<?php
/**
 * Settings → FlatRateChat: explanation, plans, Connect / Disconnect, plan + usage, links to the dashboard.
 *
 * @package FlatRateChat
 */

defined( 'ABSPATH' ) || exit;

/**
 * Admin screen.
 */
class FlatRateChat_Admin {

	const PAGE = 'flatratechat';

	/**
	 * Hook up.
	 */
	public static function init() {
		add_action( 'admin_menu', array( __CLASS__, 'menu' ) );
		add_action( 'admin_post_flatratechat_connect', array( __CLASS__, 'handle_connect' ) );
		add_action( 'admin_post_flatratechat_disconnect', array( __CLASS__, 'handle_disconnect' ) );
		add_action( 'admin_post_flatratechat_refresh', array( __CLASS__, 'handle_refresh' ) );
		add_action( 'admin_post_flatratechat_paste_code', array( __CLASS__, 'handle_paste_code' ) );
		add_action( 'admin_init', array( __CLASS__, 'maybe_finish_connect' ) );
		add_action( 'admin_enqueue_scripts', array( __CLASS__, 'styles' ) );
	}

	/**
	 * Settings → FlatRateChat.
	 */
	public static function menu() {
		add_options_page(
			__( 'FlatRateChat', 'flatratechat' ),
			__( 'FlatRateChat', 'flatratechat' ),
			'manage_options',
			self::PAGE,
			array( __CLASS__, 'render' )
		);
	}

	/**
	 * Small stylesheet for our own page only.
	 *
	 * @param string $hook Current admin page hook.
	 */
	public static function styles( $hook ) {
		if ( 'settings_page_' . self::PAGE !== $hook ) {
			return;
		}
		wp_enqueue_style( 'flatratechat-admin', FLATRATECHAT_PLUGIN_URL . 'assets/admin.css', array(), FLATRATECHAT_VERSION );
	}

	/**
	 * URL of our settings page, optionally with a notice code.
	 *
	 * @param string $notice Notice key.
	 * @param string $detail Optional detail text (shown escaped).
	 * @return string
	 */
	private static function page_url( $notice = '', $detail = '' ) {
		$url = admin_url( 'options-general.php?page=' . self::PAGE );
		if ( $notice ) {
			$url = add_query_arg( 'frc_notice', rawurlencode( $notice ), $url );
		}
		if ( $detail ) {
			$url = add_query_arg( 'frc_detail', rawurlencode( wp_strip_all_tags( $detail ) ), $url );
		}
		return $url;
	}

	/**
	 * Connect: generate the one-time state, remember it for 15 minutes, send the admin to flatratechat.com.
	 * This is the first and only moment the plugin reaches out, and it happens in the admin's own browser.
	 */
	public static function handle_connect() {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'You do not have permission to do that.', 'flatratechat' ) );
		}
		check_admin_referer( 'flatratechat_connect' );
		$state = wp_generate_password( 32, false, false );
		set_transient( FlatRateChat_Service::TR_STATE, $state, 15 * MINUTE_IN_SECONDS );
		wp_redirect( FlatRateChat_Service::connect_url( $state ) ); // phpcs:ignore WordPress.Security.SafeRedirect.wp_redirect_wp_redirect -- intentional redirect to the FlatRateChat service.
		exit;
	}

	/**
	 * The service sends the browser back here with ?frc_code=&frc_state=. Check the state, exchange the code.
	 */
	public static function maybe_finish_connect() {
		if ( ! isset( $_GET['page'], $_GET['frc_code'], $_GET['frc_state'] ) || self::PAGE !== $_GET['page'] ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- the one-time state below is the CSRF check for this cross-site return.
			return;
		}
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}
		$state    = sanitize_text_field( wp_unslash( $_GET['frc_state'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$code     = sanitize_text_field( wp_unslash( $_GET['frc_code'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$expected = (string) get_transient( FlatRateChat_Service::TR_STATE );
		if ( '' === $expected || ! hash_equals( $expected, $state ) ) {
			wp_safe_redirect( self::page_url( 'state' ) );
			exit;
		}
		delete_transient( FlatRateChat_Service::TR_STATE ); // single use.
		$r = FlatRateChat_Service::exchange_code( $code );
		if ( is_wp_error( $r ) ) {
			wp_safe_redirect( self::page_url( 'error', $r->get_error_message() ) );
			exit;
		}
		wp_safe_redirect( self::page_url( 'connected' ) );
		exit;
	}

