bubble/feeds.py

import re
import urllib.parse as urlparse
from model import User, Post, Segment, Subspace, LogEntry, Commit, Crossref, \
    FOLLOW_SUBSPACE, FOLLOW_USER, FOLLOW_POST, \
    MUTE_SUBSPACE, MUTE_USER, MUTE_POST
from subspace import subspace_admin_actions
from user import make_user_index_page
from utils import *


def make_post_page_or_configure_feed(session):
    # This function may return None, in which case should make a feed page.
    # TODO: Should refactor this to make the session configuration a separate step.

    db = session.db
    req = session.req
    path = req.path[len(session.path):]
    found = re.match(r'(u|s)/([\w%-]+)(/(post|compose|image|file|issues|admin|tag|index))?(/([\w\d-]+)(.*))?', path)
    if not found and not path.startswith('tag'):
        return 59, 'Bad request'

    # Set up the feed parameters.
    if found:
        session.feed_type = found.group(1)
        url_name = urlparse.unquote(found.group(2))
        action = found.group(4)
        arg = found.group(6)
        arg2 = found.group(7)
    else:
        # Tag filtering All Posts.
        found = re.match(r'(tag)(/([\w\d-]+)(.*))?', path)
        action = found[1]
        arg = found[3]
        arg2 = found[4]

    if session.feed_type == 'u':
        session.c_user = db.get_user(name=url_name)
        if not session.c_user:
            return 51, 'Not found: u/' + url_name
        session.context = db.get_subspace(owner=session.c_user.id)
        session.is_context_locked = False
        session.is_user_mod = (session.user.id == session.c_user.id or \
            session.user.role == User.ADMIN) if session.user else False
    elif session.feed_type == 's':
        session.c_user = None
        session.context = db.get_subspace(name=url_name)
        if not session.context:
            return 51, 'Not found: s/' + url_name
        if session.context.owner:
            return 30, '/u' + req.path[2:]
        session.get_mods(session.context.id)
        session.is_user_mod = \
            (session.user.role == User.ADMIN or \
            session.user.id in map(lambda m: m.id, session.context_mods)) \
                if session.user else False
        if session.user and session.user.role == User.ADMIN:
            session.is_context_locked = False  # admin is unaffected by locks
        else:
            session.is_context_locked = len(session.context_mods) == 0
        session.is_context_tracker = (session.context.flags & Subspace.ISSUE_TRACKER) != 0

        if session.is_context_tracker:
            session.feed_mode = 'open'
            if req.query != None:
                params = req.query.split('&')
                if 'open' in params and 'closed' in params:
                    session.feed_mode = 'all'
                elif 'open' in params:
                    session.feed_mode = 'open'
                elif 'closed' in params:
                    session.feed_mode = 'closed'

    if session.feed_type == 's' and action == 'admin':
        return subspace_admin_actions(session, arg)

    if session.is_context_tracker and action == 'issues':
        return 30, f"/s/{session.context.name}/{arg}"

    if session.feed_type == 'u' and action in ('image', 'file'):
        file = db.get_file(int(arg))
        return 20, file.mimetype, file.data

    if session.feed_type == 'u' and action == 'index':
        return make_user_index_page(session, found[6])

    if action == 'tag':
        if not arg:
            page = f'Choose a tag for filtering {session.context.title() if session.context else "All Posts"}:\n'
            page += f'=> {session.path}{session.context.title() if session.context else ""} ❌ None\n\n'
            for tag in sorted(db.get_popular_tags(session.context), key=str.lower):
                if tag == Post.TAG_CLOSED:
                    continue
                page += f'=> {session.path}{session.context.title() + "/" if session.context else ""}tag/{tag} 🏷️ #{tag}\n'
            return page
        session.feed_tag_filter = arg
        arg = None  # don't show a post page

    elif action == 'compose':
        if not session.user:
            return 60, 'Login required'
        if session.c_user and session.user.id != session.c_user.id:
            return 61, "Cannot post to another user's subspace"
        if session.is_context_locked:
            return 61, "Subspace is locked"
        if session.user.role == User.LIMITED and (not session.c_user or
                                                  session.c_user.id != session.user.id):
            return 61, "Not authorized"
        if session.user.role == User.LIMITED and not db.verify_token(session.user, arg):
            return 61, "Expired"
        if session.user.role == User.LIMITED and \
                db.get_access_rate(3600, req.remote_address, LogEntry.POST_CREATED) >= session.bubble.rate_post:
            return 44, "Rate limit exceeded"
        draft_id = db.create_post(session.user, session.context.id)
        db.add_log_entry(req.remote_address, LogEntry.POST_CREATED)
        return 30, '/edit/%d' % draft_id

    elif action == 'post':
        if not session.user:
            return 60, 'Login required'
        if session.c_user and session.user.id != session.c_user.id:
            return 61, "Cannot post to another user's subspace"
        if session.is_context_locked:
            return 61, "Subspace is locked"
        if session.user.role == User.LIMITED and not session.c_user:
            return 61, "Not authorized"
        if session.user.role == User.LIMITED and not db.verify_token(session.user, arg):
            return 61, "Expired"
        if session.user.role == User.LIMITED and \
                db.get_access_rate(3600, req.remote_address, LogEntry.POST_CREATED) >= session.bubble.rate_post:
            return 44, "Rate limit exceeded"

        if session.is_gemini:
            if is_empty_query(req):
                if session.is_context_tracker:
                    return 10, f'Title for new issue in {session.context.title()}:'
                return 10, f'New post in {session.context.title()}: (see Help for special commands)'
            seg_text = clean_query(req)
        else:
            if not req.content_mime.startswith('text/'):
                return 50, 'Content must be text'
            seg_text = req.content.decode('utf-8')

