Fix extension setup script

.gitignore

@@ -1,3 +1,4 @@
 dist/
+bin/
 coverage.out
 ghsetup

gh-setup

@@ -1,53 +1,69 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 
-repo="github.com/k1LoW/gh-setup"
+# Get extension repository path
+extPath="$(dirname "$0")"
 
-extensionPath="$(dirname "$0")"
-cd "${extensionPath}" > /dev/null
-tag="$(git tag | tail -1)"
+# Get latest version
+cd "${extPath}" > /dev/null
+ver="$(git tag | grep ^v | sort --version-sort | tail -1)"
+if [ "${ver}" = "" ]; then
+  git fetch --tags > /dev/null 2>&1
+  ver="$(git tag | grep ^v | sort --version-sort | tail -1)"
+fi
 cd - > /dev/null
 
+# Get arch
 arch="$(uname -m)"
 
-exe=""
-
+# Get binary file name
+exe="gh-setup" # default
 if uname -a | grep Msys > /dev/null; then
-  if [ $arch = "x86_64" ]; then
-    exe="gh-setup_${tag}_windows_amd64.exe"
+  if [ "${arch}" = "x86_64" ]; then
+    exe="gh-setup_${ver}_windows_amd64.exe"
   fi
 elif uname -a | grep Darwin > /dev/null; then
-  if [ $arch = "x86_64" ]; then
-    exe="gh-setup_${tag}_darwin_amd64"
-  elif [ $arch = "arm64" ]; then
-    exe="gh-setup_${tag}_darwin_arm64"
+  if [ "${arch}" = "x86_64" ]; then
+    exe="gh-setup_${ver}_darwin_amd64"
+  elif [ "${arch}" = "arm64" ]; then
+    exe="gh-setup_${ver}_darwin_arm64"
   fi
 elif uname -a | grep Linux > /dev/null; then
-  if [ $arch = "x86_64" ]; then
-    exe="gh-setup_${tag}_linux_amd64"
+  if [ "${arch}" = "x86_64" ]; then
+    exe="gh-setup_${ver}_linux_amd64"
+  elif [ "${arch}" = "arm64" ] || [ "${arch}" = "aarch64" ]; then
+    exe="gh-setup_${ver}_linux_arm64"
   fi
 fi
 
-if [ "${exe}" == "" ]; then
+# Cleanup bin/ dir
+rm -f "${extPath}/bin/*"
+mkdir -p "${extPath}/bin"
+
+binPath="${extPath}/bin/${exe}"
+
+if [ "${exe}" == "gh-setup" ]; then
+  # Build binary
   if [ "$(which go)" = "" ]; then
     echo "go must be installed to use this gh extension on this platform"
     exit 1
   fi
 
   exe="cmd.out"
 
-  cd "${extensionPath}" > /dev/null
-  go build -o "${exe}" cmd/gh-setup/main.go
+  cd "${extPath}" > /dev/null
+  go build -o "${binPath}"
   cd - > /dev/null
-  mv "${exe}" "${extensionPath}/bin/${exe}"
-  chmod +x "${extensionPath}/bin/${exe}"
 else
-  if [[ ! -x "${extensionPath}/bin/${exe}" ]]; then
-    mkdir -p "${extensionPath}/bin"
-    rm -f ${extensionPath}/bin/gh-setup*
-    gh release -R "${repo}" download "${tag}" -p "${exe}" --dir="${extensionPath}/bin"
-    chmod +x "${extensionPath}/bin/${exe}"
+  # Download release binary
+  if [[ ! -x "${binPath}" ]]; then
+    if [ "$(which curl)" = "" ]; then
+      echo "curl must be installed to use this gh extension on this platform"
+      exit 1
+    fi
+    curl -sL -o "${binPath}" "https://github.com/k1LoW/gh-setup/releases/download/${ver}/${exe}"
   fi
 fi
+chmod +x "${binPath}"
 
-exec "${extensionPath}/bin/${exe}" "$@"
+exec "${binPath}" "$@"