<?php
namespace Zadex\Site;

defined('ABSPATH') || exit;

use Zadex\Assets;
use Zadex\Documents\Sanitizer;
use Zadex\Editor\EditorLoader;
use Zadex\Settings;

/**
 * Site-wide floating buttons (T103): WhatsApp, call, email, link and scroll-to-top.
 *
 * Configured in the editor's Global panel ("Floating buttons") and stored in the global settings
 * (`zadex_global` option, key `floatingButtons`). Rendered on wp_footer as fixed stacks, one per corner.
 * Their colours, size, offsets and device visibility are generated in JS with the global CSS
 * (src/editor/core/site.ts floatingButtonsCss); the structural CSS and the scroll-to-top behaviour ship as
 * the small `src/frontend/floating.ts` entry, loaded only when at least one button is printed.
 * The markup mirrors src/editor/canvas/FloatingLayer.vue (editor preview), which draws the same layer
 * marked `data-zx-ignore` so editor overlays and drag & drop skip it; PHP never prints it in preview mode.
 */
final class FloatingButtons
{
    public const TYPES = ['whatsapp', 'call', 'email', 'link', 'scroll_top'];
    public const POSITIONS = ['bottom-end', 'bottom-start', 'top-end', 'top-start'];
    public const DISPLAYS = ['all', 'only', 'except', 'logged_in', 'logged_out'];
    public const ANIMATIONS = ['none', 'fade', 'slide', 'bounce'];
    public const LABEL_MODES = ['tooltip', 'label', 'none'];

    private Settings $settings;
    private ?Assets $assets;
    /** @var array<string, string>|null */
    private static ?array $icons = null;

    public function __construct(Settings $settings, ?Assets $assets = null)
    {
        $this->settings = $settings;
        $this->assets = $assets;
    }

    public function register(): void
    {
        // Before WordPress prints the footer scripts/styles (priority 20) so the enqueued entry still lands.
        add_action('wp_footer', [$this, 'print_buttons'], 8);
    }

    /** @return array<string, string> type => inline SVG (shared with the editor through floating-icons.json) */
    public static function icons(): array
    {
        if (self::$icons === null) {
            $file = __DIR__ . '/floating-icons.json';
            $decoded = is_readable($file) ? wp_json_file_decode($file, ['associative' => true]) : null;
            self::$icons = is_array($decoded) ? array_map('strval', $decoded) : [];
        }
        return self::$icons;
    }

    /** Normalizes the saved list (same rules as normalizeFloatingButton() in src/editor/core/site.ts). */
    public static function sanitize($input): array
    {
        $out = [];
        foreach (is_array($input) ? array_values($input) : [] as $i => $raw) {
            if (!is_array($raw)) {
                continue;
            }
            $type = self::pick($raw['type'] ?? '', self::TYPES, 'whatsapp');
            $id = isset($raw['_id']) && is_string($raw['_id']) ? preg_replace('/[^a-zA-Z0-9_\-]/', '', $raw['_id']) : '';
            $icon = null;
            if (isset($raw['icon']) && is_array($raw['icon']) && (!empty($raw['icon']['value']) || !empty($raw['icon']['svg']))) {
                $icon = [
                    'library' => sanitize_text_field((string) ($raw['icon']['library'] ?? '')),
                    'value'   => sanitize_text_field((string) ($raw['icon']['value'] ?? '')),
                ];
                if (!empty($raw['icon']['svg']) && is_string($raw['icon']['svg'])) {
                    $icon['svg'] = Sanitizer::clean_svg($raw['icon']['svg']);
                }
            }
            $pages = [];
            foreach ((array) ($raw['pages'] ?? []) as $p) {
                if (is_numeric($p) && (int) $p > 0 && !in_array((int) $p, $pages, true)) {
                    $pages[] = (int) $p;
                }
            }
            $item = [
                '_id'         => $id !== '' ? $id : 'fb' . $i,
                'type'        => $type,
                'value'       => sanitize_text_field(self::str($raw['value'] ?? '')),
                'message'     => self::clean_message(self::str($raw['message'] ?? '')),
                'label'       => sanitize_text_field(self::str($raw['label'] ?? '')),
                'labelMode'   => self::pick($raw['labelMode'] ?? '', self::LABEL_MODES, 'tooltip'),
                'newTab'      => isset($raw['newTab']) ? (bool) $raw['newTab'] : in_array($type, ['whatsapp', 'link'], true),
                'bg'          => self::color($raw['bg'] ?? ''),
                'color'       => self::color($raw['color'] ?? ''),
                'bgHover'     => self::color($raw['bgHover'] ?? ''),
                'colorHover'  => self::color($raw['colorHover'] ?? ''),
                'size'        => self::num($raw['size'] ?? null, 56, 24, 160),
                'radius'      => self::num($raw['radius'] ?? null, 60, 0, 100),
                'position'    => self::pick($raw['position'] ?? '', self::POSITIONS, 'bottom-end'),
                'offsetX'     => self::num($raw['offsetX'] ?? null, 20, 0, 400),
                'offsetY'     => self::num($raw['offsetY'] ?? null, 20, 0, 400),
                'showDesktop' => isset($raw['showDesktop']) ? (bool) $raw['showDesktop'] : true,
                'showTablet'  => isset($raw['showTablet']) ? (bool) $raw['showTablet'] : true,
                'showMobile'  => isset($raw['showMobile']) ? (bool) $raw['showMobile'] : true,
                'display'     => self::pick($raw['display'] ?? '', self::DISPLAYS, 'all'),
                'pages'       => $pages,
                'animation'   => self::pick($raw['animation'] ?? '', self::ANIMATIONS, 'fade'),
            ];
            if ($icon !== null) {
                $item['icon'] = $icon;
            }
            $out[] = $item;
        }
        return $out;
    }

