<?php

/**
 * Copyright (C) 2026 Moko Consulting <hello@mokoconsulting.tech>
 *
 * This file is part of a Moko Consulting project.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * FILE INFORMATION
 * DEFGROUP: MokoStandards.Enterprise
 * INGROUP: MokoStandards
 * REPO: https://git.mokoconsulting.tech/MokoConsulting/moko-platform
 * PATH: /lib/Enterprise/MokoStandardsParser.php
 * BRIEF: Parser for the XML-based .mokostandards repository manifest
 */

declare(strict_types=1);

namespace MokoEnterprise;

use DOMDocument;
use SimpleXMLElement;

/**
 * MokoStandards Parser
 *
 * Reads, writes, and validates the .mokostandards repository manifest.
 * The file uses XML format (no file extension) and lives at .mokogitea/.mokostandards.
 *
 * @package MokoStandards\Enterprise
 * @version 04.07.00
 */
class MokoStandardsParser
{
    public const SCHEMA_VERSION = '1.0';
    public const NAMESPACE_URI = 'https://git.mokoconsulting.tech/MokoConsulting/MokoStandards-API';
    public const STANDARDS_SOURCE = 'https://git.mokoconsulting.tech/MokoConsulting/MokoStandards';

    /** Valid platform slugs — must match definitions/default/*.tf filenames. */
    public const VALID_PLATFORMS = [
        'default-repository',
        'crm-module',
        'crm-platform',
        'generic-repository',
        'github-private-repository',
        'joomla-template',
        'standards-repository',
        'waas-component',
    ];

    /**
     * Parse a .mokostandards XML string into a structured array.
     *
     * @param string $xmlContent Raw XML content of .mokostandards
     * @return array{
     *   identity: array{name: string, org: string, description?: string, license?: string, license_spdx?: string, topics?: list<string>},
     *   governance: array{platform: string, standards_version: string, standards_source: string, last_synced?: string},
     *   build?: array,
     *   deploy?: array,
     *   scripts?: array,
     *   overrides?: array
     * }
     * @throws \RuntimeException If XML is invalid or missing required elements
     */
    public function parse(string $xmlContent): array
    {
        libxml_use_internal_errors(true);
        $xml = simplexml_load_string($xmlContent);

        if ($xml === false) {
            $errors = libxml_get_errors();
            libxml_clear_errors();
            $msg = !empty($errors) ? $errors[0]->message : 'Unknown XML parse error';
            throw new \RuntimeException("Invalid .mokostandards XML: " . trim($msg));
        }

        // Register namespace for XPath
        $xml->registerXPathNamespace('m', self::NAMESPACE_URI);

        $result = [
            'schema_version' => (string) ($xml['schema-version'] ?? self::SCHEMA_VERSION),
            'identity' => $this->parseIdentity($xml),
            'governance' => $this->parseGovernance($xml),
        ];

        if (isset($xml->build)) {
            $result['build'] = $this->parseBuild($xml->build);
        }
        if (isset($xml->deploy)) {
            $result['deploy'] = $this->parseDeploy($xml->deploy);
        }
        if (isset($xml->scripts)) {
            $result['scripts'] = $this->parseScripts($xml->scripts);
        }
        if (isset($xml->overrides)) {
            $result['overrides'] = $this->parseOverrides($xml->overrides);
        }

        return $result;
    }

    /**
     * Try to parse content, returning null on failure instead of throwing.
     *
     * @param string $content Raw file content (XML or legacy YAML-like)
     * @return array|null Parsed data or null if unparseable
     */
    public function tryParse(string $content): ?array
    {
        // Try XML first
        if (str_contains($content, '<mokostandards')) {
            try {
                return $this->parse($content);
            } catch (\RuntimeException $e) {
                return null;
            }
        }

        // Try legacy YAML-like format (e.g. "platform: default-repository")
        return $this->parseLegacy($content);
    }

    /**
     * Parse the legacy single-line YAML-like format.
     *
     * @param string $content e.g. "platform: default-repository\n"
     * @return array|null Minimal parsed structure or null
     */
    public function parseLegacy(string $content): ?array
    {
        $platform = null;
        $fields = [];

        foreach (explode("\n", $content) as $line) {
            $line = trim($line);
            if ($line === '' || str_starts_with($line, '#')) {
                continue;
            }
            if (preg_match('/^(\w[\w_-]*)\s*:\s*"?([^"]*)"?\s*$/', $line, $m)) {
                $fields[$m[1]] = $m[2];
            }
        }

