# ri completion for Ruby documentation                     -*- shell-script -*-
# by Ian Macdonald <ian@caliban.org>

_ri_get_methods()
{
    local regex

    if [[ $ri_version == integrated ]]; then
        if [[ -z $separator ]]; then
            regex="(Instance|Class)"
        elif [[ $separator == "#" ]]; then
            regex=Instance
        else
            regex=Class
        fi

        COMPREPLY+=( \
            "$( ri ${classes[@]} 2>/dev/null | ruby -ane \
            'if /^'"$regex"' methods:/.../^------------------|^$/ and \
            /^ / then print $_.split(/, |,$/).grep(/^[^\[]*$/).join("\n"); \
            end' 2>/dev/null | sort -u )" )
    else
        # older versions of ri didn't distinguish between class/module and
        # instance methods
        COMPREPLY+=( \
            "$( ruby -W0 $ri_path ${classes[@]} | ruby -ane \
            'if /^-/.../^-/ and ! /^-/ and ! /^ +(class|module): / then \
            print $_.split(/, |,$| +/).grep(/^[^\[]*$/).join("\n"); \
            end' | sort -u )" )
    fi
    COMPREPLY=( $( compgen $prefix -W '${COMPREPLY[@]}' -- $method ) )
}

# needs at least Ruby 1.8.0 in order to use -W0
_ri()
{
    local cur prev words cword
    _init_completion || return

    local class method prefix ri_path ri_version separator IFS
    local -a classes

    ri_path=$(type -p ri)
    # which version of ri are we using?
    # -W0 is required here to stop warnings from older versions of ri
    # from being captured when used with Ruby 1.8.1 and later
    ri_version="$(ruby -W0 $ri_path -v 2>&1)" || ri_version=integrated
    [[ $ri_version != ${ri_version%200*} ]] && ri_version=integrated

    # need to also split on commas
    IFS=$', \n\t'
    if [[ "$cur" == [A-Z]*[#.]* ]]; then
        [[ "$cur" == *#* ]] && separator=# || separator=.
        # we're completing on class and method
        class=${cur%$separator*}
        method=${cur#*$separator}
        classes=( $class )
        prefix="-P $class$separator"
        _ri_get_methods
        return 0
    fi

    if [[ $ri_version == integrated ]]; then
        # integrated ri from Ruby 1.9
        classes=( $( ri -c 2>/dev/null | ruby -ne 'if /^\s*$/..$stdin.eof then \
        if /, [A-Z]+/ then print; end; end' 2>/dev/null ) )
    elif [[ $ri_version == "ri 1.8a" ]]; then
        classes=( $( ruby -W0 $ri_path | \
            ruby -ne 'if /^'"'"'ri'"'"' has/..$stdin.eof then \
            if /^ .*[A-Z]/ then print; end; end' ))
    else
        classes=( $( ruby -W0 $ri_path | \
            ruby -ne 'if /^I have/..$stdin.eof then \
                if /^ .*[A-Z]/ then print; end; end' ))
    fi

    COMPREPLY=( $( compgen -W '${classes[@]}' -- "$cur" ) )
    if [[ "$cur" == [A-Z]* ]]; then
        # we're completing on class or module alone
        return 0
    fi

    # we're completing on methods
    method=$cur
    _ri_get_methods
} &&
complete -F _ri ri

# ex: ts=4 sw=4 et filetype=sh