    public function buttons(): array
    {
        $global = $this->settings->global();
        return self::sanitize($global['floatingButtons'] ?? []);
    }

    /** Link target ('' = nothing usable, the button is skipped). Mirrors floatingButtonHref() in site.ts. */
    public static function href(array $b): string
    {
        $value = trim((string) ($b['value'] ?? ''));
        switch ($b['type'] ?? '') {
            case 'whatsapp':
                $digits = preg_replace('/\D+/', '', $value) ?? '';
                if ($digits === '') {
                    return '';
                }
                $text = trim((string) ($b['message'] ?? ''));
                return 'https://wa.me/' . $digits . ($text !== '' ? '?text=' . rawurlencode($text) : '');
            case 'call':
                $digits = preg_replace('/\D+/', '', $value) ?? '';
                return $digits === '' ? '' : 'tel:' . (str_starts_with($value, '+') ? '+' : '') . $digits;
            case 'email':
                return preg_match('/^[^\s@<>"]+@[^\s@<>"]+$/', $value) ? 'mailto:' . $value : '';
            case 'link':
                if ($value === '' || preg_match('/^(javascript|vbscript|data):/i', $value)) {
                    return '';
                }
                return $value;
            case 'scroll_top':
                return '#';
        }
        return '';
    }

    /** Accessible name / tooltip text. */
    public static function name(array $b): string
    {
        $label = trim((string) ($b['label'] ?? ''));
        if ($label !== '') {
            return $label;
        }
        switch ($b['type'] ?? '') {
            case 'whatsapp':
                return __('Chat on WhatsApp', 'zadex');
            case 'call':
                return __('Call us', 'zadex');
            case 'email':
                return __('Email us', 'zadex');
            case 'scroll_top':
                return __('Back to top', 'zadex');
        }
        return __('Open link', 'zadex');
    }

    /** Display conditions for the current request. Mirrors floatingButtonVisible() in site.ts. */
    public static function matches(array $b, int $page_id, bool $logged_in): bool
    {
        $pages = array_map('intval', (array) ($b['pages'] ?? []));
        switch ($b['display'] ?? 'all') {
            case 'only':
                return $page_id > 0 && in_array($page_id, $pages, true);
            case 'except':
                return !($page_id > 0 && in_array($page_id, $pages, true));
            case 'logged_in':
                return $logged_in;
            case 'logged_out':
                return !$logged_in;
        }
        return true;
    }

    /** Buttons for this request, grouped per corner (the stack takes the first button's id for its offsets). */
    public static function stacks(array $buttons, int $page_id, bool $logged_in): array
    {
        $stacks = [];
        foreach ($buttons as $b) {
            if (self::href($b) === '' || !self::matches($b, $page_id, $logged_in)) {
                continue;
            }
            $pos = $b['position'];
            if (!isset($stacks[$pos])) {
                $stacks[$pos] = ['position' => $pos, 'id' => $b['_id'], 'buttons' => []];
            }
            $stacks[$pos]['buttons'][] = $b;
        }
        return array_values($stacks);
    }

