<?php

namespace app\api\controller;

class Latex extends Base
{
    public function __construct(\think\Request $request = null)
    {
        parent::__construct($request);
    }

    public function generateLatexPdf()
    {
        $data = $this->request->post();
        $rule = new Validate([
            'p_article_id' => 'require|number'
        ]);

        if (!$rule->check($data)) {
            return jsonError($rule->getError());
        }

        try {
            // 获取文章信息
            $p_info = $this->production_article_obj->where('p_article_id', $data['p_article_id'])->find();
            if (!$p_info) {
                return jsonError('文章实例不存在');
            }

            // 获取作者信息
            $authors = $this->production_article_author_obj->where('p_article_id', $data['p_article_id'])->where('state', 0)->select();

            // 获取机构信息
            $organs = $this->production_article_organ_obj->where('p_article_id', $data['p_article_id'])->where('state', 0)->select();

            // 获取正文内容
            $main_contents = $this->production_article_main_obj->where('p_article_id', $data['p_article_id'])->where('state', 0)->order('p_main_id')->select();

            // 获取参考文献
            $references = $this->production_article_refer_obj->where('p_article_id', $data['p_article_id'])->where('state', 0)->order('index')->select();

            // 构建LaTeX内容
            $latex_content = $this->buildLatexContent($p_info, $authors, $organs, $main_contents, $references);

            // 创建临时目录
            $temp_dir = ROOT_PATH . 'public' . DS . 'temp_latex' . DS;
            if (!is_dir($temp_dir)) {
                mkdir($temp_dir, 0755, true);
            }

            // 生成唯一的文件名
            $filename = 'article_' . $p_info['p_article_id'] . '_' . time();
            $tex_file = $temp_dir . $filename . '.tex';
            $pdf_file = $temp_dir . $filename . '.pdf';

            // 写入LaTeX文件
            file_put_contents($tex_file, $latex_content);

            // 执行LaTeX编译命令生成PDF
            $command = sprintf(
                'cd %s && pdflatex -interaction=nonstopmode -output-directory=%s %s',
                escapeshellarg($temp_dir),
                escapeshellarg($temp_dir),
                escapeshellarg($tex_file)
            );

            // 执行命令
            $output = [];
            $return_var = 0;
            exec($command, $output, $return_var);

            // 检查PDF是否生成成功
            if (!file_exists($pdf_file) || filesize($pdf_file) == 0) {
                return jsonError('PDF生成失败，请检查LaTeX内容或系统环境');
            }

            // 移动PDF到正式目录
            $pdf_dir = ROOT_PATH . 'public' . DS . 'latex_pdfs' . DS;
            if (!is_dir($pdf_dir)) {
                mkdir($pdf_dir, 0755, true);
            }

            $final_pdf_path = $pdf_dir . $filename . '.pdf';
            rename($pdf_file, $final_pdf_path);

            // 清理临时文件
            if (file_exists($tex_file)) {
                unlink($tex_file);
            }

            // 清理辅助文件(.aux, .log等)
            $aux_file = $temp_dir . $filename . '.aux';
            $log_file = $temp_dir . $filename . '.log';
            if (file_exists($aux_file)) unlink($aux_file);
            if (file_exists($log_file)) unlink($log_file);

            // 返回PDF路径
            $relative_path = 'latex_pdfs/' . $filename . '.pdf';
            return jsonSuccess([
                'pdf_url' => $relative_path,
                'message' => 'PDF生成成功'
            ]);

        } catch (\Exception $e) {
            return jsonError('生成过程中发生错误: ' . $e->getMessage());
        }
    }

    /**
     * 构建LaTeX文档内容
     * @param $p_info
     * @param $authors
     * @param $organs
     * @param $main_contents
     * @param $references
     * @return string
     */
    private function buildLatexContent($p_info, $authors, $organs, $main_contents, $references)
    {
        // 构建机构映射
        $organ_map = [];
        foreach ($organs as $index => $organ) {
            $organ_map[$organ['p_article_organ_id']] = $index + 1;
        }

