class Fagin

# File lib/fagin.rb, line 4
def self.find_children(
    parent,
    dir,
    recursive = false,
    withfile = false
)
    children = Hash.new
    path = Pathname.new(dir).expand_path
    return children if (!path.exist?)

    pattern = "\"^class +[^ ]+ *< *#{parent}\""
    cmd = "grep -EHors #{pattern} #{path}"
    cmd += "/*.rb" if (!recursive)

    %x(#{cmd}).each_line do |line|
        line.match(/^([^:]+\.rb).+class\s+(\S+)\s*</) do |match|
            file = match[1]
            next if (file.nil? || file.empty?)
            clas = match[2]
            next if (clas.nil? || clas.empty?)
            begin
                require_relative file
                child = clas.split("::").inject(Object) do |m, c|
                    m.const_get(c)
                end
                if (withfile)
                    children[clas] = [child, file]
                else
                    children[clas] = child
                end
            rescue NameError
                raise Error::UnknownChildClass.new(clas)
            end
        end
    end

    return children
end

# File lib/fagin.rb, line 43
def self.find_children_recursively(parent, dir)
    return find_children(parent, dir, true)
end

# File lib/fagin.rb, line 47
def self.find_children_with_file(parent, dir)
    return find_children(parent, dir, false, true)
end

# File lib/fagin.rb, line 51
def self.find_children_with_file_recursively(parent, dir)
    return find_children(parent, dir, true, true)
end