<?php
/**
 * Plugin Name: Wycan Back to Top
 * Description: Bouton "Back to Top" avec remplissage progressif basé sur le scroll. Utilise automatiquement la couleur principale d'Elementor.
 * Version: 1.0.0
 * Author: Wycan
 * Author URI: https://wycan.fr
 * License: GPL-2.0+
 *
 */

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

class Wycan_Back_To_Top {

    public function __construct() {
        add_action( 'wp_footer', [ $this, 'render_button' ] );
        add_action( 'wp_footer', [ $this, 'inline_styles' ] );
        add_action( 'wp_footer', [ $this, 'inline_scripts' ] );
    }

    /**
     * Récupère la couleur principale définie dans Elementor.
     */
    private function get_primary_color(): string {
        $default = '#000000';

        if ( ! did_action( 'elementor/loaded' ) ) {
            return $default;
        }

        // Elementor stocke le kit (Global Colors) dans un post type dédié.
        $kit = \Elementor\Plugin::$instance->kits_manager->get_active_kit_for_frontend();

        if ( ! $kit ) {
            return $default;
        }

        $settings = $kit->get_settings();

        // Les couleurs globales sont dans system_colors.
        if ( ! empty( $settings['system_colors'] ) && is_array( $settings['system_colors'] ) ) {
            foreach ( $settings['system_colors'] as $color ) {
                if ( isset( $color['_id'] ) && $color['_id'] === 'primary' && ! empty( $color['color'] ) ) {
                    return $color['color'];
                }
            }
        }

        // Fallback : custom_colors si la couleur primaire a été définie là.
        if ( ! empty( $settings['custom_colors'] ) && is_array( $settings['custom_colors'] ) ) {
            foreach ( $settings['custom_colors'] as $color ) {
                if ( isset( $color['_id'] ) && $color['_id'] === 'primary' && ! empty( $color['color'] ) ) {
                    return $color['color'];
                }
            }
        }

        return $default;
    }

    /**
     * Rendu HTML du bouton.
     */
    public function render_button(): void {
        ?>
        <div id="wycan-btt" class="wycan-btt" aria-label="<?php esc_attr_e( 'Retour en haut', 'wycan' ); ?>" role="button" tabindex="0">
            <svg class="wycan-btt-progress" viewBox="0 0 100 100">
                <circle class="wycan-btt-track" cx="50" cy="50" r="46"></circle>
                <circle class="wycan-btt-fill" cx="50" cy="50" r="46"></circle>
            </svg>
            <span class="wycan-btt-icon">
                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
                    <polyline points="17 11 12 6 7 11"></polyline>
                    <polyline points="17 18 12 13 7 18"></polyline>
                </svg>
            </span>
        </div>
        <?php
    }

    /**
     * Styles inline (aucun fichier externe requis).
     */
    public function inline_styles(): void {
        $color = $this->get_primary_color();
        ?>
        <style id="wycan-btt-css">
            .wycan-btt {
                --wycan-btt-color: <?php echo esc_attr( $color ); ?>;
                --wycan-btt-size: 48px;

                position: fixed;
                bottom: 30px;
                right: 30px;
                width: var(--wycan-btt-size);
                height: var(--wycan-btt-size);
                cursor: pointer;
                z-index: 9999;
                opacity: 0;
                visibility: hidden;
                transform: translateY(12px);
                transition: opacity .3s ease, visibility .3s ease, transform .3s ease;
            }

            .wycan-btt.is-visible {
                opacity: 1;
                visibility: visible;
                transform: translateY(0);
            }

            /* Cercle SVG de progression */
            .wycan-btt-progress {
                position: absolute;
                inset: 0;
                width: 100%;
                height: 100%;
                transform: rotate(-90deg);
            }

            .wycan-btt-track {
                fill: #ffffff;
                stroke: #e0e0e0;
                stroke-width: 4;
                filter: drop-shadow(0 2px 6px rgba(0, 0, 0, .08));
            }

            .wycan-btt-fill {
                fill: none;
                stroke: var(--wycan-btt-color);
                stroke-width: 4;
                stroke-dasharray: 289.027;
                stroke-dashoffset: 289.027;
                stroke-linecap: round;
                transition: stroke-dashoffset .1s linear;
            }

            /* Icône centrale */
            .wycan-btt-icon {
                position: absolute;
                inset: 0;
                display: flex;
                align-items: center;
                justify-content: center;
                color: var(--wycan-btt-color);
            }

            .wycan-btt-icon svg {
                width: 20px;
                height: 20px;
            }

            /* Hover */
            .wycan-btt:hover .wycan-btt-track {
                fill: var(--wycan-btt-color);
                transition: fill .25s ease;
            }

            .wycan-btt:hover .wycan-btt-icon {
                color: #ffffff;
                transition: color .25s ease;
            }

            .wycan-btt:hover .wycan-btt-fill {
                stroke: #ffffff;
            }

            /* Responsive */
            @media (max-width: 768px) {
                .wycan-btt {
                    --wycan-btt-size: 42px;
                    bottom: 20px;
                    right: 20px;
                }

                .wycan-btt-icon svg {
                    width: 17px;
                    height: 17px;
                }
            }
        </style>
        <?php
    }

    /**
     * JavaScript inline pour le scroll tracking et le smooth scroll.
     */
    public function inline_scripts(): void {
        ?>
        <script id="wycan-btt-js">
        (function () {
            var btn = document.getElementById('wycan-btt');
            if (!btn) return;

            var fill = btn.querySelector('.wycan-btt-fill');
            var circumference = 2 * Math.PI * 46; // r = 46
            var showThreshold = 300; // px avant d'afficher le bouton
            var ticking = false;

            function updateProgress() {
                var scrollTop = window.pageYOffset || document.documentElement.scrollTop;
                var docHeight = document.documentElement.scrollHeight - document.documentElement.clientHeight;
                var progress = docHeight > 0 ? Math.min(scrollTop / docHeight, 1) : 0;

                // Remplissage du cercle
                fill.style.strokeDashoffset = circumference * (1 - progress);

                // Afficher / masquer
                if (scrollTop > showThreshold) {
                    btn.classList.add('is-visible');
                } else {
                    btn.classList.remove('is-visible');
                }

                ticking = false;
            }

            window.addEventListener('scroll', function () {
                if (!ticking) {
                    window.requestAnimationFrame(updateProgress);
                    ticking = true;
                }
            }, { passive: true });

            // Scroll to top au clic
            btn.addEventListener('click', function () {
                window.scrollTo({ top: 0, behavior: 'smooth' });
            });

            // Accessibilité clavier
            btn.addEventListener('keydown', function (e) {
                if (e.key === 'Enter' || e.key === ' ') {
                    e.preventDefault();
                    window.scrollTo({ top: 0, behavior: 'smooth' });
                }
            });

            // État initial
            updateProgress();
        })();
        </script>
        <?php
    }
}

new Wycan_Back_To_Top();