<?php
if (!defined('ABSPATH')) exit;

/**
 * One-click install of wp-site-recovery from a private Gitea repo.
 *
 * Config sources (in order — constants beat options):
 *   define('WPH_GITEA_HOST',  'https://git.example.com');
 *   define('WPH_GITEA_OWNER', 'steve');
 *   define('WPH_GITEA_REPO',  'site-recovery');
 *   define('WPH_GITEA_TOKEN', 'xxx');  // read-only PAT, scoped to this repo
 *
 *   …or set the same values via the settings panel (stored in WP options).
 *
 * Ref resolution (in order):
 *   1. Latest release  — /api/v1/repos/:o/:r/releases/latest → tag_name
 *   2. Latest tag      — /api/v1/repos/:o/:r/tags?limit=1   → name
 *   3. main branch HEAD
 *
 * Install path:
 *   GET https://<host>/<owner>/<repo>/archive/<ref>.zip with Authorization: token <pat>
 *   → Plugin_Upgrader::install() with upgrader_source_selection filter renaming
 *     the unpacked folder to 'site-recovery' so the destination is consistent.
 *   → activate_plugin() against the freshly-installed plugin file.
 */
final class WPH_Recovery_Installer {

    private const OPT_HOST  = 'wph_gitea_host';
    private const OPT_OWNER = 'wph_gitea_owner';
    private const OPT_REPO  = 'wph_gitea_repo';
    private const OPT_TOKEN = 'wph_gitea_token';

    public static function config(): array {
        return [
            'host'  => defined('WPH_GITEA_HOST')  ? (string) WPH_GITEA_HOST  : (string) get_option(self::OPT_HOST,  ''),
            'owner' => defined('WPH_GITEA_OWNER') ? (string) WPH_GITEA_OWNER : (string) get_option(self::OPT_OWNER, ''),
            'repo'  => defined('WPH_GITEA_REPO')  ? (string) WPH_GITEA_REPO  : (string) get_option(self::OPT_REPO,  ''),
            'token' => defined('WPH_GITEA_TOKEN') ? (string) WPH_GITEA_TOKEN : (string) get_option(self::OPT_TOKEN, ''),
        ];
    }

    /** Returns whether each config field comes from a constant (true) or an option (false). */
    public static function config_origin(): array {
        return [
            'host'  => defined('WPH_GITEA_HOST'),
            'owner' => defined('WPH_GITEA_OWNER'),
            'repo'  => defined('WPH_GITEA_REPO'),
            'token' => defined('WPH_GITEA_TOKEN'),
        ];
    }

    public static function is_configured(): bool {
        $c = self::config();
        return $c['host'] && $c['owner'] && $c['repo'] && $c['token'];
    }

    public static function save_options(array $input): void {
        // Constants win — only persist fields not already constant-overridden.
        $origin = self::config_origin();
        if (!$origin['host'])  update_option(self::OPT_HOST,  esc_url_raw((string) ($input['host']  ?? '')), false);
        if (!$origin['owner']) update_option(self::OPT_OWNER, sanitize_text_field((string) ($input['owner'] ?? '')), false);
        if (!$origin['repo'])  update_option(self::OPT_REPO,  sanitize_text_field((string) ($input['repo']  ?? '')), false);
        if (!$origin['token']) update_option(self::OPT_TOKEN, sanitize_text_field((string) ($input['token'] ?? '')), false);
    }

    /** Find the ref to install: release → tag → main. */
    public static function resolve_latest_ref() {
        $c = self::config();
        if (!self::is_configured()) {
            return new WP_Error('not_configured', 'Gitea host/owner/repo/token not configured.');
        }
        $base = rtrim($c['host'], '/');
        $auth = ['Authorization' => 'token ' . $c['token'], 'Accept' => 'application/json'];

        $r = wp_remote_get("$base/api/v1/repos/{$c['owner']}/{$c['repo']}/releases/latest", ['timeout' => 10, 'headers' => $auth]);
        if (!is_wp_error($r) && (int) wp_remote_retrieve_response_code($r) === 200) {
            $body = json_decode((string) wp_remote_retrieve_body($r), true);
            if (is_array($body) && !empty($body['tag_name'])) {
                return ['type' => 'release', 'ref' => (string) $body['tag_name']];
            }
        }

