#!/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=54af61e36635af71cbfa0ca152bf4a1d25d23806536dbd39ee95d54145bd8f01
        path=z58l78izb0z11njdsivc67fph1mv6x1g/nix-2.33.0-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=70384f35a9b30a845dce7ae3a27fa620c45a13600388d8082f6772205607b8f1
        path=g8mdn43j7zrlmkldh5y4l4rx6drz7j1z/nix-2.33.0-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=5c4362b5df96f2784fef9a4f0fb30d50eff48495310d8b47014a9bea1a067fec
        path=dyjk89bj67cpzdyiljpdhjl927ww9crr/nix-2.33.0-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=26dae9d725bf1e34c1da5a042316c132d36d697b38cc8554a25fd80821d053f3
        path=lqpg2jp94abf0c34jwclwlckf4wjs0ph/nix-2.33.0-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=39fd56ac315e782e54acff8362ab0195f0e506c476daae1169d5550761dce84a
        path=8hg40qm6j2svv3j9wg3v1sinx3d9g7mi/nix-2.33.0-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=8ddf301510af0e3c33c13d37bf28b9974d077b217b8b395529cfa08a2af445d0
        path=djwr3h3v0px3g5k0qcwg250qwn5za5sd/nix-2.33.0-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=d19fed75cb71c1414dffbc1a745b46e9acdd61ba707ba5a46fae23ed725ae5fc
        path=sbyvaggxmhnd25m01fj8khm40r4g05ql/nix-2.33.0-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=cb24dfa5d8b2ff87492cd34082e51139f1f35970f04a8da3fb90e2e4894346ed
        path=r16rpa1aa7qbqidjlwy1j3kxkgd0yyhk/nix-2.33.0-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-2.33.0/nix-2.33.0-$system.tar.xz
fi

tarball=$tmpDir/nix-2.33.0-$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 2.33.0 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