#!/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=5911a556551e651ccf06be7d9cf44dbaaca1577444629273556c593e628bfc3b
        path=hx0059p7kch6d7xbcjhrl3vmm4jqgcv2/nix-2.30.3-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=9c0814434bc09b8d97b9cc9bb0eb28b2dc3e735bf2157eca7dd1db9586efe982
        path=42qb7nh3jln64mjs6g5pwvkb2hj5sz4x/nix-2.30.3-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=79e8938c70b7d4da97441c79d9c96c31de72a870dd7863b60f436bcdf2accd0c
        path=wm6df7bzi14q5nfw8jnrqkpckin931f4/nix-2.30.3-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=2beb7c35a5bacd8825388627cdc03c259bd8ae36636bb48e869d12f38c6bae2e
        path=nv4faydl9gy1risgb7cmxz8h9iyx9vv1/nix-2.30.3-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=6a83648aae60a1af0bbae42456afd7efea033477aa7db55eb7101ef515e7ebb1
        path=yknnwmnlr3x5b4fz4hiw37grp7xldhw9/nix-2.30.3-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=cb542632b7e245642ff10114839bd30fda51009960913f0f298e3f16dc7be8d5
        path=88cjybfrnip99wbizfa8szkcnb9nssnk/nix-2.30.3-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=62fbde3fd967f2799536dbc28881ca45609837bd80f33ff52e92f546c5b558be
        path=gp4ikyb95wz6in618lvmf3vid249gsnp/nix-2.30.3-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=5c4e22f6bbc67293ef2d83bd24000b0b7e6a285994da0cdff9c24347237c2e5f
        path=z6ranp86k3cnh948snb896i1gflqqrnz/nix-2.30.3-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-2.30.3/nix-2.30.3-$system.tar.xz
fi

tarball=$tmpDir/nix-2.30.3-$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 2.30.3 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