	/**
	 * Fallback: the admin pastes the connection code shown on flatratechat.com.
	 */
	public static function handle_paste_code() {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'You do not have permission to do that.', 'flatratechat' ) );
		}
		check_admin_referer( 'flatratechat_paste_code' );
		$code = isset( $_POST['frc_code'] ) ? sanitize_text_field( wp_unslash( $_POST['frc_code'] ) ) : '';
		$r    = FlatRateChat_Service::exchange_code( $code );
		if ( is_wp_error( $r ) ) {
			wp_safe_redirect( self::page_url( 'error', $r->get_error_message() ) );
			exit;
		}
		wp_safe_redirect( self::page_url( 'connected' ) );
		exit;
	}

	/**
	 * Disconnect: remove the script and our options from this site.
	 */
	public static function handle_disconnect() {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'You do not have permission to do that.', 'flatratechat' ) );
		}
		check_admin_referer( 'flatratechat_disconnect' );
		FlatRateChat_Service::disconnect();
		wp_safe_redirect( self::page_url( 'disconnected' ) );
		exit;
	}

	/**
	 * Refresh the cached plan + usage.
	 */
	public static function handle_refresh() {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'You do not have permission to do that.', 'flatratechat' ) );
		}
		check_admin_referer( 'flatratechat_refresh' );
		delete_transient( FlatRateChat_Service::TR_STATUS );
		wp_safe_redirect( self::page_url() );
		exit;
	}

	/**
	 * Notices after a redirect.
	 */
	private static function notices() {
		if ( ! isset( $_GET['frc_notice'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- display only.
			return;
		}
		$notice = sanitize_key( wp_unslash( $_GET['frc_notice'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$detail = isset( $_GET['frc_detail'] ) ? sanitize_text_field( wp_unslash( $_GET['frc_detail'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$map    = array(
			'connected'    => array( 'success', __( 'Connected. The chat bubble is now on your site. It can take a few minutes until all your pages are read.', 'flatratechat' ) ),
			'disconnected' => array( 'info', __( 'Disconnected. The chat bubble was removed from your site. Your FlatRateChat account still exists at flatratechat.com.', 'flatratechat' ) ),
			'state'        => array( 'error', __( 'That connection attempt was not started from this site or has expired (15 minutes). Click Connect again.', 'flatratechat' ) ),
			'error'        => array( 'error', $detail ? $detail : __( 'Something went wrong. Click Connect again.', 'flatratechat' ) ),
		);
		if ( ! isset( $map[ $notice ] ) ) {
			return;
		}
		printf( '<div class="notice notice-%1$s is-dismissible"><p>%2$s</p></div>', esc_attr( $map[ $notice ][0] ), esc_html( $map[ $notice ][1] ) );
	}

	/**
	 * The settings page.
	 */
	public static function render() {
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}
		$connected = FlatRateChat_Service::is_connected();
		$status    = $connected ? FlatRateChat_Service::status() : null;
		if ( $connected && is_wp_error( $status ) && FlatRateChat_Service::is_stale_error( $status ) ) {
			$connected = false; // status() already dropped the key and token.
		}
		$dashboard = FlatRateChat_Service::base_url() . '/dashboard';
		?>
		<div class="wrap frc-wrap">
			<h1><img src="<?php echo esc_url( FLATRATECHAT_PLUGIN_URL . 'assets/icon.svg' ); ?>" alt="" width="36" height="36" class="frc-logo"> <?php esc_html_e( 'FlatRateChat', 'flatratechat' ); ?></h1>
			<?php self::notices(); ?>
			<?php if ( ! $connected && FlatRateChat_Service::is_stale() ) : ?>
				<div class="notice notice-warning"><p>
					<?php
					printf(
						/* translators: %s: site host name */
						esc_html__( 'Disconnected: FlatRateChat no longer accepts this site’s connection for %s (it was disconnected elsewhere, connected from another install, or the website was deleted in the dashboard). The chat bubble has been removed from your pages. Please Connect again.', 'flatratechat' ),
						esc_html( (string) get_option( FlatRateChat_Service::OPT_HOST, '' ) )
					);
					?>
				</p></div>
			<?php endif; ?>