        // LaTeX文档开始
        $latex = '\documentclass[twocolumn]{article}' . "\n";
        $latex .= '\usepackage[utf8]{inputenc}' . "\n";
        $latex .= '\usepackage[T1]{fontenc}' . "\n";
        $latex .= '\usepackage{geometry}' . "\n";
        $latex .= '\usepackage{graphicx}' . "\n";
        $latex .= '\usepackage{amsmath}' . "\n";
        $latex .= '\usepackage{amsfonts}' . "\n";
        $latex .= '\usepackage{amssymb}' . "\n";
        $latex .= '\usepackage{setspace}' . "\n";
        $latex .= '\usepackage{titlesec}' . "\n";
        $latex .= '\usepackage{hyperref}' . "\n";
        $latex .= '\usepackage{caption}' . "\n";
        $latex .= '\usepackage{multicol}' . "\n";
        $latex .= '\usepackage{abstract}' . "\n";

        $latex .= '\geometry{left=1.5cm,right=1.5cm,top=2.5cm,bottom=2.5cm}' . "\n";
        $latex .= '\setstretch{1.5}' . "\n";

        $latex .= '\title{' . $this->escapeLatexText($p_info['title']) . '}' . "\n";

        // 处理作者和机构
        if (!empty($authors)) {
            $author_text = '';
            $affiliations = [];

            foreach ($authors as $author) {
                if ($author_text !== '') {
                    $author_text .= ', ';
                }
                $author_text .= $this->escapeLatexText($author['first_name'] . ' ' . $author['last_name']);

                // 获取作者的机构
                $author_organs = $this->production_article_author_to_organ_obj
                    ->where('p_article_author_id', $author['p_article_author_id'])
                    ->where('state', 0)
                    ->select();

                foreach ($author_organs as $ao) {
                    if (isset($organ_map[$ao['p_article_organ_id']])) {
                        $author_text .= '$^{' . $organ_map[$ao['p_article_organ_id']] . '}$';
                    }
                }

                if ($author['is_report'] == 1) {
                    $author_text .= '$^{*}$';
                }
            }

            $latex .= '\author{' . $author_text . "\n";

            // 添加机构信息
            foreach ($organs as $index => $organ) {
                $latex .= '\\\\$' . ($index + 1) . '$ ' . $this->escapeLatexText($organ['organ_name']) . "\n";
            }
            if (!empty($authors)) {
                // 查找通讯作者
                $corresponding_authors = array_filter($authors, function($author) {
                    return $author['is_report'] == 1;
                });

                if (!empty($corresponding_authors)) {
                    $corr_author = reset($corresponding_authors);
                    $latex .= '\\\\$*$ Corresponding author: ' .
                        $this->escapeLatexText($corr_author['email']) . "\n";
                }
            }

            $latex .= '}' . "\n";
        }

        $latex .= '\date{}' . "\n";
        $latex .= '\begin{document}' . "\n";
        $latex .= '\maketitle' . "\n";

        // 摘要
        if (!empty($p_info['abstract'])) {
            $latex .= '\begin{abstract}' . "\n";
            $latex .= $this->escapeLatexText($p_info['abstract']) . "\n";
            $latex .= '\end{abstract}' . "\n";
        }

        // 关键词
        if (!empty($p_info['keywords'])) {
            $latex .= '\textbf{Keywords:} ' . $this->escapeLatexText($p_info['keywords']) . "\n";
            $latex .= '\sectionbreak' . "\n";
        }

        // 正文内容
        $in_section = false;
        $section_count = 0;

        foreach ($main_contents as $content) {
            $text = trim($content['content']);

            // 跳过空内容
            if (empty($text)) {
                continue;
            }

            // 检查是否是标题
            $clean_text = strip_tags($text);
            $lower_text = strtolower($clean_text);

