# Invoke tab-completion script to be sourced with the Z shell.
# Known to work on zsh 5.0.x, probably works on later 4.x releases as well (as
# it uses the older compctl completion system).

_complete_{binary}() {{
    # `words` contains the entire command string up til now (including
    # program name).
    #
    # We hand it to Invoke so it can figure out the current context: spit back
    # core options, task names, the current task's options, or some combo.
    #
    # Before doing so, we attempt to tease out any collection flag+arg so we
    # can ensure it is applied correctly.
    collection_arg=''
    if [[ "${{words}}" =~ "(-c|--collection) [^ ]+" ]]; then
        collection_arg=$MATCH
    fi
    # `reply` is the array of valid completions handed back to `compctl`.
    # Use ${{=...}} to force whitespace splitting in expansion of
    # $collection_arg
    reply=( $({binary} ${{=collection_arg}} --complete -- ${{words}}) )
}}


# Tell shell builtin to use the above for completing our given binary name(s).
# * -K: use given function name to generate completions.
# * +: specifies 'alternative' completion, where options after the '+' are only
#   used if the completion from the options before the '+' result in no matches.
# * -f: when function generates no results, use filenames.
# * positional args: program names to complete for.
compctl -K _complete_{binary} + -f {spaced_names}

# vim: set ft=sh :
