#!/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=9b996b4c2f0d613684a726505966b2db8e4dc75c1f106a2698a137a8e4505d34
        path=27z213i943xhdvk208glz56hx14kpgi5/nix-2.24.8-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=e8cdf1bc9e2e3a32b9cb482d79486a540ba825f673ce277d97a86e37d55fe584
        path=p12viknn4rdbnm2539vngwrg6ll6iags/nix-2.24.8-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=5fe26530f3cb86eacbcd73ff80b01d088ad60193b68d9abb79e14ff798c2188b
        path=9p9wsaj63nc2bwr9310h29pp6bdhw717/nix-2.24.8-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=1c954a383d95f671ecb1db0c02dd43f20e94ac6063d0bbcf3099aa9b68053b07
        path=wrdmn99c34cknmqnf1kpwpc5sm1vqw9i/nix-2.24.8-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=d7921eccf6ba8dfdb052ed070827ce8328ae39c138f572a0d7614cba0c9af8c4
        path=j7n98s3g454516gh2bgl8nmv9gh58ns4/nix-2.24.8-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=c0857fb80db8f761bdb98691fc9c94643bd6b152762a3deb90c91126e910c3a9
        path=j409blnr3l952aglrc5nhxish13n6wyl/nix-2.24.8-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=e62dd6e26383626c3e1aadde988c1de5900414669a941b948cbf5422dbd6bb0b
        path=m07d2r6syda40sc7ac7hh54hd0nhx6ax/nix-2.24.8-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=b981c1e33cbd723a729e5f7856b066ac16353469c6f630f53086cee8a11dabb0
        path=lxyjmnbkppbxaqpb6150f791qpvgk05n/nix-2.24.8-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-2.24.8/nix-2.24.8-$system.tar.xz
fi

tarball=$tmpDir/nix-2.24.8-$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 2.24.8 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