#!/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=0f13fa4190d8921ba1ba975bfe50915fff17209c1d2292f72df1575a0748e97a
        path=nv0y6cvizrarifif8k57hr85izlsbyc0/nix-2.24.5-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=0bf481159f30ae598c2cae993c90208db94ed06cd08efe079092b9633702add7
        path=4j3bahph7ja26nhz10r7xa9aniw494sh/nix-2.24.5-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=379560f2505e427480d4420ee733cc19a6eb3a802e54261b2caa6de2d97a3ddf
        path=m7k6fgvb191y7ijjaqd2ic20iqycrsc6/nix-2.24.5-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=2485e85051a2e19a3c03cd3f2dab3fbdac023fd535487f6f456aef6617805854
        path=wrh22ij0y3rrhqlcacnqll01wl6s1jax/nix-2.24.5-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=fcdd5064972cb46f5e424f305947749abb698bfd21fe7810b4a3bc3fca6efea0
        path=jk9dd3s2jgkjkfih4mhx0dq9j9fx7nn2/nix-2.24.5-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=4e81b84ec77d21be5be214c379a5f307e47b52118e5ae68362282deda538553d
        path=vwmy9nlhnpb9wxivi0l8nyyr2a9jlzsb/nix-2.24.5-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=06b40d67834ec43a4b573978c4190fe286c73b74c51fb058bd82369f869c3de7
        path=2sbrphkv7ar51d83wbr8ffi134hlr4rm/nix-2.24.5-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=ce0525012fd7dd61b1b1bb6ed94f3329fcfb6d24e842b14d942a72e05713d3ad
        path=ahjjnaja9llx6dd8pd6hh6iiqlr86yqm/nix-2.24.5-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-2.24.5/nix-2.24.5-$system.tar.xz
fi

tarball=$tmpDir/nix-2.24.5-$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 2.24.5 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