2 files changed, 142 insertions, 0 deletions
diff --git a/web/blog/default.nix b/web/blog/default.nix
new file mode 100644
index 000000000000..05367588e3fb
--- /dev/null
+++ b/web/blog/default.nix
@@ -0,0 +1,41 @@
+# This creates the static files that make up my blog from the Markdown
+# files in this repository.
+#
+# All blog posts are rendered from Markdown by cheddar.
+{ depot, lib, pkgs, ... }@args:
+
+with depot.nix.yants;
+
+let
+  # Type definition for a single blog post.
+  post = struct "blog-post" {
+    key = string; #
+    title = string;
+    date = int;
+
+    # Optional time at which this post was last updated.
+    updated = option int;
+
+    # Path to the Markdown file containing the post content.
+    content = path;
+
+    # Should this post be included in the index? (defaults to true)
+    listed = option bool;
+
+    # Is this a draft? (adds a banner indicating that the link should
+    # not be shared)
+    draft = option bool;
+
+    # Previously each post title had a numeric ID. For these numeric
+    # IDs, redirects are generated so that old URLs stay compatible.
+    oldKey = option string;
+  };
+
+  posts = list post (import ./posts.nix);
+  fragments = import ./fragments.nix args;
+
+  includePost = post: !(fragments.isDraft post) && !(fragments.isUnlisted post);
+in {
+  inherit post includePost;
+  inherit (fragments) renderPost;
+}
diff --git a/web/blog/fragments.nix b/web/blog/fragments.nix
new file mode 100644
index 000000000000..eb46a09fd044
--- /dev/null
+++ b/web/blog/fragments.nix
@@ -0,0 +1,101 @@
+# This file defines various fragments of the blog, such as the header
+# and footer, as functions that receive arguments to be templated into
+# them.
+#
+# An entire post is rendered by `renderPost`, which assembles the
+# fragments together in a runCommand execution.
+#
+# The post index is generated by //users/tazjin/homepage, not by this
+# code.
+{ depot, lib, pkgs, ... }:
+
+let
+  inherit (builtins) filter map hasAttr replaceStrings;
+  inherit (pkgs) runCommandNoCC writeText;
+  inherit (depot.nix) renderMarkdown;
+
+  # Generate a post list for all listed, non-draft posts.
+  isDraft = post: (hasAttr "draft" post) && post.draft;
+  isUnlisted = post: (hasAttr "listed" post) && !post.listed;
+
+  escape = replaceStrings [ "<" ">" "&" "'" ] [ "&lt;" "&gt;" "&amp;" "&#39;" ];
+
+  header = title: ''
+  <!DOCTYPE html>
+  <head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <meta name="description" content="tazjin&#39;s blog">
+    <link rel="stylesheet" type="text/css" href="/static/tvl.css" media="all">
+    <link rel="icon" type="image/webp" href="/static/favicon.webp">
+    <link rel="alternate" type="application/atom+xml" title="Atom Feed" href="/feed.atom">
+    <title>tazjin&#39;s blog: ${escape title}</title>
+  </head>
+  <body class="light">
+    <header>
+      <h1><a class="blog-title" href="/">tazjin&#39;s interblag</a> </h1>
+      <hr>
+    </header>
+  '';
+
+  footer = ''
+    <hr>
+    <footer>
+      <p class="footer">
+        <a class="uncoloured-link" href="https://tazj.in">homepage</a>
+        |
+        <a class="uncoloured-link" href="https://cs.tvl.fyi/">code</a>
+      </p>
+      <p class="lod">ಠ_ಠ</p>
+    </footer>
+  </body>
+  '';
+
+  draftWarning = writeText "draft.html" ''
+    <p class="cheddar-callout cheddar-warning">
+      <b>Note:</b> This post is a <b>draft</b>! Please do not share
+      the link to it without asking me first.
+    </p>
+    <hr>
+  '';
+
+  unlistedWarning = writeText "unlisted.html" ''
+    <p class="cheddar-callout cheddar-warning">
+      <b>Note:</b> This post is <b>unlisted</b>! Please do not share
+      the link to it without asking me first.
+    </p>
+    <hr>
+  '';
+
+  renderPost = post: runCommandNoCC "${post.key}.html" {} ''
+    cat ${writeText "header.html" (header post.title)} > $out
+
+    # Write the post title & date
+    echo '<article><h2 class="inline">${escape post.title}</h2>' >> $out
+    echo '<aside class="date">' >> $out
+    date --date="@${toString post.date}" '+%Y-%m-%d' >> $out
+    ${
+      if post ? updated
+      then ''date --date="@${toString post.updated}" '+ (updated %Y-%m-%d)' >> $out''
+      else ""
+    }
+    echo '</aside>' >> $out
+
+    ${
+      # Add a warning to draft/unlisted posts to make it clear that
+      # people should not share the post.
+
+      if (isDraft post) then "cat ${draftWarning} >> $out"
+      else if (isUnlisted post) then "cat ${unlistedWarning} >> $out"
+      else "# Your ads could be here?"
+    }
+
+    # Write the actual post through cheddar's about-filter mechanism
+    cat ${renderMarkdown post.content} >> $out
+    echo '</article>' >> $out
+
+    cat ${writeText "footer.html" footer} >> $out
+  '';
+in {
+  inherit renderPost isDraft isUnlisted;
+}