<?php
namespace Zadex\Frontend;

defined('ABSPATH') || exit;

use Zadex\Assets;

/**
 * Interactions (T211): `_interactions` element setting -> `data-zx-ix` attribute on the element root.
 *
 * Mirrors src/frontend/lib/interactions-config.ts exactly (same normalisation, same key order), so the live page
 * and the editor canvas carry identical markup. The runtime is the lazy `src/frontend/interactions.ts` entry,
 * enqueued on wp_footer only when a rendered element got the attribute.
 *
 * Also sanitizes the stored values of the `interactions` and `scrollKeyframes` control types (Sanitizer).
 */
final class Interactions
{
    public const ENTRY = 'src/frontend/interactions.ts';
    public const TRIGGERS = ['load', 'scroll', 'hover', 'leave', 'click'];
    public const ACTION_TYPES = ['animate', 'toggleClass', 'addClass', 'removeClass', 'show', 'hide', 'toggle', 'scrollTo', 'openPopup', 'closePopup'];
    public const TARGETS = ['self', 'element', 'selector'];
    public const PRESETS = ['fadeIn', 'fadeOut', 'slideInUp', 'slideInDown', 'slideInLeft', 'slideInRight', 'zoomIn', 'zoomOut', 'pulse', 'shake', 'bounce', 'spin', 'flash', 'custom'];
    public const EASINGS = ['linear', 'ease', 'ease-in', 'ease-out', 'ease-in-out'];
    public const PROP_KEYS = ['opacity', 'x', 'y', 'scale', 'rotate', 'blur', 'bg'];
    private const PROP_RANGE = [
        'opacity' => [0, 1],
        'x'       => [-5000, 5000],
        'y'       => [-5000, 5000],
        'scale'   => [0, 20],
        'rotate'  => [-3600, 3600],
        'blur'    => [0, 200],
    ];
    public const MAX_INTERACTIONS = 20;
    public const MAX_ACTIONS = 20;
    public const MAX_MS = 60000;
    public const DEFAULT_DURATION = 600;
    public const DEFAULT_THRESHOLD = 20;

    private ?Assets $assets;
    private bool $used = false;

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

    public function register(): void
    {
        add_filter('zadex/render/attrs', [$this, 'filter_attrs'], 10, 3);
        add_action('wp_footer', [$this, 'enqueue'], 5);
    }

    /**
     * @param array<string, mixed> $attrs
     * @param array<string, mixed> $element
     * @param array<string, mixed> $settings
     * @return array<string, mixed>
     */
    public function filter_attrs($attrs, $element = [], $settings = [])
    {
        if (!is_array($attrs) || !is_array($settings)) {
            return $attrs;
        }
        $ix = self::attrs($settings);
        if ($ix) {
            $this->used = true;
            $attrs = array_merge($attrs, $ix);
        }
        return $attrs;
    }

    public function used(): bool
    {
        return $this->used;
    }

    /** Loads the runtime when an element used it (never in the editor preview: the canvas drives it itself). */
    public function enqueue(): void
    {
        $is_preview = \Zadex\Editor\EditorLoader::is_preview();
        if (!$this->used || $is_preview || $this->assets === null) {
            return;
        }
        $this->assets->enqueue_entry(self::ENTRY, 'zadex-interactions');
    }

    /** @return array<string, string> */
    public static function attrs(array $settings): array
    {
        $list = self::normalize($settings['_interactions'] ?? null);
        if (!$list) {
            return [];
        }
        return ['data-zx-ix' => (string) wp_json_encode($list, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE)];
    }

