<?php
namespace Agentsia_Agents;

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

/**
 * Per-post overrides for the chatbot widget.
 *
 * Adds an "Agentsia — Chatbot" meta box on every public post-type. Each post
 * can choose:
 *   - a scenario name (e.g. "sos", "devis") — declared in the chatbot config
 *     under `metadata.scenarios`
 *   - a free-form context hint that is concatenated to the scenario's static
 *     contextHint and injected into the LLM system prompt
 *   - whether the floating bubble is shown / hidden on this page
 *
 * These overrides are applied automatically by {@see Chatbot::maybe_render_global()}
 * when the global chatbot is enabled.
 */
final class Post_Meta {

	// Non-protected keys (no leading underscore) so the block editor can write
	// them via the REST API — protected meta is not reliably saved by Gutenberg.
	private const META_SCENARIO     = 'agentsia_scenario';
	private const META_CONTEXT_HINT = 'agentsia_context_hint';
	private const META_BUBBLE       = 'agentsia_bubble'; // "inherit" | "show" | "hide"
	private const NONCE_FIELD       = 'agentsia_chatbot_meta_nonce';
	private const NONCE_ACTION      = 'agentsia_chatbot_meta_save';

	private static ?self $instance = null;

	public static function instance(): self {
		if ( self::$instance === null ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	public function register(): void {
		add_action( 'init', [ $this, 'register_meta' ] );
		add_action( 'add_meta_boxes', [ $this, 'add_meta_box' ] );
		add_action( 'save_post', [ $this, 'save' ], 10, 2 );
		add_action( 'enqueue_block_editor_assets', [ $this, 'enqueue_editor_panel' ] );
	}

	/**
	 * Expose the per-page overrides to the REST API so the block editor reads and
	 * writes them reliably. A classic meta box does not reliably trigger a save in
	 * Gutenberg when it is the only thing changed — the sidebar panel + registered
	 * meta fix that.
	 */
	public function register_meta(): void {
		$post_types = get_post_types( [ 'public' => true ], 'names' );
		unset( $post_types['attachment'] );

		$auth = static function ( $allowed, $meta_key, $post_id ) {
			return current_user_can( 'edit_post', (int) $post_id );
		};

		foreach ( $post_types as $type ) {
			// Required for the block editor to persist post meta via REST.
			add_post_type_support( $type, 'custom-fields' );
			register_post_meta( $type, self::META_SCENARIO, [
				'type'              => 'string',
				'single'            => true,
				'default'           => '',
				'show_in_rest'      => true,
				'auth_callback'     => $auth,
				'sanitize_callback' => static function ( $v ) {
					// Keep accents/unicode; only whitespace → dash (mirrors the backend's
					// scenario-name format). Stripping accents ("dépannage" → "dpannage")
					// would break the match with the scenario defined in the chatbot config.
					$v = preg_replace( '/\s+/u', '-', sanitize_text_field( (string) $v ) );
					return (string) mb_substr( (string) $v, 0, 80 );
				},
			] );
			register_post_meta( $type, self::META_CONTEXT_HINT, [
				'type'              => 'string',
				'single'            => true,
				'default'           => '',
				'show_in_rest'      => true,
				'auth_callback'     => $auth,
				'sanitize_callback' => static function ( $v ) {
					return (string) substr( sanitize_textarea_field( (string) $v ), 0, 2000 );
				},
			] );
			register_post_meta( $type, self::META_BUBBLE, [
				'type'              => 'string',
				'single'            => true,
				'default'           => '',
				'show_in_rest'      => true,
				'auth_callback'     => $auth,
				'sanitize_callback' => static function ( $v ) {
					return in_array( $v, [ 'show', 'hide' ], true ) ? (string) $v : '';
				},
			] );
		}
	}

	/**
	 * Enqueue the block-editor sidebar panel that edits the per-page overrides.
	 */
	public function enqueue_editor_panel(): void {
		$handle = 'agentsia-chatbot-editor-panel';
		wp_register_script(
			$handle,
			AGENTSIA_AGENTS_URL . 'assets/js/editor-panel.js',
			[ 'wp-plugins', 'wp-editor', 'wp-edit-post', 'wp-element', 'wp-components', 'wp-data', 'wp-core-data', 'wp-i18n' ],
			AGENTSIA_AGENTS_VERSION,
			true
		);
		wp_set_script_translations( $handle, 'agentsia-agents' );

