#!/bin/sh
# memspine installer: downloads a prebuilt release tarball from
# memspine.com, verifies its sha256, and installs memspine-server +
# memspine-admin into ~/.local/bin (override with MEMSPINE_INSTALL_DIR).
#
# Usage:
#   curl -fsSL https://memspine.com/install.sh | sh
#
# Environment:
#   MEMSPINE_INSTALL_DIR  install destination (default: ~/.local/bin)
#   MEMSPINE_BASE_URL     download base (default: https://memspine.com/dl)

set -eu

BASE="${MEMSPINE_BASE_URL:-https://memspine.com/dl}"
DEST="${MEMSPINE_INSTALL_DIR:-$HOME/.local/bin}"
DEST="${DEST%/}"

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

os="$(uname -s)"
arch="$(uname -m)"
case "$os/$arch" in
  Linux/x86_64)          target="linux-x86_64" ;;
  Darwin/arm64)          target="macos-arm64" ;;
  *) die "no prebuilt binary for $os/$arch yet (have: Linux/x86_64, Darwin/arm64). See memspine.com for updates." ;;
esac

command -v curl >/dev/null 2>&1 || die "curl not found"

if command -v sha256sum >/dev/null 2>&1; then
  sha() { sha256sum "$1" | cut -d' ' -f1; }
elif command -v shasum >/dev/null 2>&1; then
  sha() { shasum -a 256 "$1" | cut -d' ' -f1; }
else
  die "need sha256sum or shasum to verify the download"
fi

tmp="$(mktemp -d "${TMPDIR:-/tmp}/memspine-install.XXXXXX")"
trap 'rm -rf "$tmp"' EXIT INT TERM

tarball="memspine-$target.tar.gz"
say "Downloading $tarball ..."
curl -fsSL -o "$tmp/$tarball.sha256" "$BASE/$tarball.sha256"
want="$(cut -d' ' -f1 < "$tmp/$tarball.sha256")"
# The checksum rides along as a query string. The CDN caches tarballs
# by URL, so without it a new release keeps serving the old tarball (or
# an old 404) against the new checksum until the cache expires.
curl -fsSL -o "$tmp/$tarball" "$BASE/$tarball?sha256=$want"

got="$(sha "$tmp/$tarball")"
[ "$want" = "$got" ] || die "checksum mismatch: expected $want, got $got"
say "Checksum OK."

mkdir -p "$DEST"
tar -C "$tmp" -xzf "$tmp/$tarball"
install -m 0755 "$tmp/memspine-server" "$tmp/memspine-admin" "$DEST/"

# Print the destination the way people write it: ~/.local/bin.
shown="$DEST"
home="${HOME:-}"
if [ -n "$home" ]; then
  case "$DEST" in
    "$home"/*) shown="~/${DEST#"$home"/}" ;;
  esac
fi
say "Installed memspine-server and memspine-admin to $shown"
case ":$PATH:" in
  *":$DEST:"*) ;;
  *) say "Note: $shown is not on your PATH. Add:  export PATH=\"$DEST:\$PATH\"" ;;
esac

say ""
say "Start the server:"
say "  MEMSPINE_BIND=127.0.0.1:7777 $shown/memspine-server"