#!/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=62d25bf8c484b318bcf6d4327681f5e951fab3b36c6fb08f5b6545e01abd7513
        path=g7zxk7xl0p29swdldjn4v008dkis38la/nix-2.32.6-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=54d0e575a1c27fd81c68e033f7748df2dee1275559ea35f0248204a5477ec971
        path=g39czfq9lcz1ki2fii2q319zqlx8g8l8/nix-2.32.6-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=159c8ceff6295674d5009e6fc0467810c82566b1adc2974c7fc81b65e56bdc42
        path=xpvlfkfry6qxvdwynln4sd17xhbcff3l/nix-2.32.6-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=58eefe7e4dfc92865b6f1484e8c00f0a9579bdb30d3ddfb2067b3b29487c3af9
        path=f6cgja619zml6np2d53sjz27kqmvnww5/nix-2.32.6-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=9a85ea4e2f27d10de63e262f2fc5aacdbc1f16bc4f6e17d60bdfdc7d90fe32ad
        path=n7c940qmcdhvzffynpx81dj4j0f72vkv/nix-2.32.6-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=18774657dc326f58ffc8a52162f7aa15456cbbed89af69b64deb8e316942c99b
        path=dzv46w0xnh6pl92k9jknmvzj5p8pksna/nix-2.32.6-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=83a6725c5040b1effc6fbf67359606af1883c95a46854c04d1a5d1fe57cf5793
        path=vf6wlw4b2qi7m4lw99hn0izlq7r1s69a/nix-2.32.6-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=58162a5b1505b8c422f43a89141f5301d90c6085c75ba6df1989944ff3924dbf
        path=wqrdh5hyir33ckqmwsb01qvn0b08jaff/nix-2.32.6-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-2.32.6/nix-2.32.6-$system.tar.xz
fi

tarball=$tmpDir/nix-2.32.6-$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 2.32.6 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