From 7efd5b8317e6641abffc4251fec275922e7a6af0 Mon Sep 17 00:00:00 2001
From: valentin gagarin <valentin.gagarin@tweag.io>
Date: Wed, 13 Nov 2024 15:24:41 +0100
Subject: [PATCH] allow prefixing output paths of collection items

---
 website/content/default.nix             |  5 ++++-
 website/content/navigation.nix          |  4 +---
 website/content/news/project-launch.nix |  4 ++--
 website/lib.nix                         | 17 ++++++-----------
 website/presentation/default.nix        | 13 +++----------
 website/presentation/templates.nix      |  8 ++++----
 website/structure/article.nix           |  5 +----
 website/structure/default.nix           | 24 ++++++++++++++++++------
 website/structure/document.nix          | 11 ++++++++---
 website/structure/navigation.nix        |  9 +++++++--
 10 files changed, 54 insertions(+), 46 deletions(-)

diff --git a/website/content/default.nix b/website/content/default.nix
index 8cc4daa..c4d0f58 100644
--- a/website/content/default.nix
+++ b/website/content/default.nix
@@ -5,7 +5,10 @@ in
 {
   imports = lib.nixFiles ./.;
 
-  collections.news.type = config.content-types.article;
+  collections.news = {
+    type = config.content-types.article;
+    prefixes = [ "news" ];
+  };
 
   pages.index = { link, ... }: {
     title = "Fediversity";
diff --git a/website/content/navigation.nix b/website/content/navigation.nix
index f757762..20ca4d9 100644
--- a/website/content/navigation.nix
+++ b/website/content/navigation.nix
@@ -18,9 +18,7 @@ in
           in
           map
             (page: {
-              page = lib.recursiveUpdate page {
-                title = "${page.date}: ${page.title}";
-              };
+              page = lib.recursiveUpdate page { title = "${page.date}: ${page.title}"; };
             })
             (lib.take 3 sorted);
       }
diff --git a/website/content/news/project-launch.nix b/website/content/news/project-launch.nix
index bf86f22..05edc4c 100644
--- a/website/content/news/project-launch.nix
+++ b/website/content/news/project-launch.nix
@@ -1,6 +1,6 @@
-{ ... }:
+{ config, lib, ... }:
 {
-  collections.news.entry = {
+  collections.news.entry = { link, ... }: {
     title = "Fediversity project publicly announced";
     description = "The Fediversity project has officially been announced";
     date = "2024-01-01";
diff --git a/website/lib.nix b/website/lib.nix
index cedef3c..5071c0b 100644
--- a/website/lib.nix
+++ b/website/lib.nix
@@ -52,16 +52,17 @@ rec {
       inherit (lib) lists;
 
       path1 = subpath.components path1';
+      prefix1 = with lib; take (length path1 - 1) path1;
       path2 = subpath.components path2';
+      prefix2 = with lib; take (length path1 - 1) path2;
 
       commonPrefixLength = with lists;
         findFirstIndex (i: i.fst != i.snd)
-          { fst = null; snd = null; }
-          (zipLists path1 path2);
+          (length prefix1)
+          (zipLists prefix1 prefix2);
 
       relativeComponents = with lists;
-        [ "." ] ++ (replicate (length path1 - commonPrefixLength - 1) "..") ++
-        (drop commonPrefixLength path2);
+        [ "." ] ++ (replicate (length prefix1 - commonPrefixLength) "..") ++ (drop commonPrefixLength path2);
     in
     join "/" relativeComponents;
 
@@ -98,13 +99,7 @@ rec {
         merge = loc: defs:
           map
             (def:
-              let
-                merged = lib.mergeDefinitions
-                  (loc ++ [ "[definition ${toString def.file}]" ])
-                  elemType
-                  [{ inherit (def) file; value = def.value; }];
-              in
-              if merged ? mergedValue then merged.mergedValue else merged.value
+              elemType.merge (loc ++ [ "[definition ${toString def.file}]" ]) [{ inherit (def) file; value = def.value; }]
             )
             defs;
         check = elemType.check;
diff --git a/website/presentation/default.nix b/website/presentation/default.nix
index 7c472dd..69fa34c 100644
--- a/website/presentation/default.nix
+++ b/website/presentation/default.nix
@@ -41,7 +41,7 @@ in
           <link rel="canonical" href="${page.outPath}" />
         '';
         body = ''
-          ${templates.nav { menu = { menu = config.menus.main; }; }}
+          ${templates.nav { inherit page; menu = { menu = config.menus.main; }; }}
           ${builtins.readFile (commonmark page.name page.body)}
         '';
       });
@@ -55,7 +55,7 @@ in
           }
         '';
         body = ''
-          ${templates.nav { menu = { menu = config.menus.main; }; }}
+          ${templates.nav { inherit page; menu = { menu = config.menus.main; }; }}
           ${builtins.readFile (commonmark page.name page.body)}
         '';
       });
@@ -76,20 +76,13 @@ in
     let
       pages = lib.attrValues config.pages;
       collections = with lib; concatMap (collection: collection.entry) (attrValues config.collections);
-      collections' = with lib; map
-        (
-          entry: recursiveUpdate entry {
-            locations = map (l: "${entry.collection.name}/${l}") entry.locations;
-          }
-        )
-        collections;
     in
     with lib; foldl
       (acc: elem: acc // {
         "${head elem.locations}" = builtins.toFile "${elem.name}.html" elem.outputs.html;
       })
       { }
-      (pages ++ collections');
+      (pages ++ collections);
 
