<?php

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

class AdGhost_Script_Generator {

    public function build_config() {
        $network_code = trim((string) get_option('adghost_network_code', ''));
        if ($network_code === '') {
            return null;
        }

        $units       = [];
        $seen        = [];
        $formats     = [];
        $any_refresh = false;
        $adblock_on  = (bool) get_option('adghost_enable_adblock_detection', false);

        foreach (AdGhost_Helper::units() as $unit) {
            $code = AdGhost_Helper::gam_code($unit);
            if ($code === '') {
                continue;
            }

            if (AdGhost_Helper::unavailable_reason($unit) !== null) {
                continue;
            }
            $sizes    = self::size_list($unit['sizes'] ?? '300x250');
            $position = AdGhost_Helper::get_unit_position($unit);

            if ($position === 'interstitial') {
                $formats['interstitial'] = $formats['interstitial'] ?? ['enabled' => true, 'unit' => $code];
                continue;
            }
            if ($position === 'reward') {
                $formats['rewarded'] = $formats['rewarded'] ?? [
                    'enabled' => true,
                    'unit'    => $code,
                    'prompt'  => [
                        'headline'    => 'Watch a short ad to unlock this content',
                        'buttonText'  => 'Watch ad',
                        'dismissText' => 'No thanks',
                    ],
                ];
                continue;
            }

            if ($position === 'anchor') {
                if (!isset($formats['anchor']) && get_option('adghost_enable_anchor', true)) {
                    [$mobile, $desktop] = self::split_anchor_sizes($sizes);
                    $formats['anchor'] = [
                        'enabled'       => true,
                        'mode'          => 'native',
                        'position'      => ($unit['anchorPosition'] ?? 'bottom') === 'top' ? 'top' : 'bottom',
                        'unit'          => $code,
                        'fallback'      => true,

                        'fallbackSizes' => null,
                        'closeable'     => true,
                        'sizes'         => ['mobile' => $mobile, 'desktop' => $desktop],
                    ];
                }
                continue;
            }

            if (in_array($position, AdGhost_Helper::screen_positions(), true)) {
                continue;
            }

            if (isset($seen[$code])) {
                continue;
            }
            $seen[$code] = true;

            $entry = [
                'id'    => $code,
                'sizes' => $sizes,
            ];

            if (!empty($unit['targeting']) && is_array($unit['targeting'])) {
                $entry['targeting'] = $unit['targeting'];
            }

            if ($position === 'header') {
                $entry['priority'] = 'high';
            }

            $format = AdGhost_Ad_Container::behaviour_formats()[AdGhost_Helper::served_feature($unit)] ?? null;
            if ($format !== null) {
                $entry['format'] = $format;
                $entry['formatOptions'] = $format === 'floating'
                    ? ['variant' => 'on-pass', 'corner' => self::corner($unit)]
                    : [
                        'mode'        => $format === 'elevator' ? 'smooth' : 'css',
                        'topOffsetPx' => min(400, absint($unit['stickyOffset'] ?? 16)),
                        'align'       => ($unit['elevatorAlign'] ?? 'top') === 'center' ? 'center' : 'top',
                        'desktopOnly' => ($unit['devices'] ?? '') === 'desktop',
                    ];
                if (!in_array($format, ['elevator', 'floating'], true)) {

                    $entry['formatOptions'] = $unit['options'];
                }
            }

            $refresh     = !empty($unit['refresh']) || (bool) get_option('adghost_enable_auto_refresh', false);
            $any_refresh = $any_refresh || $refresh;
            if (!$refresh) {
                $entry['refresh'] = false;
            }

            if (!empty($unit['backfillPath'])) {
                $entry['backfillPath'] = (string) $unit['backfillPath'];
            }

            $units[] = $entry;
        }

        $ivt_mode = AdGhost_IVT_Manager::mode();

        $config = [
            'networkCode' => $network_code,
            'units'       => $units,
            'formats'     => $formats,

