From 74d917df67f7b099ba477dfd6879a4a7c84b73dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20van=20Br=C3=BCgge?= <supermanitu@gmail.com>
Date: Fri, 22 Mar 2024 22:15:10 +0000
Subject: [PATCH] Add post lists for the tags

---
 blog.cabal                |  1 +
 src/Main.hs               | 19 +++++++++++--------
 static/main.css           |  5 ++---
 templates/postHeader.html |  2 +-
 templates/postList.html   |  3 +++
 5 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/blog.cabal b/blog.cabal
index ba94553..428bc3d 100644
--- a/blog.cabal
+++ b/blog.cabal
@@ -21,6 +21,7 @@ executable blog
                       , OverloadedStrings
                       , LambdaCase
     build-depends: base ^>=4.18.0.0
+                 , containers
                  , aeson
                  , slick
                  , shake
diff --git a/src/Main.hs b/src/Main.hs
index 806f311..68a4cba 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -12,7 +12,7 @@ import Data.Aeson.Types qualified as A
 import Data.Text qualified as T
 import Slick (markdownToHTML, compileTemplate', substitute)
 import Slick.Utils (convert)
-import qualified Data.Aeson.KeyMap as KM
+import Data.Aeson.KeyMap qualified as KM
 import Development.Shake.FilePath (dropDirectory1, (</>), dropExtension)
 import Data.Functor (void)
 import Data.Maybe (fromMaybe)
@@ -20,6 +20,7 @@ import Control.Monad (foldM)
 import Data.Aeson.Key (fromText)
 import Data.List (sortOn)
 import Data.Ord (Down(..))
+import Data.Set qualified as Set
 
 outputFolder :: FilePath
 outputFolder = "build/"
@@ -76,7 +77,9 @@ getRendered _ = error "Could not find content key in object"
 buildRules :: Action ()
 buildRules = do
   allPosts <- mapP buildPost =<< getDirectoryFiles "." ["articles//*.md"]
-  buildPostList allPosts
+  buildPostList Nothing allPosts
+  let allTags = Set.toList $ foldr (Set.union . Set.fromList . tags) Set.empty allPosts
+  void . forP allTags $ \tag -> buildPostList (Just (tag, "tags" </> tag)) (filter (elem tag . tags) allPosts)
   copyStaticFiles
 
 buildPost :: FilePath -> Action Post
@@ -93,15 +96,15 @@ buildPost srcPath = cacheAction ("build" :: T.Text, srcPath) $ do
   writeFile' (outputFolder </> T.unpack postUrl </> "index.html") . T.unpack $ rendered
   convert $ A.Object postData'
 
-buildPostList :: [Post] -> Action ()
-buildPostList posts = do
+buildPostList :: Maybe (String, FilePath) -> [Post] -> Action ()
+buildPostList tag posts = do
   let posts' = sortOn (Down . date) posts
-  let postData = A.Object $ KM.fromList
+  let postData = A.Object $ KM.fromList $
         [ (fromText "posts", A.toJSON posts')
-        , (fromText "prefix", A.String ".")
-        ]
+        , (fromText "prefix", A.String (maybe "." (const "../..") tag))
+        ] <> maybe [] (\(t, _) -> [(fromText "tag", A.String (T.pack t))]) tag
   rendered <- getRendered <$> renderTemplates postData ["postList.html", "shell.html"]
-  writeFile' (outputFolder </> "index.html") . T.unpack $ rendered
+  writeFile' (outputFolder <> maybe "" snd tag </> "index.html") . T.unpack $ rendered
 
 copyStaticFiles :: Action ()
 copyStaticFiles = do
diff --git a/static/main.css b/static/main.css
index 61c180f..6985b89 100644
--- a/static/main.css
+++ b/static/main.css
@@ -76,7 +76,6 @@ nav > ul {
 }
 
 main {
-  margin-top: 1.5em;
   height: auto;
   padding-bottom: 1em;
 
@@ -84,7 +83,7 @@ main {
   font-size: 18px;
 }
 
-article + article {
+article {
   margin-top: 2em;
 }
 
@@ -126,7 +125,7 @@ article > header ul {
   color: var(--secondary-text);
 }
 
-article > header li {
+.tag {
   border: 0.05em solid white;
   border-radius: 0.2em;
   padding: 0 0.2em;
diff --git a/templates/postHeader.html b/templates/postHeader.html
index 28910db..a06288d 100644
--- a/templates/postHeader.html
+++ b/templates/postHeader.html
@@ -3,7 +3,7 @@ <h1><a href="{{prefix}}/{{url}}">{{title}}</a></h1>
   <time datetime="{{date}}">{{readableDate}}</time>
   <ul>
     {{#tags}}
-    <li><a href="{{prefix}}/tags/{{.}}">{{.}}</a></li>
+    <li class="tag"><a href="{{prefix}}/tags/{{.}}">{{.}}</a></li>
     {{/tags}}
   </ul>
 </header>
diff --git a/templates/postList.html b/templates/postList.html
index 74cf1d7..68c4761 100644
--- a/templates/postList.html
+++ b/templates/postList.html
@@ -1,3 +1,6 @@
+{{#tag}}
+  <span>All posts in <span class="tag">{{.}}</span>:</span>
+{{/tag}}
 {{#posts}}
 <article>
   {{> templates/postHeader.html}}