#!/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=67baeab9af98802102994e99af16a03b10f8f04e236acbf092748ed762b86854
        path=f35i135h2q9zmhwg5wjyzxwfxkdkhqhp/nix-2.31.3-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=c891cbdba61f6d00a14d0f4dc956e4beb364d7d02e72f6335e494c367d2f68b5
        path=v1mvw361nlgar0i47a0r9q2lcipsl7v7/nix-2.31.3-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=4b706d8f761df27747cb3af7d873e7b5471db9fb714f0993091e96b02e29b692
        path=nnmfz31airb8sxm8g7gxb6yn0671fxkl/nix-2.31.3-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=e594f9a502d8694c27457ea4ab4c9c5b2fddc1f522aa559b3306aa205231dee2
        path=4xg45q82ykghwbp1awxwwxsmnpibb1h1/nix-2.31.3-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=8c9a6aa103acda4806d217a3ac20edb069628843b3cddabdd37416ee9ef6fe13
        path=2y5l0i1d2v2ql5qpdhyzf3262zifw16f/nix-2.31.3-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=e876636424c766910388a8972331000fba1ac414823ce47c9a1bde543d9c1d25
        path=w8x0npwa9p54nwclj24nn2gpwk6mxv86/nix-2.31.3-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=12b85aef6b6c24aeff9abac7239f98e00628b4e08eab6b85e8557e9c5a33b8ea
        path=9vssn0iqnwjipqqsxnl6bcg6z8ybq9rn/nix-2.31.3-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=35c806c9bce421e37bad0fb5184f984c94013fde3e336a58d3a6ac4705b03f66
        path=g2l9lnskdx4s8hnhml264njlrl6m89b0/nix-2.31.3-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-2.31.3/nix-2.31.3-$system.tar.xz
fi

tarball=$tmpDir/nix-2.31.3-$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 2.31.3 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