#!/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=ac11429f02b90da0455db6ac5fea3f8a5ae181b47e48521661f8dd312da38ef1
        path=6hp53z00g8z6si50879h5f7mmcbhnrp7/nix-2.28.8-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=27f1a36ffc7ff2a16caf4ed416f54ccbfadb78b3845acf22452ef3d3e6d7b300
        path=1mlavj9jhqyicrn6is33fakh3bjbnd7z/nix-2.28.8-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=042e3d126960d0abef79249ca8635a927bb8fedc9d5fb9c004c26a7982ad3e54
        path=5pgdf4jinx7lz1wzrc1mwnw569i0c8fn/nix-2.28.8-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=c467a1ef86bed1c01611f0a4ab68c327e47e73d3038895962caf3dd960f3d2d4
        path=x5x8nwl615ivmy1bmqrlfkpyw9zykigd/nix-2.28.8-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=adc8893f3145a162faabd99623716f150fd06520b8e14c63af8bb095c9472759
        path=wliippjn3fvy94q3jr03szfsd2nwhhg0/nix-2.28.8-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=f15fa0b7065df0dde297892d1396664673bdaede79b8d59c0b4251e0de600412
        path=cakwmj6g0kk9p3m5lhgg5ag9k6b0qmxv/nix-2.28.8-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=08c1bb7546bcb0daf002b4d668048789bfaeb09316edbe2348667656dbe68716
        path=sjl6d22l3lq0li71f6gv84350g0hhjr1/nix-2.28.8-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=52ec01eb0305100d0d0371f1dece715a5f2670443eeaa6622e9fab0aac2e5746
        path=dlsxqds1r80jbn8zdgfwhsr87a6x9q26/nix-2.28.8-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-2.28.8/nix-2.28.8-$system.tar.xz
fi

tarball=$tmpDir/nix-2.28.8-$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 2.28.8 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