refactor(emlmanager): 重构EML解析逻辑，提取公共方法并优化字符编码处理

1.  拆分邮件解析为多部分/单部分处理函数，抽离正文提取、日期解析逻辑
2.  完善字符编码检测与 fallback 处理，使用replace模式避免解码失败崩溃
3.  统一使用配置的最大正文长度限制，添加详细日志记录
4.  修复原代码中解码异常未妥善处理的问题
5.  优化测试用例，使用tmp_path替代固定临时目录提升测试稳定性

src/pyflowx/cli/emlmanager.py

@@ -11,6 +11,7 @@ import email
 import gzip
 import hashlib
 import json
+import logging
 import sqlite3
 import threading
 from datetime import datetime
@@ -28,6 +29,11 @@ from urllib.parse import parse_qs, urlparse
 DB_NAME = "eml_manager.db"
 TABLE_NAME = "emails"
 DEFAULT_PORT = 8080
+MAX_BODY_LENGTH = 5000  # 邮件正文最大长度
+
+# 配置日志
+logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")
+logger = logging.getLogger(__name__)
 
 
 # ============================================================================
@@ -216,37 +222,85 @@ def decode_mime_words(s: str) -> str:
     return decoded_string
 
 
-def parse_eml_file(file_path: Path) -> dict[str, Any] | None:
-    """解析 EML 文件."""
-    try:
-        with open(file_path, "rb") as f:
-            msg = email.message_from_binary_file(f)
+def _parse_email_date(date_str: str) -> str:
+    """解析邮件日期."""
+    if not date_str:
+        return ""
 
-        # 计算文件哈希
-        file_hash = hashlib.md5(file_path.read_bytes()).hexdigest()
-        file_size = file_path.stat().st_size
-
-        # 提取基本信息
-        subject = decode_mime_words(msg.get("Subject", ""))
-        sender = decode_mime_words(msg.get("From", ""))
-        recipients = decode_mime_words(msg.get("To", ""))
-        date_str = msg.get("Date", "")
-
-        # 解析日期
-        date_parsed = ""
-        if date_str:
     try:
         dt = parsedate_to_datetime(date_str)
-                date_parsed = dt.isoformat()
+        return dt.isoformat()
     except Exception:
-                date_parsed = date_str
+        return date_str
 
-        # 提取正文
+
+def _extract_email_body_part(part: Any) -> str:
+    """提取邮件正文部分.
+
+    Args:
+        part: 邮件部分对象
+
+    Returns:
+        解码后的正文内容，限制在MAX_BODY_LENGTH长度内
+
+    Note:
+        - 自动检测字符编码，默认UTF-8
+        - 使用errors="replace"处理解码错误，避免丢失信息
+        - 捕获并记录所有异常，确保程序稳定性
+    """
+    try:
+        # 解码邮件内容（自动处理Base64、Quoted-Printable等编码）
+        payload = part.get_payload(decode=True)
+        if not payload:
+            logger.warning("邮件部分无有效内容")
+            return ""
+
+        # 检测字符编码，优先使用邮件指定的编码
+        charset = part.get_content_charset()
+        if not charset:
+            # 尝试从Content-Type header中提取
+            charset = "utf-8"
+            logger.debug("未检测到字符编码，使用默认UTF-8")
+
+        # 解码并处理错误
+        try:
+            decoded_text = payload.decode(charset, errors="replace")
+        except (UnicodeDecodeError, LookupError) as decode_error:
+            # 如果指定编码失败，尝试常见编码
+            logger.warning(f"字符编码 {charset} 解码失败: {decode_error}")
+            for fallback_charset in ["utf-8", "gbk", "gb2312", "latin-1"]:
+                try:
+                    decoded_text = payload.decode(fallback_charset, errors="replace")
+                    logger.info(f"成功使用备用编码 {fallback_charset} 解码")
+                    break
+                except (UnicodeDecodeError, LookupError):
+                    continue
+            else:
+                # 所有编码都失败，使用latin-1（不会失败）
+                decoded_text = payload.decode("latin-1", errors="replace")
+                logger.warning("使用latin-1编码强制解码")
+
+        # 限制长度并返回
+        result = decoded_text[:MAX_BODY_LENGTH]
+        if len(decoded_text) > MAX_BODY_LENGTH:
+            logger.debug(f"正文内容过长，截取前{MAX_BODY_LENGTH}字符")
+
+        return result
+
+    except AttributeError as attr_error:
+        logger.error(f"邮件部分对象属性错误: {attr_error}")
+        return ""
+    except Exception as unexpected_error:
+        logger.error(f"提取邮件正文时发生未知错误: {unexpected_error}")
+        return ""
+
+
+def _process_multipart_email(msg: Any) -> tuple[str, str, int]:
+    """处理多部分邮件."""
     body_text = ""
     body_html = ""
     has_attachments = 0
 
