# Source code for scrapy.extensions.statsmailer

    """
    StatsMailer extension sends an email when a spider finishes scraping.

    Use STATSMAILER_RCPTS setting to enable and give the recipient mail address
    """

    from __future__ import annotations

    from typing import TYPE_CHECKING

    from scrapy import Spider, signals
    from scrapy.exceptions import NotConfigured
    from scrapy.mail import MailSender

    if TYPE_CHECKING:
        from twisted.internet.defer import Deferred

        # typing.Self requires Python 3.11
        from typing_extensions import Self

        from scrapy.crawler import Crawler
        from scrapy.statscollectors import StatsCollector

    class StatsMailer:
        def __init__(self, stats: StatsCollector, recipients: list[str], mail: MailSender):
            self.stats: StatsCollector = stats
            self.recipients: list[str] = recipients
            self.mail: MailSender = mail

        @classmethod
        def from_crawler(cls, crawler: Crawler) -> Self:
            recipients: list[str] = crawler.settings.getlist("STATSMAILER_RCPTS")
            if not recipients:
                raise NotConfigured
            mail: MailSender = MailSender.from_crawler(crawler)
            assert crawler.stats
            o = cls(crawler.stats, recipients, mail)
            crawler.signals.connect(o.spider_closed, signal=signals.spider_closed)
            return o

        def spider_closed(self, spider: Spider) -> Deferred[None] | None:
            spider_stats = self.stats.get_stats()
            body = "Global stats\n\n"
            body += "\n".join(f"{k:<50} : {v}" for k, v in self.stats.get_stats().items())
            body += f"\n\n{spider.name} stats\n\n"
            body += "\n".join(f"{k:<50} : {v}" for k, v in spider_stats.items())
            return self.mail.send(self.recipients, f"Scrapy stats for: {spider.name}", body)