<?php
/**
 * Templates Endpoint
 *
 * REST API endpoint for managing schema templates. Supports both
 * built-in templates loaded from JSON files and user-created templates
 * stored in the database.
 *
 * @package    Schema_AI
 * @subpackage Schema_AI/includes/api/endpoints
 * @since      1.0.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Schema_AI_Templates_Endpoint extends Schema_AI_REST_Controller {

	/**
	 * Route base.
	 *
	 * @var string
	 */
	protected $rest_base = 'templates';

	/**
	 * Register REST API routes.
	 */
	public function register_routes() {
		// GET /templates - List all templates.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base,
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_items' ),
					'permission_callback' => array( $this, 'get_items_permissions_check' ),
					'args'                => array(
						'schema_type' => array(
							'description'       => __( 'Filter templates by schema type.', 'ai-schema-gen' ),
							'type'              => 'string',
							'sanitize_callback' => 'sanitize_text_field',
						),
					),
				),
			)
		);

		// POST /templates - Create a user template.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base,
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'create_item' ),
					'permission_callback' => array( $this, 'create_item_permissions_check' ),
					'args'                => array(
						'name' => array(
							'description'       => __( 'Template name.', 'ai-schema-gen' ),
							'type'              => 'string',
							'required'          => true,
							'sanitize_callback' => 'sanitize_text_field',
						),
						'description' => array(
							'description'       => __( 'Template description.', 'ai-schema-gen' ),
							'type'              => 'string',
							'sanitize_callback' => 'sanitize_textarea_field',
						),
						'schema_type' => array(
							'description'       => __( 'The schema.org type this template is for.', 'ai-schema-gen' ),
							'type'              => 'string',
							'required'          => true,
							'sanitize_callback' => 'sanitize_text_field',
						),
						'template_data' => array(
							'description' => __( 'The template schema data.', 'ai-schema-gen' ),
							'type'        => array( 'object', 'string' ),
							'required'    => true,
						),
						'is_public' => array(
							'description' => __( 'Whether the template is publicly visible.', 'ai-schema-gen' ),
							'type'        => 'boolean',
							'default'     => false,
						),
					),
				),
			)
		);

		// GET /templates/{id} - Get a single template.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/(?P<id>[\w-]+)',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_item' ),
					'permission_callback' => array( $this, 'get_items_permissions_check' ),
					'args'                => array(
						'id' => array(
							'description'       => __( 'Template ID (numeric) or built-in template slug.', 'ai-schema-gen' ),
							'type'              => 'string',
							'required'          => true,
							'sanitize_callback' => 'sanitize_text_field',
						),
					),
				),
			)
		);

		// DELETE /templates/{id} - Delete a user template.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/(?P<id>[\d]+)',
			array(
				array(
					'methods'             => WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'delete_item' ),
					'permission_callback' => array( $this, 'delete_item_permissions_check' ),
					'args'                => array(
						'id' => array(
							'description'       => __( 'Template ID to delete.', 'ai-schema-gen' ),
							'type'              => 'integer',
							'required'          => true,
							'sanitize_callback' => 'absint',
						),
					),
				),
			)
		);
	}

	/**
	 * List all templates, merging built-in and user templates.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response Response object.
	 */
	public function get_items( $request ) {
		$schema_type = sanitize_text_field( $request->get_param( 'schema_type' ) );

		// Load built-in templates from JSON files.
		$builtin = $this->get_builtin_templates();

		// Load user templates from the database.
		$user_templates = $this->get_user_templates();

		// Merge them.
		$all_templates = array_merge( $builtin, $user_templates );

		// Filter by schema type if requested.
		if ( $schema_type ) {
			$all_templates = array_filter(
				$all_templates,
				function ( $template ) use ( $schema_type ) {
					return isset( $template['schema_type'] ) && $template['schema_type'] === $schema_type;
				}
			);
			$all_templates = array_values( $all_templates );
		}

		return $this->success_response(
			array(
				'templates' => $all_templates,
				'total'     => count( $all_templates ),
			)
		);
	}

	/**
	 * Create a new user template.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object or error.
	 */
	public function create_item( $request ) {
		global $wpdb;

		$name          = sanitize_text_field( $request->get_param( 'name' ) );
		$description   = sanitize_textarea_field( $request->get_param( 'description' ) );
		$schema_type   = sanitize_text_field( $request->get_param( 'schema_type' ) );
		$template_data = $request->get_param( 'template_data' );
		$is_public     = (bool) $request->get_param( 'is_public' );

