#!/bin/sh
# sigiro installer.
#
#   curl -fsSL https://sigiro.com/install | sh
#
# Served from www/public/install, so the path is a static asset and not a
# redirect. It used to be a 307 to a GitHub release that did not exist, which
# means the published short link answered 404 to everyone who tried it.
#
# Environment:
#   SIGIRO_VERSION      version to install. Default: whatever /dl/LATEST names.
#   SIGIRO_INSTALL_DIR  where to put the binary. Default: ~/.local/bin.
#
# POSIX sh, no bashisms: this runs under dash on Debian and Ubuntu images.

set -eu

BASE="${SIGIRO_BASE_URL:-https://sigiro.com/dl}"
DIR="${SIGIRO_INSTALL_DIR:-$HOME/.local/bin}"

say() { printf '%s\n' "$*"; }
die() { printf 'install: %s\n' "$*" >&2; exit 1; }

need() { command -v "$1" >/dev/null 2>&1 || die "this script needs $1"; }

need uname
need tar
need mkdir

# curl or wget, whichever the machine has.
if command -v curl >/dev/null 2>&1; then
  fetch() { curl -fsSL "$1" -o "$2"; }
  read_url() { curl -fsSL "$1"; }
elif command -v wget >/dev/null 2>&1; then
  fetch() { wget -qO "$2" "$1"; }
  read_url() { wget -qO- "$1"; }
else
  die 'this script needs curl or wget'
fi

# sha256sum on Linux, shasum on macOS. The download is verified or it is not
# installed — a corrupt or substituted archive must never reach $DIR.
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
  die 'this script needs sha256sum or shasum'
fi

case "$(uname -s)" in
  Linux)  os='unknown-linux-gnu' ;;
  Darwin) os='apple-darwin' ;;
  *) die "no build for $(uname -s). Run the container instead: ghcr.io/sigiroai/sigiro" ;;
esac

case "$(uname -m)" in
  x86_64 | amd64)  arch='x86_64' ;;
  aarch64 | arm64) arch='aarch64' ;;
  *) die "no build for $(uname -m). Run the container instead: ghcr.io/sigiroai/sigiro" ;;
esac

target="${arch}-${os}"

version="${SIGIRO_VERSION:-}"
if [ -z "$version" ]; then
  version="$(read_url "$BASE/LATEST")" || die "cannot reach $BASE/LATEST"
  [ -n "$version" ] || die "$BASE/LATEST is empty"
fi

archive="sigiro-${version}-${target}.tar.gz"
url="$BASE/${version}/${archive}"

tmp="$(mktemp -d)"
# Runs on error and on success, so a failed download leaves nothing behind.
trap 'rm -rf "$tmp"' EXIT INT TERM

say "sigiro ${version} for ${target}"

# A missing archive is the normal way a reader finds out their platform has no
# build yet, so it must not read like a network fault. Not every target is
# published for every version.
fetch "$url" "$tmp/$archive" || die "no ${version} build for ${target}. Run the container instead: ghcr.io/sigiroai/sigiro"
fetch "$BASE/${version}/SHA256SUMS" "$tmp/SHA256SUMS" || die 'cannot download SHA256SUMS'

want="$(grep " ${archive}\$" "$tmp/SHA256SUMS" | cut -d' ' -f1)"
[ -n "$want" ] || die "SHA256SUMS names no ${archive}"

got="$(sum "$tmp/$archive")"
[ "$want" = "$got" ] || die "checksum mismatch for ${archive}: expected ${want}, got ${got}"

# GNU tar warns on the xattr headers macOS tar writes:
#   Ignoring unknown extended header keyword 'LIBARCHIVE.xattr.com.apple.provenance'
# Harmless, and 0.1.0's archives carry it because they were packaged by hand on
# a Mac. Pack with `COPYFILE_DISABLE=1 tar --no-xattrs --no-mac-metadata` if you
# ever build a release outside CI again; the workflow tars on Linux and is clean.
# Not worth suppressing here — hiding tar's stderr would hide real errors too.
tar -xzf "$tmp/$archive" -C "$tmp"
[ -f "$tmp/sigiro" ] || die "the archive contains no sigiro binary"

mkdir -p "$DIR"
# Move into place through a temporary name in the same directory, so a running
# sigiro is replaced atomically and never read half-written.
chmod 755 "$tmp/sigiro"
mv "$tmp/sigiro" "$DIR/sigiro.new"
mv "$DIR/sigiro.new" "$DIR/sigiro"

say "installed $DIR/sigiro"

case ":${PATH}:" in
  *":${DIR}:"*) say 'run: sigiro serve' ;;
  *)
    say ''
    say "$DIR is not on your PATH. Add it:"
    say "  export PATH=\"$DIR:\$PATH\""
    say ''
    say "Or run it directly: $DIR/sigiro serve"
    ;;
esac