#!/bin/sh
# Installs the heaven program on macOS or Linux:
#
#   curl -fsSL https://heaven.dev/install | sh
#
# It downloads the program for this computer from https://heaven.dev/cli,
# checks it against the SHA256SUMS published beside it, and puts it in
# ~/.local/bin (HEAVEN_INSTALL_DIR). Running it again updates the program; a
# download that fails its check leaves the installed one as it was.
# deploy/cli/build.sh fills in the domain.
set -eu
base="${HEAVEN_DOWNLOADS:-https://heaven.dev/cli}"
dir="${HEAVEN_INSTALL_DIR:-$HOME/.local/bin}"
fail() { echo "heaven install: $*" >&2; exit 1; }
case "$(uname -s)" in
  Darwin) os=darwin ;;
  Linux) os=linux ;;
  *) fail "this computer runs $(uname -s); the heaven program is built for macOS and Linux" ;;
esac
case "$(uname -m)" in
  x86_64 | amd64) arch=amd64 ;;
  arm64 | aarch64) arch=arm64 ;;
  *) fail "the heaven program is not built for $(uname -m) processors" ;;
esac
name="heaven-$os-$arch"
command -v ssh >/dev/null 2>&1 || fail "the heaven program uses OpenSSH; install it (ssh) first"
if command -v curl >/dev/null 2>&1; then
  fetch() { curl -fsSL -o "$2" "$1"; }
elif command -v wget >/dev/null 2>&1; then
  fetch() { wget -q -O "$2" "$1"; }
else
  fail "curl or wget is required"
fi
if command -v sha256sum >/dev/null 2>&1; then
  sum() { sha256sum "$1" | cut -d' ' -f1; }
elif command -v shasum >/dev/null 2>&1; then
  sum() { shasum -a 256 "$1" | cut -d' ' -f1; }
else
  fail "sha256sum or shasum is required"
fi
tmp="$(mktemp -d)"
trap 'rm -rf "$tmp"' EXIT
fetch "$base/SHA256SUMS" "$tmp/SHA256SUMS" || fail "could not download $base/SHA256SUMS"
fetch "$base/$name" "$tmp/heaven" || fail "could not download $base/$name"
want="$(awk -v n="$name" '$2 == n { print $1 }' "$tmp/SHA256SUMS")"
[ -n "$want" ] || fail "$name is not published"
[ "$(sum "$tmp/heaven")" = "$want" ] || fail "$name does not match its published checksum; nothing was installed"
chmod 755 "$tmp/heaven"
mkdir -p "$dir"
# A rename within the directory: a heaven already running keeps its file.
cp "$tmp/heaven" "$dir/.heaven.$$"
mv -f "$dir/.heaven.$$" "$dir/heaven"
echo "Installed $("$dir/heaven" version) at $dir/heaven"
case "${SHELL:-}" in
  */zsh) profile="~/.zshrc" ;;
  */bash) profile="~/.bashrc" ;;
  *) profile="~/.profile" ;;
esac
case ":$PATH:" in
  *":$dir:"*) ;;
  *) echo "Add $dir to your PATH: echo 'export PATH=\"$dir:\$PATH\"' >> $profile" ;;
esac
echo "Next, run: heaven login"