#!/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=c05cc1b2bc95aa5460bdf3c890d0e65d584fcf7fea8ee5c60b142084308782bc
        path=p8p12b38rbpqd3qrli3dj4mxkl37cxs7/nix-2.4pre-rc1-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=9807450a0a472b339da75ceb087d634b2d781145be37b808bdfd9b4eed2a4212
        path=mlnwd7s05aid8rdp0yk9f7gbv5p6xwrg/nix-2.4pre-rc1-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=156c50b596708b4dcccdd840efe5761770fb0fdd2eef24b512d573e6e503d67b
        path=kybxdr9c262wqfhvmy8zydnvaz88qqbq/nix-2.4pre-rc1-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l_linux)
        hash=cf2502d3c61de948247220a611bd56e2f272d75d53b3e3aafbc2be3e09263363
        path=anjwmimli8c1sskp45qbc654wp0ixmiq/nix-2.4pre-rc1-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l_linux)
        hash=7ecbbb1bebd8a799f5bd780dd1ffe30f86f22e27e58bbf23804579ae332fd2f0
        path=immslysbskc73rvk0pwb8z1q2z81x3lp/nix-2.4pre-rc1-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Darwin.x86_64)
        hash=780dbd991564b2e9e5cd9b22287758d9bc3a471ea47111fefbb56e04ff6b6ed9
        path=x26j52dd4mzx8dpr3j8wvs7w47m9mjp1/nix-2.4pre-rc1-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=d2d9cf4f2dc7f47a361ff4483c38899a096ccadc124eba8394e48ae3994d2fd2
        path=cg4dl9zdx4addpfshw2grrfwdq2f6x9j/nix-2.4pre-rc1-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-2.4pre-rc1/nix-2.4pre-rc1-$system.tar.xz
fi

tarball=$tmpDir/nix-2.4pre-rc1-$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 wget > /dev/null 2>&1; then
    fetch() { wget "$1" -O "$2"; }
elif command -v curl > /dev/null 2>&1; then
    fetch() { curl -L "$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 2.4pre-rc1 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