        # Check special commands.
        title = None
        body = seg_text
        url = None
        special = None
        if len(seg_text) == 0:
            special = 'draft'
        elif seg_text == '.' or seg_text == '/':
            special = 'draft'
            body = ''
        elif seg_text == ':':
            if session.is_context_tracker:
                return 50, 'Not supported when posting issues'
            return 30, session.server_root('titan') + req.path
        elif seg_text.endswith('\\'):
            body = seg_text[:-1].strip()
            special = 'draft'

        # Detect a solitary link, and a headline on the first line.
        lines = body.split('\n')

        if len(lines) == 1:
            link = re.match(r'^\s*(=>\s*)?((gemini|gopher|finger|https?)://[^ ]+)(\s+(.*))?', lines[0])
            if link:
                url = link[2]
                body = link[5] if link[5] else ''
                title = ''

        if not url:
            found = re.match(r'^\s*#\s*(.+)$', lines[0])
            if found:
                title = found[1]
                body = '\n'.join(lines[1:]).strip()
            elif session.is_context_tracker:
                title = lines[0]
                body = '\n'.join(lines[1:]).strip()
            else:
                title = ''

        post_id = db.create_post(session.user, session.context.id, title=title)
        post = db.get_post(post_id, draft=True)
        if url:
            db.create_segment(post, Segment.LINK, url=url, content=body)
        elif body:
            if session.user.flags & User.COMPOSER_SPLIT_FLAG and session.is_gemini:
                parts = split_paragraphs(body)
            else:
                parts = [body]
            for part in parts:
                db.create_segment(post, Segment.TEXT, content=part)
            # If there are plain URIs in the content, make segments for them.
            nonlinks = parse_nonlink_uris(body)
            if nonlinks:
                db.update_post(post, flags=post.flags | Post.DISABLE_FEATURED_LINK_FLAG)
                for uri in nonlinks:
                    db.create_segment(post, Segment.LINK, url=uri, content='')
        db.update_post_summary(post)

        # Further content is required for issues.
        if (session.is_context_tracker and not body) or special == 'draft':
            return 30, f'{session.server_root()}/edit/{post.id}'

        db.publish_post(post)
        db.add_log_entry(req.remote_address, LogEntry.POST_CREATED)
        return 30, session.server_root() + post.page_url()

    if session.user:
        session.user_follows = db.get_follows(session.user)
        session.user_mutes = db.get_mutes(session.user)

    if arg:
        # Viewing a single post.
        post = None
        if session.is_context_tracker:
            # In issue trackers, posts are identified by the issue numbers.
            post = db.get_post_for_issueid(session.context, int(arg))
        if not post:
            post = db.get_post(id=int(arg), draft=False)
        if not post:
            # Maybe it is a draft?
            if session.user:
                post = db.get_post(id=int(arg), draft=True)
                if post and post.user == session.user.id:
                    return 30, f'/edit/{post.id}'
            return 51, 'Not found'

        if post.parent != 0:
            return make_post_page(session, post)

        if post.subspace != session.context.id:
            # Redirect to the correct subspace.
            post_sub = db.get_subspace(id=post.subspace)
            if post_sub.flags & Subspace.ISSUE_TRACKER:
                return 31, f'{session.path}{post_sub.title()}/{post.issueid}'
            else:
                return 31, f'{session.path}{post_sub.title()}/{post.id}'

        if arg2 == '/more':
            if not session.user:
                return 60, "Login required"

            # Additional post actions.
            page = session.gemini_feed_entry(post)
            page += "\n## More Actions\n"

            actions = []
            kind = 'issue' if session.is_context_tracker else 'post'

            if not session.is_context_tracker and (session.user.id == post.user or session.is_user_mod):
                actions.append(f'=> /edit-tags/{post.id} 🏷️ Add/remove tags\n')
            actions.append(f'=> /remind/{post.id} 🔔 Remind me\n')
            if session.is_lockable(post):
                if post.flags & Post.LOCKED_FLAG:
                    actions.append(f'=> /unlock/{post.id} 🔓 Unlock comments\n')
                else:
                    actions.append(f'=> /lock/{post.id} 🔒 Lock comments\n')
            if session.is_moderated(post) and post.user != session.user.id:
                if session.user.role == User.ADMIN:
                    actions.append(f'=> /settings/flair/{post.poster_name}/add/ 📛 Set flair on {post.poster_name}\n')
                else:
                    actions.append(f'=> /settings/flair/{post.poster_name}/add/-/{post.sub_name} 📛 Set subspace flair on {post.poster_name}\n')
            if session.is_movable(post):
                actions.append(f'=> /edit/{post.id}/move/{session.get_token()} Move to subspace\n')
            if post.user != session.user.id and not session.is_user_mod and session.user.role != User.ADMIN:
                actions.append(f'=> /report/{post.id} ⚠️ Report\n')

            if actions:
                actions.append('\n')

