#!/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=40b2f7c48a8f760b30aa9ca13821bd4187c835171e40839257e9f3b11a7db678
        path=g9znyg42dhlgi9aaddbpa3n8rmpgnyyp/nix-2.24.14-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=a2fe2e4762a8d73af67b1931136cb09c2ab28db6ff8b489b8087e6c9683dd0e1
        path=9040zaszrmz9gvpqzlimal5ihb3s7p3a/nix-2.24.14-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=2d0fc1d524eedde4b3bb1486e703f58a28a8ae3227f93d41269e5975fb25576f
        path=19pag76ysx8p09y8ay13vqwam31zbh75/nix-2.24.14-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=4ae83029ebf1028faef55a3206e9f5fbb8558b0ff4a5dcfc39454ca166f79a17
        path=v1fiv0cypmjxi08mkfzalvj1qv0x8rz7/nix-2.24.14-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=1922d7b57dbc0e78c60fcbd4376dae311358da372860d95e552641a0fefae868
        path=46v1qj50fb8gksskf3hl2w8bxjjli4wp/nix-2.24.14-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=6b198b0d6ede8f5013a819760d455824d37f4c92471ffb5c80c07d8aa33858da
        path=xiws65349l6vhc8ad588169klhhz33c8/nix-2.24.14-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=3c912c36a453bcff13a869cd2632c13b121e7e2840d03568692cd33bc99c69c1
        path=ziybirqjc1dq09isbpkrnmz822fda538/nix-2.24.14-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=380f7aa3a9a5b36d04314c5df2dc1eb08252479d41eff5546ccb8dd6a09a4e1b
        path=68l83pljxiw8pvlbmsrrh9yml67nf5vm/nix-2.24.14-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-2.24.14/nix-2.24.14-$system.tar.xz
fi

tarball=$tmpDir/nix-2.24.14-$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 2.24.14 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