#!/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=bb3b461dafc4322fcbdd121384b605ac91c60d39b236316221440ecc3ee39074
        path=1wky3bi2nham9ypnx01y5x6gfgqm5ijd/nix-2.32.5-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=dc14730a5c11aae6b3f8cce9612f5d8d0348698458e7425ebbe2052caaffbe05
        path=6yxki624w52wpi8wmn0zx6ndh9k2ld8c/nix-2.32.5-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=64626fa4a8ab9d9682fa4eac885ed51ece72e8bc8c924db39d333a64f92d6908
        path=i8fjnmcb4218bi4qc4dyc5g24h8nim1g/nix-2.32.5-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=276c5b980023fc517f1403bc2a81219795cfcd04f307c94c9b02e491866ef9c9
        path=vf9xk977gxdyr78343ibvnh1zqj53s9i/nix-2.32.5-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=afd621b92f796338b992baa46e77f94586359685066c7b8829b80a430df7d174
        path=rri558jh6cwc3spggz4r7s05mdi7gk41/nix-2.32.5-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=5d513c2291884157d39f602ef77be4a834944974cfbf0875cd830ffd88d08456
        path=88bi4g10pl7c6zafl345jf9y6z17jijj/nix-2.32.5-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=e7c1dce9bfa6b1ee1e88cb10d5a07e3c1d944f8140754c3dcc1aad3310f70a43
        path=q1jinj7nbb6fmh2702j0ihqbx6372sri/nix-2.32.5-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=425e5e1cdc146793f65698114c2d383e7aa1273c43401534f05628761d8b7b9f
        path=3x4m2vm7yxy4ikmkq0nk87y2aymw1f8k/nix-2.32.5-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-2.32.5/nix-2.32.5-$system.tar.xz
fi

tarball=$tmpDir/nix-2.32.5-$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 2.32.5 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