            if session.user.id != post.user:
                if (FOLLOW_POST, post.id) in session.user_follows:
                    actions.append(f'=> /unfollow/post/{post.id} ➖ Unfollow {kind}\n')
                else:
                    if (MUTE_POST, post.id) in session.user_mutes:
                        actions.append(f'=> /unmute/post/{post.id} 🔈 Unmute {kind}\n')
                    else:
                        actions.append(f'=> /follow/post/{post.id} ➕ Follow {kind}\n')
                        actions.append(f'=> /mute/post/{post.id} 🔇 Mute {kind}\n')
            else:
                # Own posts can be muted.
                if (MUTE_POST, post.id) in session.user_mutes:
                    actions.append(f'=> /unmute/post/{post.id} 🔈 Unmute {kind}\n')
                else:
                    actions.append(f'=> /mute/post/{post.id} 🔇 Mute {kind}\n')

            if session.is_antenna_enabled() and session.user.id == post.user and not post.parent:
                actions.append('\n')
                for i, label in enumerate(session.bubble.antenna_labels):
                    actions.append(f'=> /transmit/{i}/post/{post.id} Submit {kind} to {label}\n')

            if session.is_deletable(post) and not session.is_editable(post):
                actions.append('\n')
                actions.append(f'=> /edit/{post.id}/delete/{session.get_token()} ❌ Delete {kind}\n')

            if actions:
                page += ''.join(actions)
            return page

        if arg2 == '/group':
            subspace = db.get_subspace(id=post.subspace)
            if session.c_user:
                page = f'# {session.c_user.avatar} {session.c_user.name}\n'
                if session.c_user.flair:
                    flair = User.render_flair(session.c_user.flair, session.context,
                                              long_form=True, db=session.db)
                    if flair:
                        page += f"\n{flair}\n"
            else:
                page = f'# {subspace.title()}\n'
            page += f'=> /{subspace.title()} {subspace.title()}\n'
            page += '=> / Back to front page\n'
            page += '\n## Grouped Posts\n'
            user = session.user
            for post in db.get_posts(rotation_group_of_post=post,
                                     comment=False,
                                     draft=False,
                                     notifs_for_user_id=user.id if user else 0,
                                     muted_by_user_id=user.id if user else 0):
                page += '\n'
                page += session.feed_entry(post, session.context, omit_rotate_info=True)
            return page

        if arg2 == '/antenna':
            # Special viewing mode for Antenna submissions, with the bare minimum.
            page = f'# {session.feed_title()}\n'
            page += session.gemini_feed_entry(post, session.context)
            return page

        if arg2.startswith('/clear-notif/'):
            token = arg2[arg2.rindex('/') + 1:]
            if not db.verify_token(session.user, token):
                return 61, "Not authorized"
            db.get_notifications(session.user, post_id=post.id, clear=True)
            return 30, post.page_url()

        return make_post_page(session, post)

    return None


def make_post_page(session, post):
    """Page containing a post and its discussion thread. If `post` is a comment, a partial
    discussion thread is shown."""

    db = session.db
    user = session.user
    post_id = post.id
    is_comment_page = post.parent != 0
    display_order_desc = session.user and \
        session.user.sort_cmt == User.SORT_COMMENT_NEWEST
    page = ''
    focused_cmt = None

    def commenter_flair(cmt, post, abbreviate, with_context=None):
        flair = User.render_flair(cmt.poster_flair,
                                  with_context if with_context else session.context,
                                  abbreviate=abbreviate,
                                  user_mod=cmt.user in session.context_mod_ids,
                                  user_op=post and cmt.user == post.user)
        return f' [{flair}]' if flair else ''

    if is_comment_page:
        # Switch to the parent post, but display it in preview mode.
        focused_cmt = post
        post_id = post.parent
        post = db.get_post(id=post_id)
        page += f'# Comment by {focused_cmt.poster_avatar} {focused_cmt.poster_name}\n\n'
        if post:
            session.get_mods(post.subspace)
            page += f'=> {post.page_url()} Re: {post.quoted_title()}\n'
            sub_name = ("u/" if post.sub_owner else "s/") + post.sub_name
            page += f'=> /{sub_name} In: {sub_name}\n\n'
        else:
            if not session.user or session.user.id != focused_cmt.user:
                # Can't view others' comments on deleted posts, just your own.
                return 51, 'Not found'
            page += f'=> /help/deleted-post 🔒 Comment on a deleted post (ID:{post_id})\n\n'
        page += session.render_post(focused_cmt)
        flair = commenter_flair(focused_cmt, post,
                                abbreviate=False,
                                with_context=db.get_subspace(post.subspace))
        page += f'\n=> /u/{focused_cmt.poster_name} {focused_cmt.poster_avatar} {focused_cmt.poster_name}{flair}\n'
        page += f'{focused_cmt.age()}\n'

