From 4849128fcdeaf7b5b8032493c8fb5eb82d431b56 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sergio=20Mart=C3=ADnez=20Portela?=
 <sergio@codigoparallevar.com>
Date: Wed, 9 Nov 2022 01:01:34 +0100
Subject: [PATCH] Add simple backlink connections.

---
 scripts/generate.py | 31 +++++++++++++++++++++++++++++--
 static/style.css    |  4 ++++
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/scripts/generate.py b/scripts/generate.py
index e300386..ae8e554 100644
--- a/scripts/generate.py
+++ b/scripts/generate.py
@@ -182,6 +182,7 @@ def regen_all(src_top, dest_top, *, docs=None, db=None):
 
     # Build graph
     graph = {}
+    backlink_graph = {}
     for headline in all_headlines:
         links = []
         headline_links = list(headline.get_links())
@@ -216,6 +217,19 @@ def regen_all(src_top, dest_top, *, docs=None, db=None):
                     "target": headline.parent.id,
                     "relation": "in"
                 })
+        for backlink in links:
+            if 'relation' in  backlink and backlink['relation'] == 'in':
+                continue
+
+            target = backlink['target']
+            if target.startswith('id:'):
+                target = target[len('id:'):]
+
+            if target not in backlink_graph:
+                backlink_graph[target] = set()
+
+            backlink_graph[target].add(headline.id)
+
         graph[headline.id] = {
             "title": org_rw.org_rw.token_list_to_plaintext(headline.title.contents).strip(),
             "links": links,
@@ -247,7 +261,7 @@ def regen_all(src_top, dest_top, *, docs=None, db=None):
 
     # Render docs after we've built the graph
     # Render main headlines
-    full_graph_info = { "nodes": graph, "main_headlines": main_headlines_by_path }
+    full_graph_info = { "nodes": graph, "backlinks": backlink_graph, "main_headlines": main_headlines_by_path }
     for _docpath, main_headline in main_headlines_by_path.items():
         if main_headline.doc.id:
             endpath = os.path.join(dest_top, main_headline.doc.id + ".node.html")
@@ -428,7 +442,6 @@ def render_code_block(element, acc, headline, graph):
 
 def render_results_block(element, acc, headline, graph):
     items = [e.get_raw() for e in element.children]
-    print(items)
     content = '\n'.join(items)
     if len(content.strip()) > 0:
         render_block(content, acc, _class='results lang-text', is_code=False)
@@ -576,6 +589,17 @@ def render_as_document(headline, doc, headlineLevel, graph, title):
     else:
         return as_document(render(headline, doc, graph=graph, headlineLevel=headlineLevel), title)
 
+def render_connections(headline_id, content, graph):
+    if headline_id not in graph['backlinks']:
+        return
+
+    content.append("<div class='connections'><span class='backlink-explanation'>These notes link here:</span><ul>")
+    for backlink in sorted(graph['backlinks'][headline_id], key=lambda x: graph['nodes'][x]['title']):
+        link = graph["nodes"][backlink]
+        title = link["title"]
+        content.append(f"<li><a class='internal backlink' href='./{backlink}.node.html'>{html.escape(title)}</a></li>")
+    content.append("</ul></div>")
+
 def render(headline, doc, graph, headlineLevel):
     try:
         dom = headline.as_dom()
@@ -586,6 +610,9 @@ def render(headline, doc, graph, headlineLevel):
 
     content = []
     render_tree(dom, content, headline, graph)
+    if headline.id:
+        render_connections(headline.id, content, graph)
+
     for child in headline.children:
         content.append(render(child, doc, headlineLevel=headlineLevel+1, graph=graph))
 
diff --git a/static/style.css b/static/style.css
index 60f8b3a..b9e6afd 100644
--- a/static/style.css
+++ b/static/style.css
@@ -173,6 +173,10 @@ h1 p,h2 p,h3 p,h4 p,h5 p,h6 p, li p {
   display: inline;
 }
 
+.connections ul {
+  margin-top: 0;
+}
+
 /* Headers */
 body > .node > h1 {
     text-align: center;