class MisterBin::CommandMeta

def commands_string
  return nil if commands.empty?
  key_value_block 'Commands:', commands
end

def description
  summary || help || ''
end

def docopt
  [
    summary_string, help_string, usage_string, commands_string,
    options_string, params_string, env_string, examples_string
  ].compact.join "\n"
end

def env_string
  return nil if env_vars.empty?
  key_value_block 'Environment Variables:', env_vars
end

def examples_string
  return nil if examples.empty?
  result = ['Examples:']
  examples.each { |text| result << word_wrap("  #{text}") }
  result << ''
  result.join "\n"
end

def help_string
  help ? "#{word_wrap(help)}\n" : nil
end

def initialize
  @version  = nil
  @help     = nil
  @summary  = nil
  @usages   = []
  @options  = []
  @params   = []
  @commands = []
  @examples = []
  @env_vars = []
end

def key_value_block(caption, pairs)
  result = [caption]
  pairs.each do |key, value|
    result << "  #{key}"
    result << word_wrap("    #{value}")
    result << ''
  end
  result.join "\n"
end

def long_description
  summary && help ? "#{summary}\n\n#{help}" : description
end

def options_string
  result = ['Options:']
  options.each do |option|
    result << "  #{option[0]}"
    result << word_wrap("    #{option[1]}")
    result << ''
  end
  result << '  -h --help'
  result << "    Show this help\n"
  if version
    result << '  --version'
    result << "    Show version number\n"
  end
  result.join "\n"
end

def params_string
  return nil if params.empty?
  key_value_block 'Parameters:', params
end

def summary_string
  summary ? "#{word_wrap(summary)}\n" : nil
end

def usage_string
  result = ['Usage:']
  usages.each { |text| result << word_wrap("  #{text}") }
  result << ''
  result.join "\n"
end