            'lazyLoad'    => ['enabled' => (bool) get_option('adghost_enable_lazy_loading', true)],

            'loadAfter'   => in_array(get_option('adghost_load_after', 'load'), ['load', 'interactive', 'immediate'], true)
                ? get_option('adghost_load_after', 'load')
                : 'load',
            'cls'         => ['mode' => AdGhost_Helper::cls_mode()],

            'performance' => [
                'maxAds'           => 30,
                'adaptSlowNetwork' => (bool) get_option('adghost_adapt_slow_network', true),
            ],

            'adblock'     => [
                'detect'       => $adblock_on,
                'title'        => $adblock_on ? AdGhost_Helper::adblock_text('title') : null,
                'messageHtml'  => $adblock_on ? AdGhost_Helper::adblock_text('message') : null,
                'buttonLabel'  => $adblock_on ? AdGhost_Helper::adblock_text('button') : null,
                'dismissLabel' => $adblock_on ? AdGhost_Helper::adblock_text('dismiss') : null,
            ],

            'ivt'         => [
                'enabled' => AdGhost_IVT_Manager::enabled(),
                'mode'    => $ivt_mode !== 'monitor' ? 'no-ads' : 'monitor',
            ],

            'privacy'     => self::privacy_config(),

            'ivtEnabled'  => AdGhost_IVT_Manager::enabled(),

            'ivtSample'   => AdGhost_IVT_Manager::enabled() ? self::ivt_sample_rate($ivt_mode) : 0,
            'ivtEndpoint' => esc_url_raw(rest_url('adghost/v1/ivt/verdict')),
        ];

        if ($any_refresh) {
            $config['refresh'] = [
                'enabled'         => true,
                'intervalSeconds' => max(30, (int) get_option('adghost_auto_refresh_interval', 30)),
            ];
        }

        $config = (array) apply_filters('adghost_runtime_config', $config, AdGhost_Helper::units());
        if (empty($config['formats'])) {
            $config['formats'] = new stdClass();
        }

        return $config;
    }

    private static function privacy_config() {
        $mode = (string) get_option('adghost_consent_mode', 'auto');
        if (!in_array($mode, ['auto', 'npa', 'off'], true)) {
            $mode = 'auto';
        }
        return [
            'auto'               => $mode === 'auto',
            'nonPersonalizedAds' => $mode === 'npa',
        ];
    }

    private static function ivt_sample_rate($ivt_mode) {
        if ($ivt_mode !== 'monitor') {
            return 1.0;
        }
        $rate = (float) apply_filters('adghost_ivt_sample_rate', 0.25);
        return max(0.0, min(1.0, $rate));
    }

    private static function size_list($sizes) {
        $out = [];
        foreach (preg_split('/[;,]/', (string) $sizes) as $size) {
            $size = strtolower(trim($size));
            if ($size === 'fluid' || preg_match('/^\d{1,4}x\d{1,4}$/', $size)) {
                $out[] = $size;
            }
        }
        return $out ? implode(',', array_unique($out)) : '300x250';
    }

    private static function split_anchor_sizes($sizes) {
        $mobile = $desktop = [];
        foreach (explode(',', $sizes) as $size) {
            if (!preg_match('/^(\d+)x(\d+)$/', $size, $m) || (int) $m[1] <= 1 || (int) $m[2] > 120) {
                continue;
            }
            if ((int) $m[1] >= 728) {
                $desktop[] = $size;
            } else {
                $mobile[] = $size;
            }
        }
        return [
            $mobile ? implode(',', $mobile) : '320x50,320x100',
            $desktop ? implode(',', $desktop) : '728x90',
        ];
    }

    private static function corner(array $unit) {
        $corner = (string) ($unit['corner'] ?? 'bottom-right');
        return in_array($corner, ['bottom-right', 'bottom-left', 'top-right', 'top-left'], true) ? $corner : 'bottom-right';
    }