			<?php if ( ! $connected ) : ?>
				<div class="frc-card">
					<h2><?php esc_html_e( 'An AI chat bubble that answers from your own pages', 'flatratechat' ); ?></h2>
					<p><?php esc_html_e( 'Connect your site and FlatRateChat reads your public pages. Visitors ask a question in the bubble; the answer comes only from your pages and links the page it came from. When the answer is not on your site, it says so and shows your contact details instead. Like any AI, it can be wrong sometimes. Your content is not used to train AI models.', 'flatratechat' ); ?></p>
					<p class="frc-fine"><?php esc_html_e( 'Nothing is sent to FlatRateChat until you click Connect. Connect opens flatratechat.com, where you sign in with your email (no password). Your site then starts on the Free plan. You come straight back here.', 'flatratechat' ); ?></p>
					<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>">
						<?php wp_nonce_field( 'flatratechat_connect' ); ?>
						<input type="hidden" name="action" value="flatratechat_connect">
						<?php submit_button( __( 'Connect to FlatRateChat', 'flatratechat' ), 'primary large', 'submit', false ); ?>
					</form>
					<p class="frc-fine">
						<?php
						printf(
							/* translators: 1: privacy policy link, 2: terms link */
							esc_html__( 'By connecting you agree to the FlatRateChat %1$s and %2$s.', 'flatratechat' ),
							'<a href="https://flatratechat.com/privacy" target="_blank" rel="noopener">' . esc_html__( 'Privacy Policy', 'flatratechat' ) . '</a>',
							'<a href="https://flatratechat.com/terms" target="_blank" rel="noopener">' . esc_html__( 'Terms', 'flatratechat' ) . '</a>'
						);
						?>
					</p>
				</div>
				<?php self::render_plans( null ); ?>
				<div class="frc-card">
					<h2><?php esc_html_e( 'Already have a connection code?', 'flatratechat' ); ?></h2>
					<p class="frc-fine"><?php esc_html_e( 'If flatratechat.com showed you a connection code instead of bringing you back here, paste it below.', 'flatratechat' ); ?></p>
					<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>">
						<?php wp_nonce_field( 'flatratechat_paste_code' ); ?>
						<input type="hidden" name="action" value="flatratechat_paste_code">
						<label class="screen-reader-text" for="frc_code"><?php esc_html_e( 'Connection code', 'flatratechat' ); ?></label>
						<input type="text" id="frc_code" name="frc_code" class="regular-text code" autocomplete="off" required>
						<?php submit_button( __( 'Use code', 'flatratechat' ), 'secondary', 'submit', false ); ?>
					</form>
				</div>
			<?php else : ?>
				<div class="frc-card">
					<h2><?php esc_html_e( 'Connected', 'flatratechat' ); ?></h2>
					<table class="form-table frc-table" role="presentation">
						<tr><th scope="row"><?php esc_html_e( 'Website', 'flatratechat' ); ?></th><td><?php echo esc_html( (string) get_option( FlatRateChat_Service::OPT_HOST, wp_parse_url( home_url(), PHP_URL_HOST ) ) ); ?></td></tr>
						<tr><th scope="row"><?php esc_html_e( 'Site key', 'flatratechat' ); ?></th><td><code><?php echo esc_html( FlatRateChat_Service::site_key() ); ?></code></td></tr>
						<?php if ( is_wp_error( $status ) ) : ?>
							<tr><th scope="row"><?php esc_html_e( 'Plan', 'flatratechat' ); ?></th><td><?php echo esc_html( $status->get_error_message() ); ?></td></tr>
						<?php else : ?>
							<tr><th scope="row"><?php esc_html_e( 'Plan', 'flatratechat' ); ?></th><td><strong><?php echo esc_html( self::plan_label( $status ) ); ?></strong> <?php echo esc_html( self::plan_detail( $status ) ); ?></td></tr>
							<tr><th scope="row"><?php esc_html_e( 'AI answers this month', 'flatratechat' ); ?></th><td>
								<?php
								$used     = isset( $status['answers_used'] ) ? (int) $status['answers_used'] : 0;
								$included = isset( $status['answers_included'] ) ? (int) $status['answers_included'] : 0;
								printf(
									/* translators: 1: answers used, 2: answers included */
									esc_html__( '%1$s of %2$s included', 'flatratechat' ),
									esc_html( number_format_i18n( $used ) ),
									esc_html( number_format_i18n( $included ) )
								);
								if ( $included > 0 ) {
									$pct = min( 100, (int) round( $used * 100 / $included ) );
									echo '<div class="frc-bar"><span style="width:' . esc_attr( $pct ) . '%"></span></div>';
								}
								if ( ! empty( $status['resets_on'] ) ) {
									echo '<p class="description">' . esc_html( sprintf( /* translators: %s: date */ __( 'Counter resets on %s.', 'flatratechat' ), date_i18n( get_option( 'date_format' ), strtotime( (string) $status['resets_on'] ) ) ) ) . '</p>';
								}
								?>
							</td></tr>
							<tr><th scope="row"><?php esc_html_e( 'Pages read', 'flatratechat' ); ?></th><td>
								<?php
								printf(
									/* translators: 1: pages indexed, 2: pages included */
									esc_html__( '%1$s of up to %2$s', 'flatratechat' ),
									esc_html( number_format_i18n( isset( $status['pages_indexed'] ) ? (int) $status['pages_indexed'] : 0 ) ),
									esc_html( number_format_i18n( isset( $status['pages_included'] ) ? (int) $status['pages_included'] : 0 ) )
								);
								if ( ! empty( $status['crawl']['status'] ) && in_array( $status['crawl']['status'], array( 'queued', 'running' ), true ) ) {
									echo ' <em>' . esc_html__( '(reading your site now)', 'flatratechat' ) . '</em>';
								}
								?>
							</td></tr>
						<?php endif; ?>
					</table>
					<p class="frc-actions">
						<a class="button button-primary" href="<?php echo esc_url( $dashboard ); ?>" target="_blank" rel="noopener"><?php esc_html_e( 'Open dashboard', 'flatratechat' ); ?></a>
						<a class="button" href="<?php echo esc_url( $dashboard . '#convo-box' ); ?>" target="_blank" rel="noopener"><?php esc_html_e( 'Conversations', 'flatratechat' ); ?></a>
						<a class="button" href="<?php echo esc_url( $dashboard . '#settings-box' ); ?>" target="_blank" rel="noopener"><?php esc_html_e( 'Chat settings', 'flatratechat' ); ?></a>
						<?php if ( ! is_wp_error( $status ) && 'free' === self::plan_slug( $status ) ) : ?>
							<a class="button" href="<?php echo esc_url( $dashboard . '#wp-plans-box' ); ?>" target="_blank" rel="noopener"><?php esc_html_e( 'Upgrade', 'flatratechat' ); ?></a>
						<?php endif; ?>
					</p>
					<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>" class="frc-inline">
						<?php wp_nonce_field( 'flatratechat_refresh' ); ?>
						<input type="hidden" name="action" value="flatratechat_refresh">
						<?php submit_button( __( 'Refresh', 'flatratechat' ), 'link', 'submit', false ); ?>
					</form>
					<p class="frc-fine"><?php esc_html_e( 'Chat settings, conversations, your contact details for the fallback, billing and account deletion live in the FlatRateChat dashboard. This page only connects your site and shows the plan.', 'flatratechat' ); ?></p>
				</div>
				<?php self::render_plans( is_wp_error( $status ) ? null : $status ); ?>
				<div class="frc-card frc-danger">
					<h2><?php esc_html_e( 'Disconnect', 'flatratechat' ); ?></h2>
					<p class="frc-fine"><?php esc_html_e( 'Removes the chat bubble and the site key from this WordPress site. Your FlatRateChat account and any subscription are not changed; manage or cancel them in the dashboard. Deleting the plugin does the same clean-up.', 'flatratechat' ); ?></p>
					<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>">
						<?php wp_nonce_field( 'flatratechat_disconnect' ); ?>
						<input type="hidden" name="action" value="flatratechat_disconnect">
						<?php submit_button( __( 'Disconnect', 'flatratechat' ), 'delete', 'submit', false ); ?>
					</form>
				</div>
			<?php endif; ?>
		</div>
		<?php
	}

