#!/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=56f16548e603830234c0fa74b0f7c4f670ce7fbf006ce73e7bc7f5cb48010c11
        path=hdj3fwlij8ldwna36pjwz2lv2n32ll12/nix-2.30.1-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=ac70938f674fec7c94467dec427c83dd23a07786274fbb358045a99d58d4ee94
        path=cld9mfjmyibl73yrbr4h6n9sx161isq8/nix-2.30.1-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=0ade182652e8a2c1a3a5ccb14b5d861322345b41407599f5f0c9de6b026aa104
        path=qdlzg3fy9yvnwm03ds0ipbxcy5rs2zdm/nix-2.30.1-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=1e5071d80b3fd6c96786b72dee9ce6d134127d6e25b0be045d9e728bf314ee3c
        path=a470jaja1nz53nijjys82525ardhn1z9/nix-2.30.1-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=775321d0fd5bf5d7c0838b24e36c05cd8a4eeed68b58142b585897ba7921534d
        path=2yqdkfhl1jwjy75qjl3adkinz8k2p85h/nix-2.30.1-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=0df51ae8ba8a9f6eadf506076b4a948f4a766c7ca82af9bebed15017cd882549
        path=zzc9prr21y6d87fg9m3fv3a50qbzx9wi/nix-2.30.1-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=7d627e6361537e3e68c89555c99d14260ebedb56028d7a80731bf8fcbf0c82bc
        path=b3z3q30p3dah2n0wgqnb86rcy9ffgj73/nix-2.30.1-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=5111a1cb403b713acae6b511df8cc64a913deec25886c201c5bd3908aa9af3fd
        path=ksshamlbp0hfp9pchz7yr30w1whrq57z/nix-2.30.1-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-2.30.1/nix-2.30.1-$system.tar.xz
fi

tarball=$tmpDir/nix-2.30.1-$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 2.30.1 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