		$settings  = Plugin::get_settings();
		$config_id = (string) ( $settings['chatbot_config_id'] ?? '' );
		$scenarios = [];
		if ( $config_id !== '' ) {
			foreach ( Api_Client::list_chatbots() as $bot ) {
				if ( ( $bot['chatbotConfigId'] ?? '' ) === $config_id && isset( $bot['scenarios'] ) && is_array( $bot['scenarios'] ) ) {
					$scenarios = array_values( $bot['scenarios'] );
					break;
				}
			}
		}
		$default_scenario = (string) ( $settings['default_scenario'] ?? '' );

		wp_localize_script( $handle, 'AgentsiaEditorPanel', [
			'scenarios'       => $scenarios,
			'hasScenarioList' => ! empty( $scenarios ),
			'defaultLabel'    => $default_scenario !== ''
				? __( 'Défaut', 'agentsia-agents' ) . ' (' . $default_scenario . ')'
				: __( '— Scénario par défaut —', 'agentsia-agents' ),
		] );
		wp_enqueue_script( $handle );
	}

	/**
	 * Display the meta box on every public post type (post, page, custom types
	 * marked `public => true`).
	 */
	public function add_meta_box(): void {
		// In the block editor the JS sidebar panel handles these overrides; the
		// classic meta box stays only for the classic editor / page builders.
		$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;
		if ( $screen && method_exists( $screen, 'is_block_editor' ) && $screen->is_block_editor() ) {
			return;
		}
		$post_types = get_post_types( [ 'public' => true ], 'names' );
		// Drop "attachment" — useless there.
		unset( $post_types['attachment'] );

		foreach ( $post_types as $type ) {
			add_meta_box(
				'agentsia-chatbot-overrides',
				__( 'Agentsia — Chatbot', 'agentsia-agents' ),
				[ $this, 'render_meta_box' ],
				$type,
				'side',
				'default'
			);
		}
	}

	public function render_meta_box( \WP_Post $post ): void {
		wp_nonce_field( self::NONCE_ACTION, self::NONCE_FIELD );

		$scenario      = (string) get_post_meta( $post->ID, self::META_SCENARIO, true );
		$context_hint  = (string) get_post_meta( $post->ID, self::META_CONTEXT_HINT, true );
		$bubble        = (string) get_post_meta( $post->ID, self::META_BUBBLE, true );
		if ( $bubble === '' ) {
			$bubble = 'inherit';
		}

		$settings         = Plugin::get_settings();
		$default_scenario = (string) ( $settings['default_scenario'] ?? '' );

		// Scénarios définis pour le chatbot sélectionné (exposés par l'API si dispo).
		$scenario_names = [];
		$config_id      = (string) ( $settings['chatbot_config_id'] ?? '' );
		if ( $config_id !== '' ) {
			foreach ( Api_Client::list_chatbots() as $bot ) {
				if ( ( $bot['chatbotConfigId'] ?? '' ) === $config_id && isset( $bot['scenarios'] ) && is_array( $bot['scenarios'] ) ) {
					$scenario_names = $bot['scenarios'];
					break;
				}
			}
		}
		?>
		<p>
			<label for="agentsia_meta_scenario">
				<strong><?php esc_html_e( 'Scénario', 'agentsia-agents' ); ?></strong>
			</label>
			<?php if ( ! empty( $scenario_names ) ) : ?>
				<select id="agentsia_meta_scenario" name="agentsia_meta_scenario" class="widefat">
					<option value=""><?php echo esc_html( $default_scenario !== '' ? __( 'Défaut', 'agentsia-agents' ) . ' (' . $default_scenario . ')' : __( '— Scénario par défaut —', 'agentsia-agents' ) ); ?></option>
					<?php foreach ( $scenario_names as $name ) : ?>
						<option value="<?php echo esc_attr( (string) $name ); ?>" <?php selected( (string) $name, $scenario ); ?>><?php echo esc_html( (string) $name ); ?></option>
					<?php endforeach; ?>
				</select>
				<small class="description">
					<?php esc_html_e( 'Scénario appliqué au chatbot sur cette page. « Défaut » suit le réglage global.', 'agentsia-agents' ); ?>
				</small>
			<?php else : ?>
				<input
					type="text"
					id="agentsia_meta_scenario"
					name="agentsia_meta_scenario"
					value="<?php echo esc_attr( $scenario ); ?>"
					class="widefat"
					placeholder="<?php echo esc_attr( $default_scenario !== '' ? $default_scenario : 'ex. sos, devis, default' ); ?>"
				/>
				<small class="description">
					<?php
					if ( $default_scenario !== '' ) {
						printf(
							/* translators: %s: default scenario name */
							esc_html__( 'Laisser vide pour utiliser le scénario par défaut (%s).', 'agentsia-agents' ),
							'<code>' . esc_html( $default_scenario ) . '</code>'
						);
					} else {
						esc_html_e( 'Nom d\'un scénario défini dans la configuration du chatbot (étape « Scénarios »).', 'agentsia-agents' );
					}
					?>
				</small>
			<?php endif; ?>
		</p>

