#!/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=ebae1ef391c67221f7ade9f40c5c8fa7ed2a11cb46635a22a7a42f1d58ddfbe7
        path=kp32pq1mx3kfjjl3gy0wxixf20cxpg1k/nix-2.33.4-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=5cf1849ae3ab41e83bfa962fff60a2081a04b14bc97e63d9abd5ec11945a6820
        path=jqymzprw2k21jp3pik011296i9ns3wsb/nix-2.33.4-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=d26bf56d6e6bb0e5982293665fbd0c7504fa8f5d51a12c4b7c6941e93c56e7e8
        path=2dz4kr0ydb23zw421nvx6rr8f6chmnw7/nix-2.33.4-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=ce395a1ba5fd0058ac0c46b4130a00c095e6ccc11060bad16d8b516bbd5340a0
        path=m82qsxd9qwx3bw2apczfw1rgby2hn9d8/nix-2.33.4-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=c719b4f1ea550dc1aae6464aeeaff38aeee4abac0e7c24a779b106f9aa788082
        path=xxh826cynfypd3z85ac4mr51gkjppg3k/nix-2.33.4-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=7806b35af69f3f04a5f9c641ecc8faa086bafccf5fe2832cadc64ebd68297c72
        path=8rrwcj8a1n69v4av9aib3ar35hh3cfsr/nix-2.33.4-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=a6175ecbc5077b32fe19c790d085841ab57e15db348ba5e6ca9c195f97459c35
        path=hnypdjk5w33llr5xj39fcza6j3k05mp8/nix-2.33.4-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=50e17c68266398c61e3ac4fd0af3164e0818a8f0b00d2469a814d75af44f8dd1
        path=1kfav5qkx9qwx56kfcxf0mzfkdc9a7x3/nix-2.33.4-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-2.33.4/nix-2.33.4-$system.tar.xz
fi

tarball=$tmpDir/nix-2.33.4-$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 2.33.4 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