#!/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=0a0462692a10ff1eb8a608f713f38d1f25a208ad55963a9c00b239da398de5a1
        path=8agjyj3h8f6fln1hjx0cg2m7ss6vf7x5/nix-2.34.5-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=65ad3ac36194d5f94d1b40e180d2f985fd5984ab1145e8ef046f7781a3f182bc
        path=sfxjlksqjbr9zpx6idbp0ncf0q1zzsw5/nix-2.34.5-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=771e4b6f719243b9481f19eaedfbbbacc2f4a0282d6e043df4f33bb449ea3c57
        path=i3rarq9sik672hqf3hqbxmqwzgnbap3m/nix-2.34.5-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=b3610cdb4d41dac56cba175b384126e1eff2c84a462ca61b4be15bc5ea23410c
        path=1a07vdbqcyvpagf9x7xlspaq4n1zjcfh/nix-2.34.5-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=83e3ef9b82c8aa45c2d7848528ce967ff962a67a4990a63e8732eceaf0d8ae2f
        path=nj5799xcd2l67aaf42jbd8j987g7049w/nix-2.34.5-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=7e91dec3947df65f6f6fc8e731cbf54dd0a57aedd50bc26826dfb962b498358b
        path=zs6xvd6d1zfqsfgp01iphihrhb95y3vj/nix-2.34.5-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=a14b529bcdbeffe47b7afe36991a4ea6b157bb33ac539441de209becb1f008c2
        path=mj9ixngccirqia7kf6klyasp6wxz7fbz/nix-2.34.5-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=ec563e3d2bc0ce992956a2fafe09b2b1e91ddaf68be3c59c7d1be71c69cb9672
        path=z6x8m4fxzxyq5dawdc5ql2lnbnv4ydmq/nix-2.34.5-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-2.34.5/nix-2.34.5-$system.tar.xz
fi

tarball=$tmpDir/nix-2.34.5-$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 2.34.5 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