        $r = wp_remote_get("$base/api/v1/repos/{$c['owner']}/{$c['repo']}/tags?limit=1", ['timeout' => 10, 'headers' => $auth]);
        if (!is_wp_error($r) && (int) wp_remote_retrieve_response_code($r) === 200) {
            $body = json_decode((string) wp_remote_retrieve_body($r), true);
            if (is_array($body) && !empty($body[0]['name'])) {
                return ['type' => 'tag', 'ref' => (string) $body[0]['name']];
            }
        }

        return ['type' => 'branch', 'ref' => 'main'];
    }

    /** Run install + activate. Returns true on success or a WP_Error. */
    public static function install_and_activate() {
        if (!self::is_configured()) {
            return new WP_Error('not_configured', 'Gitea is not configured — fill in host, owner, repo and a read-only token.');
        }

        $ref_info = self::resolve_latest_ref();
        if (is_wp_error($ref_info)) return $ref_info;
        $c = self::config();
        $url = rtrim($c['host'], '/') . "/{$c['owner']}/{$c['repo']}/archive/{$ref_info['ref']}.zip";

        // Inject auth header on outbound requests to this host so download_url() succeeds.
        $auth_filter = function ($args, $req_url) use ($c) {
            if (strpos((string) $req_url, rtrim($c['host'], '/')) === 0) {
                if (!isset($args['headers']) || !is_array($args['headers'])) $args['headers'] = [];
                $args['headers']['Authorization'] = 'token ' . $c['token'];
            }
            return $args;
        };
        add_filter('http_request_args', $auth_filter, 10, 2);

        // Force the unpacked folder name to 'site-recovery' regardless of the
        // gitea archive's wrapper folder (which gets a -<ref> suffix).
        $rename_filter = function ($source, $remote_source, $upgrader, $hook_extra) {
            if (!is_string($source) || !is_dir($source)) return $source;
            $name = basename(rtrim($source, '/\\'));
            if ($name === 'site-recovery') return $source;
            global $wp_filesystem;
            $new = trailingslashit(dirname($source)) . 'site-recovery';
            if ($wp_filesystem->exists($new)) $wp_filesystem->delete($new, true);
            $wp_filesystem->move($source, $new);
            return $new;
        };
        add_filter('upgrader_source_selection', $rename_filter, 10, 4);

        // Load WP's upgrader machinery.
        require_once ABSPATH . 'wp-admin/includes/plugin.php';
        require_once ABSPATH . 'wp-admin/includes/file.php';
        require_once ABSPATH . 'wp-admin/includes/misc.php';
        require_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
        if (!class_exists('Automatic_Upgrader_Skin')) {
            require_once ABSPATH . 'wp-admin/includes/class-automatic-upgrader-skin.php';
        }

        // Need a writable FS first.
        $creds = request_filesystem_credentials('', '', false, false, null);
        if (!$creds || !WP_Filesystem($creds)) {
            remove_filter('http_request_args', $auth_filter, 10);
            remove_filter('upgrader_source_selection', $rename_filter, 10);
            return new WP_Error('fs', 'Could not initialise WP_Filesystem.');
        }

        $skin     = new Automatic_Upgrader_Skin();
        $upgrader = new Plugin_Upgrader($skin);
        $result   = $upgrader->install($url);

        remove_filter('http_request_args', $auth_filter, 10);
        remove_filter('upgrader_source_selection', $rename_filter, 10);

        if (is_wp_error($result)) return $result;
        if ($result === false) {
            $msgs = method_exists($skin, 'get_upgrade_messages') ? implode(' · ', $skin->get_upgrade_messages()) : 'unknown';
            return new WP_Error('install_failed', 'Install returned false. Upgrader messages: ' . $msgs);
        }

        // Find the freshly-installed plugin and activate it.
        if (method_exists('WPH_Recovery_Bootstrap', 'plugin_file')) {
            // Bust the static cache so we re-scan get_plugins().
            $rc = new ReflectionClass('WPH_Recovery_Bootstrap');
            // No public reset; just call get_plugins() in our context — Bootstrap will re-scan
            // because get_plugins() builds a fresh array on each call.
            wp_cache_delete('plugins', 'plugins');
        }
        if (function_exists('wp_clean_plugins_cache')) wp_clean_plugins_cache();
        if (!function_exists('get_plugins')) require_once ABSPATH . 'wp-admin/includes/plugin.php';

        $plugin_file = null;
        foreach (get_plugins() as $file => $meta) {
            if (($meta['Name'] ?? '') === 'Site Recovery') { $plugin_file = $file; break; }
        }
        if (!$plugin_file) {
            return new WP_Error('post_install', 'Install completed but cannot locate the Site Recovery plugin file.');
        }
        $activate = activate_plugin($plugin_file);
        if (is_wp_error($activate)) return $activate;

        return ['plugin_file' => $plugin_file, 'ref' => $ref_info];
    }
}