#!/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=7888ca3b586d026e149e866cda9ecb228811bd98d9f56b8c58a5e9106151ffd0
        path=484finmmkg3gk55y40vr92jlf1zxrqcw/nix-2.34.3-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=ad2f676ffb6b286ffae860ef68f18c09b85be032a6536ad56d8c4882c8874c09
        path=ara6g43ds1qr74pkvj9j9iif0vqvshga/nix-2.34.3-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=21364e7696b673759fea19c3614efd1ce3d25a8f83c607f8d52d61bc2c9e4e30
        path=i19cp24r879ppz8x74cwkyw8dmcp3viz/nix-2.34.3-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=56e9a9c8e78a6031d1df5b14992734cd9eb9c3c15e971b3d4d88ddce5e102fd2
        path=i5blj95257a3cn85g5hl303fzhbgcg6z/nix-2.34.3-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=c7e4fd48c62e13b726352b2e1d9bf4391a46a8714e080680245a5876d0de5121
        path=55y50v0qgcajlpxszbpzm6p71w88n6j6/nix-2.34.3-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=9bd821af63649deb35b4d6e8f9a8130399d7368af8426d41b7b1148dc8780905
        path=1gsaphl4d7j4lfqh7jsv3b7vci4yg0lk/nix-2.34.3-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=1e94ed394b06d0777a4e3cf6bc520efc7cf827ff3eeaf12ad2535fcadae8e15e
        path=vjq8687filhvmrj5kxhpv1x3fbsd2rn4/nix-2.34.3-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=cdc15811969d85549b88a3a87ce2fcbbcda79ac314d6d490da4b80a4fa944675
        path=47cxfbb13zm0y1hlrrbbm6cngd27vbmi/nix-2.34.3-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://mirror.nju.edu.cn/nix/nix-2.34.3/nix-2.34.3-$system.tar.xz
fi

tarball=$tmpDir/nix-2.34.3-$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 2.34.3 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