        # Comment actions.
        if user:
            actions = []
            if post:
                if session.is_editable(focused_cmt):
                    actions.append(f'=> /edit/{focused_cmt.id} ✏️ Edit\n')
                if post and session.user and not session.is_context_locked and \
                        session.user.role != User.LIMITED and session.is_commenting_enabled(post):
                    actions.append(f'=> /comment/{post.id} 💬 Comment\n')
                if session.is_thanks_enabled() and focused_cmt.user != user.id:
                    actions.append(f'=> /thanks/{focused_cmt.id} 🙏 Give thanks\n')
                actions.append(f'=> /remind/{focused_cmt.id} 🔔 Remind me\n')

                if session.is_moderated(focused_cmt) and focused_cmt.user != user.id:
                    if session.user.role == User.ADMIN:
                        actions.append(f'=> /settings/flair/{focused_cmt.poster_name}/add/ 📛 Set flair on {focused_cmt.poster_name}\n')
                    else:
                        actions.append(f'=> /settings/flair/{focused_cmt.poster_name}/add/-/{focused_cmt.sub_name} 📛 Set subspace flair on {focused_cmt.poster_name}\n')

                actions.append(f'=> /report/{focused_cmt.id} ⚠️ Report\n')
                if not session.is_editable(focused_cmt) and session.is_deletable(focused_cmt):
                    actions.append(f'=> /edit/{focused_cmt.id}/delete/{session.get_token()} ❌ Delete comment\n')
            else:
                if session.is_deletable(focused_cmt):
                    actions.append(f'=> /edit/{focused_cmt.id}/delete/{session.get_token()} ❌ Delete comment\n')
            if actions:
                page += '\n## Actions\n' + ''.join(actions)
            page += '\n' + session.dashboard_link()

        if post:
            op_section = '\n# Original Post\n\n' + session.feed_entry(post)
        else:
            op_section = ''

    else:
        page += session.render_post(post)

    commits = []
    incoming_xrefs = []
    outgoing_xrefs = {}
    repo = None

    # Poll options/results.
    if post:
        poll = session.render_poll(post, show_results=not session.user)
        if poll:
            # Ensure separation.
            if len(page) and not page.endswith('\n\n'):
                page += '\n'
            page += poll

        if post.issueid:
            repo = db.get_repository(subspace=session.context)
            commits = db.get_commits(repo, issueid=post.issueid)
            if not is_comment_page:
                incoming_xrefs = db.get_issue_crossrefs(session.context,
                                                        incoming_to_issueid=post.issueid)
                outgoing_xrefs = db.get_issue_crossrefs(session.context,
                                                        outgoing_from_issueid=post.issueid)

            # Issue and commit cross references outgoing from the post body.
            if repo and repo.view_url:
                first = True
                for commit in db.find_commits_by_hash(repo, parse_likely_commit_hashes(page)):
                    if first:
                        page += '\n'
                        first = False
                    page += commit.entry(repo.view_url, outgoing=True)
            if outgoing_xrefs and post_id in outgoing_xrefs:
                page += '\n'
                for xref in outgoing_xrefs[post_id]:
                    page += xref.outgoing_entry()
        else:
            repo = None

    if not is_comment_page:
        # Post metadata.
        if len(page):
            page += '\n'
        if post.tags:
            page += '### ' + post.tags + '\n'
        #flair = f" [{post.poster_flair}]" if post.poster_flair else ""

        flair = User.render_flair(post.poster_flair,
                                  session.context,
                                  user_mod=post.user in session.context_mod_ids)
        if flair: flair = f" [{flair}]"

        poster_link = f'=> /u/{post.poster_name} {post.poster_avatar} {post.poster_name}{flair}\n'
        if session.is_context_tracker:
            page += f'=> /{session.context.title()} 🐞 Issue #{post.issueid} in {session.context.title()}\n'
        elif not session.c_user:
            page += f'=> /{session.context.title()} Posted in: {session.context.title()}\n'
        page += poster_link
        post_age = post.age() if not session.is_archive else post.ymd_hm()
        page += f'{post_age}'
        if (MUTE_POST, post.id) in session.user_mutes:
            page += ' 🔇'
        if session.is_likes_enabled():
            liked = []
            if post.num_likes:
                liked = db.get_likes(post, session.user_mutes)
                page += ' · 👍 ' + ', '.join(liked)
        if session.is_reactions_enabled():
            reactions = db.get_reactions(post, session.user_mutes)
            listed = []
            for r in reactions:
                listed.append(f'{r} {reactions[r]}')
            if listed:
                page += ' · ' + ' '.join(listed)
        if post.flags & Post.LOCKED_FLAG:
            page += '\n🔒 Locked'
        page += '\n'

        # Post actions.
        kind = 'issue' if session.is_context_tracker else 'post'
        if session.user and not session.is_context_locked:
            page += '\n## Actions\n'
            if session.is_editable(post):
                page += f'=> /edit/{post.id} ✏️ Edit {kind}\n'
            if session.user.role != User.LIMITED and session.is_commenting_enabled(post):
                page += f'=> /comment/{post.id} 💬 Comment\n'

            # Reactions.
            if session.user.id != post.user:
                if session.is_likes_enabled():
                    if session.user.name not in liked:
                        page += f'=> /like/{post.id} 👍 Like\n'
                    else:
                        page += f'=> /unlike/{post.id} 👎 Undo like\n'
                if session.is_reactions_enabled():
                    reaction = db.get_user_reaction(post, session.user.id)
                    if reaction:
                        page += f'=> /react/{post.id} Change reaction: {reaction}\n'
                    else:
                        page += f'=> /react/{post.id} {session.bubble.user_reactions[0]} React\n'
                if session.is_thanks_enabled():
                    page += f'=> /thanks/{post.id} 🙏 Give thanks\n'

