<?php
/**
 * Admin analytics AJAX handlers.
 *
 * @package ClickToChat
 * @since 1.0.2
 */

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

/**
 * Analytics admin endpoints.
 */
class CTC_Chat_Analytics_Admin {

	/**
	 * Analytics service.
	 *
	 * @var CTC_Chat_Analytics
	 */
	private $analytics;

	/**
	 * Constructor.
	 */
	public function __construct() {
		$this->analytics = new CTC_Chat_Analytics();

		add_action( 'wp_ajax_ctc_analytics_kpis', array( $this, 'ajax_kpis' ) );
		add_action( 'wp_ajax_ctc_analytics_trend', array( $this, 'ajax_trend' ) );
		add_action( 'wp_ajax_ctc_analytics_funnel', array( $this, 'ajax_funnel' ) );
		add_action( 'wp_ajax_ctc_analytics_top_products', array( $this, 'ajax_top_products' ) );
		add_action( 'wp_ajax_ctc_analytics_top_numbers', array( $this, 'ajax_top_numbers' ) );
		add_action( 'wp_ajax_ctc_analytics_report_clicks', array( $this, 'ajax_report_clicks' ) );
		add_action( 'wp_ajax_ctc_analytics_report_aggregate', array( $this, 'ajax_report_aggregate' ) );
		add_action( 'wp_ajax_ctc_analytics_export_csv', array( $this, 'ajax_export_csv' ) );
	}

	/**
	 * Verify admin analytics request.
	 *
	 * @return array{start_date:string,end_date:string,compare:bool,analytics_filters:array,filter_context:array}
	 */
	private function verify_request() {
		if ( ! ctc_chat_analytics_capability() ) {
			wp_send_json_error( array( 'message' => __( 'Permission denied.', 'aicoso-click-to-chat' ) ), 403 );
		}

		check_ajax_referer( 'ctc_chat_admin_nonce', 'nonce' );

		$start_date = isset( $_POST['start_date'] ) ? sanitize_text_field( wp_unslash( $_POST['start_date'] ) ) : '';
		$end_date   = isset( $_POST['end_date'] ) ? sanitize_text_field( wp_unslash( $_POST['end_date'] ) ) : '';

		if ( ! $start_date || ! $end_date ) {
			$end_date   = wp_date( 'Y-m-d' );
			$start_date = wp_date( 'Y-m-d', strtotime( '-29 days' ) );
		}

		if ( ! preg_match( '/^\d{4}-\d{2}-\d{2}$/', $start_date ) || ! preg_match( '/^\d{4}-\d{2}-\d{2}$/', $end_date ) ) {
			wp_send_json_error( array( 'message' => __( 'Invalid date range.', 'aicoso-click-to-chat' ) ), 400 );
		}

		if ( strtotime( $end_date ) < strtotime( $start_date ) ) {
			wp_send_json_error( array( 'message' => __( 'End date must be after start date.', 'aicoso-click-to-chat' ) ), 400 );
		}

		$days = (int) floor( ( strtotime( $end_date ) - strtotime( $start_date ) ) / DAY_IN_SECONDS ) + 1;
		if ( $days > 366 ) {
			wp_send_json_error( array( 'message' => __( 'Date range cannot exceed 366 days.', 'aicoso-click-to-chat' ) ), 400 );
		}

		$compare       = ! isset( $_POST['compare'] ) || filter_var( wp_unslash( $_POST['compare'] ), FILTER_VALIDATE_BOOLEAN );
		$number_filter = $this->resolve_number_filter();

		return array(
			'start_date'        => $start_date,
			'end_date'          => $end_date,
			'compare'           => $compare,
			'analytics_filters' => $number_filter['filters'],
			'filter_context'    => $number_filter['context'],
		);
	}

	/**
	 * Resolve the dashboard number filter at the protected request boundary.
	 *
	 * @return array{filters:array,context:array}
	 */
	private function resolve_number_filter() {
		$provided = null !== $this->get_verified_post( 'number_filter', null );
		$raw      = $this->get_verified_post( 'number_filter', 'all' );
		$context  = array(
			'requested' => 'all',
			'resolved'  => 'all',
			'mode'      => 'all',
			'fell_back' => false,
			'message'   => '',
		);

		if ( ! $provided || 'all' === $raw ) {
			return array(
				'filters' => array(),
				'context' => $context,
			);
		}

		if ( 'unattributed' === $raw ) {
			$context['requested'] = 'unattributed';
			$context['resolved']  = 'unattributed';
			$context['mode']      = 'unattributed';

