<?php
// +----------------------------------------------------------------------
// | YwxApp [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2026-2036 http://ywxapp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Author: ywxapp<admin@ywxapp.cn>
// +----------------------------------------------------------------------
declare (strict_types = 1);

namespace addon\docs\controller;

use addon\docs\model\DocsDoc;
use addon\docs\model\DocsProject;
use addon\docs\model\DocsVersion;
use addon\docs\service\DocTreeService;

/**
 * 文档阅读页（三栏布局）
 *
 * @author ywxapp <admin@ywxapp.cn>
 */
class Read extends DocsFrontend
{
    /**
     * 项目入口：跳转到该项目第一篇文档
     *
     * @param string $project 项目标识
     */
    public function entry($project = '')
    {
        $projectModel = DocsProject::findByName((string) $project);
        if (!$projectModel) {
            return $this->notFound('文档项目不存在或已下线');
        }

        $version = DocsVersion::resolve((int) $projectModel->id, (string) $projectModel->default_version);
        if (!$version) {
            return $this->notFound('该项目尚未创建版本');
        }

        $first = DocTreeService::firstDoc((int) $projectModel->id, (int) $version->id);
        if (!$first) {
            return $this->notFound('该项目暂无可阅读的文档');
        }

        return redirect('/docs/' . $projectModel->name . '/' . $first['name']);
    }

    /**
     * 文档正文
     *
     * @param string $project 项目标识
     * @param string $name    文档标识
     * @param string $version 版本标识，可为空
     */
    public function index($project = '', $name = '', $version = '')
    {
        $projectModel = DocsProject::findByName((string) $project);
        if (!$projectModel) {
            return $this->notFound('文档项目不存在或已下线');
        }

        $versionModel = DocsVersion::resolve(
            (int) $projectModel->id,
            (string) ($version !== '' ? $version : $projectModel->default_version)
        );
        if (!$versionModel) {
            return $this->notFound('该项目尚未创建版本');
        }

        $projectId = (int) $projectModel->id;
        $versionId = (int) $versionModel->id;

        $doc = DocsDoc::findByName($projectId, $versionId, (string) $name);
        if (!$doc) {
            return $this->notFound('文档不存在或已下线');
        }

        // 纯目录节点没有正文，跳到它下面第一篇可读文档
        if ((int) $doc->is_dir === 1) {
            $child = DocsDoc::where('project_id', $projectId)
                ->where('version_id', $versionId)
                ->where('pid', $doc->id)
                ->where('status', 1)
                ->where('is_dir', 0)
                ->order('sort', 'asc')->order('id', 'asc')
                ->find();
            if ($child) {
                return redirect($this->docUrl($projectModel, $versionModel, (string) $child->name));
            }
        }

        DocsDoc::addViews((int) $doc->id);

        $tree     = DocTreeService::buildTree($projectId, $versionId);
        $siblings = DocTreeService::siblings($projectId, $versionId, (int) $doc->id);
        $crumbs   = DocTreeService::breadcrumb($projectId, $versionId, (int) $doc->id);

        // 给正文标题补 id 锚点，供右侧目录跳转
        [$content, $toc] = $this->buildToc((string) $doc->content);

        // 默认版本用短地址，非默认版本地址里带版本段
        $baseUrl = '/docs/' . $projectModel->name;
        if ((int) $versionModel->is_default !== 1) {
            $baseUrl .= '/' . $versionModel->name;
        }

        $treeHtml = $this->renderTree(
            $tree,
            $baseUrl,
            (int) $doc->id,
            array_column($crumbs, 'id')
        );

        $updateAt = $doc->update_at;
        $updateTs = !is_numeric($updateAt) ? strtotime((string) $updateAt) : (int) $updateAt;
        $updateDate = date('Y-m-d', (int) $updateTs);

