<?php
/**
 * Context Detector
 *
 * Gathers upload context information from the current environment
 * to determine which upload rule should apply.
 *
 * @package Gatewell
 * @since 1.2.0
 */

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * GATEWELL_Context_Detector class.
 *
 * Detects the current upload context by gathering information about:
 * - The post type being edited
 * - The upload context (featured image, content, media library)
 * - The current user's role
 *
 * Context can be gathered from:
 * - Server-side: current screen, post type, user role
 * - Client-side: passed via AJAX (upload context, block type)
 *
 * @since 1.2.0
 */
class GATEWELL_Context_Detector {

	/**
	 * Build context from the current server-side environment.
	 *
	 * Used when loading the editor page to pre-fetch applicable rules.
	 *
	 * @since 1.2.0
	 * @param int|null $post_id Optional post ID to detect context for.
	 * @return array Context data.
	 */
	public static function get_current_context( $post_id = null ) {
		$context = array(
			'post_type' => '',
			'post_id'   => 0,
			'context'   => 'media-library',
			'user_role' => self::get_primary_role(),
		);

		// Detect post type from post ID.
		if ( $post_id ) {
			$context['post_id']   = (int) $post_id;
			$context['post_type'] = get_post_type( $post_id );
		} elseif ( ! empty( $_GET['post'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended
			$context['post_id']   = (int) $_GET['post']; // phpcs:ignore WordPress.Security.NonceVerification.Recommended
			$context['post_type'] = get_post_type( $context['post_id'] );
		}

		// Detect from current screen if available.
		$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;
		if ( $screen ) {
			if ( ! empty( $screen->post_type ) && empty( $context['post_type'] ) ) {
				$context['post_type'] = $screen->post_type;
			}
		}

		return $context;
	}

	/**
	 * Build context from an AJAX request.
	 *
	 * Reads context data sent by the frontend JavaScript.
	 * All values are sanitized.
	 *
	 * @since 1.2.0
	 * @return array Context data.
	 */
	public static function get_ajax_context() {
		$context = array(
			'post_type' => '',
			'post_id'   => 0,
			'context'   => 'media-library',
			'user_role' => self::get_primary_role(),
		);

		// Read from POST data (sent by frontend). phpcs:ignore WordPress.Security.NonceVerification -- nonce verified in calling handler.
		if ( ! empty( $_POST['post_type'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Missing
			$context['post_type'] = sanitize_key( wp_unslash( $_POST['post_type'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Missing
		}

		if ( ! empty( $_POST['post_id'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Missing
			$context['post_id'] = (int) $_POST['post_id']; // phpcs:ignore WordPress.Security.NonceVerification.Missing

			// Auto-detect post type from post ID if not provided.
			if ( empty( $context['post_type'] ) && $context['post_id'] > 0 ) {
				$context['post_type'] = get_post_type( $context['post_id'] );
			}
		}

		if ( ! empty( $_POST['upload_context'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Missing
			$upload_context = sanitize_key( wp_unslash( $_POST['upload_context'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Missing
			if ( in_array( $upload_context, GATEWELL_Rule_Storage::VALID_CONTEXTS, true ) ) {
				$context['context'] = $upload_context;
			}
		}

		return $context;
	}

	/**
	 * Get the primary role of the current user.
	 *
	 * WordPress users can have multiple roles. This returns the first role
	 * which is typically the primary one.
	 *
	 * @since 1.2.0
	 * @return string Primary role slug, or 'subscriber' as fallback.
	 */
	public static function get_primary_role() {
		$user = wp_get_current_user();

		if ( ! $user || ! $user->exists() ) {
			return '';
		}

		$roles = $user->roles;
		if ( ! empty( $roles ) ) {
			return reset( $roles );
		}

		return 'subscriber';
	}

	/**
	 * Build context data to pass to JavaScript via wp_localize_script.
	 *
	 * @since 1.2.0
	 * @param int|null $post_id Optional post ID.
	 * @return array Context data for JavaScript.
	 */
	public static function get_js_context( $post_id = null ) {
		$context = self::get_current_context( $post_id );

		return array(
			'postType' => $context['post_type'],
			'postId'   => $context['post_id'],
			'userRole' => $context['user_role'],
		);
	}
}