#!/usr/bin/env bash

# This bash completion script works by invoking the mesos command itself with a
# "magic" subcommand called "__autocomplete__" and then forwarding all of the
# arguments to it. The mesos command takes care of parsing the arguments and
# returning the list of valid completions for the current word.
_mesos() {
    local cur cmd args rets
    local option words
    local OIFS

    cur="${COMP_WORDS[${COMP_CWORD}]}"
    cmd="${COMP_WORDS[0]}"
    args=(${COMP_WORDS[@]:1})

    # The __autocomplete__ command will return two lines of text (the first
    # being the completion mode (default, nospace, etc.) and the second being a
    # space-separated list of completion words). To handle this, we temporarily
    # change the shell separator to '\n' instead of ' ' in order to interpret
    # the results as exactly two values.
    OIFS=${IFS}
    IFS=$'\n'
    rets=($(${cmd} __autocomplete__ "${cur}" ${args[*]}))
    IFS=${OIFS}

    option="${rets[0]}"
    words="${rets[1]}"

    # Reset the completion mode to be whatever value was returned by
    # the __autocomplete__ command.
    complete -o ${option} -F _mesos mesos

    # Build the array of completion words.
    COMPREPLY=( $(compgen -W "${words}" -- ${cur}) )

    # If there are no completion words, then reset the completion to "nospace"
    # mode so that hitting tab will not produce a space after the current word.
    # This step is necessary since the mode might have been changed above.
    if [ "${#COMPREPLY[@]}" = "0" ]; then
        complete -o nospace -F _mesos mesos
        COMPREPLY=()
    fi

    return 0
}
complete -F _mesos mesos