#!/bin/sh

_scs_col="\e[0;32m"
_wrn_col='\e[1;31m'
_trn_col='\e[0;33m'
_res_col='\e[0m'

# set -x

stderr_color() {
    color_code="$1"
    shift
    printf -- "${color_code}%s${_res_col}" "$@"  >&2
}

info() {
    stderr_color "${_scs_col}" "$@"
}

error() {
    stderr_color "${_wrn_col}" "$@"
}

stderr_endline() {
    printf -- "\n" >&2
}

println() {
    printf -- "%s\n" "$@"
}

remote_hostname="localhost"
remote_port="15756"

inside_ssh() {
    if [ -n "$SSH_CLIENT" ] || [ -n "$SSH_TTY" ]; then
        return 0
    fi
    # many other tests omitted
    case $(ps -o comm= -p "$PPID") in
    sshd|*/sshd)
        return 0
        ;;
    esac
    return 1
}

help() {
    printf '%s\n' "$(basename "$0"): Copies a string to the clipboard." >&2
    printf '%s\n' "" >&2
    printf '%s\n' "Usage: $(basename "$0") <string>" >&2
    printf '%s\n' "       echo <string> | cb" >&2
    printf '\n' >&2
    printf '\t%s\n' "If a pipe exists, this script copy the piped inputs" >&2
    printf '\t%s\n' "to system clipboard. Otherwise, the given argument" >&2
    printf '\t%s\n' "will be copied instead." >&2
    printf '\n' >&2
    printf '%s\n' "Options:" >&2
    printf '\t%s\t%s\n' "--help  " "display help message" >&2
    printf '\t%s\t%s\n' "-r, --hostname" "set remote address to listen to in remote netcat mode (default: $remote_hostname)" >&2
    printf '\t%s\t%s\n' "-p, --port" "set remote port to listen to in remote netcat mode (default: $remote_port)" >&2
    printf '\t%s\t%s\n' "-r, --remote" "set role to remote listener. This will make $(basename $0) listens input from netcat" >&2
    printf '\t%s\t%s\n' "--remote-sender" "set role to remote sender. This is not necessary as the script auto detect being inside ssh." >&2
}

raw_send_text_via_socket() (
    # exec 3<>/dev/tcp/localhost/5556; cat >&3; cat <&3; exec 3<&-
    # The following version closes on EOF
    exec 3<>/dev/tcp/"$remote_hostname"/"$remote_port"; cat >&3; exec 3<&-
)


EOL=$(echo '\00\07\01\00')
if [ "$#" != 0 ]; then
  set -- "$@" "$EOL"
  while [ "$1" != "$EOL" ]; do
    opt="$1"; shift
    case "$opt" in
      --help)
        help
        exit
        ;;
      -h|--hostname)
        remote_hostname="$1"
        shift
        ;;
      -p|--port)
        remote_hostname="$1"
        shift
        ;;
      --remote-sender)
        remote_mode="sender"
        ;;
      --remote-listener|--remote|-r)
        remote_mode="listener"
        ;;
      --*=*)  # convert '--name=arg' to '--name' 'arg'
        set -- "${opt%%=*}" "${opt#*=}" "$@";;
      -[!-]?*)  # convert '-abc' to '-a' '-b' '-c'
        # shellcheck disable=SC2046  # we want word splitting
        set -- $(echo "${opt#-}" | sed 's/\(.\)/ -\1/g') "$@";;
      --)  # process remaining arguments as positional
        while [ "$1" != "$EOL" ]; do set -- "$@" "$1"; shift; done;;
      -*)
        echo "Error: Unsupported flag '$opt'" >&2
        exit 1
        ;;
      *)
        # set back any unused args
        set -- "$@" "$opt"
    esac
  done
  shift # remove the EOL token
fi

# auto select ssh mode
if [ -z "$remote_mode" ] && inside_ssh; then
    info ">> Detected inside ssh, setting current role as remote sender."
    stderr_endline
    remote_mode="sender"
fi