        $platform = $fields['platform'] ?? null;
        if ($platform === null) {
            return null;
        }

        return [
            'schema_version' => '0.0',  // legacy marker
            'identity' => [
                'name' => $fields['governed_repo'] ?? '',
                'org' => '',
            ],
            'governance' => [
                'platform' => $platform,
                'standards_version' => $fields['standards_version'] ?? '',
                'standards_source' => $fields['standards_source'] ?? '',
            ],
        ];
    }

    /**
     * Extract just the platform slug from any .mokostandards content (XML or legacy).
     *
     * @param string $content Raw file content
     * @return string|null Platform slug or null if unreadable
     */
    public function extractPlatform(string $content): ?string
    {
        $data = $this->tryParse($content);
        return $data['governance']['platform'] ?? null;
    }

    /**
     * Generate XML .mokostandards content for a repository.
     *
     * @param array $params {
     *   @type string $name            Repository name (required)
     *   @type string $org             Organization (required)
     *   @type string $platform        Platform slug (required)
     *   @type string $standards_version MokoStandards version
     *   @type string $description     Repo description
     *   @type string $license         SPDX license identifier
     *   @type list<string> $topics    Repo topics
     *   @type string $language        Primary language
     *   @type string $runtime         Runtime requirement
     *   @type string $package_type    Package format
     *   @type string $entry_point     Main entry file
     *   @type string $last_synced     ISO 8601 timestamp
     * }
     * @return string Well-formed XML content
     */
    public function generate(array $params): string
    {
        $name     = $params['name'] ?? '';
        $org      = $params['org'] ?? '';
        $platform = $params['platform'] ?? 'default-repository';
        $version  = $params['standards_version'] ?? '';

        $dom = new DOMDocument('1.0', 'UTF-8');
        $dom->formatOutput = true;

        // Add comment header
        $dom->appendChild($dom->createComment(
            "\n  MokoStandards Repository Manifest\n"
            . "  Auto-generated by MokoStandards bulk sync.\n"
            . "  Manual edits to <governance> and <last-synced> may be overwritten.\n"
            . "  See: docs/standards/mokostandards-file-spec.md\n"
        ));

        // Root element
        $root = $dom->createElementNS(self::NAMESPACE_URI, 'mokostandards');
        $root->setAttribute('schema-version', self::SCHEMA_VERSION);
        $dom->appendChild($root);

        // <identity>
        $identity = $dom->createElement('identity');
        $identity->appendChild($dom->createElement('name', $this->xmlEscape($name)));
        $identity->appendChild($dom->createElement('org', $this->xmlEscape($org)));

        if (!empty($params['description'])) {
            $identity->appendChild($dom->createElement('description', $this->xmlEscape($params['description'])));
        }

        if (!empty($params['license'])) {
            $license = $dom->createElement('license', $this->xmlEscape($this->licenseLabel($params['license'])));
            $license->setAttribute('spdx', $params['license']);
            $identity->appendChild($license);
        }

        if (!empty($params['topics'])) {
            $topics = $dom->createElement('topics');
            foreach ($params['topics'] as $topic) {
                $topics->appendChild($dom->createElement('topic', $this->xmlEscape($topic)));
            }
            $identity->appendChild($topics);
        }

        $root->appendChild($identity);

        // <governance>
        $governance = $dom->createElement('governance');
        $governance->appendChild($dom->createElement('platform', $this->xmlEscape($platform)));
        $governance->appendChild($dom->createElement('standards-version', $this->xmlEscape($version)));
        $governance->appendChild($dom->createElement('standards-source', self::STANDARDS_SOURCE));

        if (!empty($params['last_synced'])) {
            $governance->appendChild($dom->createElement('last-synced', $params['last_synced']));
        }

        $root->appendChild($governance);

