#!/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=dfd7e8a2de0dbdd8f62db4fd32b2097390e379021df237c16a6a60468761e667
        path=qlk3mw42ihhfm9hvcc8dg9hi9c2hkchq/nix-2.32.2-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=f3b00a9f68121f4d10724873604f2a92b05c8f7704c5424092c13938879175e5
        path=47kxkc28hsw4sk9igy2zrx2mpg7ksilp/nix-2.32.2-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=a2da287f525de9147cbc1b55ddda80d097f8e5dc5ca3f3bb34ad929ddb4877f6
        path=gy38s3cg6i4dl2l347fwpb8jxi3iaagy/nix-2.32.2-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=35b77da1d1807160e565569657f197a9d772e06f3ebd89e4cb20129842b46c3e
        path=c62hm4mh902h42wigicgp5222666iq9l/nix-2.32.2-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=4aaf9792d077c91b0c27e88bb898fa4db1c740dde145c74d0623ccd1f964a358
        path=xmqlrx0d9l5nah4h57f53r163pvhapb5/nix-2.32.2-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=689c9e6e8b7095b9dd7b8d9e37361f79e171c7bbba15bbbe9d052e656b9fdd37
        path=g8hhc6j8xs85gyk3fb8svh2fiqz3g03x/nix-2.32.2-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=bd7705e53132365ca2edb97d1efde243b35b9108397f0ab102b57696f6a89a17
        path=5rfd8yvlwys2knw3b5frqb2qx2dzy9gv/nix-2.32.2-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=62c03c32ec15c4e8aeca3e5d00c52c6a6a141d0f3db03654daabf6582cc413dc
        path=wsb5di8ic3wj8kn2dgdlvyp3k3qwd9wv/nix-2.32.2-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-2.32.2/nix-2.32.2-$system.tar.xz
fi

tarball=$tmpDir/nix-2.32.2-$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 2.32.2 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