			return array(
				'filters' => array( 'number_mode' => 'unattributed' ),
				'context' => $context,
			);
		}

		if ( is_string( $raw ) && preg_match( '/^[1-9][0-9]*$/D', $raw ) ) {
			$requested_id = (int) $raw;
			$settings     = get_option( 'ctc_chat_settings', array() );
			$numbers      = ! empty( $settings['whatsapp_numbers'] )
				? ctc_chat_normalize_number_record_ids( $settings['whatsapp_numbers'] )
				: array();

			foreach ( $numbers as $number ) {
				if ( absint( $number['id'] ?? 0 ) === $requested_id ) {
					$resolved             = (string) $requested_id;
					$context['requested'] = $resolved;
					$context['resolved']  = $resolved;
					$context['mode']      = 'number';

					return array(
						'filters' => array(
							'number_mode' => 'number',
							'number_id'   => $requested_id,
						),
						'context' => $context,
					);
				}
			}
		}

		$context['requested'] = 'invalid';
		$context['fell_back'] = true;
		$context['message']   = __( 'The selected WhatsApp number is no longer available. Showing all numbers.', 'aicoso-click-to-chat' );

		return array(
			'filters' => array(),
			'context' => $context,
		);
	}

	/**
	 * Read a verified POST field.
	 *
	 * @param string $key      Field key.
	 * @param mixed  $fallback Default value.
	 * @return mixed
	 */
	private function get_verified_post( $key, $fallback = null ) {
		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- Nonce verified in verify_request().
		if ( ! isset( $_POST[ $key ] ) ) {
			return $fallback;
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Missing, WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Sanitized by callers.
		return wp_unslash( $_POST[ $key ] );
	}

	/**
	 * Read a request field after caller verifies nonce.
	 *
	 * @param string $key      Field key.
	 * @param mixed  $fallback Default value.
	 * @return mixed
	 */
	private function get_request_value( $key, $fallback = null ) {
		// phpcs:disable WordPress.Security.NonceVerification.Recommended, WordPress.Security.NonceVerification.Missing -- Caller verifies nonce.
		if ( ! isset( $_REQUEST[ $key ] ) ) {
			return $fallback;
		}

		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Sanitized by callers.
		return wp_unslash( $_REQUEST[ $key ] );
		// phpcs:enable WordPress.Security.NonceVerification.Recommended, WordPress.Security.NonceVerification.Missing
	}

	/**
	 * KPI endpoint.
	 */
	public function ajax_kpis() {
		$request                = $this->verify_request();
		$data                   = $this->analytics->get_kpis( $request['start_date'], $request['end_date'], $request['compare'], $request['analytics_filters'] );
		$data['filter_context'] = $request['filter_context'];
		wp_send_json_success( $data );
	}

	/**
	 * Trend endpoint.
	 */
	public function ajax_trend() {
		$request  = $this->verify_request();
		$grouping = sanitize_key( (string) $this->get_verified_post( 'grouping', 'day' ) );
		if ( ! in_array( $grouping, array( 'day', 'week', 'month' ), true ) ) {
			$grouping = 'day';
		}
		$data                   = $this->analytics->get_trend( $request['start_date'], $request['end_date'], $grouping, $request['analytics_filters'] );
		$data['filter_context'] = $request['filter_context'];
		wp_send_json_success( $data );
	}

	/**
	 * Funnel endpoint.
	 */
	public function ajax_funnel() {
		$request                = $this->verify_request();
		$data                   = $this->analytics->get_funnel( $request['start_date'], $request['end_date'], $request['analytics_filters'] );
		$data['filter_context'] = $request['filter_context'];
		wp_send_json_success( $data );
	}

	/**
	 * Top products endpoint.
	 */
	public function ajax_top_products() {
		$request                = $this->verify_request();
		$data                   = $this->analytics->get_top_products( $request['start_date'], $request['end_date'], 5, $request['analytics_filters'] );
		$data['filter_context'] = $request['filter_context'];
		wp_send_json_success( $data );
	}

	/**
	 * Top numbers endpoint.
	 */
	public function ajax_top_numbers() {
		$request                = $this->verify_request();
		$data                   = $this->analytics->get_top_numbers( $request['start_date'], $request['end_date'], 5, $request['analytics_filters'] );
		$data['filter_context'] = $request['filter_context'];
		wp_send_json_success( $data );
	}

