#!/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=dcf8abc9c33e74af99de382b3ba8cc88c47fbf579d441540ffa383bf9936c1a8
        path=57n69cm6fiz1k7dk48m24pdgrzadczlc/nix-2.24.13-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=8c765c075a5cb49e1ef9499f3138f7a1bd77744499ac7017d4fb2002210aa3e1
        path=1axskfk95wz2sfqr4xakr7rw7gsssyqk/nix-2.24.13-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=4d90c116639de03302857a8bfc450286b731b1b4b595b21169dea5b005f7d25d
        path=v14mq196f4q53i0fb167f18rgqkr08vz/nix-2.24.13-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=d7ee7d684bf7fb842b6db776baca290ca8ab4f7dbe19932696cb607919440525
        path=5lr5gmg4d0q4zhmi3p8j0a5nj9ga5yvi/nix-2.24.13-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=548c2584b5bef2d229659cc28103838c0624d55c947503286025045c303fb71e
        path=7d3amwg117257jkr1ldvsim2gj0avvzd/nix-2.24.13-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=cd38824d15c8694a313e1fa8da0a22f4a0b511cf267703b13c35054c5823d4f6
        path=jn8rqkxkm4d42j68cs4rdhrsdlcc9rbz/nix-2.24.13-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=b55d5c9c860464bae955fcd8e0c4f7e8fbb8f6a5bfef06129dfa448853501720
        path=45fl9dlv88wirp779r80b93lm61ghsab/nix-2.24.13-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=902fe7600f561b9d144167f875eb65ca496b10be229f0e58e1cd3d2d4911385d
        path=d66ksapg32pjziha7v7vmgfgks97afhq/nix-2.24.13-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-2.24.13/nix-2.24.13-$system.tar.xz
fi

tarball=$tmpDir/nix-2.24.13-$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 2.24.13 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