		// Encode template data if it is an array.
		if ( is_array( $template_data ) ) {
			$template_data = wp_json_encode( $template_data );
		}

		if ( ! $template_data || null === json_decode( $template_data ) ) {
			return $this->error_response(
				'schema_ai_invalid_template_data',
				__( 'Invalid template data. Must be valid JSON.', 'ai-schema-gen' ),
				400
			);
		}

		$table = esc_sql( $wpdb->prefix . 'schema_ai_templates' );
		$now   = current_time( 'mysql' );

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Required for custom table; write operation (INSERT), caching not applicable.
		$inserted = $wpdb->insert(
			$table,
			array(
				'user_id'       => get_current_user_id(),
				'name'          => $name,
				'description'   => $description,
				'schema_type'   => $schema_type,
				'template_data' => $template_data,
				'is_public'     => $is_public ? 1 : 0,
				'created_at'    => $now,
				'updated_at'    => $now,
			),
			array( '%d', '%s', '%s', '%s', '%s', '%d', '%s', '%s' )
		);

		if ( false === $inserted ) {
			return $this->error_response(
				'schema_ai_db_error',
				__( 'Failed to save template.', 'ai-schema-gen' ),
				500
			);
		}

		$template_id = $wpdb->insert_id;

		return $this->success_response(
			array(
				'template' => array(
					'id'            => $template_id,
					'name'          => $name,
					'description'   => $description,
					'schema_type'   => $schema_type,
					'template_data' => json_decode( $template_data, true ),
					'is_public'     => $is_public,
					'is_builtin'    => false,
					'user_id'       => get_current_user_id(),
					'created_at'    => $now,
					'updated_at'    => $now,
				),
				'message'  => __( 'Template created successfully.', 'ai-schema-gen' ),
			),
			201
		);
	}

	/**
	 * Get a single template by ID or slug.
	 *
	 * Numeric IDs look up user templates in the database; string slugs
	 * look up built-in templates from the JSON files.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object or error.
	 */
	public function get_item( $request ) {
		$id = $request->get_param( 'id' );

		// Numeric ID: look up in the database.
		if ( is_numeric( $id ) ) {
			global $wpdb;

			$table = esc_sql( $wpdb->prefix . 'schema_ai_templates' );
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Required for custom table; no WP API alternative exists.
			$row   = $wpdb->get_row(
				$wpdb->prepare(
					// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Table name is sanitized via esc_sql() and not user input.
					"SELECT * FROM {$table} WHERE id = %d",
					absint( $id )
				)
			);

			if ( ! $row ) {
				return $this->error_response(
					'schema_ai_not_found',
					__( 'Template not found.', 'ai-schema-gen' ),
					404
				);
			}

			// Visibility check: only the owner, admins, or public templates are accessible.
			$is_owner  = (int) $row->user_id === get_current_user_id();
			$is_public = (bool) $row->is_public;
			if ( ! $is_owner && ! $is_public && ! current_user_can( 'manage_options' ) ) {
				return $this->error_response(
					'schema_ai_not_found',
					__( 'Template not found.', 'ai-schema-gen' ),
					404
				);
			}

			return $this->success_response(
				array(
					'template' => array(
						'id'            => (int) $row->id,
						'name'          => $row->name,
						'description'   => $row->description,
						'schema_type'   => $row->schema_type,
						'template_data' => json_decode( $row->template_data, true ),
						'is_public'     => (bool) $row->is_public,
						'is_builtin'    => false,
						'user_id'       => (int) $row->user_id,
						'created_at'    => $row->created_at,
						'updated_at'    => $row->updated_at,
					),
				)
			);
		}

		// String slug: look up in built-in templates.
		$slug    = sanitize_text_field( $id );
		$builtin = $this->get_builtin_templates();

		foreach ( $builtin as $template ) {
			if ( isset( $template['slug'] ) && $template['slug'] === $slug ) {
				return $this->success_response(
					array(
						'template' => $template,
					)
				);
			}
		}

		return $this->error_response(
			'schema_ai_not_found',
			__( 'Template not found.', 'ai-schema-gen' ),
			404
		);
	}

	/**
	 * Delete a user template.
	 *
	 * Built-in templates cannot be deleted.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object or error.
	 */
	public function delete_item( $request ) {
		global $wpdb;

		$id    = absint( $request->get_param( 'id' ) );
		$table = esc_sql( $wpdb->prefix . 'schema_ai_templates' );

		// Verify the template exists.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Required for custom table; no WP API alternative exists.
		$existing = $wpdb->get_row(
			$wpdb->prepare(
				// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Table name is sanitized via esc_sql() and not user input.
				"SELECT * FROM {$table} WHERE id = %d",
				$id
			)
		);

		if ( ! $existing ) {
			return $this->error_response(
				'schema_ai_not_found',
				__( 'Template not found. Built-in templates cannot be deleted.', 'ai-schema-gen' ),
				404
			);
		}

