<?php
/**
 * Plugin Name:       AsistentiAI Chat
 * Description:       Adds the AsistentiAI website chat to your site. The AI agent answers visitors around the clock from your business's own information and hands conversations to your team when needed.
 * Version:           1.0.0
 * Requires at least: 6.3
 * Requires PHP:      7.4
 * Author:            AsistentiAI
 * Author URI:        https://asistentiai.com/en
 * License:           GPLv2 or later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain:       asistentiai-chat
 *
 * @package AsistentiAI_Chat
 */

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

define( 'ASISTENTIAI_CHAT_SCRIPT_URL', 'https://asistentiai.com/widget.js' );

/**
 * Default values of the plugin settings.
 *
 * @return array
 */
function asistentiai_chat_defaults() {
	return array(
		'code'    => '',
		'enabled' => 1,
		'lang'    => 'dashboard',
		'brand'   => 0,
	);
}

/**
 * Language choices for the chat window. "dashboard" means: use the setting from the AsistentiAI dashboard.
 *
 * @return array Map of value => label.
 */
function asistentiai_chat_languages() {
	return array(
		'dashboard' => __( 'Use the setting from my AsistentiAI dashboard', 'asistentiai-chat' ),
		'sq'        => __( 'Albanian', 'asistentiai-chat' ),
		'en'        => __( 'English', 'asistentiai-chat' ),
		'auto'      => __( "Follow the visitor's browser (English for English browsers, Albanian otherwise)", 'asistentiai-chat' ),
	);
}

/**
 * Saved settings merged with the defaults.
 *
 * @return array
 */
function asistentiai_chat_get_settings() {
	$saved = get_option( 'asistentiai_chat_settings', array() );
	if ( ! is_array( $saved ) ) {
		$saved = array();
	}
	return wp_parse_args( $saved, asistentiai_chat_defaults() );
}

/**
 * Cleans the business code: lowercase letters, digits and hyphens only, at most 64 characters.
 * If the whole embed code from the dashboard was pasted, only the value of data-tenant is kept.
 *
 * @param mixed $value Raw value.
 * @return string
 */
function asistentiai_chat_sanitize_code( $value ) {
	$value = is_string( $value ) ? $value : '';
	if ( preg_match( '/data-tenant\s*=\s*["\']([^"\']*)["\']/i', $value, $matches ) ) {
		$value = $matches[1];
	}
	$value = (string) preg_replace( '/[^a-z0-9-]/', '', strtolower( trim( $value ) ) );
	return substr( $value, 0, 64 );
}

/**
 * Sanitize callback for the settings option.
 *
 * @param mixed $input Submitted values.
 * @return array
 */
function asistentiai_chat_sanitize_settings( $input ) {
	if ( ! is_array( $input ) ) {
		return asistentiai_chat_defaults();
	}

	$lang = isset( $input['lang'] ) ? sanitize_key( $input['lang'] ) : 'dashboard';
	if ( ! array_key_exists( $lang, asistentiai_chat_languages() ) ) {
		$lang = 'dashboard';
	}

	return array(
		'code'    => asistentiai_chat_sanitize_code( isset( $input['code'] ) ? $input['code'] : '' ),
		'enabled' => empty( $input['enabled'] ) ? 0 : 1,
		'lang'    => $lang,
		'brand'   => empty( $input['brand'] ) ? 0 : 1,
	);
}

/**
 * URL of the plugin's settings page.
 *
 * @return string
 */
function asistentiai_chat_settings_url() {
	return admin_url( 'options-general.php?page=asistentiai-chat' );
}

/**
 * Registers the setting, the section and the fields (Settings API).
 */
function asistentiai_chat_register_settings() {
	register_setting(
		'asistentiai_chat',
		'asistentiai_chat_settings',
		array(
			'type'              => 'array',
			'sanitize_callback' => 'asistentiai_chat_sanitize_settings',
			'default'           => asistentiai_chat_defaults(),
		)
	);

	add_settings_section(
		'asistentiai_chat_main',
		esc_html__( 'Chat on your site', 'asistentiai-chat' ),
		'asistentiai_chat_render_section',
		'asistentiai-chat'
	);

	add_settings_field(
		'asistentiai_chat_code',
		esc_html__( 'Business code', 'asistentiai-chat' ),
		'asistentiai_chat_render_code_field',
		'asistentiai-chat',
		'asistentiai_chat_main',
		array( 'label_for' => 'asistentiai_chat_code' )
	);

