<?php

namespace Service;

use Lib\Err;
use PHPMailer\PHPMailer\PHPMailer;

/**
 * 邮件导出为 eml 文件
 *
 * 逻辑来源 cmd/export_mail.php，这里抽成服务类，支持传入
 * postid（公司项目）、导出范围、数量上限，供页面调用。
 *
 * @author：dc
 * @time 2026/10/28 11:40
 * Class MailExport
 * @package Service
 */
class MailExport {

    /**
     * 星标邮件（所有文件夹）
     */
    public const SCOPE_STARRED = 'starred';

    /**
     * 收件箱全部
     */
    public const SCOPE_INBOX = 'inbox';

    /**
     * 默认导出数量
     */
    public const DEFAULT_LIMIT = 300;

    /**
     * 单次最大导出数量
     */
    public const MAX_LIMIT = 2000;

    /**
     * 清单文件名
     */
    private const MANIFEST_NAME = '导出清单.csv';

    /**
     * @var int 项目id
     */
    private int $postid = 0;

    /**
     * @var string 导出范围
     */
    private string $scope = '';

    /**
     * @var int 数量上限
     */
    private int $limit = 0;

    /**
     * @var string 本次导出目录
     */
    private string $dir = '';

    /**
     * @var array es _id 去重
     */
    private array $ids = [];

    /**
     * @var array 已生成的 eml 文件
     */
    private array $files = [];

    /**
     * @var array 已使用过的文件名，避免同一批里重名
     */
    private array $usedNames = [];

    /**
     * @var array 清单数据
     */
    private array $manifest = [];

    /**
     * @var array 失败记录
     */
    private array $errors = [];

    /**
     * @var int 成功数量
     */
    private int $success = 0;

    /**
     * @var int 失败数量
     */
    private int $fail = 0;

    /**
     * 导出范围
     * @return string[]
     * @author：dc
     * @time 2026/10/28 11:40
     */
    public static function scopeMap():array {
        return [
            self::SCOPE_STARRED => '星标邮件（所有文件夹）',
            self::SCOPE_INBOX   => '收件箱全部',
        ];
    }

    /**
     * 导出文件根目录
     * 说明：不放在 public 下面，只能通过页面鉴权后下载
     * @return string
     * @author：dc
     * @time 2026/10/28 11:40
     */
    public static function baseDir():string {
        return ROOT_PATH.'/storage/export';
    }

    /**
     * 查询命中的邮件数量
     * 返回 -1 表示 es 查询异常，与「0 封」区分开
     * @param int $postid
     * @param string $scope
     * @return int
     * @author：dc
     * @time 2026/10/28 11:40
     */
    public static function count(int $postid,string $scope):int {
        try {
            $count = es('email_lists_branch_'.$postid)->count(['query' => self::query($scope)], true);
            return max(0, intval($count));
        }catch (\Throwable $e){
            logs('邮件导出统计失败 postid:'.$postid.' '.$e->getMessage());
            return -1;
        }
    }

    /**
     * es 查询条件
     * 与 cmd/export_mail.php 保持一致：只取 ai 邮箱（source=2）、未删除
     * @param string $scope
     * @return array
     * @author：dc
     * @time 2026/10/28 11:40
     */
    public static function query(string $scope):array {
        $must = [
            ['term' => ['source' => 2]],
            ['term' => ['deleted' => 0]],
        ];

        if($scope === self::SCOPE_STARRED){
            // 星标：不限文件夹
            $must[] = ['term' => ['flagged' => 1]];
            $must[] = ['terms' => ['folder_as_int' => [1, 2, 3, 4, 5]]];
        }else{
            // 收件箱全部（含星标、含未读已读）
            $must[] = ['term' => ['folder_as_int' => 1]];
        }

        return ['constant_score' => ['filter' => ['bool' => ['must' => $must]]]];
    }

    /**
     * 文件名净化，保留中文
     * @param string $name
     * @return string
     * @author：dc
     * @time 2026/10/28 11:40
     */
    public static function sanitize(string $name):string {
        $name = preg_replace('/[^\p{L}\p{N}_\-\.\(\)]+/u', '_', $name);
        $name = preg_replace('/_+/u', '_', (string)$name);
        return trim((string)$name, '_ .');
    }

    /**
     * 执行导出
     * @param int $postid 项目id
     * @param string $scope 导出范围
     * @param int $limit 数量上限
     * @return array
     * @throws Err
     * @author：dc
     * @time 2026/10/28 11:40
     */
    public function export(int $postid,string $scope,int $limit):array {
        if(!$postid){
            throw new Err('缺少公司项目');
        }
        if(!isset(self::scopeMap()[$scope])){
            throw new Err('导出条件不支持');
        }