        // <build> (optional)
        if (!empty($params['language']) || !empty($params['runtime']) || !empty($params['package_type']) || !empty($params['entry_point'])) {
            $build = $dom->createElement('build');
            if (!empty($params['language'])) {
                $build->appendChild($dom->createElement('language', $this->xmlEscape($params['language'])));
            }
            if (!empty($params['runtime'])) {
                $build->appendChild($dom->createElement('runtime', $this->xmlEscape($params['runtime'])));
            }
            if (!empty($params['package_type'])) {
                $build->appendChild($dom->createElement('package-type', $this->xmlEscape($params['package_type'])));
            }
            if (!empty($params['entry_point'])) {
                $build->appendChild($dom->createElement('entry-point', $this->xmlEscape($params['entry_point'])));
            }
            $root->appendChild($build);
        }

        return $dom->saveXML();
    }

    /**
     * Validate XML content against the XSD schema.
     *
     * @param string $xmlContent Raw XML content
     * @param string|null $xsdPath Path to the XSD file (auto-detected if null)
     * @return array{valid: bool, errors: list<string>}
     */
    public function validate(string $xmlContent, ?string $xsdPath = null): array
    {
        if ($xsdPath === null) {
            $xsdPath = dirname(dirname(__DIR__)) . '/templates/schemas/mokostandards-schema.xsd';
        }

        if (!file_exists($xsdPath)) {
            return ['valid' => false, 'errors' => ["XSD schema not found: {$xsdPath}"]];
        }

        libxml_use_internal_errors(true);
        $dom = new DOMDocument();
        $dom->loadXML($xmlContent);

        $valid = $dom->schemaValidate($xsdPath);
        $errors = [];

        if (!$valid) {
            foreach (libxml_get_errors() as $error) {
                $errors[] = "Line {$error->line}: " . trim($error->message);
            }
        }

        libxml_clear_errors();

        return ['valid' => $valid, 'errors' => $errors];
    }

    // ──────────────────────────────────────────────────────────────
    // Private parsing helpers
    // ──────────────────────────────────────────────────────────────

    private function parseIdentity(SimpleXMLElement $xml): array
    {
        $id = $xml->identity ?? null;
        if ($id === null) {
            throw new \RuntimeException('.mokostandards: missing required <identity> element');
        }

        $result = [
            'name' => (string) ($id->name ?? ''),
            'org'  => (string) ($id->org ?? ''),
        ];

        if ($result['name'] === '') {
            throw new \RuntimeException('.mokostandards: <identity><name> is required');
        }

        if (isset($id->description)) {
            $result['description'] = (string) $id->description;
        }
        if (isset($id->license)) {
            $result['license'] = (string) $id->license;
            $spdx = (string) ($id->license['spdx'] ?? '');
            if ($spdx !== '') {
                $result['license_spdx'] = $spdx;
            }
        }
        if (isset($id->topics)) {
            $result['topics'] = [];
            foreach ($id->topics->topic as $topic) {
                $result['topics'][] = (string) $topic;
            }
        }

        return $result;
    }

    private function parseGovernance(SimpleXMLElement $xml): array
    {
        $gov = $xml->governance ?? null;
        if ($gov === null) {
            throw new \RuntimeException('.mokostandards: missing required <governance> element');
        }

        $result = [
            'platform'          => (string) ($gov->platform ?? ''),
            'standards_version' => (string) ($gov->{'standards-version'} ?? ''),
            'standards_source'  => (string) ($gov->{'standards-source'} ?? ''),
        ];

        if ($result['platform'] === '') {
            throw new \RuntimeException('.mokostandards: <governance><platform> is required');
        }

        if (isset($gov->{'last-synced'})) {
            $result['last_synced'] = (string) $gov->{'last-synced'};
        }

        return $result;
    }

    private function parseBuild(SimpleXMLElement $build): array
    {
        $result = [];

        foreach (['language', 'runtime', 'entry-point'] as $field) {
            if (isset($build->$field)) {
                $key = str_replace('-', '_', $field);
                $result[$key] = (string) $build->$field;
            }
        }
        if (isset($build->{'package-type'})) {
            $result['package_type'] = (string) $build->{'package-type'};
        }

        if (isset($build->artifact)) {
            $result['artifact'] = [];
            foreach (['format', 'path', 'filename'] as $f) {
                if (isset($build->artifact->$f)) {
                    $result['artifact'][$f] = (string) $build->artifact->$f;
                }
            }
        }

