#!/bin/sh
# FadeHost Bridge installer for Linux and macOS.
#
# Downloads the bridge program for this machine from the FadeHost release
# feed, checks it against the sha256 the feed publishes and installs it for
# the current user (no root needed, and the program can then keep itself
# up to date).
#
#   curl -fsSL https://fadehost.com/bridge/install.sh | sh
#
# BRIDGE_INSTALL_DIR chooses another directory than ~/.local/bin.
set -eu

API="${BRIDGE_API:-https://services.fadehost.com}"
DIR="${BRIDGE_INSTALL_DIR:-$HOME/.local/bin}"

fail() {
  echo "bridge: $1" >&2
  exit 1
}

os=$(uname -s | tr '[:upper:]' '[:lower:]')
case "$os" in
  linux | darwin) ;;
  *) fail "this installer covers Linux and macOS. On Windows, download bridge.exe from https://fadehost.com/bridge/" ;;
esac

arch=$(uname -m)
case "$arch" in
  x86_64 | amd64) arch=amd64 ;;
  arm64 | aarch64) arch=arm64 ;;
  *) fail "there is no build for $arch yet" ;;
esac

name="bridge-$os-$arch"

fetch() {
  if command -v curl >/dev/null 2>&1; then
    curl -fsSL "$1"
  elif command -v wget >/dev/null 2>&1; then
    wget -qO- "$1"
  else
    fail "curl or wget is needed"
  fi
}

latest=$(fetch "$API/api/bridge/agent/latest") || fail "could not reach the release feed"
version=$(printf '%s' "$latest" | sed -n 's/.*"version":"\([0-9.]*\)".*/\1/p')
sha=$(printf '%s' "$latest" | tr '{' '\n' | grep "\"name\":\"$name\"" | sed -n 's/.*"sha256":"\([a-f0-9]*\)".*/\1/p')
[ -n "$version" ] || fail "could not read the version from the release feed"
[ -n "$sha" ] || fail "version $version has no build for $os/$arch"

tmp=$(mktemp)
trap 'rm -f "$tmp"' EXIT
echo "Downloading bridge $version for $os/$arch..."
fetch "$API/api/bridge/agent/download/$name?version=$version" >"$tmp" || fail "the download failed"

if command -v sha256sum >/dev/null 2>&1; then
  got=$(sha256sum "$tmp" | cut -d' ' -f1)
else
  got=$(shasum -a 256 "$tmp" | cut -d' ' -f1)
fi
[ "$got" = "$sha" ] || fail "the download does not match its sha256, nothing was installed"

mkdir -p "$DIR"
chmod 755 "$tmp"
mv "$tmp" "$DIR/bridge"
trap - EXIT

echo "bridge $version is installed at $DIR/bridge"
case ":$PATH:" in
  *":$DIR:"*)
    echo "Start it with: bridge"
    ;;
  *)
    echo "Start it with: $DIR/bridge"
    echo "To call it as bridge, add this line to your shell profile:"
    echo "  export PATH=\"$DIR:\$PATH\""
    ;;
esac