#!/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=d5a0713970510ddc5422fd7a4c69ed383dadeed400e8187fb7a50b8af634ba70
        path=8qg6drfw1bc80d7nq7i9vk9b5j8cl6zf/nix-2.33.6-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=9767de9e458f0a6c0b1503d672fabfb0e766e245ffefc0266aa1bc09b1380833
        path=kwfd42x94syhpr1pyv747j7nskmz8c67/nix-2.33.6-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=71508d84b114d5113aa708f148662e33d1ffc66d4225506589f2e625ec434670
        path=pmf5lbjc3ljzr0b59prsv6is7sawcsg4/nix-2.33.6-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=b387a7e84388eb0c06279c00bd636f6dbb37fc2cf30414a02e591402ca3aad7c
        path=rksqr177h8c08yfjbji0jwzwij0six2c/nix-2.33.6-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=a654531ccef884ad5d00f19a49c1b7fbdfdc9715f483217bcc683847ded1056f
        path=8rn3lr7sc9grbq5zmvmzzsk273gimbsw/nix-2.33.6-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=2196ee9f1a31e7cd47f77551c1e4ad9660dd1d83c37eec9e057ab5123f04c7d9
        path=pfl7jlr6c87gawh42jczn2dy8fk4md1i/nix-2.33.6-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=324482949ff7acc0bc1520f5e6f317757a68d930179ffc524ad2584f17ae222f
        path=01xfr2vp2hh2qjdn1kkk0dldxpqc6zyp/nix-2.33.6-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=583dd02d2bbed017d4bee8532d0322388933ead177abb26068cb0415ad39c1c3
        path=2m5bs86fbs6jfpr15y31z448h5n7jxsk/nix-2.33.6-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-2.33.6/nix-2.33.6-$system.tar.xz
fi

tarball=$tmpDir/nix-2.33.6-$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 2.33.6 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