#!/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=a699cd95ebfcc27a86182a75dedb8b2c1e2108b94ed596c1aec7fa9e68dc57fc
        path=3wq10qjc2jsgb02rl17vcxw54xa5iahc/nix-2.30.6-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=ae29dae9214b6f214cccc693ec169af033bc04284deaa224b19275803e4458b5
        path=28f80y8iy73ik5xw03lzd827yflca08h/nix-2.30.6-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=2e4f69cf15d97bbd77037b8944a9e4e7503c10cee2529ab34937beb53a47de3b
        path=d0aign1pkl9lgqd65llrpmia78l2zw3w/nix-2.30.6-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=ce6b0896b3ad719f1cc98897b7270bb8d1b213597a15dc07ca5daea422215d58
        path=221mnfhmckifsxx74wxx23z6v5lqw4pw/nix-2.30.6-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=fdedd6605784e18f5407caf28d7f1e040f1ce500e255ede0642cd06e5cc0f2d9
        path=2w36vljlcy9sljlx70vl91qwbl1qwkxl/nix-2.30.6-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=e9a254ef179893f6a834e9ea08f8fdbd680916dd87efc4b6d4a6f39c00634dd3
        path=j5pr3389ym8s0cjylh1wc4v6i4za9j7j/nix-2.30.6-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=b0ac647ed75e5ba657fc563e98fc0d92cd9695ac32d15b3720aa786903b1873e
        path=lsdlibrxbz4k67ycd0dk60r51hcqi3z4/nix-2.30.6-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=51c95b7ab915b017ab64312d805351f421b439114218d88ecf7d8628ec27e86d
        path=rsyvfda51bnfkmx17xnww8nx01kabzbl/nix-2.30.6-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-2.30.6/nix-2.30.6-$system.tar.xz
fi

tarball=$tmpDir/nix-2.30.6-$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 2.30.6 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