module SongPro

# File lib/song_pro.rb, line 20
def self.parse(lines)
  song = Song.new
  current_section = nil

  lines.split("\n").each do |text|
    if text.start_with?('@')
      process_attribute(song, text)
    elsif text.start_with?('!')
      process_custom_attribute(song, text)
    elsif text.start_with?('#')
      current_section = process_section(song, text)
    else
      process_lyrics_and_chords(song, current_section, text)
    end
  end

  song
end

# File lib/song_pro.rb, line 48
def self.process_attribute(song, text)
  matches = ATTRIBUTE_REGEX.match(text)
  key = matches[1]
  value = matches[2].strip

  if song.respond_to?("#{key}=".to_sym)
    song.send("#{key}=", value)
  else
    puts "WARNING: Unknown attribute '#{key}'"
  end
end

# File lib/song_pro.rb, line 60
def self.process_custom_attribute(song, text)
  matches = CUSTOM_ATTRIBUTE_REGEX.match(text)
  key = matches[1]
  value = matches[2].strip

  song.set_custom(key, value)
end

# File lib/song_pro.rb, line 68
def self.process_lyrics_and_chords(song, current_section, text)
  return if text == ''

  if current_section.nil?
    current_section = Section.new(name: '')
    song.sections << current_section
  end

  line = Line.new

  if text.start_with?('|-')
    line.tablature = text
  elsif text.start_with?('| ')
    captures = text.scan(MEASURES_REGEX).flatten

    measures = []

    captures.each do |capture|
      chords = capture.scan(CHORDS_REGEX).flatten
      measure = Measure.new
      measure.chords = chords
      measures << measure
    end

    line.measures = measures
  elsif text.start_with?('>')
    matches = COMMENT_REGEX.match(text)
    comment = matches[1].strip
    line.comment = comment
  else
    captures = text.scan(CHORDS_AND_LYRICS_REGEX).flatten

    captures.each_slice(2) do |pair|
      part = Part.new
      chord = pair[0]&.strip || ''
      part.chord = chord.delete('[').delete(']')
      part.lyric = pair[1] || ''

      line.parts << part unless (part.chord == '') && (part.lyric == '')
    end
  end

  current_section.lines << line
end

# File lib/song_pro.rb, line 39
def self.process_section(song, text)
  matches = SECTION_REGEX.match(text)
  name = matches[1].strip
  current_section = Section.new(name: name)
  song.sections << current_section

  current_section
end