    public function format_device_rules() {
        $family_of = (array) apply_filters('adghost_format_families', [
            'anchor' => 'anchor', 'interstitial' => 'interstitial', 'reward' => 'rewarded',
        ]);
        $rules = [];
        foreach (AdGhost_Helper::units() as $unit) {
            $family = $family_of[AdGhost_Helper::get_unit_position($unit)] ?? null;
            if ($family === null || isset($rules[$family]) || $unit['devices'] === '') {
                continue;
            }
            $rules[$family] = explode(',', $unit['devices']);
        }
        return $rules;
    }

    public static function runtime_source() {
        return get_option('adghost_runtime_source', 'site') === 'custom'
            && self::custom_runtime_url() !== '' ? 'custom' : 'site';
    }

    public static function custom_runtime_url() {
        $url = trim((string) get_option('adghost_runtime_url', ''));
        return preg_match('#^(https?:)?//#i', $url) ? $url : '';
    }

    public function generate_engine_script() {
        $template_path = $this->template_path();
        if ($template_path === null) {
            return false;
        }
        $build = self::engine_build();
        return '/*! AdGhost engine build ' . $build . ' for plugin ' . ADGHOST_VERSION . ". Host this file anywhere; the page supplies the config. */\n"
            . 'window.__ADGHOST_ENGINE_BUILD__=' . wp_json_encode($build) . ";\n"
            . str_replace(['{{CONFIG}}', '{{ CONFIG }}'], '(window.__ADGHOST_CONFIG__||{})', (string) file_get_contents($template_path));
    }

    public static function engine_build() {
        $template = (new self())->template_path();
        return $template ? substr(md5_file($template), 0, 10) : '';
    }

    public function generate_local_script() {
        $config = $this->build_config();
        if ($config === null) {
            return false;
        }

        $files = $this->source_files($config);
        if (!$files) {
            return false;
        }

        $script = implode(";\n", array_map('file_get_contents', $files));

        $script = str_replace(
            ['{{CONFIG}}', '{{ CONFIG }}'],
            wp_json_encode($config, JSON_HEX_TAG | JSON_HEX_AMP),
            $script
        );

        return $script;
    }

    public function get_local_script_url($force = false) {
        $config = $this->build_config();
        if ($config === null) {
            return false;
        }

        $sources = [];
        foreach ($this->source_files($config) as $file) {
            $sources[] = basename($file) . '@' . filemtime($file) . ':' . filesize($file);
        }
        $signature = md5(wp_json_encode($config) . '|' . implode('|', $sources));

        $stored = get_option('adghost_local_script', []);
        if (!$force && is_array($stored) && ($stored['signature'] ?? '') === $signature
            && !empty($stored['path']) && file_exists($stored['path'])) {

            $uploads = wp_upload_dir(null, false);
            return empty($uploads['error'])
                ? trailingslashit($uploads['baseurl']) . 'adghost/' . basename($stored['path'])
                : (string) $stored['url'];
        }

        $lock = 'adghost_building_runtime';
        if (get_transient($lock)) {
            $stored = get_option('adghost_local_script', []);
            if (is_array($stored) && !empty($stored['path']) && file_exists($stored['path'])) {
                $uploads = wp_upload_dir(null, false);
                return empty($uploads['error'])
                    ? trailingslashit($uploads['baseurl']) . 'adghost/' . basename($stored['path'])
                    : (string) $stored['url'];
            }
            return false;
        }
        set_transient($lock, 1, 30);

        $script = $this->generate_local_script();
        if ($script === false) {
            delete_transient($lock);
            return false;
        }

        $hash     = substr(md5($script), 0, 12);
        $filename = 'adghost-' . $hash . '.js';

        $uploads = wp_upload_dir();
        if (!empty($uploads['error'])) {
            delete_transient($lock);
            return false;
        }