_get_input_local() {
    # If no tty, data should be available on stdin
    if [ -t 0 ]; then
        # echo running interactivelly
        if [ "$#" -lt 1 ]; then
            # If no input, print usage message.
            error 'No argunment given.'
            stderr_endline
            help
            exit 1
        fi
        input="$@"
    else

        input="$(tee)"
        # while read line; do
        #     input="$input\n$line"
        # done
    fi
    if [ -z "$input" ]; then
        error 'Empty input from stdin.'
        stderr_endline
        exit 1
    fi
    println "$input"
}

_get_input_remote() {
    nc -cl "$remote_hostname" -p "$remote_port"
    # the previous command might returns non zero status
    true
}


get_input() {
    if [ "$remote_mode" = "listener" ]; then
        info "Listening to remote @ $remote_hostname:$remote_port..."
        stderr_endline
        _get_input_remote
    else
        _get_input_local "$@"
    fi
}

_get_receiver_local() {
    # Check that xclip is installed.
    if command -v pbcopy >/dev/null 2>&1; then
        cb="pbcopy"
        params=""
    elif command -v xsel >/dev/null 2>&1; then
        cb="xsel"
        params="--clipboard"
    elif command -v xclip >/dev/null 2>&1; then
        cb="xclip"
        params="-selection c"
    else
        error "You must have 'xsel' or 'xclip' installed."
        stderr_endline
        exit 1
    fi
    # Check if user is NOT Root (because Root cannot access User's xorg server)
    if [ "$USER" = "root" ]; then
        error "You must be regular user (non-root) to copy to clipboard."
        stderr_endline
        exit 1
    fi
    "$cb" $params  # allows params to split on space
}

_get_receiver_remote() {

    if command -v nc >/dev/null 2>&1; then
        nc -c "$remote_hostname" "$remote_port"
    elif command -v telnet >/dev/null 2>&1; then
        # sleep to wait for telnet to first connects. It's a heuristic.
        { sleep .5; printf '%s\n' "$(tee)"; } | telnet "$remote_hostname" "$remote_port"
    else
        # use raw socket
        raw_send_text_via_socket
    fi
    status="$?"
    if [ "$status" -ne 0 ]; then
        error "Error in opening port. If you are in ssh session, have you "
        stderr_endline
        error "  (1) open port with '-R $remote_port:localhost:$remote_port', and "
        stderr_endline
        error "  (2) starts a local $(basename $0) process with '$(basename $0) -r'?"
        stderr_endline
        stderr_endline
        error "  (tip): You can use ssh escape sequence ~C and then type the previous command"
        stderr_endline
        error "         to amend a ssh session without closing it."
        stderr_endline
        exit 1
    fi

}

get_receiver() {
    set -o pipefail
    if [ "$remote_mode" = "sender" ]; then
        info "Sending to remote @ $remote_hostname:$remote_port..."
        stderr_endline
        _get_receiver_remote
    else
        _get_receiver_local
    fi
}


# if [ -n "$remote_mode" ]; then
#     echo hi | raw_send_text_via_socket
#     exit
# fi


input="$(get_input "$@")"
# echo "in4 $input"
status="$?"
if [ "$status" -ne 0 ]; then
    exit "$status"
fi

# Copy input to clipboard
printf -- '%s' "$input" | get_receiver
status="$?"
if [ "$status" -ne 0 ]; then
    exit "$status"
fi


# Truncate text for status
if [ ${#input} -gt 80 ]; then
    input="$(printf -- "%s$_trn_col..." "$(echo "$input" | head -c80)")"
fi

# Print status.
stderr_color "${_scs_col}" "Copied to clipboard: "
stderr_color "" "$input"
stderr_endline

# alias h2cb='fc -ln -1 | tail --lines=2 | head --lines=1 | cb'