feat(email): allowed for markdown inside emails

1 files changed, 75 insertions, 0 deletions

diff --git a/bin/email b/bin/email
new file mode 100755
index 0000000..231ab6c
--- /dev/null
+++ b/bin/email
@@ -0,0 +1,75 @@
+#!/usr/bin/python
+
+import sys,re
+import email
+
+from email import policy
+from subprocess import run, PIPE
+
+mstmp = "/usr/bin/msmtp"
+
+def log(*args):
+    print(*args, file=sys.stderr)
+
+def html(markdown):
+    cmd = run(["pandoc", "-s", "--metadata", "title=", "-f", "markdown", "-t", "html"], input=markdown, stdout=PIPE, encoding='utf-8')
+    if cmd.returncode != 0:
+        return None
+
+    return cmd.stdout
+
+startbang =  r"\A\s*^[ \t]*!md[ \t]*$"
+stopbang  =  r"^[ \t]*!md[ \t]*$"
+def trim(content):
+    clean, n1 = re.subn(startbang, "", content, flags=re.MULTILINE | re.DOTALL)
+    clean, n2 = re.subn(stopbang,  "", clean, flags=re.MULTILINE | re.DOTALL)
+
+    if n1 == 1 and n2 == 1:
+        return clean
+    return None
+
+def process(mail):
+    changed = False
+    for part in mail.walk():
+        if part.get_content_maintype() == "text" and part.get_content_charset() == "utf-8":
+            content  = part.get_content()
+            markdown = trim(content)
+            if markdown is None:
+                continue
+            else:
+                part.set_content(markdown)
+                part.add_alternative(html(markdown), subtype="html")
+                changed = True
+        else:
+            continue
+
+    return changed
+
+def mail(input):
+    message = email.message_from_string(input, policy=policy.default)
+
+    if process(message):
+        return message.as_bytes()
+
+    return input
+
+def send(account, to):
+    input = sys.stdin.read()
+    email = mail(input)
+
+    cmd = run([mstmp, "-a", account, "--", to], input=email)
+    if cmd.returncode != 0:
+        raise ValueError(f"did not send mail. err={cmd.returncode}")
+
+if __name__ == "__main__":
+    if len(sys.argv) != 4:
+        raise ArgumentError(f"invalid usage: recieved arguments {sys.argv[1:]}")
+
+    account = sys.argv[1]
+
+    if sys.argv[2] != "--":
+        raise ArgumentError(f"invalid usage: received {sys.argv[2:]} instead of recipient")
+
+    to = sys.argv[3]
+
+    send(account, to)