zig-dev-bin: Automatically update to the latest nightly version

zig-dev-bin/PKGBUILD

@@ -1,32 +1,101 @@
 # Maintainer: Kaizhao Zhang <zhangkaizhao@gmail.com>
-
-_buildver=0.10.0-dev.2977+7d2e14267
+# Contributor: Techcable <$USER @ techcable.net>
 
 pkgname=zig-dev-bin
-pkgver=20220712
+# Old versions of zig-dev-bin used date as pkgver (pkgver=20220712)
+#
+# Now we use something consistent with zig internal versioning.
+# Without changing the epoch, the old version scheme would be considered
+# "newer" greater than the new version scheme
+epoch=1
+# NOTE: Hyphen -> underscore
+pkgver=0.10.0_dev.3475+b3d463c9e
 pkgrel=1
 pkgdesc="A general-purpose programming language and toolchain for maintaining robust, optimal, and reusable software"
-arch=('x86_64')
+arch=('x86_64' 'aarch64')
 url="https://ziglang.org/"
 license=('MIT')
+makedepends=(curl jq)
 options=('!strip')
 provides=('zig')
 conflicts=('zig')
-source=(
-  "https://ziglang.org/builds/zig-linux-x86_64-${_buildver}.tar.xz"
-)
-sha256sums=(
-  '22faf5006338de0682bb4c62dc0f73e4df5fb837ecaff21570e4ed39dc63b9c1'
-)
+# NOTE: We don't include the "real" source until build()
+source=()
+# GPG verification is not currently possible because Zig binaries aren't signed
+# Hardcoded sha256 not possible because this is a an auto-updating (nightly) package
+#
+# Zig Issue for signed binaries: https://github.com/ziglang/zig/issues/4945
+sha256sums=()
+
+pkgver() {
+    local index_file="${srcdir}/zig-version-index.json";
+    # Invalidate old verison-index.json
+    #
+    # If we put version-index in `source` then it would be cached...
+    if [[ -x "$index_file" ]]; then
+        rm "$index_file";
+    fi
+    curl -sS "https://ziglang.org/download/index.json" -o "$index_file"
+    jq -r .master.version "$index_file" | sed 's/-/_/'
+}
+
+prepare() {
+    local newver="$(pkgver)";
+    pushd "${srcdir}" > /dev/null;
+    local index_file="zig-version-index.json";
+    local newurl="$(jq -r ".master.\"${CARCH}-linux\".tarball" $index_file)";
+    local newfile="zig-linux-${CARCH}-${newver}.tar.xz";
+    source+=("${newfile}:${newurl}")
+    local expected_hash="$(jq -r ".master.\"${CARCH}-linux\".shasum" "$index_file")"
+    sha256sums+=("$newhash")
+    if [[ -f "$newfile" ]]; then
+        echo "Reusing existing $newfile";
+    else
+        echo "Downloading Zig $newver from $newurl" >&2;
+        curl -Ss "$newurl" -o "$newfile";
+    fi;
+    echo "" >&2
+    echo "WARNING: No way to GPG/SHA verify the version ahead of time" >&2
+    echo "See Zig issue https://github.com/ziglang/zig/issues/4945 for signed binaries" >&2;
+    echo "" >&2;
+    local actual_hash="$(sha256sum "$newfile" | grep -oE '^\w+')"
+    if [[ "$expected_hash" != "$actual_hash" ]]; then
+        echo "ERROR: Expected hash $expected_hash for $newfile, but got $actual_hash" >&2;
+        exit 1;
+    fi;
+    echo "Extracting file";
+    tar -xf "$newfile";
+    popd > /dev/null;
+}
 
 package() {
-  cd "${srcdir}/zig-linux-x86_64-${_buildver}"
+  cd "${srcdir}/zig-linux-${CARCH}-${pkgver//_/-}"
   install -d "${pkgdir}/usr/bin"
   install -d "${pkgdir}/usr/lib/zig"
   cp -R lib "${pkgdir}/usr/lib/zig/lib"
   install -D -m755 zig "${pkgdir}/usr/lib/zig/zig"
   ln -s /usr/lib/zig/zig "${pkgdir}/usr/bin/zig"
-  install -D -m644 docs/langref.html "${pkgdir}/usr/share/doc/zig/langref.html"
-  cp -R docs/std "${pkgdir}/usr/share/doc/zig/"
+  # Old versions had a `docs` dir in the root dir
+  local langref_docs="${pkgdir}/usr/share/doc/zig/langref.html";
+  if [[ -d "docs" ]]; then
+    install -D -m644 docs/zig/langref.html "$langref_docs";
+    cp -R docs/std "${pkgdir}/usr/share/doc/zig/";
+  elif [[ -f "langref.html" ]]; then
+    # New versions have langref in the root dir,
+    # stdlib docs in lib/zig/docs
+    #
+    # The first install command implicitly creates
+    # the doc directory needed by stdlib :(
+    #
+    # NOTE: Currently missing data.js file
+    #
+    # https://ziglang.org/documentation/master/std/data.js
+    # TODO: Maybe just download it seperately from the tarball?
+    install -D -m644 langref.html "$langref_docs";
+    cp -R lib/zig/docs "${pkgdir}/usr/share/doc/zig/std";
+  else
+    echo "Unable to find docs!" >&2;
+    exit 1;
+  fi;
   install -D -m644 LICENSE "${pkgdir}/usr/share/licenses/zig/LICENSE"
 }