# Copyright (c) 2022, Frappe Technologies Pvt. Ltd. and Contributors
# License: MIT. See LICENSE

import frappe
from frappe import _, msgprint
from frappe.query_builder import DocType, Interval
from frappe.query_builder.functions import Now
from frappe.utils import cint, get_url, now_datetime
from frappe.utils.verified_command import get_signed_params, verify_request


def get_emails_sent_this_month(email_account=None):
	"""Get count of emails sent from a specific email account.

	:param email_account: name of the email account used to send mail

	if email_account=None, email account filter is not applied while counting
	"""
	q = """
		SELECT
			COUNT(*)
		FROM
			`tabEmail Queue`
		WHERE
			`status`='Sent'
			AND
			EXTRACT(YEAR_MONTH FROM `creation`) = EXTRACT(YEAR_MONTH FROM NOW())
	"""

	q_args = {}
	if email_account is not None:
		if email_account:
			q += " AND email_account = %(email_account)s"
			q_args["email_account"] = email_account
		else:
			q += " AND (email_account is null OR email_account='')"

	return frappe.db.sql(q, q_args)[0][0]


def get_emails_sent_today(email_account=None):
	"""Get count of emails sent from a specific email account.

	:param email_account: name of the email account used to send mail

	if email_account=None, email account filter is not applied while counting
	"""
	q = """
		SELECT
			COUNT(`name`)
		FROM
			`tabEmail Queue`
		WHERE
			`status` in ('Sent', 'Not Sent', 'Sending')
			AND
			`creation` > (NOW() - INTERVAL '24' HOUR)
	"""

	q_args = {}
	if email_account is not None:
		if email_account:
			q += " AND email_account = %(email_account)s"
			q_args["email_account"] = email_account
		else:
			q += " AND (email_account is null OR email_account='')"

	return frappe.db.sql(q, q_args)[0][0]


def get_unsubscribe_message(unsubscribe_message, expose_recipients):
	if unsubscribe_message:
		unsubscribe_html = """<a href="<!--unsubscribe_url-->"
			target="_blank">{0}</a>""".format(
			unsubscribe_message
		)
	else:
		unsubscribe_link = """<a href="<!--unsubscribe_url-->"
			target="_blank">{0}</a>""".format(
			_("Unsubscribe")
		)
		unsubscribe_html = _("{0} to stop receiving emails of this type").format(unsubscribe_link)

	html = """<div class="email-unsubscribe">
			<!--cc_message-->
			<div>
				{0}
			</div>
		</div>""".format(
		unsubscribe_html
	)

	if expose_recipients == "footer":
		text = "\n<!--cc_message-->"
	else:
		text = ""
	text += "\n\n{unsubscribe_message}: <!--unsubscribe_url-->\n".format(
		unsubscribe_message=unsubscribe_message
	)

	return frappe._dict({"html": html, "text": text})


def get_unsubcribed_url(
	reference_doctype, reference_name, email, unsubscribe_method, unsubscribe_params
):
	params = {
		"email": email.encode("utf-8"),
		"doctype": reference_doctype.encode("utf-8"),
		"name": reference_name.encode("utf-8"),
	}
	if unsubscribe_params:
		params.update(unsubscribe_params)

	query_string = get_signed_params(params)

	# for test
	frappe.local.flags.signed_query_string = query_string

	return get_url(unsubscribe_method + "?" + get_signed_params(params))


@frappe.whitelist(allow_guest=True)
def unsubscribe(doctype, name, email):
	# unsubsribe from comments and communications
	if not verify_request():
		return

	try:
		frappe.get_doc(
			{
				"doctype": "Email Unsubscribe",
				"email": email,
				"reference_doctype": doctype,
				"reference_name": name,
			}
		).insert(ignore_permissions=True)

	except frappe.DuplicateEntryError:
		frappe.db.rollback()

	else:
		frappe.db.commit()

	return_unsubscribed_page(email, doctype, name)


def return_unsubscribed_page(email, doctype, name):
	frappe.respond_as_web_page(
		_("Unsubscribed"),
		_("{0} has left the conversation in {1} {2}").format(email, _(doctype), name),
		indicator_color="green",
	)


def flush(from_test=False):
	"""flush email queue, every time: called from scheduler"""
	from frappe.email.doctype.email_queue.email_queue import send_mail

	# To avoid running jobs inside unit tests
	if frappe.are_emails_muted():
		msgprint(_("Emails are muted"))
		from_test = True

	if cint(frappe.defaults.get_defaults().get("hold_queue")) == 1:
		return

	for row in get_queue():
		try:
			func = send_mail if from_test else send_mail.enqueue
			is_background_task = not from_test
			func(email_queue_name=row.name, is_background_task=is_background_task)
		except Exception:
			frappe.get_doc("Email Queue", row.name).log_error()


def get_queue():
	return frappe.db.sql(
		"""select
			name, sender
		from
			`tabEmail Queue`
		where
			(status='Not Sent' or status='Partially Sent') and
			(send_after is null or send_after < %(now)s)
		order
			by priority desc, creation asc
		limit 500""",
		{"now": now_datetime()},
		as_dict=True,
	)


def clear_outbox(days: int = None) -> None:
	"""Remove low priority older than 31 days in Outbox or configured in Log Settings.
	Note: Used separate query to avoid deadlock
	"""
	days = days or 31
	email_queue = frappe.qb.DocType("Email Queue")
	email_recipient = frappe.qb.DocType("Email Queue Recipient")

	# Delete queue table
	(
		frappe.qb.from_(email_queue)
		.delete()
		.where((email_queue.modified < (Now() - Interval(days=days))))
	).run()

	# delete child tables, note that this has potential to leave some orphan
	# child table behind if modified time was later than parent doc (rare).
	# But it's safe since child table doesn't contain links.
	(
		frappe.qb.from_(email_recipient)
		.delete()
		.where((email_recipient.modified < (Now() - Interval(days=days))))
	).run()


def set_expiry_for_email_queue():
	"""Mark emails as expire that has not sent for 7 days.
	Called daily via scheduler.
	"""

	frappe.db.sql(
		"""
		UPDATE `tabEmail Queue`
		SET `status`='Expired'
		WHERE `modified` < (NOW() - INTERVAL '7' DAY)
		AND `status`='Not Sent'
		AND (`send_after` IS NULL OR `send_after` < %(now)s)""",
		{"now": now_datetime()},
	)