfer::templates() as $id => $template) {
			$list[] = [
				'id'      => (string) $id,
				'title'   => (string) $template['title'],
				'desc'    => (string) ($template['desc'] ?? ''),
				'remind'  => (string) ($template['remind'] ?? ''),
				'modules' => WidgetTransfer::template_modules((string) $id),
			];
		}
		wp_send_json_success(['templates' => $list]);
	}

	public static function ajax_import_template(): void {
		self::authorize();
		$sidebar = self::target_sidebar();
		$template = isset($_POST['template_id']) ? sanitize_key(wp_unslash($_POST['template_id'])) : '';
		try {
			$payload = WidgetTransfer::template_payload($template);
		} catch (\InvalidArgumentException $error) {
			wp_send_json_error(['message' => $error->getMessage()]);
		}
		$mode = self::import_mode();
		$result = self::run_import($payload, $sidebar, $mode);
		$message = $mode === 'append'
			/* translators: 1: sidebar name, 2: imported widget count */
			? __('已从模板向侧栏「%1$s」末尾追加 %2$d 个小工具。请刷新页面后查看效果。', 'jio')
			/* translators: 1: sidebar name, 2: imported widget count */
			: __('已用模板覆盖侧栏「%1$s」并导入 %2$d 个小工具。请刷新页面后查看效果。', 'jio');
		self::send_result($sidebar, $mode, $result, $message, ['template_id' => $template]);
	}

	private static function authorize(): void {
		check_ajax_referer(self::NONCE, 'nonce');
		if (!current_user_can('edit_theme_options')) {
			wp_send_json_error(['message' => __('权限不足', 'jio')], 403);
		}
	}

	private static function target_sidebar(): string {
		$sidebar = isset($_POST['sidebar_id']) ? sanitize_key(wp_unslash($_POST['sidebar_id'])) : '';
		if ($sidebar === '' || !isset($GLOBALS['wp_registered_sidebars'][$sidebar])) {
			wp_send_json_error(['message' => __('无效的侧栏。', 'jio')]);
		}
		return $sidebar;
	}

	private static function import_mode(): string {
		$mode = isset($_POST['import_mode']) ? sanitize_key(wp_unslash($_POST['import_mode'])) : 'append';
		return $mode === 'replace' ? 'replace' : 'append';
	}

	/** @return array{sidebars:int,widgets:int} */
	private static function run_import(array $payload, string $sidebar, string $mode): array {
		try {
			return WidgetTransfer::import($payload, $mode, $sidebar);
		} catch (\InvalidArgumentException $error) {
			wp_send_json_error(['message' => $error->getMessage()]);
		}
	}

	/** @param array{sidebars:int,widgets:int} $result */
	private static function send_result(string $sidebar, string $mode, array $result, string $message, array $extra = []): void {
		$name = (string) ($GLOBALS['wp_registered_sidebars'][$sidebar]['name'] ?? $sidebar);
		wp_send_json_success(array_merge([
			'imported'    => (int) $result['widgets'],
			'sidebar_id'  => $sidebar,
			'import_mode' => $mode,
			'warnings'    => [],
			'message'     => sprintf($message, $name, (int) $result['widgets']),
		], $extra));
	}
}