        $this->postid = $postid;
        $this->scope = $scope;
        $this->limit = max(1, min($limit ?: self::DEFAULT_LIMIT, self::MAX_LIMIT));

        $startTime = microtime(true);

        // 导出目录，带随机后缀，避免重复
        $this->dir = self::baseDir().'/'.$postid.'_'.date('Ymd_His').'_'.substr(md5(uniqid('', true)), 0, 6);
        if(!is_dir($this->dir) && !@mkdir($this->dir, 0775, true) && !is_dir($this->dir)){
            throw new Err('导出目录创建失败，请检查 storage 目录权限');
        }

        $hits = $this->search();
        if(!$hits){
            $this->removeDir($this->dir);
            // 没有数据时再确认一次，区分「es 挂了」和「真的没有邮件」
            if(self::count($this->postid, $this->scope) < 0){
                throw new Err('es 查询失败，请稍后再试（已记录日志）');
            }
            throw new Err('没有命中任何邮件，换个条件再试');
        }

        foreach($hits as $hit){
            $this->saveOne($hit);
        }

        if(!$this->files){
            $this->removeDir($this->dir);
            $detail = $this->errors ? $this->errors[0]['message'] : '未知原因';
            throw new Err('全部邮件导出失败：'.$detail);
        }

        // 清单
        $this->writeManifest();

        // 打包
        $zipName = $this->postid.'_'.date('Ymd_His').'.zip';
        $zipFile = $this->dir.'/'.$zipName;
        $this->zip($zipFile);

        return [
            'postid'     => $this->postid,
            'scope'      => $this->scope,
            'scope_label'=> self::scopeMap()[$this->scope],
            'limit'      => $this->limit,
            'total'      => count($hits),
            'success'    => $this->success,
            'fail'       => $this->fail,
            'errors'     => array_slice($this->errors, 0, 20),
            'dir'        => str_replace(ROOT_PATH, '', $this->dir),
            'zip_name'   => $zipName,
            'zip_size'   => is_file($zipFile) ? filesize($zipFile) : 0,
            'download'   => '/mail-export/download?f='.rawurlencode(basename($this->dir).'/'.$zipName),
            'cost'       => round(microtime(true) - $startTime, 1),
        ];
    }

    /**
     * 查询 es
     * @return array
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function search():array {
        $res = es('email_lists_branch_'.$this->postid)->search(
            ['query' => self::query($this->scope)],
            0,
            $this->limit,
            ['udate' => 'desc']
        );

        return $res['hits']['hits'] ?? [];
    }

    /**
     * 导出一封
     * @param array $hit
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function saveOne(array $hit):void {
        $esId = (string)($hit['_id'] ?? '');
        if($esId === '' || isset($this->ids[$esId])){
            return;
        }
        $this->ids[$esId] = 1;

        $src = $hit['_source'] ?? [];
        $file = $this->fileName($src);
        $subject = (string)($src['subject'] ?? '');

        try {
            $this->saveEml($src, $file);

            if(!is_file($file) || filesize($file) <= 0){
                throw new \Exception('eml 文件为空');
            }

            $this->files[] = $file;
            $this->success++;
            $this->manifest[] = [
                'subject' => $subject,
                'from'    => $this->addressText($src['from'] ?? []),
                'to'      => $this->toText($src),
                'date'    => empty($src['udate']) ? '' : date('Y-m-d H:i:s', $src['udate']),
                'uuid'    => (string)($src['uuid'] ?? ''),
                'file'    => basename($file),
                'status'  => '成功',
            ];
        }catch (\Throwable $e){
            // 半成品删掉
            if(is_file($file)){
                @unlink($file);
            }
            $this->fail++;
            $this->errors[] = [
                'subject' => $subject,
                'uuid'    => (string)($src['uuid'] ?? ''),
                'message' => $e->getMessage(),
            ];
            logs('邮件导出失败 '.(string)($src['uuid'] ?? '').' : '.$e->getMessage());
        }
    }

    /**
     * 生成 eml（逻辑同 cmd/export_mail.php 的 save_eml）
     * @param array $src es 数据
     * @param string $file
     * @throws \Exception
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function saveEml(array $src,string $file):void {
        $mail = new PHPMailer(true);

        $from = $src['from'] ?? [];
        $fromEmail = is_array($from) ? ($from['email'] ?? '') : (string)$from;
        $fromName = is_array($from) ? ($from['name'] ?? '') : '';
        if(!$fromEmail){
            throw new \Exception('发件人为空');
        }
        $mail->setFrom($fromEmail, $fromName);