    /** @return array<int, array<string, mixed>> */
    public static function normalize($value): array
    {
        if (!is_array($value) || !array_is_list($value)) {
            return [];
        }
        $out = [];
        foreach (array_slice($value, 0, self::MAX_INTERACTIONS) as $raw) {
            if (!is_array($raw)) {
                continue;
            }
            $actions = [];
            foreach (array_slice(is_array($raw['actions'] ?? null) ? array_values($raw['actions']) : [], 0, self::MAX_ACTIONS) as $a) {
                $clean = self::normalize_action($a);
                if ($clean !== null) {
                    $actions[] = $clean;
                }
            }
            if (!$actions) {
                continue;
            }
            $trigger = self::pick($raw['trigger'] ?? null, self::TRIGGERS, 'click');
            $ix = ['trigger' => $trigger];
            if ($trigger === 'scroll') {
                $ix['threshold'] = (int) round((float) self::num($raw['threshold'] ?? null, self::DEFAULT_THRESHOLD, 0, 100));
            }
            if (self::on($raw['once'] ?? false)) {
                $ix['once'] = true;
            }
            $ix['actions'] = $actions;
            $out[] = $ix;
        }
        return $out;
    }

    /** @return array<string, mixed>|null */
    public static function normalize_action($a): ?array
    {
        if (!is_array($a)) {
            return null;
        }
        $type = self::pick($a['type'] ?? null, self::ACTION_TYPES, 'animate');
        $target = self::pick($a['target'] ?? null, self::TARGETS, 'self');
        $popup_type = $type === 'openPopup' || $type === 'closePopup';
        $out = ['target' => 'self'];
        if (!$popup_type) {
            if ($target === 'element') {
                $id = self::clean_element_id($a['targetId'] ?? ($a['id'] ?? null));
                if ($id === '') {
                    $target = 'self';
                } else {
                    $out['id'] = $id;
                }
            } elseif ($target === 'selector') {
                $sel = self::clean_selector($a['selector'] ?? ($a['sel'] ?? null));
                if ($sel === '') {
                    $target = 'self';
                } else {
                    $out['sel'] = $sel;
                }
            }
            $out['target'] = $target;
        }
        $out['type'] = $type;
        if ($type === 'animate') {
            $preset = self::pick($a['preset'] ?? null, self::PRESETS, 'fadeIn');
            $out['preset'] = $preset;
            if ($preset === 'custom') {
                $from = self::clean_props($a['from'] ?? null);
                $to = self::clean_props($a['to'] ?? null);
                if ($from === null && $to === null) {
                    return null;
                }
                if ($from !== null) {
                    $out['from'] = $from;
                }
                if ($to !== null) {
                    $out['to'] = $to;
                }
            }
        } elseif (in_array($type, ['toggleClass', 'addClass', 'removeClass'], true)) {
            $cls = self::clean_classes($a['className'] ?? ($a['cls'] ?? null));
            if ($cls === '') {
                return null;
            }
            $out['cls'] = $cls;
        } elseif ($popup_type) {
            $raw = $a['popupId'] ?? ($a['popup'] ?? null);
            $popup = is_string($raw) || is_int($raw) || is_float($raw) ? (preg_replace('/[^0-9]/', '', (string) $raw) ?? '') : '';
            if ($type === 'openPopup' && $popup === '') {
                return null;
            }
            if ($popup !== '') {
                $out['popup'] = $popup;
            }
        }
        $animated = in_array($type, ['animate', 'show', 'hide', 'toggle'], true);
        $out['delay'] = (int) round((float) self::num($a['delay'] ?? null, 0, 0, self::MAX_MS));
        $out['duration'] = $animated ? (int) round((float) self::num($a['duration'] ?? null, self::DEFAULT_DURATION, 0, self::MAX_MS)) : 0;
        $out['easing'] = $animated ? self::clean_easing($a['easing'] ?? null) : 'ease';
        return $out;
    }

    /* ---- stored value sanitizers (Sanitizer, control types `interactions` / `scrollKeyframes`) ---- */

