From fb892d5553e92940c904b5e86b12a89527a2ae14 Mon Sep 17 00:00:00 2001
From: Charles Baynham <c.baynham@imperial.ac.uk>
Date: Fri, 17 Jan 2025 12:17:47 +0000
Subject: [PATCH] Build all years in the github pipeline

Also provide individual years as nix outputs, for local building using
e.g.
`nix build .#pdf-2025`
---
 .github/workflows/build.yml | 33 ++++++++--------
 flake.nix                   | 77 ++++++++++++++++++++++++++++---------
 2 files changed, 75 insertions(+), 35 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 9b61ef5b..09c7bdc5 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,21 +1,22 @@
-name: "Build 2023"
+name: "Build all PDFs"
 on:
-  pull_request:
   push:
 jobs:
-  build:
+  build-pdfs:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        build-output: ["pdf-all", "pdf-next"]
     steps:
-    - uses: actions/checkout@v3
-    - uses: cachix/install-nix-action@v19
-    - name: Build PDFs
-      run: nix build
-    - name: Copy PDFs
-      run: cp result/*.pdf .
-    - name: Output PDFs
-      uses: actions/upload-artifact@v3
-      with:
-        name: result
-        path: ./*.pdf
-        if-no-files-found: error
-
+      - uses: actions/checkout@v3
+      - uses: cachix/install-nix-action@v19
+      - name: Build PDFs
+        run: nix build .#${{ matrix.build-output }}
+      - name: Copy PDFs
+        run: cp result/*.pdf .
+      - name: Output PDFs
+        uses: actions/upload-artifact@v3
+        with:
+          name: result
+          path: ./*.pdf
+          if-no-files-found: error
diff --git a/flake.nix b/flake.nix
index 6a92db38..e18029f9 100644
--- a/flake.nix
+++ b/flake.nix
@@ -51,6 +51,7 @@
               ;
           })
         ];
+
       in
       rec
       {
@@ -65,27 +66,65 @@
           ] ++ goDeps ++ texDeps;
         };
 
-        defaultPackage = pdfs;
+        defaultPackage = packages.pdf-next;
 
-        pdfs = pkgs.stdenv.mkDerivation
-          {
-            name = "pdfs";
-            # Minimal set of dependencies to build the pdfs
-            # Latex, "rev" and the built plannergen binary
-            buildInputs = texDeps ++ [ plannergen ];
-            PLANNER_YEAR = 2023;
-            src = "${self}";
-            buildCommand = ''
-              cp -r $src/* .
-              patchShebangs .
-              chmod -R 770 *
-              chmod +x *.sh
-              PLANNERGEN_BINARY=plannergen eval $PWD/build.sh
-              mkdir $out
-              cp *.pdf $out/.
-            '';
-          };
+        packages =
+          let
+            # Next year, as a string
+            next-year = builtins.readFile (
+              pkgs.stdenv.mkDerivation {
+                name = "current-year";
+                buildInputs = [ pkgs.coreutils ];
+                buildCommand = ''
+                  date -d "+1 year" +%Y > $out
+                '';
+              });
+
+            # List of years to always build
+            build-years = [
+              "2025"
+              "2026"
+              "2027"
+              "2028"
+              "2029"
+              "2030"
+            ];
 
+            # Function that, given a year, builds a pdf for it
+            make-PDF = year: pkgs.stdenv.mkDerivation
+              {
+                name = "pdfs";
+                # Minimal set of dependencies to build the pdfs:
+                # Latex and the built plannergen binary
+                buildInputs = texDeps ++ [ plannergen ];
+                src = "${self}";
+                buildCommand = ''
+                  cp -r $src/* .
+                  patchShebangs .
+                  chmod -R 770 *
+                  chmod +x *.sh
+                  PLANNERGEN_BINARY=plannergen eval $PWD/build.sh ${year}
+                  mkdir $out
+                  cp *.pdf $out/.
+                '';
+              };
+
+            list-of-pdfs = map (y: { name = "pdf-${y}"; value = make-PDF y; }) build-years;
+          in
+          builtins.listToAttrs list-of-pdfs
+          // {
+            # Append next year's pdf which is the default output
+            pdf-next = make-PDF next-year;
+
+            # Also output all pdfs in the same derivation for the GitHub action
+            pdf-all = pkgs.stdenv.mkDerivation {
+              name = "all-pdfs";
+              buildCommand = ''
+                mkdir $out
+                cp -r ${builtins.concatStringsSep " " (map (x: "${x.value}/*" ) list-of-pdfs)} $out/.
+              '';
+            };
+          };
       }
     );
 }