#!/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=bbff0dd3c6c4756f3f2c7132dfa3e5c1d9d141db4797d050cc19c8d0bdb08a7e
        path=a2rha2ka1r6fbybcn08wpnk81cffip9l/nix-2.23.4-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=bbf222a88e967fdbfc56fb7cbe630240f53e1a3b84f5f5a71c1f20e4a9c1d02e
        path=a4k3r9kv324i5bhp6igmwj5pwm8dz5yx/nix-2.23.4-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=00959fdf68e251e893efa9219a6e41e7b33ed624ac75b1c441a23f1cf3d7f7b5
        path=xcwfabcmj72kr6rg14pnrvry9x37zja7/nix-2.23.4-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=8adcfbb919f9bfc5eb6844d1cbb7a5b26ce975dc1688c1708b235b6f3b3fd025
        path=f6bzqab6613fz4zm2kc7bqs1dyly8l4b/nix-2.23.4-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=63c4cb35d394d9ab4fe6cce3c8895203a13f25294f16a24b0a61593824ca686e
        path=j6r2irmflg73lgicwnmhlb4swi0g8zgh/nix-2.23.4-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=1c740b5a44fc94d79233979985107fc917ee99a1cff1e616c37522f56aff2eef
        path=dvpghgfvxq4i4rnrsqn2sp4k658jxkrs/nix-2.23.4-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=71fce53574d9c548e49a4f1c70ba411a31a049fdb85357ff642f3a9f5bae6197
        path=hync6mc85q3xd619bzqf1hdyv84wsj3d/nix-2.23.4-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=04ea51dcb51d712999398ce1346b5867b21cf5ab5b5cf39938711e60880d7813
        path=9fz0sc50slh2rswsaxwygrp005a1hyb0/nix-2.23.4-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-2.23.4/nix-2.23.4-$system.tar.xz
fi

tarball=$tmpDir/nix-2.23.4-$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 2.23.4 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