Embedding and attachements.

2 files changed, 108 insertions, 14 deletions

diff --git a/mu4web/main.py b/mu4web/main.py
index 60ebbb8..86a0b38 100644
--- a/mu4web/main.py
+++ b/mu4web/main.py
@@ -24,6 +24,7 @@ from user.pam import PamUser
 
 import subprocess
 
+import flask
 from flask import (
     Flask,
     session,
@@ -34,6 +35,12 @@ from flask import (
     get_flashed_messages
 )
 
+#
+# A few operations depend on the index of attachements. These index
+# are all pre-order traversal indexes of the attachement tree, which
+# is also the order message.walk() returns them in.
+#
+
 login_manager = LoginManager()
 
 
@@ -60,13 +67,15 @@ def header_format(key: str, value) -> HTML:
         return value
 
 
-def attachement_tree(mail: EmailMessage) -> HTML:
+def attachement_tree(id: str, mail: EmailMessage, idx=0) -> tuple[HTML, int]:
     ct = mail.get_content_type()
     fn = mail.get_filename()
 
     children = []
+    _idx = idx
     for child in mail.iter_parts():
-        children.append(attachement_tree(cast(EmailMessage, child)))
+        tree, idx = attachement_tree(id, cast(EmailMessage, child), idx + 1)
+        children.append(tree)
 
     content: HTML
     if children:
@@ -78,7 +87,10 @@ def attachement_tree(mail: EmailMessage) -> HTML:
         body = f'{ct} {fn}'
     else:
         body = str(ct)
-    return ('li', body, content)
+    return ('li', ('a', {'data-idx': str(_idx),
+                         'href': '/part?' + urlencode({'id': id,
+                                                       'idx': _idx}),
+                         }, body), content), idx
 
 # --------------------------------------------------
 
@@ -158,6 +170,8 @@ def page_base(title: Optional[str] = None,
 
 def response_for(id: str, username: Optional[str] = None) -> str:
 
+    # TODO option to show raw message
+
     mail = cast(EmailMessage, get_mail(id))
 
     headers = {}
@@ -165,32 +179,54 @@ def response_for(id: str, username: Optional[str] = None) -> str:
         headers[key.lower()] = value
 
     head = []
+    # TODO Make the defalut set of headers configurable
     for h in ['date', 'from', 'to', 'cc', 'bcc', 'subject', 'x-original-to',
-              'in-reply-to']:
+              'in-reply-to', 'message-id']:
         if x := headers.get(h.lower()):
             head += [('dt', h.title()),
                      ('dd', header_format(h.lower(), x))]
 
-    body_part = mail.get_body(preferencelist=('html', 'plain'))
-    if not body_part:
-        raise ValueError("No suitable body in email")
-    ct = body_part.get_content_type()
-    body: HTML
-    if ct == 'text/html':
-        body = lambda: cast(EmailMessage, body_part).get_content()
-    else:
-        body = ('pre', cast(EmailMessage, body_part).get_content())
+    all_heads = []
+    for key, value in mail.items():
+        all_heads += [('dt', key.title()),
+                     ('dd', value)]
+
+    full_headers = ('details',
+                    ('summary', 'Alla mailhuvuden'),
+                    ('dl', *all_heads))
 
     if t := headers.get('subject'):
         title = f'Mail — {t}'
     else:
         title = 'Mail'
 
+    body: HTML = []
+    # Manual walk to preserve attachement index
+    for idx, at in enumerate(mail.walk()):
+        # body.append(('h2', at.get_content_type()))
+        if at.is_multipart():
+            continue
+        elif at.get_content_type() == 'text/html':
+            # ct = at.get_content_type()
+            url = '/part?' + urlencode({'id': id, 'idx': idx})
+            body.append(('iframe', {'src': url,
+                                    'height': '300',
+                                    }))
+        elif at.get_content_type() == 'text/plain':
+            body.append(('pre', at.get_content()))
+        else:
+            url = '/part?' + urlencode({'id': id, 'idx': idx})
+            body.append(('a', {'href': url},
+                         at.get_filename() or at.get_content_type()))
+
+    tree, idx = attachement_tree(id, mail)
+
     main_body = [('dl', *head),
+                 full_headers,
                  ('hr',),
                  ('main', body),
                  ('hr',),
-                 ('ul', attachement_tree(mail)),
+                 ('ul', tree),
                  ]
     html_str = render_document(page_base(title=title,
                                          body=main_body))
@@ -337,6 +373,55 @@ def search_page_():
                        request.args.get('by', None))
 
 
+def multipart_page(msg_id: str,
+                   attachement: EmailMessage,
+                   attachement_idx: int) -> str:
+    """
+    Build HTML response for a multi-part attachement.
+
+    Multi part attachements are simply containers, and can't directly be opened. Instead, build a tree of all components.
+
+    [Parameters]
+        msg_id - Message ID of the mail in question
+        attachement - The attachement to work with, must be multipart
+        attachement_idx - Index of attachement in top level mail.
+                          Needed for links to work.
+    """
+    tree, idx = attachement_tree(msg_id, attachement, attachement_idx)
+    body = [('a', {'href': '/?' + urlencode({'id': msg_id})},
+             'Återvänd till brev'),
+            ('ul', tree),
+            ]
+    return render_document(page_base(title='Multipart',
+                                     body=body))
+
+
+def attachement_response(attachement: EmailMessage):
+    """
+    Builds a response for a given attachement.
+
+    Gets content type and encoding from the attachements headers.
+    """
+    response = flask.Response()
+    response.charset = attachement.get_content_charset()
+    response.mimetype = attachement.get_content_type()
+    response.set_data(attachement.get_content())
+
+    return response
+
+@app.route('/part')
+@login_required
+def attachement_part_page():
+    msg_id = request.args.get('id')
+    attachement_idx = int(request.args.get('idx'))
+    mail = cast(EmailMessage, get_mail(msg_id))
+    attachement = list(mail.walk())[attachement_idx]
+
+    if attachement.is_multipart():
+        return multipart_page()
+    else:
+        return attachement_response(attachement)
+
 # TODO this page is really weird if you are already logged in
 @app.route('/login', methods=['GET'])
 def login_page_():
diff --git a/mu4web/static/style.css b/mu4web/static/style.css
index 2223f33..8297aab 100644
--- a/mu4web/static/style.css
+++ b/mu4web/static/style.css
@@ -105,3 +105,12 @@ footer {
 	grid-column: 2;
 }
 
+
+iframe {
+	width: 100%;
+}
+
+main pre {
+	white-space: pre-wrap;
+	border: 2px solid black;
+}