	/**
	 * Click log endpoint.
	 */
	public function ajax_report_clicks() {
		$request  = $this->verify_request();
		$page     = absint( $this->get_verified_post( 'page', 1 ) );
		$per_page = absint( $this->get_verified_post( 'per_page', 20 ) );
		$filters = $this->parse_filters();

		$data = $this->analytics->get_click_log( $request['start_date'], $request['end_date'], $filters, $page, $per_page );
		wp_send_json_success( $data );
	}

	/**
	 * Aggregate report endpoint.
	 */
	public function ajax_report_aggregate() {
		$request  = $this->verify_request();
		$report   = sanitize_key( (string) $this->get_verified_post( 'report', 'placements' ) );
		$page     = absint( $this->get_verified_post( 'page', 1 ) );
		$per_page = absint( $this->get_verified_post( 'per_page', 20 ) );

		$data = $this->analytics->get_aggregate_report( $report, $request['start_date'], $request['end_date'], $page, $per_page );
		wp_send_json_success( $data );
	}

	/**
	 * CSV export endpoint.
	 */
	public function ajax_export_csv() {
		if ( ! ctc_chat_analytics_capability() ) {
			wp_die( esc_html__( 'Permission denied.', 'aicoso-click-to-chat' ), 403 );
		}

		check_ajax_referer( 'ctc_chat_admin_nonce', 'nonce' );

		$start_date = isset( $_REQUEST['start_date'] ) ? sanitize_text_field( wp_unslash( $_REQUEST['start_date'] ) ) : wp_date( 'Y-m-d', strtotime( '-29 days' ) );
		$end_date   = isset( $_REQUEST['end_date'] ) ? sanitize_text_field( wp_unslash( $_REQUEST['end_date'] ) ) : wp_date( 'Y-m-d' );
		$filters    = $this->parse_filters_from_request();

		$rows = $this->analytics->get_export_rows( $start_date, $end_date, $filters );

		$filename = 'ctc-click-log-' . $start_date . '-to-' . $end_date . '.csv';

		nocache_headers();
		header( 'Content-Type: text/csv; charset=utf-8' );
		header( 'Content-Disposition: attachment; filename=' . $filename );

		$output = fopen( 'php://output', 'w' );
		fputcsv(
			$output,
			array(
				__( 'Date', 'aicoso-click-to-chat' ),
				__( 'Placement', 'aicoso-click-to-chat' ),
				__( 'Product', 'aicoso-click-to-chat' ),
				__( 'Order', 'aicoso-click-to-chat' ),
				__( 'Cart total', 'aicoso-click-to-chat' ),
				__( 'Number', 'aicoso-click-to-chat' ),
				__( 'Device', 'aicoso-click-to-chat' ),
				__( 'Page URL', 'aicoso-click-to-chat' ),
			)
		);

		foreach ( $rows as $row ) {
			fputcsv(
				$output,
				array(
					$row['clicked_at'],
					$row['button_label'],
					$row['product_name'],
					$row['order_number'],
					$row['cart_total_formatted'],
					$row['number_label'],
					$row['device_type'],
					$row['page_url'],
				)
			);
		}

		// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- Required for the php://output CSV stream; WP_Filesystem is not applicable.
		fclose( $output );
		exit;
	}

	/**
	 * Parse filters from POST.
	 *
	 * @return array
	 */
	private function parse_filters() {
		return $this->parse_filters_from_request();
	}

	/**
	 * Parse filters from request superglobal.
	 *
	 * @return array
	 */
	private function parse_filters_from_request() {
		$filters = array();

		$button_types = $this->get_request_value( 'button_type' );
		if ( ! empty( $button_types ) ) {
			$types = (array) $button_types;
			$filters['button_types'] = array_map( 'sanitize_key', $types );
		}

		$number_id = $this->get_request_value( 'number_id' );
		if ( ! empty( $number_id ) ) {
			$filters['number_id'] = absint( $number_id );
		}

		$product_id = $this->get_request_value( 'product_id' );
		if ( ! empty( $product_id ) ) {
			$filters['product_id'] = absint( $product_id );
		}

		$device_type = $this->get_request_value( 'device_type' );
		if ( ! empty( $device_type ) ) {
			$filters['device_type'] = sanitize_key( (string) $device_type );
		}

		$search = $this->get_request_value( 'search' );
		if ( ! empty( $search ) ) {
			$filters['search'] = sanitize_text_field( (string) $search );
		}

		return $filters;
	}
}