<?php

namespace Quiztech\AssessmentPlatform\Includes\Ajax;

use Quiztech\AssessmentPlatform\Includes\Invitations; // Added use statement

/**
 * Handles AJAX requests related to the front-end assessment process.
 */
class AssessmentAjaxHandler {

	/**
	 * Constructor. Registers AJAX hooks.
	 */
	public function __construct() {
		add_action('wp_ajax_quiztech_submit_prescreening', [$this, 'handle_submit_prescreening']);
		add_action('wp_ajax_quiztech_save_answer', [$this, 'handle_save_answer']);
		add_action('wp_ajax_quiztech_submit_assessment', [$this, 'handle_submit_assessment']);
		add_action('wp_ajax_nopriv_quiztech_save_answer', [$this, 'handle_save_answer']);
		add_action('wp_ajax_nopriv_quiztech_submit_assessment', [$this, 'handle_submit_assessment']);
	}

	/**
	 * Initialize the handler.
	 * Static method to instantiate the class and register hooks.
	 */
	public static function init() {
		new self();
	}

	/**
	 * Helper method to find an existing user_evaluation CPT by invitation ID
	 * or create a new one if it doesn't exist.
	 *
	 * @param int $invitation_id The database ID of the invitation record.
	 * @return int The post ID of the user_evaluation CPT, or 0 on failure.
	 */
	private function get_or_create_user_evaluation(int $invitation_id): int {
		if ( ! $invitation_id ) {
			error_log("Quiztech AJAX Error: get_or_create_user_evaluation called with invalid invitation ID: " . $invitation_id);
			return 0;
		}

		$args = [
			'post_type' => 'user_evaluation',
			'post_status' => 'any', // Find it regardless of status initially
			'meta_query' => [
				[
					'key' => 'quiztech_invitation_id',
					'value' => $invitation_id,
					'compare' => '=',
				]
			],
			'posts_per_page' => 1,
			'fields' => 'ids', // Only get the ID
		];
		$evaluation_posts = get_posts($args);

		if ( ! empty( $evaluation_posts ) ) {
			// Found existing evaluation
			return $evaluation_posts[0];
		} else {
			// Not found, create a new one
			$post_data = [
				'post_type'    => 'user_evaluation',
				'post_status'  => 'publish', // Start as published (or maybe 'pending'/'in-progress' if custom statuses are added)
				'post_title'   => sprintf( __( 'Evaluation for Invitation #%d', 'quiztech' ), $invitation_id ),
				'post_content' => '', // No content needed initially
				// 'post_author' => ?? // Assign to an admin or system user? Default is current user (likely none in AJAX)
			];
			$evaluation_id = wp_insert_post( $post_data, true ); // Pass true for WP_Error on failure

			if ( is_wp_error( $evaluation_id ) ) {
				error_log("Quiztech AJAX Error: Failed to create user_evaluation CPT for invitation ID {$invitation_id}: " . $evaluation_id->get_error_message());
				return 0;
			}

			// Add the linking meta field
			$meta_updated = update_post_meta( $evaluation_id, 'quiztech_invitation_id', $invitation_id );
			if ( ! $meta_updated ) {
				// Log error, but maybe don't fail the whole request? Or should we delete the post?
				error_log("Quiztech AJAX Warning: Failed to add quiztech_invitation_id meta to new evaluation ID {$evaluation_id} for invitation ID {$invitation_id}.");
				// Depending on requirements, might return 0 here or proceed. Let's proceed for now.
			}

			error_log("Quiztech AJAX Info: Created new user_evaluation CPT ID {$evaluation_id} for invitation ID {$invitation_id}.");
			return $evaluation_id;
		}
	}


	/**
	 * Handles the AJAX submission of the pre-screening form.
	 * Expects 'nonce', 'invitation_id', and 'pre_screen_answer' array in $_POST.
	 */
	public function handle_submit_prescreening() {
		// 1. Verify Nonce
		check_ajax_referer('quiztech_prescreening_nonce', 'nonce');

		// 2. Get and Sanitize Core Data
		$invitation_id = isset($_POST['invitation_id']) ? absint($_POST['invitation_id']) : 0;
		if ( ! $invitation_id ) {
			wp_send_json_error(['message' => __('Missing invitation ID.', 'quiztech')], 400);
		}

