1"""
 2Email backend that writes messages to console instead of sending them.
 3"""
 4
 5from __future__ import annotations
 6
 7import sys
 8import threading
 9from typing import TYPE_CHECKING, Any
10
11from .base import BaseEmailBackend
12
13if TYPE_CHECKING:
14    from ..message import EmailMessage
15
16
17class EmailBackend(BaseEmailBackend):
18    def __init__(self, *args: Any, **kwargs: Any) -> None:
19        self.stream = kwargs.pop("stream", sys.stdout)
20        self._lock = threading.RLock()
21        super().__init__(*args, **kwargs)
22
23    def write_message(self, message: EmailMessage) -> None:
24        msg = message.message()
25        msg_data = msg.as_bytes()
26        msg_charset = msg.get_charset()
27        if msg_charset is None:
28            charset = "utf-8"
29        elif isinstance(msg_charset, str):
30            charset = msg_charset
31        else:
32            charset = msg_charset.get_output_charset() or "utf-8"
33        msg_data = msg_data.decode(charset)
34        self.stream.write(f"{msg_data}\n")
35        self.stream.write("-" * 79)
36        self.stream.write("\n")
37
38    def send_messages(self, email_messages: list[EmailMessage]) -> int:
39        """Write all messages to the stream in a thread-safe way."""
40        if not email_messages:
41            return 0
42        msg_count = 0
43        with self._lock:
44            try:
45                stream_created = self.open()
46                for message in email_messages:
47                    self.write_message(message)
48                    self.stream.flush()  # flush after each message
49                    msg_count += 1
50                if stream_created:
51                    self.close()
52            except Exception:
53                if not self.fail_silently:
54                    raise
55        return msg_count