#!/bin/sh
# Installs `surf` into ~/.surf/bin (ADR-0101).
#
#   curl -fsSL https://git.solenovis.com/henning.liemant/surface/raw/branch/main/scripts/install.sh | sh
#
# SURF_HOME changes the folder ~/.surf. SURF_VERSION chooses a version: the default is the newest
# release.
set -eu

# The address of the releases. crates/surf-cli/src/toolchain.rs has the same address.
RELEASES=${SURF_RELEASES:-https://git.solenovis.com/henning.liemant/surface/releases}

fail() {
  echo "install.sh: $1" >&2
  exit 1
}

case "$(uname -s) $(uname -m)" in
  "Darwin arm64") host=aarch64-apple-darwin ;;
  "Linux x86_64") host=x86_64-unknown-linux-gnu ;;
  *) fail "surf has no release for $(uname -s) $(uname -m)" ;;
esac

for tool in curl tar; do
  command -v "$tool" > /dev/null 2>&1 || fail "this script needs $tool"
done

# An https address must not go to http after a redirect. A mirror on http keeps its redirects.
case "$RELEASES" in
  https://*) https_only="--proto =https --proto-redir =https" ;;
  *) https_only= ;;
esac

# Downloads with the options of this script. The options of https_only are separate words.
get() {
  # shellcheck disable=SC2086
  curl -fsSL $https_only "$@"
}

sha256() {
  if command -v sha256sum > /dev/null 2>&1; then
    sha256sum "$1" | cut -d ' ' -f 1
  elif command -v shasum > /dev/null 2>&1; then
    shasum -a 256 "$1" | cut -d ' ' -f 1
  else
    fail "this script needs sha256sum or shasum"
  fi
}

# The page of the newest release ends with its tag.
if [ -z "${SURF_VERSION:-}" ]; then
  page=$(get -o /dev/null -w '%{url_effective}' "$RELEASES/latest") || fail "cannot read $RELEASES/latest"
  SURF_VERSION=${page##*/v}
  case "$SURF_VERSION" in
    [0-9]*) ;;
    *) fail "$RELEASES/latest does not name a version. It goes to $page" ;;
  esac
fi

archive=surf-$host.tar.gz
address=$RELEASES/download/v$SURF_VERSION
work=$(mktemp -d)
trap 'rm -rf "$work"' EXIT

echo "downloading surf $SURF_VERSION for $host"
get -o "$work/SHA256SUMS" "$address/SHA256SUMS" || fail "cannot download $address/SHA256SUMS"
get -o "$work/$archive" "$address/$archive" || fail "cannot download $address/$archive"

wanted=$(awk -v file="$archive" '$2 == file { print $1 }' "$work/SHA256SUMS")
[ -n "$wanted" ] || fail "SHA256SUMS has no line for $archive"
found=$(sha256 "$work/$archive")
[ "$found" = "$wanted" ] || fail "the SHA-256 of $archive is not correct. Expected $wanted, found $found"

tar -xzf "$work/$archive" -C "$work"
bin=${SURF_HOME:-$HOME/.surf}/bin
mkdir -p "$bin"
mv "$work/surf" "$bin/surf"
echo "surf $SURF_VERSION is in $bin"

case ":$PATH:" in
  *":$bin:"*) ;;
  *)
    echo "Add this line to the profile of your shell:"
    echo "  export PATH=\"$bin:\$PATH\""
    ;;
esac