module IrcFormat

# File lib/irc_format.rb, line 143
def accent_paren(*parts)
  text = meta_join(*parts)
  return "" if text.empty?

  load_extended_colors!
  bits = named_style(:accent)
  main = named_style(:footer)
  "#{bits}(#{RESET}#{main}#{text}#{bits})#{RESET}#{main}"
end

# File lib/irc_format.rb, line 75
def bold(text)
  value = text.to_s
  return value if value.empty?

  "#{IRC_BOLD}#{value}#{IRC_BOLD}"
end

# File lib/irc_format.rb, line 114
def bracket_label(text, label_style: nil)
  label = text.to_s.strip
  return "" if label.empty?

  load_extended_colors!
  label_style ||= named_style(:tag)
  shell = named_style(:panel)
  after = named_style(:footer)
  "#{shell}#{BRACKET_LEFT_CHAR}#{label_style}#{IRC_BOLD}#{label}#{IRC_BOLD}#{shell}#{BRACKET_RIGHT_CHAR}#{after}"
end

# File lib/irc_format.rb, line 98
def classic_menu_heading_style
  @classic_menu_heading_style ||= color(0, 4)
end

# File lib/irc_format.rb, line 94
def classic_muted_style
  @classic_muted_style ||= color(15, 14)
end

# File lib/irc_format.rb, line 102
def classic_nick_style
  @classic_nick_style ||= color(0, 10)
end

# File lib/irc_format.rb, line 30
def color(fg, bg = nil)
  fg_code = format_color_code(fg)
  return "#{CTRL}#{fg_code}" unless bg

  bg_code = format_color_code(bg)
  "#{CTRL}#{fg_code},#{bg_code}"
end

# File lib/irc_format.rb, line 68
def decorate(text, style)
  value = text.to_s
  return value if value.empty?

  "#{style}#{value}#{RESET}"
end

# File lib/irc_format.rb, line 158
def divider(title = nil, width: 40, char: "=", style: nil)
  line = divider_line(title, width: width, char: char)
  decorate(line, style || color(14))
end

# File lib/irc_format.rb, line 163
def divider_line(title, width:, char:)
  if title.nil? || title.to_s.strip.empty?
    return char * width
  end

  label = " #{title.to_s.strip} "
  pad = [width - label.length, 0].max
  left = pad / 2
  right = pad - left
  "#{char * left}#{label}#{char * right}"
end

# File lib/irc_format.rb, line 38
def format_color_code(value)
  code = value.to_i
  raise ArgumentError, "IRC colour must be #{MIN_COLOR}-#{MAX_COLOR} or #{DEFAULT_COLOR}" unless valid_color?(code)

  code.to_s.rjust(2, "0")
end

# File lib/irc_format.rb, line 206
def load_extended_colors!
  require_relative "irc_extended_colors" unless defined?(IrcExtendedColors)
end

# File lib/irc_format.rb, line 125
def menu_heading(title, style: menu_heading_style)
  label = title.to_s.strip
  return "" if label.empty?

  decorate("-=// #{label} \\=-", style)
end

# File lib/irc_format.rb, line 110
def menu_heading_style
  @menu_heading_style ||= named_style(:title)
end

# File lib/irc_format.rb, line 132
def menu_subheading(title, style: menu_heading_style)
  label = title.to_s.strip
  return "" if label.empty?

  decorate("--==// #{label} \\==--", style)
end

# File lib/irc_format.rb, line 139
def meta_join(*parts)
  parts.flatten.map(&:to_s).map(&:strip).reject(&:empty?).join(" · ")
end

# File lib/irc_format.rb, line 82
def muted(text)
  decorate(text, muted_style)
end

# File lib/irc_format.rb, line 106
def muted_style
  @muted_style ||= named_style(:muted)
end

# File lib/irc_format.rb, line 86
def named_style(name)
  load_extended_colors!
  fg, bg = IrcExtendedColors.resolve_pair(name)
  raise ArgumentError, "Unknown named colour pair: #{name.inspect}" unless fg

  bg ? color(fg, bg) : color(fg)
end

# File lib/irc_format.rb, line 175
def nick(name, op: false, classic: false)
  value = name.to_s.strip
  return value if value.empty?

  prefix = op ? "@" : ""
  style = classic ? classic_nick_style : named_style(:nick)
  decorate("#{prefix}#{value}", style)
end

# File lib/irc_format.rb, line 49
def parse_colour_spec(value)
  match = value.to_s.match(COLOUR_SPEC_PATTERN)
  return { error: "Invalid colour — use fg or fg,bg (0-98)." } unless match

  fg = match[1].to_i
  bg = match[2] ? match[2].to_i : nil
  return { error: "Invalid colour — use fg or fg,bg (0-98)." } unless valid_color?(fg)
  return { error: "Invalid colour — use fg or fg,bg (0-98)." } if bg && !valid_color?(bg)

  { fg: fg, bg: bg }
end

# File lib/irc_format.rb, line 191
def report_footer(*parts)
  accent_paren(*parts)
end

# File lib/irc_format.rb, line 184
def report_header(tag:, title:, style: menu_heading_style)
  [
    bracket_label(tag),
    menu_heading(title, style: style)
  ].join(" ")
end

# File lib/irc_format.rb, line 153
def tag(name, style: nil)
  _ = style # legacy callers may pass style; Ibis brackets use fixed palette
  bracket_label(name)
end

# File lib/irc_format.rb, line 61
def underline(text)
  value = text.to_s
  return value if value.empty?

  "#{IRC_UNDERLINE}#{value}#{IRC_UNDERLINE}"
end

# File lib/irc_format.rb, line 196
def unescape_literal_color_codes(text)
  value = text.to_s
  return value if value.empty?

  value.gsub(/\\(?:x03|003)(\d{1,2}(?:,\d{1,2})?)?/) do
    spec = Regexp.last_match(1)
    spec ? "#{CTRL}#{spec}" : CTRL
  end
end

# File lib/irc_format.rb, line 45
def valid_color?(code)
  (MIN_COLOR..MAX_COLOR).cover?(code) || code == DEFAULT_COLOR
end