#!/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=52fd6f2ce64bd48b495814702348959c78dd8c3b50058fda49404f16f35471ae
        path=86kmf3h4cbsvsgi7gpvp2a6nml5x4g51/nix-2.30.5-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=9972415d3460bf34cd41707de416ba5f249ef8146389cb9cf491c1d824dda7d8
        path=avwiq59lmzng5abv8gay2yp8wsaz2n57/nix-2.30.5-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=f37564fa98137756d50370ea5814dde1070c203b8382cdff890d6d888d1d88c5
        path=wbwivl1rzvgkzinwkf92kl2mksdkawsr/nix-2.30.5-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=49fc9e8ab58b09ada4fb478d74c5b9b67e7d1cba3fdc4a34d223d227119207c8
        path=s2hhms80hjhqwzxsydfvf2vaqymxaf9s/nix-2.30.5-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=177b03da1cc521c1c66d3d189095265485eca5820bc0cfd09c3a8c1084fb9c07
        path=vk17pkk92yvllhrivhkabhfpjqn6qlhq/nix-2.30.5-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=b3785921c19c3bc084e45bf0f7808e7e9c8301282c505dffee617ff465524124
        path=mighm82f9vdm2l1pdr6i6nh6l7b0d8y7/nix-2.30.5-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=2a1b58b01072c31b6666cc315dc9784ca89979c4ae34a20dc541f49c6f5f9f04
        path=l5y6f1y4xhsj40n4p741kg94vjv74wz6/nix-2.30.5-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=4a28b9839d4c13adb8ca03305ad9f70397b92b1bb2641dab4a275b4785be8e3f
        path=rdkjp8r0jfnjabp884s993avsk0j64nc/nix-2.30.5-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://mirror.nju.edu.cn/nix/nix-2.30.5/nix-2.30.5-$system.tar.xz
fi

tarball=$tmpDir/nix-2.30.5-$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 2.30.5 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