From 72837b563531c32b37d8ac9374b7b72995cba08b Mon Sep 17 00:00:00 2001
From: Matt Haggard <haggardii@gmail.com>
Date: Mon, 28 Aug 2023 16:10:42 -0400
Subject: [PATCH] Add `fallback` option for falling back to another
 installation method

---
 README.md                                     | 18 ++++
 action.yml                                    |  4 +-
 ...new-Add-fallback-option-20230828-160957.md |  1 +
 install-nim.sh                                | 89 +++++++++++--------
 4 files changed, 74 insertions(+), 38 deletions(-)
 create mode 100644 changes/new-Add-fallback-option-20230828-160957.md

diff --git a/README.md b/README.md
index c23eebb..91974fe 100644
--- a/README.md
+++ b/README.md
@@ -86,6 +86,24 @@ jobs:
         nimble test
 ```
 
+## Fallback to a different install method
+
+```yaml
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - uses: iffy/install-nim@v4
+      with:
+        version: binary:stable
+        fallback: git:2382937843092342342556456
+    - name: Test
+      run: |
+        nimble install -y
+        nimble test
+```
+
 If you run into trouble with GitHub rate limits, set the `GITHUB_TOKEN` environment variable like this:
 
 ```yaml
diff --git a/action.yml b/action.yml
index 04c9fe9..af197a5 100644
--- a/action.yml
+++ b/action.yml
@@ -7,6 +7,8 @@ branding:
 inputs:
   version:
     default: stable
+  fallback:
+    default: ''
 
 runs:
   using: composite
@@ -15,4 +17,4 @@ runs:
     shell: bash
     run: |
       export SHELL=/bin/bash
-      "${GITHUB_ACTION_PATH}/install-nim.sh" '${{ inputs.version }}'
+      "${GITHUB_ACTION_PATH}/install-nim.sh" '${{ inputs.version }}' '${{ inputs.fallback }}'
diff --git a/changes/new-Add-fallback-option-20230828-160957.md b/changes/new-Add-fallback-option-20230828-160957.md
new file mode 100644
index 0000000..d02afd2
--- /dev/null
+++ b/changes/new-Add-fallback-option-20230828-160957.md
@@ -0,0 +1 @@
+Add `fallback` option for falling back to another installation method
diff --git a/install-nim.sh b/install-nim.sh
index 02dcc7a..4374c6e 100755
--- a/install-nim.sh
+++ b/install-nim.sh
@@ -7,7 +7,8 @@ usage() {
   cat <<EOF
 This script will install Nim for GitHub Actions from a variety of
 sources.  Provide a single command-line argument of the following
-format:
+format. Or provide multiple arguments to try each installation target
+until one succeeds:
 
   Using choosenim:
 
@@ -331,47 +332,61 @@ install_choosenim() {
   chmod u+x "${HOME}"/.choosenim/toolchains/*/bin/*
 }
 
-#------------------------------------------------
-# main
-#------------------------------------------------
-set -e
-TARGET=$1
-if [ -z "$TARGET" ]; then
-  usage
-  exit 1
-fi
+do_installation() {
+  TARGET="$1"
+  install_type=$(echo "$TARGET" | cut -d: -f1)
+  install_arg=$(echo "$TARGET" | cut -d: -f2-)
+  if [ "$install_type" == "$install_arg" ]; then
+    install_type="choosenim"
+  fi
 
-install_type=$(echo "$TARGET" | cut -d: -f1)
-install_arg=$(echo "$TARGET" | cut -d: -f2-)
-if [ "$install_type" == "$install_arg" ]; then
-  install_type="choosenim"
-fi
+  #------------------------------------------------
+  # Install Nim
+  #------------------------------------------------
+  echo "Install type: $install_type"
+  echo "       param: $install_arg"
+  (install_${install_type} "${install_arg}")
 
-#------------------------------------------------
-# Install Nim
-#------------------------------------------------
-echo "Install type: $install_type"
-echo "       param: $install_arg"
-(install_${install_type} "${install_arg}")
+  #------------------------------------------------
+  # Set up PATH
+  #------------------------------------------------
+  echo "Setting up PATH"
+  [ -f "$NIMDIR/bin/nim" ] && add-path "$(abspath "$NIMDIR/bin")"
+  [ -f "$(pwd)/$NIMDIR/bin/nim" ] && add-path "$(pwd)/$NIMDIR/bin"
+  add-path "$HOME/.nimble/bin" && add-path "$(abspath "$HOME/.nimble/bin")"
+  #[ -f "$HOME/.nimble/bin/nim" ] && add-path "$HOME/.nimble/bin" && add-path "$(abspath "$HOME/.nimble/bin")"
 
-#------------------------------------------------
-# Set up PATH
-#------------------------------------------------
-echo "Setting up PATH"
-[ -f "$NIMDIR/bin/nim" ] && add-path "$(abspath "$NIMDIR/bin")"
-[ -f "$(pwd)/$NIMDIR/bin/nim" ] && add-path "$(pwd)/$NIMDIR/bin"
-add-path "$HOME/.nimble/bin" && add-path "$(abspath "$HOME/.nimble/bin")"
-#[ -f "$HOME/.nimble/bin/nim" ] && add-path "$HOME/.nimble/bin" && add-path "$(abspath "$HOME/.nimble/bin")"
 
+  #------------------------------------------------
+  # DLLs
+  #------------------------------------------------
+  if [ -f "$HOME/.nimble/bin/nim" ]; then
+    ensure_dlls "$HOME/.nimble/bin"
+  elif [ -f "$NIMDIR/bin/nim" ]; then
+    ensure_dlls "$NIMDIR/bin"
+  else
+    echo "Nim doesn't seem to have been installed"
+  fi
+}
 
 #------------------------------------------------
-# DLLs
+# main
 #------------------------------------------------
-if [ -f "$HOME/.nimble/bin/nim" ]; then
-  ensure_dlls "$HOME/.nimble/bin"
-elif [ -f "$NIMDIR/bin/nim" ]; then
-  ensure_dlls "$NIMDIR/bin"
-else
-  echo "Nim doesn't seem to have been installed"
+set -e
+TARGETS="$@"
+if [ -z "$TARGETS" ]; then
+  usage
+  exit 1
 fi
-
+RC=1
+for TARGET in $TARGETS; do
+  if [ -z "$TARGET" ]; then
+    break
+  fi
+  echo "Trying $TARGET ..."
+  if do_installation "$TARGET"; then
+    RC=0
+    break
+  fi
+done
+exit "$RC"