    /**
     * Keeps the editor shape (ids, field names, half-configured actions) but every field cleaned.
     *
     * @return array<int, array<string, mixed>>
     */
    public static function sanitize($value): array
    {
        if (!is_array($value)) {
            return [];
        }
        $out = [];
        foreach (array_slice(array_values($value), 0, self::MAX_INTERACTIONS) as $raw) {
            if (!is_array($raw)) {
                continue;
            }
            $ix = [
                '_id'       => self::clean_uid($raw['_id'] ?? ''),
                'trigger'   => self::pick($raw['trigger'] ?? null, self::TRIGGERS, 'click'),
                'threshold' => (int) round((float) self::num($raw['threshold'] ?? null, self::DEFAULT_THRESHOLD, 0, 100)),
                'once'      => self::on($raw['once'] ?? false),
                'actions'   => [],
            ];
            foreach (array_slice(is_array($raw['actions'] ?? null) ? array_values($raw['actions']) : [], 0, self::MAX_ACTIONS) as $a) {
                if (!is_array($a)) {
                    continue;
                }
                $action = [
                    '_id'       => self::clean_uid($a['_id'] ?? ''),
                    'target'    => self::pick($a['target'] ?? null, self::TARGETS, 'self'),
                    'targetId'  => self::clean_element_id($a['targetId'] ?? null),
                    'selector'  => self::clean_selector($a['selector'] ?? null),
                    'type'      => self::pick($a['type'] ?? null, self::ACTION_TYPES, 'animate'),
                    'preset'    => self::pick($a['preset'] ?? null, self::PRESETS, 'fadeIn'),
                    'className' => self::clean_classes($a['className'] ?? null),
                    'popupId'   => isset($a['popupId']) && is_scalar($a['popupId']) ? (preg_replace('/[^0-9]/', '', (string) $a['popupId']) ?? '') : '',
                    'delay'     => (int) round((float) self::num($a['delay'] ?? null, 0, 0, self::MAX_MS)),
                    'duration'  => (int) round((float) self::num($a['duration'] ?? null, self::DEFAULT_DURATION, 0, self::MAX_MS)),
                    'easing'    => self::clean_easing($a['easing'] ?? null),
                ];
                foreach (['from', 'to'] as $side) {
                    $props = self::clean_props($a[$side] ?? null);
                    if ($props !== null) {
                        $action[$side] = $props;
                    }
                }
                $ix['actions'][] = $action;
            }
            $out[] = $ix;
        }
        return $out;
    }

    /** `scrollKeyframes` control value (T212), editor shape kept. */
    public static function sanitize_keyframes($value): array
    {
        if (!is_array($value)) {
            return [];
        }
        $out = [
            'enabled' => self::on($value['enabled'] ?? false),
            'anchor'  => in_array($value['anchor'] ?? '', ['self', 'parent', 'page'], true) ? $value['anchor'] : 'self',
            'start'   => self::num($value['start'] ?? null, 0, 0, 100),
            'end'     => self::num($value['end'] ?? null, 100, 0, 100),
        ];
        if (isset($value['devices']) && is_array($value['devices'])) {
            $out['devices'] = MotionAttrs::devices($value['devices']);
        }
        $frames = [];
        foreach (array_slice(is_array($value['keyframes'] ?? null) ? array_values($value['keyframes']) : [], 0, MotionAttrs::MAX_KEYFRAMES * 2) as $k) {
            if (!is_array($k)) {
                continue;
            }
            $frame = ['_id' => self::clean_uid($k['_id'] ?? ''), 'at' => self::num($k['at'] ?? null, 0, 0, 100)];
            foreach (MotionAttrs::KF_PROPS as $p) {
                if (isset($k[$p]) && $k[$p] !== '' && is_numeric($k[$p])) {
                    $frame[$p] = $k[$p] + 0;
                }
            }
            if (isset($k['easing']) && in_array($k['easing'], self::EASINGS, true)) {
                $frame['easing'] = $k['easing'];
            }
            $frames[] = $frame;
        }
        $out['keyframes'] = $frames;
        return $out;
    }

    /* ---- field cleaners (same rules as the TypeScript twin) ---- */

    public static function clean_element_id($v): string
    {
        return is_string($v) && preg_match('/^[a-z][a-z0-9]{2,15}$/', $v) ? $v : '';
    }

    public static function clean_classes($v): string
    {
        if (!is_string($v)) {
            return '';
        }
        $out = [];
        foreach (preg_split('/\s+/', $v) ?: [] as $c) {
            $c = preg_replace('/[^A-Za-z0-9_-]/', '', $c) ?? '';
            if ($c !== '' && preg_match('/^[A-Za-z_-]/', $c)) {
                $out[] = $c;
            }
            if (count($out) >= 10) {
                break;
            }
        }
        return implode(' ', $out);
    }