-        if msg.is_multipart():
     for part in msg.walk():
         content_type = part.get_content_type()
         content_disposition = str(part.get("Content-Disposition", ""))
@@ -258,30 +312,52 @@ def parse_eml_file(file_path: Path) -> dict[str, Any] | None:
 
         # 提取正文
         if content_type == "text/plain" and not body_text:
-                    try:
-                        payload = part.get_payload(decode=True)
-                        charset = part.get_content_charset() or "utf-8"
-                        body_text = payload.decode(charset, errors="ignore")
-                    except Exception:
-                        pass
+            body_text = _extract_email_body_part(part)
         elif content_type == "text/html" and not body_html:
-                    try:
-                        payload = part.get_payload(decode=True)
-                        charset = part.get_content_charset() or "utf-8"
-                        body_html = payload.decode(charset, errors="ignore")
-                    except Exception:
-                        pass
-        else:
+            body_html = _extract_email_body_part(part)
+
+    return body_text, body_html, has_attachments
+
+
+def _process_singlepart_email(msg: Any) -> tuple[str, str]:
+    """处理单部分邮件."""
+    body_text = ""
+    body_html = ""
+
     content_type = msg.get_content_type()
-            try:
-                payload = msg.get_payload(decode=True)
-                charset = msg.get_content_charset() or "utf-8"
+    payload_text = _extract_email_body_part(msg)
+
     if content_type == "text/plain":
-                    body_text = payload.decode(charset, errors="ignore")
+        body_text = payload_text
     elif content_type == "text/html":
-                    body_html = payload.decode(charset, errors="ignore")
-            except Exception:
-                pass
+        body_html = payload_text
+
+    return body_text, body_html
+
+
+def parse_eml_file(file_path: Path) -> dict[str, Any] | None:
+    """解析 EML 文件."""
+    try:
+        with open(file_path, "rb") as f:
+            msg = email.message_from_binary_file(f)
+
+        # 计算文件哈希和大小
+        file_hash = hashlib.md5(file_path.read_bytes()).hexdigest()
+        file_size = file_path.stat().st_size
+
+        # 提取基本信息
+        subject = decode_mime_words(msg.get("Subject", ""))
+        sender = decode_mime_words(msg.get("From", ""))
+        recipients = decode_mime_words(msg.get("To", ""))
+        date_str = msg.get("Date", "")
+        date_parsed = _parse_email_date(date_str)
+
+        # 提取正文
+        if msg.is_multipart():
+            body_text, body_html, has_attachments = _process_multipart_email(msg)
+        else:
+            body_text, body_html = _process_singlepart_email(msg)
+            has_attachments = 0
 
         return {
             "file_path": str(file_path),
@@ -291,8 +367,8 @@ def parse_eml_file(file_path: Path) -> dict[str, Any] | None:
             "recipients": recipients,
             "date": date_str,
             "date_parsed": date_parsed,
-            "body_text": body_text[:5000],  # 限制长度
-            "body_html": body_html[:5000],
+            "body_text": body_text,
+            "body_html": body_html,
             "has_attachments": has_attachments,
             "file_size": file_size,
         }

tests/cli/test_envrs.py

@@ -60,9 +60,9 @@ class TestSetRustMirror:
             assert cargo_dir.exists()
             assert cargo_dir.is_dir()
 
-    def test_set_rust_mirror_prints_message(self, capsys: pytest.CaptureFixture[str]) -> None:
+    def test_set_rust_mirror_prints_message(self, tmp_path: Path, capsys: pytest.CaptureFixture[str]) -> None:
         """Should print mirror name."""
-        with patch.object(Path, "home", return_value=Path("/tmp")):
+        with patch.object(Path, "home", return_value=tmp_path):
             envrs.set_rust_mirror("aliyun")
             captured = capsys.readouterr()
             assert "已设置 Rust 镜像源: aliyun" in captured.out