#!/bin/sh

# This script installs the Nix package manager on your system by
# downloading a binary distribution and running its installer script
# (which in turn creates and populates /nix).

{ # Prevent execution if this script was only partially downloaded
oops() {
    echo "$0:" "$@" >&2
    exit 1
}

umask 0022

tmpDir="$(mktemp -d -t nix-binary-tarball-unpack.XXXXXXXXXX || \
          oops "Can't create temporary directory for downloading the Nix binary tarball")"
cleanup() {
    rm -rf "$tmpDir"
}
trap cleanup EXIT INT QUIT TERM

require_util() {
    command -v "$1" > /dev/null 2>&1 ||
        oops "you do not have '$1' installed, which I need to $2"
}

case "$(uname -s).$(uname -m)" in
    Linux.x86_64)
        hash=abbc5cbd390e4fe3b38bc3f15a5eda2750cfd1299db0abc6915a08391d9441dc
        path=9j2c675wimlhf9x7fa6cs0gngs03fsms/nix-2.24.12-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=df4b7fdbc073effab631bd7b1f1b76cb9bbe9b17dc304c26f1f275a76806d896
        path=zxc7xapix11lhji8cchpigi7kzcx3410/nix-2.24.12-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=6fb9d28ccf82d0dc84d9b97ab9c66faa64d4724bc3d82a100444f17396bcee3d
        path=qzm1v1kdwrwpqgb4393rlg1qvn37dfrr/nix-2.24.12-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=6c145eb72567ab8835fe7be88467a69aca1e3682681d1390aaab20d1ebb98229
        path=brbfk6nv3ncnskmgnv2ml8ayp16r2wbp/nix-2.24.12-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=542093f5a1e898776aacec7132867b4c3b8615dd877a6dc39e2abda0c328c1a9
        path=v3rghz31pah2kcmdjwgc69mz4ad3zz0p/nix-2.24.12-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=f2c11d5c75fbf05a74b8ab43a7437a95e21cf127581b610a285810ec04c4e112
        path=45im0jjywyyl7dn67xg498kn1fgsanr0/nix-2.24.12-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=9f08aa1560f87d16f656906e17efad9ca0a29977d8e56a710aaf5bead0cc396f
        path=brwddgd5lm93wxicy3hlwxi45zmzpd72/nix-2.24.12-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=3ff570e82344566dc3d96a9e7130466f4d3293d4f11a6369bc1adb4a38a581f3
        path=fvhhbi3k8h7snkyxhxrx5a08ig9pk9my/nix-2.24.12-aarch64-darwin.tar.xz
        system=aarch64-darwin
        ;;
    *) oops "sorry, there is no binary distribution of Nix for your platform";;
esac

# Use this command-line option to fetch the tarballs using nar-serve or Cachix
if [ "${1:-}" = "--tarball-url-prefix" ]; then
    if [ -z "${2:-}" ]; then
        oops "missing argument for --tarball-url-prefix"
    fi
    url=${2}/${path}
    shift 2
else
    url=https://mirrors.tuna.tsinghua.edu.cn/nix//nix-2.24.12/nix-2.24.12-$system.tar.xz
fi

tarball=$tmpDir/nix-2.24.12-$system.tar.xz

require_util tar "unpack the binary tarball"
if [ "$(uname -s)" != "Darwin" ]; then
    require_util xz "unpack the binary tarball"
fi

if command -v curl > /dev/null 2>&1; then
    fetch() { curl --fail -L "$1" -o "$2"; }
elif command -v wget > /dev/null 2>&1; then
    fetch() { wget "$1" -O "$2"; }
else
    oops "you don't have wget or curl installed, which I need to download the binary tarball"
fi

echo "downloading Nix 2.24.12 binary tarball for $system from '$url' to '$tmpDir'..."
fetch "$url" "$tarball" || oops "failed to download '$url'"

if command -v sha256sum > /dev/null 2>&1; then
    hash2="$(sha256sum -b "$tarball" | cut -c1-64)"
elif command -v shasum > /dev/null 2>&1; then
    hash2="$(shasum -a 256 -b "$tarball" | cut -c1-64)"
elif command -v openssl > /dev/null 2>&1; then
    hash2="$(openssl dgst -r -sha256 "$tarball" | cut -c1-64)"
else
    oops "cannot verify the SHA-256 hash of '$url'; you need one of 'shasum', 'sha256sum', or 'openssl'"
fi

if [ "$hash" != "$hash2" ]; then
    oops "SHA-256 hash mismatch in '$url'; expected $hash, got $hash2"
fi

unpack=$tmpDir/unpack
mkdir -p "$unpack"
tar -xJf "$tarball" -C "$unpack" || oops "failed to unpack '$url'"

script=$(echo "$unpack"/*/install)

[ -e "$script" ] || oops "installation script is missing from the binary tarball!"
export INVOKED_FROM_INSTALL_IN=1
"$script" "$@"

} # End of wrapping