		<p>
			<label for="agentsia_meta_context_hint">
				<strong><?php esc_html_e( 'Contexte de page', 'agentsia-agents' ); ?></strong>
			</label>
			<textarea
				id="agentsia_meta_context_hint"
				name="agentsia_meta_context_hint"
				rows="3"
				class="widefat"
				placeholder="<?php esc_attr_e( 'ex. L\'utilisateur consulte la fiche produit X', 'agentsia-agents' ); ?>"
			><?php echo esc_textarea( $context_hint ); ?></textarea>
			<small class="description">
				<?php esc_html_e( 'Texte court injecté dans le prompt système pour donner du contexte à l\'IA sur cette page précise.', 'agentsia-agents' ); ?>
			</small>
		</p>

		<p>
			<label for="agentsia_meta_bubble">
				<strong><?php esc_html_e( 'Bulle flottante', 'agentsia-agents' ); ?></strong>
			</label>
			<select id="agentsia_meta_bubble" name="agentsia_meta_bubble" class="widefat">
				<option value="inherit" <?php selected( 'inherit', $bubble ); ?>>
					<?php esc_html_e( 'Hériter du réglage global', 'agentsia-agents' ); ?>
				</option>
				<option value="show" <?php selected( 'show', $bubble ); ?>>
					<?php esc_html_e( 'Afficher la bulle', 'agentsia-agents' ); ?>
				</option>
				<option value="hide" <?php selected( 'hide', $bubble ); ?>>
					<?php esc_html_e( 'Masquer (déclencher via JS uniquement)', 'agentsia-agents' ); ?>
				</option>
			</select>
		</p>
		<?php
	}

	public function save( int $post_id, \WP_Post $post ): void {
		if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
			return;
		}
		if ( ! isset( $_POST[ self::NONCE_FIELD ] ) ) {
			return;
		}
		if ( ! wp_verify_nonce( sanitize_key( wp_unslash( $_POST[ self::NONCE_FIELD ] ) ), self::NONCE_ACTION ) ) {
			return;
		}
		if ( ! current_user_can( 'edit_post', $post_id ) ) {
			return;
		}

		$scenario = isset( $_POST['agentsia_meta_scenario'] )
			? sanitize_text_field( wp_unslash( $_POST['agentsia_meta_scenario'] ) )
			: '';
		// Keep accents/unicode; only normalise whitespace to dashes (mirrors the backend).
		$scenario = (string) preg_replace( '/\s+/u', '-', $scenario );
		$scenario = (string) mb_substr( $scenario, 0, 80 );

		$context_hint = isset( $_POST['agentsia_meta_context_hint'] )
			? sanitize_textarea_field( wp_unslash( $_POST['agentsia_meta_context_hint'] ) )
			: '';
		$context_hint = (string) substr( $context_hint, 0, 2000 );

		$bubble = isset( $_POST['agentsia_meta_bubble'] )
			? sanitize_key( wp_unslash( $_POST['agentsia_meta_bubble'] ) )
			: 'inherit';
		if ( ! in_array( $bubble, [ 'inherit', 'show', 'hide' ], true ) ) {
			$bubble = 'inherit';
		}

		$this->persist_meta( $post_id, self::META_SCENARIO, $scenario );
		$this->persist_meta( $post_id, self::META_CONTEXT_HINT, $context_hint );
		$this->persist_meta( $post_id, self::META_BUBBLE, $bubble === 'inherit' ? '' : $bubble );
	}

	private function persist_meta( int $post_id, string $key, string $value ): void {
		if ( $value === '' ) {
			delete_post_meta( $post_id, $key );
		} else {
			update_post_meta( $post_id, $key, $value );
		}
	}

	/**
	 * Resolve the override array consumed by {@see Chatbot::build_data_attributes()}
	 * for the post currently being rendered. Returns an empty array when no
	 * override applies (front page without ID, archive, 404…).
	 *
	 * @return array<string, mixed>
	 */
	public function resolve_overrides_for_current_request(): array {
		if ( ! is_singular() ) {
			return [];
		}
		$post_id = (int) get_queried_object_id();
		if ( $post_id <= 0 ) {
			return [];
		}

		$overrides = [];

		$scenario = (string) get_post_meta( $post_id, self::META_SCENARIO, true );
		if ( $scenario !== '' ) {
			$overrides['scenario'] = $scenario;
		}

		$context_hint = (string) get_post_meta( $post_id, self::META_CONTEXT_HINT, true );
		if ( $context_hint !== '' ) {
			$overrides['context_hint'] = $context_hint;
		}

		$bubble = (string) get_post_meta( $post_id, self::META_BUBBLE, true );
		if ( $bubble === 'show' ) {
			$overrides['hide_bubble'] = false;
		} elseif ( $bubble === 'hide' ) {
			$overrides['hide_bubble'] = true;
		}

		return $overrides;
	}
}