#!/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=e828c574555f235f2ca47c4a1432f8a07905d5cf59f087e9581be56c238818db
        path=lgbfby3yzywxy9ghbgcccr77s15mz785/nix-2.35.0-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=64dc11b5d59524bcaa79111182bbe1c7b2048eed94be2f88d97868bcd4faf868
        path=7yazqynfsjkc96jbwn4jrzk8qbq0zc9i/nix-2.35.0-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=1916bd42cfd4a65d5642a4ca75be4fe55db0a67e5fa16e18808fb5b6d2365bf8
        path=c6chdi5i1j5srg13jchwkcck9vsdaalc/nix-2.35.0-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=c30ffbcdb570f86b5e568807db558c955e4188fadfca2b0abde16352360c0cc8
        path=9k5friplqf8dlvxvqvj54zgyg3cgz8q5/nix-2.35.0-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=b18dfcbc46a42286ffdf1923bdb73aec25deb20407815ea4a09404b28f4d06da
        path=jv1xi3swacyjdfc6wz1r0bdzk515kgxg/nix-2.35.0-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=b758b3cc2774a00bbc71408b2e40a5e194e9d4291a0d26b752c80232c1d9a257
        path=k0yij452akdaiccx49vn349mfjd34y9g/nix-2.35.0-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=26b3056254c95fc818c55a9d1c998048ae8f98968eda4ded7d91bba8392e1fe5
        path=xsh27wcrnfwhslryvxci5jr9l2gxjwhj/nix-2.35.0-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=53d7583c81a1049a9187cd4bcf19442ac5a97885d9e0ca1a5cdcd841a69be7c6
        path=ky0pxmjp7gajgbc7rwidll3nbb718vyd/nix-2.35.0-aarch64-darwin.tar.xz
        system=aarch64-darwin
        ;;
    FreeBSD.amd64|FreeBSD.x86_64)
        hash=89662a13bee2402dcf771b4c8f2e294cf594138bca1fc900bfda3fe5197ff474
        path=4cgm075vgxpkx7wsh67dj8fi99nalkbx/nix-2.35.0-x86_64-freebsd.tar.xz
        system=x86_64-freebsd
        ;;
    *) 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://mirror.nju.edu.cn/nix/nix-2.35.0/nix-2.35.0-$system.tar.xz
fi

tarball=$tmpDir/nix-2.35.0-$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 2.35.0 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