#!/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=01d87773a18d3fc22bd849af2ff7bcf88941829e745074922f059494bbd99c4f
        path=bii8qjyb639j0bnr3rr6bsyz7pcwzp4j/nix-2.14.0-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=119489c2e0441a11d5348c1cb30bd68c5172b12e7f88159ae3a73c6e748cce66
        path=ww01sp5adaj8s38m3cpj8wf38yydxdcg/nix-2.14.0-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=772be333aea5935a862dcfa9353958db663966c0b2518b00e16c4d6cc2424402
        path=xkrglqnqkm0akilynqb9ag4bvz0w81ag/nix-2.14.0-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=146f92797589b4f9800886eaf5abf0f9c880272442d1cfb0933e0272ee342658
        path=c1i8pr80pblrykjw7bd1zmr8c9vpy76v/nix-2.14.0-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=8e4b9a505d65c98b2fee31c16b45f51deb832577375a089cc50742295051772a
        path=kk8yzndqmz8j8fsbf37n016bclcz62wn/nix-2.14.0-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Darwin.x86_64)
        hash=75b228f88d36c9e1cadaf840e77e1bd999b34d36a39b581bba2b9d06fffa35c2
        path=3qv5wmvgaw1i3aj1mqxkyhzy8y08lyx2/nix-2.14.0-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=dc39280042309e60cd9fd8d8826efc99c071d05bf692ca37f08b0fe04e4b2934
        path=ik0gcmzq199p801kqdq8hlhad3ilvb55/nix-2.14.0-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-2.14.0/nix-2.14.0-$system.tar.xz
fi

tarball=$tmpDir/nix-2.14.0-$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 2.14.0 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