#!/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=5f61d3cd8c7c48c7b28cba595ba31d134091014781d04dfb004ea35b256da127
        path=k8yci9l2j70xnnxdww5a0malanz8n1yb/nix-2.24.11-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=e4dda4c7b480d0a001c104ae7da3c57544a0f9970c6827760a8d99ce37565ecf
        path=c44alfky5jfcgwm5lzwm5s7p7kjj6r3x/nix-2.24.11-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=65ccafcf6754cb144294dc77696036526db4aa05417f26c6f281e2fcedb3a516
        path=xxh6qalpdy85vgdk8wgmshvjg480grlh/nix-2.24.11-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=491362667d09aaec96ae7f2afe357ef353f8b896d7593186005dfba6c50a5442
        path=m92y65ia8aiir2sxaf8qk7nics0fs92x/nix-2.24.11-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=75db62c5002021bc81969524654cc8aa5c6aecf56f2e9dd7b60e467da380ee9a
        path=vcbnqz7fxz0a6l1kr7s7l5fw8b0875wv/nix-2.24.11-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=cb72d5a7629c1230f2ffee0077d0b18c8b5f8b4a571d18cc169cfd9c9a8fa13d
        path=3410dqbblvlwp4x5dizjmgllgqavbr7y/nix-2.24.11-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=33abb52920da867dac529d9b69f6773df47b21d1c11ddabeb2f9d0f7e356f204
        path=xbqzddcx909m6r2vsg2lrk3mb2y53drz/nix-2.24.11-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=ec1ebf57c8ad45b471940bc38daa24ed6a88dadfbbc648bdca2aa5398a910a81
        path=1hlhca51i9m2q0g7h1nbr6dg74jcgxdq/nix-2.24.11-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-2.24.11/nix-2.24.11-$system.tar.xz
fi

tarball=$tmpDir/nix-2.24.11-$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 2.24.11 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