        $dir  = trailingslashit($uploads['basedir']) . 'adghost';
        $path = $dir . '/' . $filename;
        $url  = trailingslashit($uploads['baseurl']) . 'adghost/' . $filename;

        if (!file_exists($path)) {
            if (!wp_mkdir_p($dir)) {
                delete_transient($lock);
                return false;
            }

            if (!function_exists('WP_Filesystem')) {
                require_once ABSPATH . 'wp-admin/includes/file.php';
            }
            global $wp_filesystem;
            if (!WP_Filesystem() || !$wp_filesystem->put_contents($path, $script, FS_CHMOD_FILE)) {
                delete_transient($lock);
                return false;
            }

            $this->prune_old_scripts($dir, $filename);
        }

        update_option('adghost_local_script', [
            'signature' => $signature,
            'url'       => $url,
            'path'      => $path,
            'bytes'     => strlen($script),
            'built'     => current_time('mysql'),
        ]);

        delete_transient($lock);

        return $url;
    }

    const PARTS = ['config', 'detector', 'engine', 'kit', 'floating', 'reporter'];

    public function parts(array $config) {
        $format_units = false;
        $float        = false;
        foreach ((array) ($config['units'] ?? []) as $unit) {
            if (!empty($unit['format'])) {
                $format_units = true;
                $float = $float || $unit['format'] === 'floating';
            }
        }
        foreach (AdGhost_Helper::units() as $unit) {
            if (AdGhost_Helper::served_feature($unit) === 'float') {
                $float = true;
            }
        }
        $ivt  = class_exists('AdGhost_IVT_Manager') && AdGhost_IVT_Manager::enabled();
        $pro = AdGhost_Helper::pro_active();

        $want = [
            'config'   => true,
            'detector' => $ivt,
            'engine'   => true,
            'kit'      => $float || $format_units || $pro,
            'floating' => $float,
            'reporter' => $ivt,
        ];
        return array_keys(array_filter($want));
    }

    public function source_files(array $config) {
        $dir   = ADGHOST_PLUGIN_DIR . 'cdn-free/parts/';
        $files = [];
        foreach ($this->parts($config) as $part) {
            $file = $dir . $part . '.js';
            if (!is_readable($file)) {
                $files = null;
                break;
            }
            $files[] = $file;
        }
        if ($files) {
            return $files;
        }
        $template = $this->template_path();
        return $template ? [$template] : [];
    }

    public function template_path() {
        foreach (['cdn-free/adghost-lite.js', 'cdn/adghost-lite.js'] as $rel) {
            if (file_exists(ADGHOST_PLUGIN_DIR . $rel)) {
                return ADGHOST_PLUGIN_DIR . $rel;
            }
        }
        return null;
    }

    private function prune_old_scripts($dir, $keep) {
        $files = glob($dir . '/adghost-*.js');
        if (!is_array($files) || count($files) <= 2) {
            return;
        }

        usort($files, function ($a, $b) {
            return filemtime($b) <=> filemtime($a);
        });

        $kept = 0;
        foreach ($files as $file) {
            if (basename($file) === $keep) {
                continue;
            }
            $kept++;
            if ($kept > 1) {
                wp_delete_file($file);
            }
        }
    }

    public static function delete_local_scripts() {
        $uploads = wp_upload_dir(null, false);
        if (empty($uploads['error']) && !empty($uploads['basedir'])) {
            $dir = trailingslashit($uploads['basedir']) . 'adghost';
            foreach ((array) glob($dir . '/adghost-*.js') as $file) {
                if (is_file($file)) {
                    wp_delete_file($file);
                }
            }

            if (is_dir($dir) && count((array) scandir($dir)) === 2) {
                if (!function_exists('WP_Filesystem')) {
                    require_once ABSPATH . 'wp-admin/includes/file.php';
                }
                global $wp_filesystem;
                if (WP_Filesystem()) {
                    $wp_filesystem->rmdir($dir);
                }
            }
        }
        delete_option('adghost_local_script');
    }
}