        if (isset($build->dependencies)) {
            $result['dependencies'] = [];
            foreach ($build->dependencies->requires as $req) {
                $dep = ['name' => (string) ($req['name'] ?? '')];
                if (isset($req['version'])) {
                    $dep['version'] = (string) $req['version'];
                }
                if (isset($req['type'])) {
                    $dep['type'] = (string) $req['type'];
                }
                $result['dependencies'][] = $dep;
            }
        }

        return $result;
    }

    private function parseDeploy(SimpleXMLElement $deploy): array
    {
        $targets = [];
        foreach ($deploy->target as $target) {
            $t = [
                'name'    => (string) ($target['name'] ?? ''),
                'enabled' => ((string) ($target['enabled'] ?? 'true')) !== 'false',
                'host'    => (string) ($target->host ?? ''),
                'path'    => (string) ($target->path ?? ''),
            ];
            if (isset($target->method)) {
                $t['method'] = (string) $target->method;
            }
            if (isset($target->branch)) {
                $t['branch'] = (string) $target->branch;
            }
            if (isset($target->{'src-dir'})) {
                $t['src_dir'] = (string) $target->{'src-dir'};
            }
            $targets[] = $t;
        }
        return ['targets' => $targets];
    }

    private function parseScripts(SimpleXMLElement $scripts): array
    {
        $result = [];
        foreach ($scripts->script as $script) {
            $s = [
                'name'    => (string) ($script['name'] ?? ''),
                'command' => (string) ($script->command ?? ''),
            ];
            if (isset($script['phase'])) {
                $s['phase'] = (string) $script['phase'];
            }
            if (isset($script->description)) {
                $s['description'] = (string) $script->description;
            }
            if (isset($script->runner)) {
                $s['runner'] = (string) $script->runner;
            }
            $result[] = $s;
        }
        return ['scripts' => $result];
    }

    private function parseOverrides(SimpleXMLElement $overrides): array
    {
        $result = [];

        if (isset($overrides->{'skip-files'})) {
            $result['skip_files'] = [];
            foreach ($overrides->{'skip-files'}->file as $file) {
                $result['skip_files'][] = (string) $file;
            }
        }

        if (isset($overrides->{'skip-workflows'})) {
            $result['skip_workflows'] = [];
            foreach ($overrides->{'skip-workflows'}->file as $file) {
                $result['skip_workflows'][] = (string) $file;
            }
        }

        if (isset($overrides->{'extra-secrets'})) {
            $result['extra_secrets'] = [];
            foreach ($overrides->{'extra-secrets'}->secret as $secret) {
                $s = ['name' => (string) ($secret['name'] ?? '')];
                if (isset($secret['required'])) {
                    $s['required'] = ((string) $secret['required']) !== 'false';
                }
                if (isset($secret['scope'])) {
                    $s['scope'] = (string) $secret['scope'];
                }
                $result['extra_secrets'][] = $s;
            }
        }

        return $result;
    }

    /**
     * Escape a string for XML element content.
     */
    private function xmlEscape(string $value): string
    {
        return htmlspecialchars($value, ENT_XML1 | ENT_QUOTES, 'UTF-8');
    }

    /**
     * Map SPDX identifier to a human-readable license label.
     */
    private function licenseLabel(string $spdx): string
    {
        return match ($spdx) {
            'GPL-3.0-or-later'  => 'GNU General Public License v3',
            'GPL-2.0-or-later'  => 'GNU General Public License v2',
            'MIT'               => 'MIT License',
            'Apache-2.0'        => 'Apache License 2.0',
            'BSD-3-Clause'      => 'BSD 3-Clause License',
            'LGPL-3.0-or-later' => 'GNU Lesser General Public License v3',
            default             => $spdx,
        };
    }

    /**
     * Map a platform slug to its default package type.
     */
    public static function platformPackageType(string $platform): string
    {
        return match ($platform) {
            'crm-module', 'crm-platform'  => 'dolibarr-module',
            'waas-component'              => 'joomla-extension',
            'joomla-template'             => 'joomla-extension',
            'standards-repository'        => 'composer',
            default                       => 'composer',
        };
    }

    /**
     * Map a platform slug to its default primary language.
     */
    public static function platformLanguage(string $platform): string
    {
        return match ($platform) {
            'crm-module', 'crm-platform'        => 'PHP',
            'waas-component', 'joomla-template'  => 'PHP',
            'standards-repository'               => 'PHP',
            default                              => 'PHP',
        };
    }
}