From 4fdb56e43601716c8a2654057a0c9fbf426d641d 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] implement raw assets

this allows adding files to the output as they are
---
 presentation/templates.nix | 13 +++++++++++++
 structure/assets.nix       | 35 +++++++++++++++++++++++++++++++++++
 structure/collections.nix  | 12 ++++--------
 structure/default.nix      | 21 +++++++++++++++++++--
 structure/page.nix         | 11 ++---------
 5 files changed, 73 insertions(+), 19 deletions(-)
 create mode 100644 structure/assets.nix

diff --git a/presentation/templates.nix b/presentation/templates.nix
index 7a688f70..d23ee1fb 100644
--- a/presentation/templates.nix
+++ b/presentation/templates.nix
@@ -49,4 +49,17 @@ in
         </nav>
       '';
   };
+
+  config.templates.files = fs: with lib;
+    foldl'
+      # TODO: create static redirects from `tail <collection>.locations`
+      (acc: elem: acc // (mapAttrs' (type: value: {
+        name = head elem.locations + optionalString (type != "") ".${type}";
+        value = builtins.toFile
+          (elem.name + optionalString (type != "") ".${type}")
+          (toString value);
+      }))
+        elem.outputs)
+      { }
+      fs;
 }
diff --git a/structure/assets.nix b/structure/assets.nix
new file mode 100644
index 00000000..ff534286
--- /dev/null
+++ b/structure/assets.nix
@@ -0,0 +1,35 @@
+{ config, lib, ... }:
+let
+  inherit (lib)
+    mkOption
+    types
+    ;
+  cfg = config;
+in
+{
+  options.assets = mkOption {
+    description = ''
+      Collection of assets, i.e. static files that can be linked to from within documents
+    '';
+    type = with types; attrsOf (submodule ({ config, ... }: {
+      imports = [ cfg.content-types.document ];
+      options.path = mkOption {
+        type = types.path;
+      };
+      config.name = builtins.baseNameOf config.path;
+      config.outputs."" = builtins.readFile config.path;
+    }));
+    default = { };
+  };
+
+  config.files = with lib;
+    let
+      flatten = attrs: mapAttrsToList
+        (name: value:
+          # HACK: we somehow have to distinguish a module value from regular attributes.
+          #       arbitrary choice: the outputs attribute
+          if value ? outputs then value else mapAttrsToList value)
+        attrs;
+    in
+    cfg.templates.files (flatten cfg.assets);
+}
diff --git a/structure/collections.nix b/structure/collections.nix
index 7dd12610..a4f4fa66 100644
--- a/structure/collections.nix
+++ b/structure/collections.nix
@@ -61,15 +61,11 @@ in
       };
     }));
   };
+
   config.files =
-    # TODO: create static redirects from `tail <collection>.locations`
+    with lib;
     let
-      collections = with lib; concatMap (collection: collection.entry) (attrValues config.collections);
+      collections = concatMap (collection: collection.entry) (attrValues config.collections);
     in
-    with lib; foldl
-      (acc: elem: acc // {
-        "${head elem.locations}.html" = builtins.toFile "${elem.name}.html" "${elem.outputs.html}";
-      })
-      { }
-      collections;
+    cfg.templates.files collections;
 }
diff --git a/structure/default.nix b/structure/default.nix
index 62102927..a13bb95f 100644
--- a/structure/default.nix
+++ b/structure/default.nix
@@ -47,11 +47,28 @@ in
       };
       link = mkOption {
         description = "Helper function for transparent linking to other pages";
-        type = with types; functionTo str;
+        type = with types; functionTo attrs;
         # TODO: we may want links to other representations,
         #       and currently the mapping of output types to output file
         #       names is soft.
-        default = target: with lib; "${relativePath (head config.locations) (head target.locations)}.html";
+        default = with lib; target:
+          let
+            path = relativePath (head config.locations) (head target.locations);
+            links = mapAttrs
+              (type: output:
+                path + optionalString (type != "") ".${type}"
+                #                     ^^^^^^^^^^^^
+                #               convention for raw files
+              )
+              target.outputs;
+          in
+          if length (attrValues links) == 0
+          then throw "no output to link to for '${target.name}'"
+          else if length (attrValues links) == 1
+          then links // {
+            __toString = _: head (attrValues links);
+          }
+          else links;
       };
       outputs = mkOption {
         description = ''
diff --git a/structure/page.nix b/structure/page.nix
index 6c20719c..3578385b 100644
--- a/structure/page.nix
+++ b/structure/page.nix
@@ -14,15 +14,8 @@ in
     '';
     type = with types; attrsOf (submodule config.content-types.page);
   };
-  config.files = with lib;
-    foldl'
-      (acc: elem: acc // {
-        # TODO: create static redirects from `tail page.locations`
-        # TODO: the file name could correspond to the canonical location in the HTML representation
-        "${head elem.locations}.html" = builtins.toFile "${elem.name}.html" "${elem.outputs.html}";
-      })
-      { }
-      (attrValues config.pages);
+
+  config.files = with lib; cfg.templates.files (attrValues config.pages);
 
   config.content-types.page = { name, config, ... }: {
     imports = [ cfg.content-types.document ];