		// 3. Get or Create User Evaluation Record
		$evaluation_id = $this->get_or_create_user_evaluation($invitation_id);
		if ( ! $evaluation_id ) {
			 error_log("Quiztech AJAX Error: Failed to get or create user_evaluation for invitation ID: " . $invitation_id);
			 wp_send_json_error(['message' => __('Could not process evaluation record.', 'quiztech')], 500);
		}

		// 4. Sanitize Submitted Answers
		$submitted_answers = isset($_POST['pre_screen_answer']) && is_array($_POST['pre_screen_answer']) ? $_POST['pre_screen_answer'] : [];
		$sanitized_answers = [];
		foreach ($submitted_answers as $index => $answer) {
			// Use sanitize_textarea_field as pre-screening questions are currently textareas
			$sanitized_answers[sanitize_key($index)] = sanitize_textarea_field(wp_unslash($answer));
		}

		// 4. Save Answers (as user_evaluation CPT meta)
		if (!empty($sanitized_answers)) {
			update_post_meta($evaluation_id, 'quiztech_prescreening_answers', $sanitized_answers);
		} else {
			// Handle case where no answers were submitted? Or rely on form 'required' attribute?
			// For now, proceed even if empty.
		}

		// 5. Update Invitation Status
		try {
			$invitations = new Invitations();
			$updated = $invitations->update_status($invitation_id, 'pre-screening-complete');
			if (!$updated) {
				 error_log("Quiztech AJAX Error: Failed to update invitation status for ID: " . $invitation_id);
				 // Decide if this should be a user-facing error or just logged
			}
		} catch (\Exception $e) {
			error_log("Quiztech AJAX Error: Exception updating invitation status: " . $e->getMessage());
			// Decide if this should be a user-facing error
		}


		// 6. Send Response
		wp_send_json_success(['message' => __('Pre-screening submitted successfully. Starting assessment...', 'quiztech')]);

		// Ensure script execution stops
		wp_die();
	}

	/**
	 * Handles the AJAX auto-save of a single assessment answer.
	 * Expects 'nonce', 'invitation_id', 'question_id', and 'answer' in $_POST.
	 */
	public function handle_save_answer() {
		// 1. Verify Nonce
		check_ajax_referer('quiztech_assessment_nonce', 'nonce');

		// 2. Get and Sanitize Data
		$invitation_id = isset($_POST['invitation_id']) ? absint($_POST['invitation_id']) : 0;
		$question_id   = isset($_POST['question_id']) ? absint($_POST['question_id']) : 0;
		$answer        = isset($_POST['answer']) ? wp_unslash($_POST['answer']) : ''; // Sanitize based on question type later

		// Basic validation for required IDs before querying
		if ( ! $invitation_id || ! $question_id ) {
			 wp_send_json_error(['message' => __('Missing required data for saving answer.', 'quiztech')], 400);
		}

		// 3. Get or Create User Evaluation Record
		$evaluation_id = $this->get_or_create_user_evaluation($invitation_id);
		if ( ! $evaluation_id ) {
			 error_log("Quiztech AJAX Error: Failed to get or create user_evaluation for invitation ID: " . $invitation_id . " during answer save.");
			 wp_send_json_error(['message' => __('Could not process evaluation record for saving answer.', 'quiztech')], 500);
		}

		// 4. Fetch the question type meta for the given question ID
		$question_type = \get_post_meta($question_id, '_quiztech_question_type', true);
		if ( ! $question_type ) {
			// Log if type is missing, but proceed with default sanitization
			error_log("Quiztech AJAX Warning: Missing question type meta for question ID: " . $question_id);
			$question_type = 'text'; // Default to text if not set
		}

		// Sanitize the answer based on question type
		$sanitized_answer = ''; // Initialize

