#!/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=8132c325da027ccb158008c3b6745df7101b6883a491ecb8db5db3e281aa645b
        path=0qcghfkrk54ac9j47qm75bgir3piqflc/nix-2.29.2-x86_64-linux.tar.xz
        system=x86_64-linux
        ;;
    Linux.i?86)
        hash=88db2c2516f65db294b8a5177b31b17f2fabf01a19f95b06e67de98bc7570db9
        path=3j3p3gdjd9zq2gv6j28hdf07fm40abxd/nix-2.29.2-i686-linux.tar.xz
        system=i686-linux
        ;;
    Linux.aarch64)
        hash=345b33b0870117e24a358eaf3b26e59c4ae0fe2318c835e78b807ec1f6dd6d6f
        path=m1g9vljwmx5fd4i49z1510d14lkmlxwy/nix-2.29.2-aarch64-linux.tar.xz
        system=aarch64-linux
        ;;
    Linux.armv6l)
        hash=b29cb39bf699417e19062844b43e5f679ff2ce4b899c7e54e355fbba33c2928b
        path=7kqffgw9ydp4sa74y32fg8i9gfdazlpn/nix-2.29.2-armv6l-linux.tar.xz
        system=armv6l-linux
        ;;
    Linux.armv7l)
        hash=3babb7dad26592857623aae162e212ec74b4f0b45cd82c6c54076342f62a0e92
        path=mcpzschvc6gpb212lv0vyqaqh1v0c4q4/nix-2.29.2-armv7l-linux.tar.xz
        system=armv7l-linux
        ;;
    Linux.riscv64)
        hash=a6b40fc9d4982b44eecc2cf7bf198f499ae4030e41b662ef4f3ea75e7a64e0e8
        path=g7fk7gkzk35xhnc13bcykr5qn7snlk9x/nix-2.29.2-riscv64-linux.tar.xz
        system=riscv64-linux
        ;;
    Darwin.x86_64)
        hash=536a4d1751c89e9ae195c61dfe2fa65837195b65a76004516277e7527c47326c
        path=iljvxrj9zcmbk0wpzs4r40kfbb7sqfw6/nix-2.29.2-x86_64-darwin.tar.xz
        system=x86_64-darwin
        ;;
    Darwin.arm64|Darwin.aarch64)
        hash=dd6e3d0d6d1f49997f10f9c6c714dc8821d981400be406fd5005a7a345d11284
        path=npgagkj4093hr4nc5fcnp7f8k3vll6q1/nix-2.29.2-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-2.29.2/nix-2.29.2-$system.tar.xz
fi

tarball=$tmpDir/nix-2.29.2-$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 2.29.2 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