            // 判断是否为章节标题
            if (stripos($lower_text, 'introduction') === 0 ||
                stripos($lower_text, 'methods') === 0 ||
                stripos($lower_text, 'results') === 0 ||
                stripos($lower_text, 'discussion') === 0 ||
                stripos($lower_text, 'conclusion') === 0 ||
                stripos($lower_text, 'references') === 0) {

                // 结束前一节
                if ($in_section) {
                    $latex .= "\n" . '\sectionbreak' . "\n";
                }

                // 开始新节
                $section_count++;
                $section_title = $this->escapeLatexText($clean_text);
                $latex .= '\section{' . $section_title . '}' . "\n";
                $in_section = true;
            }
            // 检查是否是图片或表格占位符
            else if (preg_match('/<img[^>]*imageId=[\'"]([^\'"]+)[\'"][^>]*>/i', $text, $img_matches)) {
                $image_id = $img_matches[1];
                // 这里可以添加图片处理逻辑
                $latex .= '% 图片插入位置 (ID: ' . $image_id . ')' . "\n";
                $latex .= '\begin{figure}[htbp]' . "\n";
                $latex .= '\centering' . "\n";
                $latex .= '\includegraphics[width=0.8\textwidth]{image_' . $image_id . '}' . "\n";
                $latex .= '\caption{图片说明}' . "\n";
                $latex .= '\end{figure}' . "\n";
            }
            else if (preg_match('/<table[^>]*tableId=[\'"]([^\'"]+)[\'"][^>]*>/i', $text, $table_matches)) {
                $table_id = $table_matches[1];
                // 这里可以添加表格处理逻辑
                $latex .= '% 表格插入位置 (ID: ' . $table_id . ')' . "\n";
                $latex .= '\begin{table}[htbp]' . "\n";
                $latex .= '\centering' . "\n";
                $latex .= '\caption{表格说明}' . "\n";
                $latex .= '\begin{tabular}{|c|c|c|}' . "\n";
                $latex .= '\hline' . "\n";
                $latex .= '列1 & 列2 & 列3 \\\\' . "\n";
                $latex .= '\hline' . "\n";
                $latex .= '% 表格数据' . "\n";
                $latex .= '\hline' . "\n";
                $latex .= '\end{tabular}' . "\n";
                $latex .= '\end{table}' . "\n";
            }


            // 普通段落文本
            else {
                // 移除HTML标签并转义特殊字符
                $plain_text = $this->escapeLatexText(strip_tags($text));
                $latex .= $plain_text . "\n\n";
            }
        }

        // 参考文献
        if (!empty($references)) {
            $latex .= '\section*{References}' . "\n";
            $latex .= '\begin{thebibliography}{99}' . "\n";

            foreach ($references as $index => $ref) {
                $ref_text = isset($ref['refer_frag']) ? $ref['refer_frag'] : $ref['refer_content'];
                $latex .= '\bibitem{} ' . $this->escapeLatexText($ref_text) . "\n";
            }

            $latex .= '\end{thebibliography}' . "\n";
        }

        $latex .= '\end{document}' . "\n";

        return $latex;
    }

    /**
     * 转义LaTeX特殊字符
     * @param string $text
     * @return string
     */
    private function escapeLatexText($text)
    {
        // 移除HTML标签
        $text = strip_tags($text);

        // 转义LaTeX特殊字符
        $escape_chars = [
            '\\' => '\\textbackslash{}',
            '&' => '\\&',
            '%' => '\\%',
            '$' => '\\$',
            '#' => '\\#',
            '_' => '\\_',
            '{' => '\\{',
            '}' => '\\}',
            '~' => '\\textasciitilde{}',
            '^' => '\\textasciicircum{}',
            '"' => '\\"{}',
            '\'' => '\\\'{}',
            '<' => '\\textless{}',
            '>' => '\\textgreater{}',
        ];

        foreach ($escape_chars as $char => $replacement) {
            $text = str_replace($char, $replacement, $text);
        }

        return $text;
    }


}