    /** HTML of the floating layer ('' when nothing is shown). */
    public function render(int $page_id, bool $logged_in): string
    {
        $stacks = self::stacks($this->buttons(), $page_id, $logged_in);
        if (!$stacks) {
            return '';
        }
        $html = '<div class="zx-fab-layer" data-zx-ignore>';
        foreach ($stacks as $stack) {
            $html .= '<div class="zx-fab-stack zx-fab-stack--' . esc_attr($stack['position']) . ' zx-fab-stack--' . esc_attr($stack['id']) . '">';
            foreach ($stack['buttons'] as $b) {
                $html .= self::button_html($b);
            }
            $html .= '</div>';
        }
        return $html . '</div>';
    }

    public static function button_html(array $b): string
    {
        $href = self::href($b);
        $name = self::name($b);
        $classes = ['zx-fab', 'zx-fab--' . $b['_id'], 'zx-fab--type-' . $b['type'], 'zx-fab--label-' . $b['labelMode']];
        if ($b['animation'] !== 'none') {
            $classes[] = 'zx-fab--anim-' . $b['animation'];
        }
        $attrs = ' class="' . esc_attr(implode(' ', $classes)) . '" href="' . esc_url($href, ['http', 'https', 'mailto', 'tel']) . '"';
        if ($b['type'] === 'scroll_top') {
            $attrs .= ' data-zx-scroll-top';
        } elseif (!empty($b['newTab']) && in_array($b['type'], ['whatsapp', 'link'], true)) {
            $attrs .= ' target="_blank" rel="noopener"';
        }
        $attrs .= ' aria-label="' . esc_attr($name) . '"';
        $label = $b['labelMode'] !== 'none' ? '<span class="zx-fab__label">' . esc_html($name) . '</span>' : '';
        return '<a' . $attrs . '><span class="zx-fab__icon" aria-hidden="true">' . self::icon_html($b) . '</span>' . $label . '</a>';
    }

    public static function icon_html(array $b): string
    {
        $icon = isset($b['icon']) && is_array($b['icon']) ? $b['icon'] : [];
        if (!empty($icon['svg'])) {
            return Sanitizer::clean_svg((string) $icon['svg']);
        }
        if (!empty($icon['value'])) {
            return '<i class="' . esc_attr(trim(($icon['library'] ?? '') . ' ' . $icon['value'])) . '"></i>';
        }
        return self::icons()[$b['type']] ?? '';
    }

    /** Whether any printed button uses an icon-font glyph (the icon font entry is then enqueued). */
    public static function uses_icon_font(array $stacks): bool
    {
        foreach ($stacks as $stack) {
            foreach ($stack['buttons'] as $b) {
                if (!empty($b['icon']['value']) && empty($b['icon']['svg'])) {
                    return true;
                }
            }
        }
        return false;
    }

    /** wp_footer: prints the layer on the live site (never in the editor, the canvas draws it itself). */
    public function print_buttons(): void
    {
        if (is_admin() || EditorLoader::mode() !== '') {
            return;
        }
        $page_id = function_exists('is_singular') && is_singular() ? (int) get_queried_object_id() : 0;
        $logged_in = is_user_logged_in();
        $stacks = self::stacks($this->buttons(), $page_id, $logged_in);
        if (!$stacks) {
            return;
        }
        if ($this->assets) {
            $this->assets->enqueue_entry(Assets::ENTRY_FLOATING, 'zadex-floating');
            if (self::uses_icon_font($stacks)) {
                $this->assets->enqueue_entry(Assets::ENTRY_ICONS, 'zadex-icons');
            }
        }
        echo wp_kses($this->render($page_id, $logged_in), \Zadex\Frontend\Kses::allowed_html());
    }

    private static function pick($value, array $list, string $fallback): string
    {
        return is_string($value) && in_array($value, $list, true) ? $value : $fallback;
    }

    private static function num($value, int $fallback, int $min, int $max): int
    {
        return is_numeric($value) ? max($min, min($max, (int) round((float) $value))) : $fallback;
    }

    /**
     * Plain text. The REST layer ran the generic sanitizer (wp_kses) first, which turns `&` into `&amp;`:
     * decode it back, every output is escaped again (esc_html / esc_attr / esc_url / rawurlencode).
     */
    private static function str($value): string
    {
        if (!is_string($value) && !is_int($value) && !is_float($value)) {
            return '';
        }
        return html_entity_decode((string) $value, ENT_QUOTES | ENT_HTML5, 'UTF-8');
    }

    /** Keeps line breaks of the WhatsApp message, strips tags. */
    private static function clean_message(string $message): string
    {
        $lines = array_map(static fn(string $l): string => sanitize_text_field($l), preg_split('/\r\n|\r|\n/', $message) ?: []);
        return trim(implode("\n", $lines));
    }

    /** Same whitelist as the editor (hex, rgb/hsl functions, var(--x), keywords). */
    public static function color($value): string
    {
        if (!is_string($value)) {
            return '';
        }
        $value = trim($value);
        return preg_match('/^(#[0-9a-f]{3,8}|(rgb|rgba|hsl|hsla)\([0-9.,%\s\/+\-]+\)|var\(--[a-z0-9_\-]+\)|transparent|currentColor|[a-z]+)$/i', $value) ? $value : '';
    }
}