#!/bin/sh
# Polign installer. Downloads the latest polign_db release for this machine,
# verifies its checksum, and puts the binaries on your PATH.
#
#   curl -fsSL https://get.polign.com | sh
#
# Options, set as environment variables:
#   POLIGN_VERSION   install a specific version, e.g. v0.2.1 (default: latest)
#   POLIGN_BIN_DIR   install directory (default: /usr/local/bin when writable,
#                    otherwise ~/.local/bin)
set -eu

DL="https://dl.polign.com"

fail() { echo "install failed: $1" >&2; exit 1; }

command -v curl >/dev/null 2>&1 || fail "curl is required"
command -v tar >/dev/null 2>&1 || fail "tar is required"

os=$(uname -s)
case "$os" in
  Linux) os=linux ;;
  Darwin) os=darwin ;;
  *) fail "unsupported operating system: $os (releases cover linux and darwin)" ;;
esac

arch=$(uname -m)
case "$arch" in
  x86_64 | amd64) arch=amd64 ;;
  arm64 | aarch64) arch=arm64 ;;
  *) fail "unsupported architecture: $arch (releases cover amd64 and arm64)" ;;
esac

version=${POLIGN_VERSION:-$(curl -fsSL "$DL/latest/version")} ||
  fail "could not resolve the latest version"
case "$version" in
  v*) ;;
  *) fail "unexpected version \"$version\"" ;;
esac

asset="polign_db_${os}_${arch}.tar.gz"
tmp=$(mktemp -d)
trap 'rm -rf "$tmp"' EXIT

echo "downloading polign_db $version for $os/$arch ..."
curl -fsSL -o "$tmp/$asset" "$DL/$version/$asset?c=install" || fail "download failed"
curl -fsSL -o "$tmp/checksums.txt" "$DL/$version/checksums.txt?c=install" ||
  fail "checksum download failed"

# Verify the archive against the release checksums with whichever sha256 tool
# this machine has.
if command -v sha256sum >/dev/null 2>&1; then
  (cd "$tmp" && grep " $asset\$" checksums.txt | sha256sum -c - >/dev/null) ||
    fail "checksum mismatch for $asset"
elif command -v shasum >/dev/null 2>&1; then
  (cd "$tmp" && grep " $asset\$" checksums.txt | shasum -a 256 -c - >/dev/null) ||
    fail "checksum mismatch for $asset"
else
  echo "warning: no sha256 tool found, skipping checksum verification" >&2
fi

tar -xzf "$tmp/$asset" -C "$tmp"

# Default to /usr/local/bin, but never ask for sudo: fall back to ~/.local/bin
# when it is not writable. An explicit POLIGN_BIN_DIR must work as given.
bin_dir=${POLIGN_BIN_DIR:-/usr/local/bin}
if [ ! -d "$bin_dir" ] || [ ! -w "$bin_dir" ]; then
  if [ -n "${POLIGN_BIN_DIR:-}" ]; then
    fail "$bin_dir is not a writable directory"
  fi
  bin_dir="$HOME/.local/bin"
  mkdir -p "$bin_dir"
fi

installed=""
for b in polign polign-server polign-persistor polign-apikey polign-maintain; do
  if [ -f "$tmp/$b" ]; then
    cp "$tmp/$b" "$bin_dir/$b"
    chmod 0755 "$bin_dir/$b"
    installed="$installed $b"
  fi
done
[ -n "$installed" ] || fail "no binaries found in $asset"

echo "installed$installed to $bin_dir"
case ":$PATH:" in
  *":$bin_dir:"*) ;;
  *) echo "note: $bin_dir is not on your PATH; add it to your shell profile" ;;
esac
echo "start a development server with: polign-server"