        $this->assign([
            'baseUrl'     => $baseUrl,
            'project'     => $projectModel,
            'version'     => $versionModel,
            'versionList' => DocsVersion::listByProject($projectId),
            'doc'         => $doc,
            'content'     => $content,
            'toc'         => $toc,
            'treeHtml'    => $treeHtml,
            'updateDate'  => $updateDate,
            'crumbs'      => $crumbs,
            'prev'        => $siblings['prev'],
            'next'        => $siblings['next'],
            'activeId'    => (int) $doc->id,
            'openIds'     => array_column($crumbs, 'id'),
            'pageTitle'   => ($doc->seo_title !== '' ? $doc->seo_title : $doc->title) . ' - ' . $projectModel->title,
            'seoKeywords' => $doc->seo_keywords,
            'seoDesc'     => $doc->seo_desc !== '' ? $doc->seo_desc : mb_substr(strip_tags((string) $doc->content), 0, 150, 'UTF-8'),
        ]);

        return $this->fetch('read/index');
    }

    /**
     * 递归渲染侧边文档树为 HTML（避免模板 {php} 块内定义函数导致的编译错误）
     *
     * @param array  $nodes    树节点
     * @param string $baseUrl  文档基础 URL
     * @param int    $activeId 当前文档 ID
     * @param array  $openIds  需要展开的祖先节点 ID
     * @return string
     */
    protected function renderTree(array $nodes, string $baseUrl, int $activeId, array $openIds): string
    {
        if (empty($nodes)) {
            return '';
        }

        $html = '<ul class="dc-tree">';
        foreach ($nodes as $node) {
            $id       = (int) $node['id'];
            $isDir    = (int) ($node['is_dir'] ?? 0) === 1;
            $hasChild = !empty($node['children']);
            $isActive = $id === $activeId;
            $isOpen   = $isActive || in_array($id, $openIds, true);
            $title    = htmlspecialchars((string) $node['title'], ENT_QUOTES, 'UTF-8');
            $url      = $baseUrl . '/' . rawurlencode((string) $node['name']);

            $liClass = [];
            if ($hasChild) {
                $liClass[] = 'has-child';
            }
            if ($isOpen) {
                $liClass[] = 'is-open';
            }

            $html .= '<li class="' . implode(' ', $liClass) . '">';
            $html .= '<div class="dc-tree-item' . ($isActive ? ' is-active' : '') . '">';

            if ($hasChild) {
                $html .= '<span class="dc-tree-toggle" aria-label="展开"></span>';
            }

            if ($isDir && $hasChild) {
                $html .= '<span class="dc-tree-link is-dir">' . $title . '</span>';
            } else {
                $html .= '<a class="dc-tree-link" href="' . htmlspecialchars($url, ENT_QUOTES) . '">' . $title . '</a>';
            }

            $html .= '</div>';

            if ($hasChild) {
                $html .= $this->renderTree($node['children'], $baseUrl, $activeId, $openIds);
            }

            $html .= '</li>';
        }
        $html .= '</ul>';

        return $html;
    }

    /**
     * 为正文中的 h2 / h3 标题补充锚点并抽取目录
     *
     * @param string $html 正文 HTML
     * @return array{0: string, 1: array}
     */
    protected function buildToc(string $html): array
    {
        if ($html === '') {
            return ['', []];
        }

        $toc   = [];
        $index = 0;

        $result = preg_replace_callback(
            '#<h([23])([^>]*)>(.*?)</h\1>#is',
            function ($m) use (&$toc, &$index) {
                $level   = (int) $m[1];
                $attrs   = $m[2];
                $inner   = $m[3];
                $text    = trim(strip_tags($inner));

                if ($text === '') {
                    return $m[0];
                }

                $index++;
                $anchor = 'doc-h-' . $index;

                // 已有 id 时沿用，避免破坏作者自定义锚点
                if (preg_match('/\sid\s*=\s*["\']([^"\']+)["\']/i', $attrs, $idMatch)) {
                    $anchor = $idMatch[1];
                } else {
                    $attrs .= ' id="' . $anchor . '"';
                }

                $toc[] = [
                    'level'  => $level,
                    'text'   => $text,
                    'anchor' => $anchor,
                ];

                return '<h' . $level . $attrs . '>' . $inner . '</h' . $level . '>';
            },
            $html
        );

        return [$result ?? $html, $toc];
    }

    /**
     * 生成文档访问地址
     *
     * @param DocsProject $project 项目
     * @param DocsVersion $version 版本
     * @param string      $name    文档标识
     * @return string
     */
    protected function docUrl(DocsProject $project, DocsVersion $version, string $name): string
    {
        // 默认版本走短地址，非默认版本带上版本段
        if ((int) $version->is_default === 1) {
            return '/docs/' . $project->name . '/' . $name;
        }
        return '/docs/' . $project->name . '/' . $version->name . '/' . $name;
    }

    /**
     * 渲染 404 提示页
     *
     * @param string $message 提示语
     */
    protected function notFound(string $message)
    {
        $this->assign('message', $message);
        return $this->fetch('read/notfound');
    }
}