	add_settings_field(
		'asistentiai_chat_enabled',
		esc_html__( 'Show the chat', 'asistentiai-chat' ),
		'asistentiai_chat_render_enabled_field',
		'asistentiai-chat',
		'asistentiai_chat_main',
		array( 'label_for' => 'asistentiai_chat_enabled' )
	);

	add_settings_field(
		'asistentiai_chat_lang',
		esc_html__( 'Chat window language', 'asistentiai-chat' ),
		'asistentiai_chat_render_lang_field',
		'asistentiai-chat',
		'asistentiai_chat_main',
		array( 'label_for' => 'asistentiai_chat_lang' )
	);

	add_settings_field(
		'asistentiai_chat_brand',
		esc_html__( '"Powered by" link', 'asistentiai-chat' ),
		'asistentiai_chat_render_brand_field',
		'asistentiai-chat',
		'asistentiai_chat_main',
		array( 'label_for' => 'asistentiai_chat_brand' )
	);
}
add_action( 'admin_init', 'asistentiai_chat_register_settings' );

/**
 * Adds Settings → AsistentiAI Chat.
 */
function asistentiai_chat_add_settings_page() {
	add_options_page(
		esc_html__( 'AsistentiAI Chat', 'asistentiai-chat' ),
		esc_html__( 'AsistentiAI Chat', 'asistentiai-chat' ),
		'manage_options',
		'asistentiai-chat',
		'asistentiai_chat_render_settings_page'
	);
}
add_action( 'admin_menu', 'asistentiai_chat_add_settings_page' );

/**
 * Help text above the fields: how to get an account and where the business code is.
 */
function asistentiai_chat_render_section() {
	echo '<p>';
	printf(
		/* translators: %s: link to the page where a free trial can be requested. */
		esc_html__( 'The chat works with an AsistentiAI account. No account yet? %s: 50 agent replies, no credit card, and our team opens your account within the day.', 'asistentiai-chat' ),
		'<a href="' . esc_url( 'https://asistentiai.com/en/contact' ) . '" target="_blank" rel="noopener noreferrer">' . esc_html__( 'Request a free trial', 'asistentiai-chat' ) . '</a>'
	);
	echo '</p><p>';
	esc_html_e( 'Your business code is in the AsistentiAI dashboard, under Channels → Website widget. It is the value of data-tenant in the embed code shown there. You can also paste the whole embed code below; only the code is kept.', 'asistentiai-chat' );
	echo '</p>';
}

/**
 * Business code field.
 */
function asistentiai_chat_render_code_field() {
	$settings = asistentiai_chat_get_settings();
	printf(
		'<input type="text" id="asistentiai_chat_code" name="asistentiai_chat_settings[code]" value="%s" class="regular-text code" autocomplete="off" spellcheck="false" />',
		esc_attr( $settings['code'] )
	);
	echo '<p class="description">' . esc_html__( 'Lowercase letters, numbers and hyphens. Use the code from your own dashboard, not one copied from another site.', 'asistentiai-chat' ) . '</p>';
}

/**
 * On/off field.
 */
function asistentiai_chat_render_enabled_field() {
	$settings = asistentiai_chat_get_settings();
	printf(
		'<label><input type="checkbox" id="asistentiai_chat_enabled" name="asistentiai_chat_settings[enabled]" value="1" %s /> %s</label>',
		checked( 1, (int) $settings['enabled'], false ),
		esc_html__( 'Show the chat on my site', 'asistentiai-chat' )
	);
	echo '<p class="description">' . esc_html__( 'Untick to hide the chat without losing these settings. To pause only the agent, use your AsistentiAI dashboard.', 'asistentiai-chat' ) . '</p>';
}

/**
 * Language field.
 */
function asistentiai_chat_render_lang_field() {
	$settings = asistentiai_chat_get_settings();
	echo '<select id="asistentiai_chat_lang" name="asistentiai_chat_settings[lang]">';
	foreach ( asistentiai_chat_languages() as $value => $label ) {
		printf(
			'<option value="%s" %s>%s</option>',
			esc_attr( $value ),
			selected( $settings['lang'], $value, false ),
			esc_html( $label )
		);
	}
	echo '</select>';
	echo '<p class="description">' . esc_html__( 'Language of the buttons and labels in the chat window. The agent itself always replies in the language the visitor writes in.', 'asistentiai-chat' ) . '</p>';
}