            # Moderator actions on a post.
            mod_actions = []
            if session.user.id == post.user or session.is_user_mod:
                if not session.is_editable(post) and session.is_title_editable(post):
                    mod_actions.append(f'=> /edit/{post.id}/mod-title ✏️ Edit {kind} title\n')
                if session.is_context_tracker:
                    mod_actions.append(f'=> /edit-tags/{post.id} 🏷️ Add/remove tags\n')
                    if '✔︎' in post.tags:
                        mod_actions.append(f'=> /edit-tags/{post.id}/open 🐞 Reopen issue\n')
                    else:
                        mod_actions.append(f'=> /edit-tags/{post.id}/close ✔︎ Mark as closed\n')

            if mod_actions:
                page += ''.join(mod_actions)

            page += f'=> {post.id}/more More...\n'

            page += '\n' + session.dashboard_link()

    # Notification on this page.
    if post and user:
        notifs = db.get_notifications(user=user, post_id=post.id, sort_desc=True)
        if notifs:
            page += f'{len(notifs)} notification{plural_s(len(notifs))} about this post:\n'
            for notif in notifs:
                link, label = notif.entry(with_title=False)
                page += f'=> {link} {label}\n'
            if len(notifs) > 1:
                page += f'=> {post.page_url()}/clear-notif/{session.get_token()} 🧹 Clear\n'

    # Comments, repository commits, and issue cross-references.
    comments = db.get_posts(parent=post_id,
                            subspace=(post.subspace if post else None),
                            draft=False,
                            sort_descending=False,
                            muted_by_user_id=(user.id if user else 0),
                            limit=None)

    if is_comment_page:
        if post:
            # Omit comments older than the focused one.
            comments = list(filter(lambda p: p.ts_created > focused_cmt.ts_created, comments))
        else:
            # Deleted post; only see your own comments.
            comments = list(filter(lambda p: p.id != focused_cmt.id and p.user == focused_cmt.user,
                                   comments))

    have_other_comments = False
    n = len(comments)

    if n > 0 or commits or incoming_xrefs:
        have_other_comments = True
        if n > 1:
            dir_icon = ' ↑' if display_order_desc else ' ↓'
        else:
            dir_icon = ''
        page += f'\n## {n} {"Later " if is_comment_page and post else "Other " if is_comment_page else ""}Comment{plural_s(n)}{dir_icon}\n'

        if commits or incoming_xrefs:
            # Combine commits and commits into one list.
            comments += commits
            comments += incoming_xrefs
            comments.sort(key=lambda c: c.ts if isinstance(c, Commit) else c.ts_created)

        # TODO: This may need paging when there is a long thread.
        rendered_comments = []
        ts_now = time.time()

        for cmt in comments:

            # Commits are shown as links to the Git viewer.
            if isinstance(cmt, Commit):
                if not focused_cmt or cmt.ts > focused_cmt.ts_created:
                    rendered_comments.append(cmt.entry(repo.view_url))
                continue

            # Cross-references incoming from other issues.
            if isinstance(cmt, Crossref):
                rendered_comments.append(cmt.incoming_entry())
                continue

            if session.is_archive:
                comment_age = cmt.ymd_hm(tz=session.tz, time_prefix='at ')
            else:
                elapsed_hours = (ts_now - cmt.ts_created) / 3600
                comment_age = cmt.age() if elapsed_hours < 24 else \
                    cmt.ymd_hm(tz=session.tz, date_fmt='%b %d', time_prefix='at ') if elapsed_hours < 24 * 180 else \
                    cmt.ymd_hm(tz=session.tz, time_prefix='at ')

            cmt_flair = commenter_flair(cmt, post, abbreviate=True)
            if not session.is_archive:
                src = f'=> /u/{cmt.poster_name}/{cmt.id} {cmt.poster_avatar} {cmt.poster_name}{cmt_flair} · {comment_age}:\n'
            else:
                src = f'=> /u/{cmt.poster_name} {cmt.poster_avatar} {cmt.poster_name}{cmt_flair} · {comment_age}:\n'
            comment_body = session.render_post(cmt)
            src += comment_body

            # Commit references.
            if repo and repo.view_url:
                for commit in db.find_commits_by_hash(repo, parse_likely_commit_hashes(comment_body)):
                    src += commit.entry(repo.view_url, outgoing=True)

            # Cross-references to other issues.
            if outgoing_xrefs and cmt.id in outgoing_xrefs:
                for xref in outgoing_xrefs[cmt.id]:
                    src += xref.outgoing_entry()

            # Hide the `age` if it's the same as the previous entry (in reading order).
            # comment_age = cmt.age() if not session.is_archive else cmt.ymd_hm()
            # if comment_age != last_age:
            #     last_age = comment_age
            # else:
            #     comment_age = ''

            # if session.user and (cmt.user == session.user.id or session.is_user_mod) and \
            #         not session.is_context_locked:
            #     # Actions on your own comments.
            #     age_suffix = f" · {comment_age}" if len(comment_age) else comment_age
            #     if session.is_editable(cmt) and post:
            #         src += f'=> /edit/{cmt.id} ✏️ Edit{age_suffix}\n'
            #     elif session.is_deletable(cmt):
            #         src += f'=> /edit/{cmt.id}/delete/{session.get_token()} ❌ Delete{age_suffix}\n'
            # elif len(comment_age):
            #     src += comment_age + '\n'

            rendered_comments.append(src)

        # Print in the appropriate order.
        if display_order_desc:
            rendered_comments.reverse()
        for rendered in rendered_comments:
            page += '\n' + rendered

