#!/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=ec1023e4c0e01da4bbec64c19e9a2bc94d36feae421402abbf3a2db848a1c6b5
        path=sccdqbmdj8ibwlgx174a7hargnabbsgs/nix-2.24.10-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=2ab7afada8e5caf7b13cc346862fccca0a7df7fb584bff625a97a95133df160e
        path=0xf6ypm7bsn153jkhg2dsfag4fhkdb82/nix-2.24.10-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=1d8cf1d0760a4ca70d3d5c0becef1183ad4d5c87b4afb0e77085da3fd88b0bfb
        path=kbybindsf3hq3j7hm53rar2vsrhxkn34/nix-2.24.10-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=61915a006510cbcc0c7a5c8cd7f5ad304fbc07191904e0e8ead6bc3756d3fbdc
        path=m5jqqhydy288mckrgqqb3z5sddqyljdk/nix-2.24.10-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=bc02b2113ab6149384e4fc4bc76b9a2da39ccfc60d7d8d82c8a8de60e42c4da5
        path=yy78iha68qh39m65qpz4xh3fi2zihrmi/nix-2.24.10-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=6392f6434c95c438eafbcdd1a699b5291663dedcf1c8187efc6cacfcc28ce7eb
        path=diqjmwxlbw3nws80jvcydlzkja80a8mr/nix-2.24.10-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=748535d66afe19370436ffa5048f12ea236a4196fb6de77131a09adcf80d5fa2
        path=2mkysa4nd6sr8wj0lfk5cp5fqmb93hnc/nix-2.24.10-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=93c9098b88f84f6bbdfffa17ac54434156865ae1405fae080e95763871a558a2
        path=m6z13hyfngsxklxr0bzkk0as8ns1p6ma/nix-2.24.10-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-2.24.10/nix-2.24.10-$system.tar.xz
fi

tarball=$tmpDir/nix-2.24.10-$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 2.24.10 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