    public static function clean_selector($v): string
    {
        if (!is_string($v)) {
            return '';
        }
        $v = trim(preg_replace('/[<{};\\\\\x00-\x1f\x7f]/', '', $v) ?? '');
        return function_exists('mb_substr') ? mb_substr($v, 0, 200) : substr($v, 0, 200);
    }

    public static function clean_easing($v): string
    {
        if (!is_string($v)) {
            return 'ease';
        }
        $s = strtolower(trim($v));
        if (in_array($s, self::EASINGS, true)) {
            return $s;
        }
        if (preg_match('/^cubic-bezier\(\s*(-?\d*\.?\d+)\s*,\s*(-?\d*\.?\d+)\s*,\s*(-?\d*\.?\d+)\s*,\s*(-?\d*\.?\d+)\s*\)$/', $s, $m)) {
            [$a, $b, $c, $d] = array_map('floatval', array_slice($m, 1));
            if ($a >= 0 && $a <= 1 && $c >= 0 && $c <= 1 && abs($b) <= 10 && abs($d) <= 10) {
                return 'cubic-bezier(' . self::js_number($a) . ', ' . self::js_number($b) . ', ' . self::js_number($c) . ', ' . self::js_number($d) . ')';
            }
        }
        return 'ease';
    }

    public static function clean_color($v): string
    {
        if (!is_string($v)) {
            return '';
        }
        $s = trim($v);
        if (preg_match('/^#([0-9a-f]{3,4}|[0-9a-f]{6}|[0-9a-f]{8})$/i', $s)
            || preg_match('/^(rgba?|hsla?|oklch|oklab|color|color-mix)\([\w\s%.,\/\-#()]+\)$/i', $s)
            || preg_match('/^var\(--[a-z0-9-]+\)$/i', $s)
            || preg_match('/^[a-z]+$/i', $s)) {
            return $s;
        }
        return '';
    }

    /** @return array<string, mixed>|null */
    private static function clean_props($v): ?array
    {
        if (!is_array($v) || (array_is_list($v) && $v !== [])) {
            return null;
        }
        $out = [];
        foreach (self::PROP_KEYS as $key) {
            if (!array_key_exists($key, $v) || $v[$key] === null || $v[$key] === '') {
                continue;
            }
            if ($key === 'bg') {
                $c = self::clean_color($v[$key]);
                if ($c !== '') {
                    $out['bg'] = $c;
                }
                continue;
            }
            [$min, $max] = self::PROP_RANGE[$key];
            $n = self::num($v[$key], null, $min, $max, in_array($key, ['opacity', 'scale'], true) ? 3 : 2);
            if ($n !== null) {
                $out[$key] = $n;
            }
        }
        return $out ? $out : null;
    }

    private static function clean_uid($v): string
    {
        return is_string($v) ? substr(preg_replace('/[^a-zA-Z0-9_-]/', '', $v) ?? '', 0, 32) : '';
    }

    private static function on($v): bool
    {
        return $v === true || $v === 1 || $v === '1' || $v === 'true';
    }

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

    /** Clamped + rounded number (whole numbers as int, like JSON from JavaScript); `$def` when not numeric. */
    private static function num($v, $def, $min, $max, int $digits = 2)
    {
        if (is_string($v) && trim($v) !== '' && is_numeric(trim($v))) {
            $v = (float) trim($v);
        }
        if (is_bool($v) || (!is_int($v) && !is_float($v)) || (is_float($v) && !is_finite($v))) {
            return $def;
        }
        $n = round(min($max, max($min, (float) $v)), $digits);
        if ($n == 0.0) {
            return 0;
        }
        return floor($n) === $n ? (int) $n : $n;
    }

    /** Number as JavaScript's String(n) prints it (no trailing `.0`). */
    private static function js_number(float $n): string
    {
        if (floor($n) === $n && abs($n) < 1e15) {
            return (string) (int) $n;
        }
        return rtrim(rtrim(sprintf('%.10F', $n), '0'), '.');
    }
}