	/**
	 * Plan cards. Prices and limits are set by the service; this is a description, not an enforcement.
	 *
	 * @param array|null $status Current status, if connected.
	 */
	private static function render_plans( $status ) {
		$current = $status ? self::plan_slug( $status ) : '';
		$plans   = array(
			'free'    => array( __( 'Free', 'flatratechat' ), '$0', __( '50 pages read. 100 AI answers a month. No card. At the limit the bubble stays on your site and shows your contact details until the 1st.', 'flatratechat' ) ),
			'starter' => array( __( 'Starter', 'flatratechat' ), '$19/month', __( '100 pages read. 1,000 AI answers a month. 14-day free trial on a site’s first paid plan, card required.', 'flatratechat' ) ),
			'full'    => array( __( 'Full', 'flatratechat' ), '$59/month', __( '500 pages read. 5,000 AI answers a month. 14-day free trial on a site’s first paid plan, card required.', 'flatratechat' ) ),
		);
		?>
		<div class="frc-card">
			<h2><?php esc_html_e( 'Plans', 'flatratechat' ); ?></h2>
			<div class="frc-plans">
				<?php foreach ( $plans as $slug => $p ) : ?>
					<div class="frc-plan<?php echo $current === $slug ? ' frc-current' : ''; ?>">
						<h3><?php echo esc_html( $p[0] ); ?></h3>
						<p class="frc-price"><?php echo esc_html( $p[1] ); ?></p>
						<p class="frc-fine"><?php echo esc_html( $p[2] ); ?></p>
						<?php if ( $current === $slug ) : ?>
							<p class="frc-fine frc-current-label"><?php esc_html_e( 'Your current plan', 'flatratechat' ); ?></p>
						<?php endif; ?>
					</div>
				<?php endforeach; ?>
			</div>
			<p class="frc-fine"><?php esc_html_e( 'Paid plans: above the included answers the bot keeps answering at up to 10 answers an hour until the next monthly cycle. No overage charges. Your price stays locked while you stay subscribed. Monthly billing. Plans are chosen and billed in the FlatRateChat dashboard (Stripe); nothing is charged through WordPress.', 'flatratechat' ); ?></p>
		</div>
		<?php
	}

