<?php
/**
 * AICP Statistics Handler
 *
 * Handles fetching and displaying statistics from AICP.
 *
 * @package AICP
 */

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

/**
 * Statistics Handler Class
 */
class AICP_Statistics {

    /**
     * API handler
     *
     * @var AICP_API
     */
    private $api;

    /**
     * Constructor
     *
     * @param AICP_API $api API handler
     */
    public function __construct(AICP_API $api) {
        $this->api = $api;

        add_action('wp_ajax_aicp_refresh_statistics', array($this, 'ajax_refresh_statistics'));
    }

    /**
     * Get statistics data
     *
     * @param bool $force_refresh Force refresh from API
     * @return array|WP_Error Statistics data or error
     */
    public function get_statistics($force_refresh = false) {
        return $this->api->get_statistics($force_refresh);
    }

    /**
     * Get articles published this month
     *
     * @return int
     */
    public function get_articles_this_month() {
        $stats = $this->get_statistics();
        if (is_wp_error($stats)) {
            return 0;
        }
        return isset($stats['articlesPublishedThisMonth']) ? (int) $stats['articlesPublishedThisMonth'] : 0;
    }

    /**
     * Get total articles all time
     *
     * @return int
     */
    public function get_total_articles() {
        $stats = $this->get_statistics();
        if (is_wp_error($stats)) {
            return 0;
        }
        return isset($stats['totalArticlesAllTime']) ? (int) $stats['totalArticlesAllTime'] : 0;
    }

    /**
     * Get publishing history
     *
     * @return array
     */
    public function get_publishing_history() {
        $stats = $this->get_statistics();
        if (is_wp_error($stats)) {
            return array();
        }
        return isset($stats['publishingHistory']) ? $stats['publishingHistory'] : array();
    }

    /**
     * Format history for chart display
     *
     * @return array Chart-ready data
     */
    public function get_chart_data() {
        $history = $this->get_publishing_history();
        $labels = array();
        $data = array();

        foreach ($history as $item) {
            // Convert YYYY-MM to readable format
            $date = DateTime::createFromFormat('Y-m', $item['month']);
            $labels[] = $date ? $date->format('M Y') : $item['month'];
            $data[] = (int) $item['count'];
        }

        // Reverse to show oldest first
        return array(
            'labels' => array_reverse($labels),
            'data'   => array_reverse($data)
        );
    }

    /**
     * AJAX: Refresh statistics
     */
    public function ajax_refresh_statistics() {
        check_ajax_referer('aicp_stats_nonce', 'nonce');

        if (!current_user_can('manage_aicp_settings')) {
            wp_send_json_error(array('message' => __('Permission denied.', 'ai-content-plan')));
        }

        $stats = $this->get_statistics(true); // Force refresh

        if (is_wp_error($stats)) {
            wp_send_json_error(array('message' => $stats->get_error_message()));
        }

        wp_send_json_success(array(
            'articles_this_month' => isset($stats['articlesPublishedThisMonth']) ?
                                   (int) $stats['articlesPublishedThisMonth'] : 0,
            'total_articles'      => isset($stats['totalArticlesAllTime']) ?
                                   (int) $stats['totalArticlesAllTime'] : 0,
            'chart_data'          => $this->get_chart_data()
        ));
    }
}