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Required for custom table; write operation (DELETE), caching not applicable.
		$deleted = $wpdb->delete(
			$table,
			array( 'id' => $id ),
			array( '%d' )
		);

		if ( false === $deleted ) {
			return $this->error_response(
				'schema_ai_db_error',
				__( 'Failed to delete template.', 'ai-schema-gen' ),
				500
			);
		}

		return $this->success_response(
			array(
				'deleted' => 1,
				'message' => __( 'Template deleted successfully.', 'ai-schema-gen' ),
			)
		);
	}

	/**
	 * Load all built-in templates from JSON files.
	 *
	 * Scans the templates/schema-types/ directory for JSON files and
	 * parses each one into a template array.
	 *
	 * @return array Array of built-in template arrays.
	 */
	private function get_builtin_templates() {
		$templates_dir = dirname( dirname( dirname( dirname( __FILE__ ) ) ) ) . '/templates/schema-types';

		if ( ! is_dir( $templates_dir ) ) {
			return array();
		}

		$files     = glob( $templates_dir . '/*.json' );
		$templates = array();

		if ( ! $files ) {
			return array();
		}

		foreach ( $files as $file ) {
			$content = file_get_contents( $file ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents
			$data    = json_decode( $content, true );

			if ( ! is_array( $data ) ) {
				continue;
			}

			$slug = basename( $file, '.json' );

			$templates[] = array(
				'id'            => 'builtin_' . $slug,
				'slug'          => $slug,
				'name'          => isset( $data['name'] ) ? $data['name'] : $slug,
				'description'   => isset( $data['description'] ) ? $data['description'] : '',
				'schema_type'   => isset( $data['schema_type'] ) ? $data['schema_type'] : $slug,
				'template_data' => isset( $data['template'] ) ? $data['template'] : $data,
				'is_public'     => true,
				'is_builtin'    => true,
				'user_id'       => 0,
				'created_at'    => null,
				'updated_at'    => null,
			);
		}

		return $templates;
	}

	/**
	 * Load user-created templates from the database.
	 *
	 * Returns all templates visible to the current user: their own
	 * templates plus any marked as public.
	 *
	 * @return array Array of user template arrays.
	 */
	private function get_user_templates() {
		global $wpdb;

		$table   = esc_sql( $wpdb->prefix . 'schema_ai_templates' );
		$user_id = get_current_user_id();

		// Get the user's own templates and public templates from others.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Required for custom table; no WP API alternative exists.
		$results = $wpdb->get_results(
			$wpdb->prepare(
				// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Table name is sanitized via esc_sql() and not user input.
				"SELECT * FROM {$table} WHERE user_id = %d OR is_public = 1 ORDER BY created_at DESC",
				$user_id
			)
		);

		if ( ! $results ) {
			return array();
		}

		$templates = array();

		foreach ( $results as $row ) {
			$templates[] = array(
				'id'            => (int) $row->id,
				'slug'          => null,
				'name'          => $row->name,
				'description'   => $row->description,
				'schema_type'   => $row->schema_type,
				'template_data' => json_decode( $row->template_data, true ),
				'is_public'     => (bool) $row->is_public,
				'is_builtin'    => false,
				'user_id'       => (int) $row->user_id,
				'created_at'    => $row->created_at,
				'updated_at'    => $row->updated_at,
			);
		}

		return $templates;
	}

	/**
	 * Permission check for reading templates.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if allowed.
	 */
	public function get_items_permissions_check( $request ) {
		if ( ! current_user_can( 'edit_posts' ) ) {
			return new WP_Error(
				'schema_ai_forbidden',
				__( 'You do not have permission to view templates.', 'ai-schema-gen' ),
				array( 'status' => 403 )
			);
		}

		return true;
	}

	/**
	 * Permission check for creating templates.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if allowed.
	 */
	public function create_item_permissions_check( $request ) {
		if ( ! current_user_can( 'manage_options' ) ) {
			return new WP_Error(
				'schema_ai_forbidden',
				__( 'You do not have permission to create templates.', 'ai-schema-gen' ),
				array( 'status' => 403 )
			);
		}

		return true;
	}

	/**
	 * Permission check for deleting templates.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if allowed.
	 */
	public function delete_item_permissions_check( $request ) {
		if ( ! current_user_can( 'manage_options' ) ) {
			return new WP_Error(
				'schema_ai_forbidden',
				__( 'You do not have permission to delete templates.', 'ai-schema-gen' ),
				array( 'status' => 403 )
			);
		}

		return true;
	}
}