    # Show the Comment action at the appropriate place wrt reading direction.
    if (have_other_comments
        and session.user
        and session.user.role != User.LIMITED
        and post
        and session.is_commenting_enabled(post)
        and not session.is_context_locked
        and not display_order_desc
        and (is_comment_page or len(comments) >= 1)):
        page += f'\n=> /comment/{post.id} 💬 Add comment\n'

    if is_comment_page:
        page += op_section

    return page


def make_feed_page(session):
    # NOTE: Some parameters were configured in `make_post_page_or_configure_feed()`.

    req = session.req
    db = session.db
    c_user = session.c_user
    context = session.context
    context_mods = session.context_mods
    is_issue_tracker = session.is_context_tracker
    user = session.user
    user_follows = session.user_follows
    user_mutes = session.user_mutes
    query_params = req.query.split('&') if req.query else []
    page = ''

    # Determine format of feed.
    is_atom_feed = False
    is_gemini_feed = False
    is_tinylog = False
    is_bubble_feed = False

    if 'feed' in query_params:
        is_gemini_feed = True
    elif 'atom' in query_params:
        is_atom_feed = True
    elif 'tinylog' in query_params:
        is_tinylog = True
    else:
        is_bubble_feed = True

    is_flat_feed = (is_bubble_feed
                    and not is_issue_tracker
                    and user
                    and user.sort_post == User.SORT_POST_FLAT)
    feed_sort_mode = Post.SORT_CREATED
    omit_user_subspaces = False
    omit_nonuser_subspaces = False
    rotate_per_day = False
    page_size = 50 if is_gemini_feed else 100 if is_tinylog else 25
    page_index = 0

    if is_tinylog and not c_user:
        return 51, "Tinylogs are only for user feeds"

    # Page title.
    if is_atom_feed:
        # Just print the entries, and add the header/footer in the end.
        ts_last_updated = 0
    elif is_gemini_feed or is_tinylog:
        page += f'# {session.feed_title()}\n'
    elif c_user:
        page += f'# {c_user.avatar} {context.title()}\n'
    elif context:
        page += f'# {context.title()}\n'
    else:
        page += session.BANNER

    # Subspace description.
    topinfo = ''
    if is_atom_feed:
        pass
    elif not context:
        topinfo += f"{session.bubble.site_info if session.user else session.bubble.site_info_nouser}\n"
    else:
        if c_user and (c_user.info or c_user.url or c_user.flair):
            if c_user.info:
                topinfo += clean_description(c_user.info) + '\n'
            if c_user.url:
                topinfo += f'=> {c_user.url}\n'
            if c_user.flair and not is_tinylog:
                flair = User.render_flair(c_user.flair, context=None, long_form=True, db=session.db)
                topinfo += f'\n{flair}'
        elif context:
            if context.info:
                topinfo += clean_description(context.info) + '\n'
            if context.url:
                topinfo += f'=> {context.url}\n'
            # Users moderating this subspace.
            now = time.time()
            for mod in context_mods:
                dormant_days = (now - mod.ts_active) / 3600 / 24
                dormant = f' · 😴 {int(dormant_days)} days' if dormant_days > 60 else ''
                topinfo += f'=> /u/{mod.name} {mod.avatar} Moderated by: {mod.name}{dormant}\n'
            if session.is_context_locked:
                topinfo += '=> /help/locked 🔒 Locked\n'

    if topinfo:
        page += topinfo if not is_tinylog else re.sub(r"\n+", "\n", clean_tinylog(topinfo))
        page += '\n'

    filter_by_followed = user if session.feed_mode == 'followed' else None
    filter_issue_status = True if session.feed_mode == 'open' else \
                          False if session.feed_mode == 'closed' else None

    if is_bubble_feed:
        # Sorting mode and current page.
        if user:
            if user.sort_post == User.SORT_POST_HOTNESS:
                feed_sort_mode = Post.SORT_HOTNESS
            elif user.sort_post == User.SORT_POST_ACTIVITY:
                feed_sort_mode = Post.SORT_ACTIVE
        if not is_empty_query(req):
            for param in query_params:
                if param == 'sort=hot':
                    feed_sort_mode = Post.SORT_HOTNESS
                elif param == 'sort=new':
                    feed_sort_mode = Post.SORT_CREATED
                elif param == 'sort=active':
                    feed_sort_mode = Post.SORT_ACTIVE
                elif re.match(r'p\d+', param):
                    page_index = int(param[1:]) - 1
        sort_mode = ' 🔥' if feed_sort_mode == Post.SORT_HOTNESS \
            else ' 🗣️' if feed_sort_mode == Post.SORT_ACTIVE else ''

        if is_flat_feed:
            sort_mode = ' 💬'
            feed_sort_mode = Post.SORT_CREATED

        if not is_issue_tracker and not context:
            if user:
                omit_user_subspaces = (user.flags & User.HOME_NO_USERS_FEED_FLAG) != 0
                omit_nonuser_subspaces = (user.flags & User.HOME_USERS_FEED_FLAG) != 0
            rotate_per_day = (session.is_rotation_enabled()
                            and not is_flat_feed
                            and feed_sort_mode == Post.SORT_CREATED
                            and not filter_by_followed)