        // 收件人
        $toName = @json_decode((string)($src['to_name'] ?? ''), true);
        if(is_array($toName) && $toName){
            foreach($toName as $item){
                if(empty($item['email'])) continue;
                try {
                    $mail->addAddress($item['email'], $item['name'] ?? '');
                }catch (\Throwable $e){}
            }
        }
        if(!$mail->getToAddresses() && !empty($src['to'])){
            foreach(explode(',', (string)$src['to']) as $item){
                $item = trim($item);
                if($item === '') continue;
                try {
                    $mail->addAddress($item);
                }catch (\Throwable $e){}
            }
        }

        $mail->Subject = (string)($src['subject'] ?? '');

        $uuid = (string)($src['uuid'] ?? '');
        // uuid 实际是 lists 表的自增id
        $body = ctype_digit($uuid) ? getMailBody((int)$uuid) : [];
        $html = getBodyHtml($body);

        // 没有 body，尝试同步一次
        if(!$html && ctype_digit($uuid) && !empty($src['email_id']) && !empty($src['uid'])){
            try {
                $folder = db()->value(\Model\folderSql::first($src['folder_id'] ?? 0, 'origin_folder'));
                (new SyncMail($src['email_id']))->mail($folder, [(string)$src['uid']], true);
                $body = getMailBody((int)$uuid);
                $html = getBodyHtml($body);
            }catch (\Throwable $e){
                logs('邮件导出补拉正文失败 '.$uuid.' : '.$e->getMessage());
            }
        }

        // 正文为空也要能生成 eml（否则 PHPMailer 会报 Message body empty）
        $mail->Body = $html ?: '<div></div>';
        $mail->Encoding = 'quoted-printable';
        $mail->CharSet = 'utf-8';
        // 用 MessageDate 保留原始收发时间（不要用 addCustomHeader，会出两个 Date 头）
        if(!empty($src['udate'])){
            $mail->MessageDate = date('D, d M Y H:i:s O', intval($src['udate']));
        }
        if(!empty($src['uuid'])){
            $mail->addCustomHeader('Uuid', (string)$src['uuid']);
        }

        // 附件
        foreach((array)$body as $item){
            if(!empty($item['path']) && is_file($item['path'])){
                try {
                    $mail->addAttachment($item['path'], $item['filename'] ?? '');
                }catch (\Throwable $e){}
            }
        }

        // 抄送
        foreach($this->addressList($src['cc'] ?? '') as $cc){
            try {
                $mail->addCC($cc['email'], $cc['name']);
            }catch (\Throwable $e){}
        }
        // 密送
        foreach($this->addressList($src['bcc'] ?? '') as $bcc){
            try {
                $mail->addBCC($bcc['email'], $bcc['name']);
            }catch (\Throwable $e){}
        }

        $mail->isHTML(true);
        $mail->preSend();

        $content = $mail->getSentMIMEMessage();
        if(!$content){
            throw new \Exception('eml 内容生成失败');
        }

        if(file_put_contents($file, $content) === false){
            throw new \Exception('eml 写入失败');
        }
    }

    /**
     * cc / bcc 解析
     * @param mixed $value
     * @return array
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function addressList(mixed $value):array {
        if(empty($value)){
            return [];
        }
        $list = is_array($value) ? $value : (@json_decode((string)$value, true) ?: []);
        $ret = [];
        foreach($list as $item){
            if(!is_array($item)){
                $item = ['email' => (string)$item];
            }
            if(empty($item['email'])) continue;
            $ret[] = ['email' => $item['email'], 'name' => $item['name'] ?? ''];
        }
        return $ret;
    }

    /**
     * 发件人文本
     * @param mixed $from
     * @return string
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function addressText(mixed $from):string {
        if(is_array($from)){
            $email = $from['email'] ?? '';
            $name = $from['name'] ?? '';
            return $name ? "{$name} <{$email}>" : (string)$email;
        }
        return (string)$from;
    }

    /**
     * 收件人文本
     * @param array $src
     * @return string
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function toText(array $src):string {
        $toName = @json_decode((string)($src['to_name'] ?? ''), true);
        if(is_array($toName) && $toName){
            $arr = [];
            foreach($toName as $item){
                if(empty($item['email'])) continue;
                $arr[] = empty($item['name']) ? $item['email'] : "{$item['name']} <{$item['email']}>";
            }
            if($arr){
                return implode('; ', $arr);
            }
        }
        return (string)($src['to'] ?? '');
    }

    /**
     * 生成不重复的文件名
     * @param array $src
     * @return string
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function fileName(array $src):string {
        $name = self::sanitize((string)($src['subject'] ?? ''));
        if($name === ''){
            $name = '无主题';
        }
        $name = mb_substr($name, 0, 80);