   options.build = mkOption {
     description = ''
diff --git a/website/presentation/templates.nix b/website/presentation/templates.nix
index f412442..f4567aa 100644
--- a/website/presentation/templates.nix
+++ b/website/presentation/templates.nix
@@ -14,23 +14,23 @@ rec {
       <body>
     </html>
   '';
-  nav = { menu }:
+  nav = { page, menu }:
     let
       render-item = item:
         if item ? menu then
           ''
             <li>${item.menu.label}
-            ${lib.indent "  " (nav { menu = item; })}
+            ${lib.indent "  " (nav { inherit page; menu = item; })}
           ''
         else
-          if item ? page then ''<li><a href="${item.page}">${item.page.title}</a></li>''
+          if item ? page then ''<li><a href="${page.link item.page}">${item.page.title}</a></li>''
           else ''<li><a href="${item.link.url}">${item.link.label}</a></li>''
       ;
     in
     ''
       <nav>
         <ul>
-        ${with lib; indent "    " (join "\n" (map render-item menu.menu.items))}
+          ${with lib; indent "    " (join "\n" (map render-item menu.menu.items))}
         </ul>
       </nav>
     '';
diff --git a/website/structure/article.nix b/website/structure/article.nix
index 2cc82c1..ca7495d 100644
--- a/website/structure/article.nix
+++ b/website/structure/article.nix
@@ -7,7 +7,7 @@ let
   cfg = config;
 in
 {
-  content-types. article = { config, collection, ... }: {
+  content-types.article = { config, collection, ... }: {
     imports = [ cfg.content-types.page ];
     options = {
       collection = mkOption {
@@ -27,9 +27,6 @@ in
       };
     };
     config.name = lib.slug config.title;
-    # TODO: this should be covered by the TBD `link` function instead,
-    #       taking a historical list of collection names into account
-    config.outPath = "${collection.name}/${lib.head config.locations}";
     config.outputs.html = lib.mkForce (cfg.templates.html.article cfg config);
   };
 }
diff --git a/website/structure/default.nix b/website/structure/default.nix
index 4150f25..6c2f541 100644
--- a/website/structure/default.nix
+++ b/website/structure/default.nix
@@ -52,13 +52,25 @@ in
             type = types.str;
             default = name;
           };
-          entry = mkOption {
-            description = "An entry in the collection";
-            type = types.collection (types.submodule ({
-              _module.args.collection = config;
-              imports = [ config.type ];
-            }));
+          prefixes = mkOption {
+            description = ''
+              List of historic output locations for files in the collection
+
+              The first element is the canonical location.
+              All other elements are used to create redirects to the canonical location.
+            '';
+            type = with types; nonEmptyListOf str;
+            example = [ "." ];
           };
+          entry = mkOption
+            {
+              description = "An entry in the collection";
+              type = types.collection (types.submodule ({
+                imports = [ config.type ];
+                _module.args.collection = config;
+                process-locations = ls: with lib; concatMap (l: map (p: "${p}/${l}") config.prefixes) ls;
+              }));
+            };
         };
       }));
     };
diff --git a/website/structure/document.nix b/website/structure/document.nix
index ba02c7f..285e8ac 100644
--- a/website/structure/document.nix
+++ b/website/structure/document.nix
@@ -6,7 +6,7 @@ let
     ;
 in
 {
-  content-types.document = { name, config, link, ... }: {
+  content-types.document = { name, config, options, link, ... }: {
     config._module.args.link = config.link;
     options = {
       name = mkOption {
@@ -17,7 +17,6 @@ in
       # TODO: reconsider using `page.outPath` and what to put into `locations`.
       #       maybe we can avoid having ".html" suffixes there.
       #       since templates can output multiple files, `html` is merely one of many things we *could* produce.
-      # TODO: make `apply` configurable so one can programmatically modify locations
       locations = mkOption {
         description = ''
           List of historic output locations for the resulting file
@@ -26,11 +25,17 @@ in
           All other elements are used to create redirects to the canonical location.
         '';
         type = with types; nonEmptyListOf str;
+        apply = config.process-locations;
+      };
+      process-locations = mkOption {
+        description = "Function to post-process the output locations of contained document";
+        type = types.functionTo options.locations.type;
+        default = lib.id;
       };
       link = mkOption {
         description = "Helper function for transparent linking to other pages";
         type = with types; functionTo str;
-        default = target: with lib; relativePath (head config.locations) (head target.locations);
+        default = target: with lib; relativePath config.outPath target.outPath;
       };
       # TODO: may not need it when using `link`; could repurpose it to render the default template
       outPath = mkOption {
diff --git a/website/structure/navigation.nix b/website/structure/navigation.nix
index 17bae29..1267027 100644
--- a/website/structure/navigation.nix
+++ b/website/structure/navigation.nix
@@ -1,4 +1,4 @@
-{ config, lib, ... }:
+{ config, options, lib, ... }:
 let
   inherit (lib)
     mkOption
@@ -7,7 +7,12 @@ let
   cfg = config;
   subtype = baseModule: types.submodule [
     baseModule
-    { _module.freeformType = types.attrs; }
+    {
+      _module.freeformType = types.attrs;
+      # XXX: this is supposed to be used with a finished value,
+      #      and we don't want to process locations again.
+      process-locations = lib.mkForce lib.id;
+    }
   ];
 in
 {