        # Pagination.
        num_total = db.count_posts(subspace=context,
                                   draft=False,
                                   is_comment=None if is_flat_feed else False,
                                   filter_by_followed=filter_by_followed,
                                   filter_issue_status=filter_issue_status,
                                   filter_tag=session.feed_tag_filter,
                                   omit_user_subspaces=omit_user_subspaces,
                                   omit_nonuser_subspaces=omit_nonuser_subspaces,
                                   muted_by_user_id=(user.id if user else 0),
                                   rotate_per_day=rotate_per_day)
        num_pages = int((num_total + page_size - 1) / page_size)

        # Filter status.
        filter_mode = ''
        if session.feed_tag_filter:
            filter_mode = f' [#{session.feed_tag_filter}]'

        # Navigation menu.
        if not user:
            page += f'=> /s/ {session.bubble.site_icon} Subspaces\n'
            page += session.FOOTER_MENU
            page += '=> /?register Sign up\n'
        else:
            if session.user.role == User.LIMITED:
                link_suffix = '/' + session.get_token()
            else:
                link_suffix = ''
            page += session.dashboard_link()
            if not session.is_context_locked:
                if c_user and c_user.id == user.id:
                    page += f'=> /u/{user.name}/post{link_suffix} 💬 New post\n'
                    page += f'=> /u/{user.name}/compose{link_suffix} ✏️ Compose draft\n'
                elif context and context.owner == 0:
                    if is_issue_tracker:
                        if session.user.role != User.LIMITED:
                            page += f'=> /{context.title()}/post 🐞 New issue in s/{context.name}\n'
                    else:
                        if session.user.role != User.LIMITED:
                            page += f'=> /{context.title()}/post 💬 New post in s/{context.name}\n'
                        page += f'=> /{context.title()}/compose{link_suffix} ✏️ Compose draft in s/{context.name}\n'
                else:
                    page += f'=> /u/{user.name}/post{link_suffix} 💬 New post in u/{user.name}\n'
                    page += f'=> /u/{user.name}/compose{link_suffix} ✏️ Compose draft in u/{user.name}\n'
            page += f'=> /s/ {session.bubble.site_icon} Subspaces\n'

            if is_issue_tracker:
                page += f'\n=> /{context.title()}/search 🔍 Search\n'
                page += f'=> /{context.title()}/tag 🏷️ Tags\n'
                if session.feed_mode in ('all', 'closed'):
                    page += f'=> ? 🐞 Show open\n'
                if session.feed_mode in ('all', 'open'):
                    page += f'=> ?closed ✔︎ Show closed\n'
                if session.feed_mode in ('open', 'closed'):
                    page += f'=> ?open&closed Show all\n'

    # Page title.
    if session.feed_mode == 'all':
        if is_issue_tracker:
            page_title = 'Issues'
        elif not context:
            if omit_nonuser_subspaces:
                page_title = 'User Posts'
            elif omit_user_subspaces:
                page_title = 'Subspace Posts'
            else:
                page_title = 'All Posts'
        else:
            page_title ='Posts'
    elif session.feed_mode in ('open', 'closed'):
        page_title = 'Open Issues' if session.feed_mode == 'open' else 'Closed Issues'
    else:
        page_title = 'Followed'

    posts = db.get_posts(subspace=context,
                         comment=None if is_flat_feed else False,
                         draft=False,
                         sort=feed_sort_mode,
                         notifs_for_user_id=(user.id if user else 0),
                         filter_by_followed=filter_by_followed,
                         filter_issue_status=filter_issue_status,
                         filter_tag=session.feed_tag_filter,
                         omit_user_subspaces=omit_user_subspaces,
                         omit_nonuser_subspaces=omit_nonuser_subspaces,
                         muted_by_user_id=(user.id if user else 0),
                         gemini_feed=is_gemini_feed or is_atom_feed,
                         rotate_per_day=rotate_per_day,
                         limit=page_size,
                         page=page_index)
    is_empty_feed = len(posts) == 0

    if is_bubble_feed and (is_issue_tracker or not is_empty_feed):
        if is_issue_tracker:
            title_count = f'{num_total} '
        else:
            title_count = ''
        page += f'\n## {title_count}{page_title}{sort_mode}{filter_mode}\n\n'
    elif is_tinylog:
        page += f'author: @{c_user.name}@{session.bubble.hostname}\n'
        page += f'avatar: {c_user.avatar}\n\n'

    if is_empty_feed and page_index == 0:
        if is_issue_tracker:
            if session.feed_mode == 'open':
                page += "All clear! "
            page += "There are no issues.\n\n"
        elif is_bubble_feed:
            #page += "There are no posts.\n"
            if user:
                page += f"\n{session.EMPTY_FEED_PLACEHOLDER}\n\n"
    elif is_gemini_feed:
        for post in posts:
            page += session.gemini_feed_entry(post, context)
    elif is_atom_feed:
        for post in posts:
            page += session.atom_feed_entry(post, context)
            ts_last_updated = max(ts_last_updated, post.ts_created)
    elif is_tinylog:
        for post in posts:
            page += session.tinylog_entry(post) + '\n'
    else:
        # Render the Bubble feed as multiple pages.
        pager_feed_mode = f'&{session.feed_mode}' if session.feed_mode != 'all' else ''

        def page_range(n):
            return f'{n + 1} / {num_pages}'

        if page_index > 0:
            page += f'=> ?p{page_index}{pager_feed_mode} Previous page\n\n'

        for post in posts:
            page += session.feed_entry(post, context,
                                       is_activity_feed=(feed_sort_mode == Post.SORT_ACTIVE)) + '\n'

        if len(posts) > 0 and page_index < num_pages - 1:
            page += f'=> ?p{page_index + 2}{pager_feed_mode} Next page\n'

        if num_pages > 1:
            page += f'Page {page_index + 1} of {num_pages}\n\n'