		if (is_array($answer)) {
			// Handle array answers (likely checkboxes)
			if ('checkbox' === $question_type) {
				// Sanitize each value in the array
				$sanitized_answer = array_map('sanitize_text_field', $answer);
				// Note: update_post_meta can handle arrays directly, storing them serialized.
			} else {
				// Unexpected array answer for this question type
				error_log("Quiztech AJAX Error: Received array answer for non-checkbox question ID: " . $question_id);
				// Sanitize by joining elements (simple approach, might need refinement)
				$sanitized_answer = sanitize_text_field(implode(', ', $answer));
			}
		} else {
			// Handle string/scalar answers
			switch ($question_type) {
				case 'textarea':
					$sanitized_answer = sanitize_textarea_field($answer);
					break;
				case 'numeric':
					// Allow integers and potentially floats. Use floatval for broader acceptance.
					// Ensure it's actually numeric before casting to avoid warnings/errors.
					$sanitized_answer = is_numeric($answer) ? floatval($answer) : 0;
					break;
				case 'multiple-choice': // Assuming the value is a simple key/identifier
					$sanitized_answer = sanitize_key($answer);
					break;
				case 'text':
				default: // Default to sanitize_text_field for 'text' or unknown/missing types
					$sanitized_answer = sanitize_text_field($answer);
					break;
			}
		}


		// 3. Save Answer (as user_evaluation CPT meta)
		// Use a meta key structure like 'quiztech_answer_{question_id}' or store in a single array meta field.
		// Using individual meta keys might be simpler for querying later if needed.
		$meta_key = 'quiztech_answer_' . $question_id;
		update_post_meta($evaluation_id, $meta_key, $sanitized_answer);

		// 4. Send Response
		wp_send_json_success(['message' => __('Answer saved.', 'quiztech')]);

		// Ensure script execution stops
		wp_die();
	}

	/**
	 * Handles the final AJAX submission of the assessment.
	 * Expects 'nonce' and 'invitation_id' in $_POST.
	 */
	public function handle_submit_assessment() {
		// 1. Verify Nonce
		check_ajax_referer('quiztech_assessment_nonce', 'nonce'); // Reuse assessment nonce

		// 2. Get Data
		$invitation_id = isset($_POST['invitation_id']) ? absint($_POST['invitation_id']) : 0;
		if ( ! $invitation_id ) {
			wp_send_json_error(['message' => __('Missing invitation ID.', 'quiztech')], 400);
		}

		// 3. Get or Create User Evaluation Record
		$evaluation_id = $this->get_or_create_user_evaluation($invitation_id);
		if ( ! $evaluation_id ) {
			 error_log("Quiztech AJAX Error: Failed to get or create user_evaluation for invitation ID: " . $invitation_id . " during final submission.");
			 wp_send_json_error(['message' => __('Could not process evaluation record for submission.', 'quiztech')], 500);
		}

		// 4. Update Invitation Status
		try {
			$invitations = new Invitations();
			// Assuming $invitation_id passed in POST *is* the record ID.
			$updated = $invitations->update_status($invitation_id, 'assessment-complete');
			if (!$updated) {
				 error_log("Quiztech AJAX Error: Failed to update invitation status to complete for ID: " . $invitation_id);
				 // Decide if this should be a user-facing error or just logged
			}
		} catch (\Exception $e) {
			error_log("Quiztech AJAX Error: Exception updating invitation status to complete: " . $e->getMessage());
			// Decide if this should be a user-facing error
		}


		// 5. Update User Evaluation CPT Status to 'completed'
		$post_update_data = [
			'ID'          => $evaluation_id,
			'post_status' => 'completed', // Use a custom status if needed, but 'completed' seems appropriate
		];
		$post_updated = wp_update_post($post_update_data, true); // Pass true for WP_Error object on failure

		if (is_wp_error($post_updated)) {
			error_log("Quiztech AJAX Error: Failed to update user_evaluation CPT status for ID {$evaluation_id}: " . $post_updated->get_error_message());
			// Decide if this should be a user-facing error
			// wp_send_json_error(['message' => __('Failed to finalize assessment record.', 'quiztech')], 500);
		}


		// 6. Get the Assessment ID associated with the invitation
		// This requires a method in Invitations class to get the full record by ID
		$invitation_record = $invitations->get_invitation_by_id($invitation_id); // Assuming this method exists or will be added
		$assessment_id = $invitation_record ? $invitation_record->assessment_id : 0;

		// 7. Get the custom completion message
		$completion_message = '';
		if ($assessment_id) {
			$completion_message = \get_post_meta($assessment_id, '_quiztech_completion_message', true);
		}
		// Use a default message if the custom one is empty
		if (empty($completion_message)) {
			$completion_message = __('Assessment submitted successfully!', 'quiztech');
		}

		// 8. Send Response
		wp_send_json_success(['completionMessage' => $completion_message]); // Send completion message

		// Ensure script execution stops
		wp_die();
	}
}