        $date = empty($src['udate']) ? '' : date('Ymd_His', $src['udate']);
        $base = trim(($date ? $date.'_' : '').$name, '_');

        $fileName = $base.'.eml';
        if(isset($this->usedNames[$fileName]) || is_file($this->dir.'/'.$fileName)){
            $i = 1;
            while(isset($this->usedNames[$base.'('.$i.').eml']) || is_file($this->dir.'/'.$base.'('.$i.').eml')){
                $i++;
            }
            $fileName = $base.'('.$i.').eml';
        }

        $this->usedNames[$fileName] = 1;

        return $this->dir.'/'.$fileName;
    }

    /**
     * 写导出清单
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function writeManifest():void {
        $file = $this->dir.'/'.self::MANIFEST_NAME;
        $fp = @fopen($file, 'wb');
        if(!$fp){
            return;
        }
        // excel 打开不乱码
        fwrite($fp, "\xEF\xBB\xBF");
        fputcsv($fp, ['序号', '主题', '发件人', '收件人', '日期', 'UUID', '文件名', '状态']);

        $i = 0;
        foreach($this->manifest as $item){
            fputcsv($fp, [
                ++$i,
                $item['subject'],
                $item['from'],
                $item['to'],
                $item['date'],
                $item['uuid'],
                $item['file'],
                $item['status'],
            ]);
        }
        // 失败的也记一下
        foreach($this->errors as $item){
            fputcsv($fp, [++$i, $item['subject'], '', '', '', $item['uuid'], '', '失败：'.$item['message']]);
        }

        fclose($fp);
        $this->files[] = $file;
    }

    /**
     * 打包
     * @param string $zipFile
     * @throws Err
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function zip(string $zipFile):void {
        if(class_exists('\ZipArchive')){
            $zip = new \ZipArchive();
            if($zip->open($zipFile, \ZipArchive::CREATE | \ZipArchive::OVERWRITE) === true){
                foreach($this->files as $file){
                    $zip->addFile($file, basename($file));
                }
                if($zip->close() && is_file($zipFile) && filesize($zipFile) > 0){
                    return;
                }
            }
        }

        // 没有 zip 扩展时用不压缩的 zip
        $this->storeZip($zipFile);

        if(!is_file($zipFile) || filesize($zipFile) <= 0){
            throw new Err('打包失败，请检查 php-zip 扩展或目录权限');
        }
    }

    /**
     * 不压缩的 zip（无 php-zip 扩展时的兜底）
     * @param string $zipFile
     * @throws Err
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function storeZip(string $zipFile):void {
        $fp = @fopen($zipFile, 'wb');
        if(!$fp){
            throw new Err('zip 文件创建失败');
        }

        $central = '';
        $offset = 0;
        $count = 0;

        foreach($this->files as $file){
            $data = @file_get_contents($file);
            if($data === false){
                continue;
            }
            $name = basename($file);
            $crc = crc32($data);
            $size = strlen($data);
            $nameLen = strlen($name);
            $mtime = @filemtime($file) ?: time();
            $dosTime = (int)((date('H', $mtime) << 11) | (date('i', $mtime) << 5) | (date('s', $mtime) / 2));
            $dosDate = (int)(((date('Y', $mtime) - 1980) << 9) | (date('n', $mtime) << 5) | date('j', $mtime));

            // 本地文件头，0x0800 表示文件名是 utf-8
            $local = pack('VvvvvvVVVvv', 0x04034b50, 20, 0x0800, 0, $dosTime, $dosDate, $crc, $size, $size, $nameLen, 0).$name;
            fwrite($fp, $local);
            fwrite($fp, $data);

            // 中央目录
            $central .= pack('VvvvvvvVVVvvvvvVV', 0x02014b50, 20, 20, 0x0800, 0, $dosTime, $dosDate, $crc, $size, $size, $nameLen, 0, 0, 0, 0, 0, $offset).$name;

            $offset += strlen($local) + $size;
            $count++;
        }

        fwrite($fp, $central);
        fwrite($fp, pack('VvvvvVVv', 0x06054b50, 0, 0, $count, $count, strlen($central), $offset, 0));
        fclose($fp);
    }

    /**
     * 删除本次导出目录
     * @param string $dir
     * @author：dc
     * @time 2026/10/28 11:40
     */
    private function removeDir(string $dir):void {
        if(!$dir || !is_dir($dir)){
            return;
        }
        foreach((array)@scandir($dir) as $item){
            if($item === '.' || $item === '..' || $item === false){
                continue;
            }
            $path = $dir.'/'.$item;
            if(is_file($path)){
                @unlink($path);
            }
        }
        @rmdir($dir);
    }

}