/**
 * "Powered by AsistentiAI" field. Off by default.
 */
function asistentiai_chat_render_brand_field() {
	$settings = asistentiai_chat_get_settings();
	printf(
		'<label><input type="checkbox" id="asistentiai_chat_brand" name="asistentiai_chat_settings[brand]" value="1" %s /> %s</label>',
		checked( 1, (int) $settings['brand'], false ),
		esc_html__( 'Show "Powered by AsistentiAI" at the bottom of the chat window', 'asistentiai-chat' )
	);
	echo '<p class="description">' . esc_html__( 'Off by default. When on, the line links to asistentiai.com.', 'asistentiai-chat' ) . '</p>';
}

/**
 * The settings page.
 */
function asistentiai_chat_render_settings_page() {
	if ( ! current_user_can( 'manage_options' ) ) {
		return;
	}
	$settings = asistentiai_chat_get_settings();
	?>
	<div class="wrap">
		<h1><?php echo esc_html( get_admin_page_title() ); ?></h1>
		<?php if ( '' === $settings['code'] ) : ?>
			<div class="notice notice-warning inline">
				<p><?php esc_html_e( 'The chat stays hidden until you enter your business code.', 'asistentiai-chat' ); ?></p>
			</div>
		<?php endif; ?>
		<form action="options.php" method="post">
			<?php
			settings_fields( 'asistentiai_chat' );
			do_settings_sections( 'asistentiai-chat' );
			submit_button();
			?>
		</form>
	</div>
	<?php
}

/**
 * Reminder on the Plugins screen while the business code is empty.
 */
function asistentiai_chat_admin_notice() {
	if ( ! current_user_can( 'manage_options' ) ) {
		return;
	}
	$screen = get_current_screen();
	if ( ! $screen || 'plugins' !== $screen->id ) {
		return;
	}
	$settings = asistentiai_chat_get_settings();
	if ( '' !== $settings['code'] ) {
		return;
	}
	printf(
		'<div class="notice notice-warning"><p>%s <a href="%s">%s</a></p></div>',
		esc_html__( 'AsistentiAI Chat is active, but the chat is not on your site yet: it needs your business code.', 'asistentiai-chat' ),
		esc_url( asistentiai_chat_settings_url() ),
		esc_html__( 'Add the code', 'asistentiai-chat' )
	);
}
add_action( 'admin_notices', 'asistentiai_chat_admin_notice' );

/**
 * "Settings" link in the plugin's row on the Plugins screen.
 *
 * @param array $links Existing action links.
 * @return array
 */
function asistentiai_chat_action_links( $links ) {
	$settings_link = '<a href="' . esc_url( asistentiai_chat_settings_url() ) . '">' . esc_html__( 'Settings', 'asistentiai-chat' ) . '</a>';
	array_unshift( $links, $settings_link );
	return $links;
}
add_filter( 'plugin_action_links_' . plugin_basename( __FILE__ ), 'asistentiai_chat_action_links' );

/**
 * Loads the chat script on the front end only, when it is switched on and a business code is saved.
 */
function asistentiai_chat_enqueue_script() {
	if ( is_admin() ) {
		return;
	}
	$settings = asistentiai_chat_get_settings();
	if ( empty( $settings['enabled'] ) || '' === $settings['code'] ) {
		return;
	}
	wp_enqueue_script(
		'asistentiai-chat',
		ASISTENTIAI_CHAT_SCRIPT_URL,
		array(),
		null, // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- Remote script versioned by the AsistentiAI service; a ?ver= query would only add a second cached copy.
		array(
			'in_footer' => true,
			'strategy'  => 'defer',
		)
	);
}
add_action( 'wp_enqueue_scripts', 'asistentiai_chat_enqueue_script' );

/**
 * Adds the data-* attributes the chat script reads (business code, language, "Powered by" line).
 *
 * @param string $tag    The script tag.
 * @param string $handle The script handle.
 * @return string
 */
function asistentiai_chat_script_attributes( $tag, $handle ) {
	if ( 'asistentiai-chat' !== $handle ) {
		return $tag;
	}
	$settings = asistentiai_chat_get_settings();

	$attributes = ' data-tenant="' . esc_attr( $settings['code'] ) . '"';
	if ( 'dashboard' !== $settings['lang'] ) {
		$attributes .= ' data-lang="' . esc_attr( $settings['lang'] ) . '"';
	}
	if ( empty( $settings['brand'] ) ) {
		$attributes .= ' data-brand="0"';
	}

	$position = strpos( $tag, '<script' );
	if ( false === $position ) {
		return $tag;
	}
	return substr_replace( $tag, '<script' . $attributes, $position, strlen( '<script' ) );
}
add_filter( 'script_loader_tag', 'asistentiai_chat_script_attributes', 10, 2 );