module SingFormat

# File lib/sing_format.rb, line 30
def filter_script_lines(lines)
  lines.reject { |line| script_line?(line) }
end

# File lib/sing_format.rb, line 60
def format_lyric_lines(lyrics)
  lines = merge_lyric_lines(normalize_lyrics(lyrics).split("\n"))
  return "" if lines.empty?

  lines.join("\n")
end

# File lib/sing_format.rb, line 85
def format_lyrics(artist, title, lyrics)
  body = format_lyric_lines(lyrics)
  return NO_LYRICS_MESSAGE if body.empty?

  "#{artist.to_s.strip} — #{title.to_s.strip}:\n#{body}"
end

# File lib/sing_format.rb, line 39
def merge_lyric_lines(lines, max_chars: MAX_LYRIC_LINE_CHARS)
  cleaned = lines.map(&:to_s).map(&:strip).reject(&:empty?)
  return [] if cleaned.empty?

  merged = []
  current = +cleaned.first

  cleaned.drop(1).each do |line|
    candidate = "#{current} #{line}"
    if current.length >= BASE_MAX_LYRIC_LINE_CHARS && candidate.length <= max_chars
      current = candidate
    else
      merged << current
      current = +line
    end
  end

  merged << current
  merged
end

# File lib/sing_format.rb, line 34
def normalize_lyrics(text)
  lines = text.to_s.strip.gsub(/\n{2,}/, "\n").gsub(/[ \t]+\n/, "\n").split("\n")
  filter_script_lines(lines).map(&:rstrip).reject(&:empty?).join("\n")
end

# File lib/sing_format.rb, line 71
def reply_pieces(text, message:, outgoing_line_limit:, chunker: CHUNK_HELPER.method(:chunk_text))
  limit = scaled_line_byte_limit(outgoing_line_limit)
  pieces = []

  text.to_s.split("\n").each do |line|
    line = line.rstrip
    next if line.empty?

    pieces.concat(chunker.call(line, max_bytes: limit))
  end

  pieces
end

# File lib/sing_format.rb, line 67
def scaled_line_byte_limit(base_limit)
  (base_limit.to_f * LINE_LENGTH_FACTOR).floor
end

# File lib/sing_format.rb, line 23
def script_line?(line)
  text = line.to_s.strip
  return false if text.empty?

  text.match?(SCRIPT_LINE_PATTERN) || text.include?(IRC_CTRL)
end