#!/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=2c2e146b80834fe0ca201b51deeb939405b4f18e8d2071bf80b10f8123c50464
        path=spikfidyzynmawpicywa15x9q7vnq122/nix-2.34.8-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=90a5aeb423fdadd6019193db4d52c266e41492df9eac7091d6947afef549da12
        path=38cq5f2f94cq1xhjxqidswl9s9iasnbv/nix-2.34.8-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=b4e565fe4db5c352547b8146488cab81db06be89301a4c67b081c76f1e457760
        path=67fprznkw7lqmd313gcdb0c7k44zy5r7/nix-2.34.8-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=f36fe1e263bc952e6066ed2bf2b917c6256ced77f41a65505542c0a7c516e144
        path=ch6kpdh7875vx3i8z0kj7bvfrizj5b34/nix-2.34.8-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=0620390b323f58c3c01331a1da8a211df3398acdb35d6d56601f74f2b3715b9f
        path=ifkl8z2n4xmah91faqn8z07khj245s0q/nix-2.34.8-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=f7ee14add97b6a62f97309e01b72d74eed5edb1ebedeeee09f1d9799749a709d
        path=r8l32sg9qa0vvcs7rnphyw8xzjggabk9/nix-2.34.8-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=14d3af62d1c1755da7e048519a73baeab3e856cba766e53fca5ceec4e6fe67e2
        path=pkpn5s0rc3jfn21ghcz40hyg71s02rpv/nix-2.34.8-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=ae3b2b1a74b956110d14dd813bee80ea46626a51ddce28d142e0805379a34acf
        path=s2cf5x20ivavfc2wsfrziaxqjy1adfvb/nix-2.34.8-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://releases.nixos.org/nix/nix-2.34.8/nix-2.34.8-$system.tar.xz
fi

tarball=$tmpDir/nix-2.34.8-$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 2.34.8 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