    # Footer.
    if is_atom_feed:
        origin_url = f"{session.server_root()}/{urlparse.quote(context.title()) if context else ''}"
        atom_header = f"""<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
<title>{session.feed_title()}</title>
<link href="{origin_url}" />
<link rel="self" type="application/atom+xml" href="{session.req.url()}" />
<id>{session.req.url()}</id>
<updated>{atom_timestamp(ts_last_updated if ts_last_updated else time.time())}</updated>
<generator uri="https://gmi.skyjake.fi/bubble/" version="{session.bubble.version}">Bubble</generator>
"""
        atom_footer = "\n</feed>\n"
        return 20, 'application/atom+xml', atom_header + page + atom_footer

    elif not is_tinylog:
        if not is_gemini_feed:
            if user or not is_empty_feed:
                page += "## Options\n"
            if not is_flat_feed and not is_empty_feed:
                if feed_sort_mode != Post.SORT_CREATED:
                    page += "=> ?sort=new 🕑 Sort by most recent\n"
                if feed_sort_mode != Post.SORT_ACTIVE:
                    page += "=> ?sort=active 🗣️ Sort by activity\n"
                if feed_sort_mode != Post.SORT_HOTNESS:
                    page += "=> ?sort=hot 🔥 Sort by hotness\n"
            if not context:
                if session.feed_mode == 'followed':
                    page += '=> /all All Posts\n'
                else:
                    page += '=> /followed Followed\n'
            if not is_empty_feed:
                page += "=> ?feed Gemini feed\n"
                page += "=> ?atom Atom feed\n"
                if c_user:
                    page += "=> ?tinylog Tinylog\n"
            if user:
                # Search.
                if not is_issue_tracker and not is_empty_feed:
                    if context:
                        page += f'=> /{context.title()}/search 🔍 Search in {context.title()}\n'
                        page += f'=> /{context.title()}/tag 🏷️ Tags\n'
                    else:
                        page += '\n=> /search 🔍 Search\n'
                        page += '=> /tag 🏷️ Tags\n'

                # Settings.
                page += "\n=> /settings ⚙️ Settings\n"
                if user.role == User.ADMIN and c_user and user.id != c_user.id:
                    page += f'=> /settings/flair/{c_user.name} 📛 Flairs on {c_user.name}\n'
                if context and (not c_user or user.id == c_user.id):
                    page += f'=> /settings/flair/{user.name}/add/-/{context.name} 📛 Set subspace flair\n'
                    if session.is_user_mod and not c_user:
                        page += f'=> /{context.title()}/admin 🌒 Subspace admin\n'
                page += '\n'

                if session.is_antenna_enabled() and c_user and user.id == c_user.id:
                    for i, label in enumerate(session.bubble.antenna_labels):
                        page += f"=> /transmit/{i}/feed/{user.name}{'/' + session.feed_tag_filter if session.feed_tag_filter else ''} Submit feed to {label}\n"

                # Following and muting.
                if c_user and user.id != c_user.id:
                    if (FOLLOW_USER, c_user.id) in user_follows:
                        page += f'=> /unfollow/{c_user.name} ➖ Unfollow {c_user.name}\n'
                    elif not (MUTE_USER, c_user.id) in user_mutes:
                        page += f'=> /follow/{c_user.name} ➕ Follow {c_user.name}\n'
                        page += f'You will be notified when {c_user.name} posts anywhere on {session.bubble.site_name}.\n'
                    if (MUTE_USER, c_user.id) in user_mutes:
                        page += f'=> /unmute/{c_user.name} 🔈 Unmute {c_user.name}\n'
                    elif not (FOLLOW_USER, c_user.id) in user_follows:
                        page += f'=> /mute/{c_user.name} 🔇 Mute {c_user.name}\n'
                        page += f'You will not see posts or comments by {c_user.name} anywhere on {session.bubble.site_name}.\n'
                if context and context.owner != user.id and not session.is_context_locked:
                    if not c_user or not (MUTE_USER, c_user.id) in user_mutes:
                        if not page.endswith('\n\n'):
                            page += '\n'
                        if (MUTE_SUBSPACE, context.id) in user_mutes:
                            page += f'=> /unmute/{context.title()} 🔈 Unmute subspace {context.title()}\n'
                        elif (FOLLOW_SUBSPACE, context.id) in user_follows:
                            page += f'=> /unfollow/{context.title()} ➖ Unfollow subspace {context.title()}\n'
                        else:
                            page += f'=> /follow/{context.title()} ➕ Follow subspace {context.title()}\n'
                            if context.id not in user.moderated_subspace_ids:
                                page += f'=> /mute/{context.title()} 🔇 Mute subspace {context.title()}\n'
                                page += "Posts from the subspace will not appear in All Posts.\n"

                if not page.endswith('\n\n'):
                    page += '\n'

                page += session.FOOTER_MENU
        else:
            page += '\n'
            if c_user:
                page += c_user.subspace_link()
            elif context:
                page += context.subspace_link()
            page += session.FOOTER_MENU
    return page