	/**
	 * 'free' | 'starter' | 'full'.
	 *
	 * @param array $status Status payload.
	 * @return string
	 */
	private static function plan_slug( $status ) {
		$plan = isset( $status['plan'] ) ? (string) $status['plan'] : 'free';
		return in_array( $plan, array( 'free', 'starter', 'full' ), true ) ? $plan : 'free';
	}

	/**
	 * Human label.
	 *
	 * @param array $status Status payload.
	 * @return string
	 */
	private static function plan_label( $status ) {
		$labels = array(
			'free'    => __( 'Free plan', 'flatratechat' ),
			'starter' => __( 'Starter plan', 'flatratechat' ),
			'full'    => __( 'Full plan', 'flatratechat' ),
		);
		return $labels[ self::plan_slug( $status ) ];
	}

	/**
	 * Secondary line: trial / renewal / cancellation.
	 *
	 * @param array $status Status payload.
	 * @return string
	 */
	private static function plan_detail( $status ) {
		$s    = isset( $status['status'] ) ? (string) $status['status'] : '';
		$date = ! empty( $status['access_through'] ) ? date_i18n( get_option( 'date_format' ), strtotime( (string) $status['access_through'] ) ) : '';
		if ( 'free' === self::plan_slug( $status ) ) {
			return '';
		}
		if ( 'trialing' === $s ) {
			/* translators: %s: date */
			return $date ? sprintf( __( 'Free trial until %s.', 'flatratechat' ), $date ) : __( 'Free trial.', 'flatratechat' );
		}
		if ( ! empty( $status['cancel_at_period_end'] ) ) {
			/* translators: %s: date */
			return $date ? sprintf( __( 'Cancelled; returns to the Free plan on %s.', 'flatratechat' ), $date ) : __( 'Cancelled at the end of the period.', 'flatratechat' );
		}
		if ( 'grace' === $s ) {
			return __( 'Payment failed; please update your card in the dashboard.', 'flatratechat' );
		}
		/* translators: %s: date */
		return $date ? sprintf( __( 'Renews on %s.', 'flatratechat' ), $date ) : '';
	}
}