#!/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=99f244734b4d03b85e985917c99827aded97fa6edd1d57a49e9ab8ecb90f8930
        path=why7dhyiv7mkvm5hk0797fzgf7y1v02l/nix-2.32.1-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=2385da802688fb8d286042fda8cda8ed5b9647af5b6777acf30b1155ad10f769
        path=8941irwlj75vr9svhdz1a9k3k4a6m4n7/nix-2.32.1-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=4f58a17b06494ed6ba5d5ea45c3e2b0c57eb86fff92c029d0ea2170a7683bd66
        path=b9vhzbjbkwkjvm2rwspy1x2m4ipvjc4d/nix-2.32.1-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=183121d614f5f68060f9574487c90fd8a5305e3f8c84330746c594a32e66499a
        path=1dl07pf6j8wv9izaqbh34sj9d5hnx1x7/nix-2.32.1-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=4ba3fc6c376850861695e52ee20b9488124b18c018fca551b4f3a9bb8fc0f0ee
        path=pvb5yba5mglzvk99x0smqijqnwx90szv/nix-2.32.1-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=43e13d953b6ace38d8d36b88732090c3f925761d8c161be82d63baec9d270048
        path=idqp4p83a8b8lgcl5ix7qv3l9ljlmnv3/nix-2.32.1-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=35eba8e1bbec8aedb06366d5134f3e0fcf7dafa25644ad265898cee524641adf
        path=nmskhrh7g0rby0r9qp4c0kjid3wkbmx2/nix-2.32.1-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=45aabab6e7ab1bdfbdbe985dc746a8d3892d94d2d0e92b07895b3bb534625271
        path=2h2w5xw8pgf4xkgqd6phfhrkgnhbl3yg/nix-2.32.1-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-2.32.1/nix-2.32.1-$system.tar.xz
fi

tarball=$tmpDir/nix-2.32.1-$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 2.32.1 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