class RuboCop::Cop::Layout::IndentHeredoc

def adjust_minus(corrector, node)
  heredoc_beginning = node.loc.expression.source
  corrected = heredoc_beginning.sub(/<<-?/, '<<~')
  corrector.replace(node.loc.expression, corrected)
end

def adjust_squiggly(corrector, node)
  corrector.replace(node.loc.heredoc_body, indented_body(node))
  corrector.replace(node.loc.heredoc_end, indented_end(node))
end

def autocorrect(node)
  check_style!
  case style
  when :squiggly
    correct_by_squiggly(node)
  else
    correct_by_library(node)
  end
end

def base_indent_level(node)
  base_line_num = node.loc.expression.line
  base_line = processed_source.lines[base_line_num - 1]
  indent_level(base_line)
end

def check_style!
  case style
  when nil
    raise Warning, "Auto-correction does not work for #{cop_name}. " \
                   'Please configure EnforcedStyle.'
  when :squiggly
    if target_ruby_version < 2.3
      raise Warning, '`squiggly` style is selectable only on Ruby ' \
                     "2.3 or higher for #{cop_name}."
    end
  end
end

def correct_by_library(node)
  lambda do |corrector|
    corrector.replace(node.loc.heredoc_body, indented_body(node))
    corrected = ".#{STRIP_METHODS[style]}"
    corrector.insert_after(node.loc.expression, corrected)
  end
end

def correct_by_squiggly(node)
  return if target_ruby_version < 2.3
  lambda do |corrector|
    if heredoc_indent_type(node) == '~'
      adjust_squiggly(corrector, node)
    else
      adjust_minus(corrector, node)
    end
  end
end

def heredoc_body(node)
  node.loc.heredoc_body.source.scrub
end

def heredoc_end(node)
  node.loc.heredoc_end.source.scrub
end

def heredoc_indent_type(node)
  node.source[/^<<([~-])/, 1]
end

def indent_level(str)
  indentations = str.lines
                    .map { |line| line[/^\s*/] }
                    .reject { |line| line == "\n" }
  indentations.empty? ? 0 : indentations.min_by(&:size).size
end

def indentation_width
  @config.for_cop('IndentationWidth')['Width'] || 2
end

def indented_body(node)
  body = heredoc_body(node)
  body_indent_level = indent_level(body)
  correct_indent_level = base_indent_level(node) + indentation_width
  body.gsub(/^\s{#{body_indent_level}}/, ' ' * correct_indent_level)
end

def indented_end(node)
  end_ = heredoc_end(node)
  end_indent_level = indent_level(end_)
  correct_indent_level = base_indent_level(node)
  if end_indent_level < correct_indent_level
    end_.gsub(/^\s{#{end_indent_level}}/, ' ' * correct_indent_level)
  else
    end_
  end
end

def library_message(indentation_width, method)
  format(
    LIBRARY_MSG,
    indentation_width: indentation_width,
    method: method
  )
end

def line_too_long?(node)
  return false if unlimited_heredoc_length?
  body = heredoc_body(node)
  expected_indent = base_indent_level(node) + indentation_width
  actual_indent = indent_level(body)
  increase_indent_level = expected_indent - actual_indent
  longest_line(body).size + increase_indent_level >= max_line_length
end

def longest_line(lines)
  lines.each_line.max_by { |line| line.chomp.size }.chomp
end

def max_line_length
  config.for_cop('Metrics/LineLength')['Max']
end

def message(node)
  case style
  when :squiggly
    current_indent_type = "<<#{heredoc_indent_type(node)}"
    ruby23_message(indentation_width, current_indent_type)
  when nil
    method = "some library(e.g. ActiveSupport's `String#strip_heredoc`)"
    library_message(indentation_width, method)
  else
    method = "`String##{STRIP_METHODS[style]}`"
    library_message(indentation_width, method)
  end
end

def on_heredoc(node)
  body = heredoc_body(node)
  return if body.strip.empty?
  body_indent_level = indent_level(body)
  if heredoc_indent_type(node) == '~'
    expected_indent_level = base_indent_level(node) + indentation_width
    return if expected_indent_level == body_indent_level
  else
    return unless body_indent_level.zero?
  end
  return if line_too_long?(node)
  add_offense(node, location: :heredoc_body)
end

def ruby23_message(indentation_width, current_indent_type)
  if current_indent_type == '<<~'
    ruby23_width_message(indentation_width)
  else
    ruby23_type_message(indentation_width, current_indent_type)
  end
end

def ruby23_type_message(indentation_width, current_indent_type)
  format(
    RUBY23_TYPE_MSG,
    indentation_width: indentation_width,
    current_indent_type: current_indent_type
  )
end

def ruby23_width_message(indentation_width)
  format(
    RUBY23_WIDTH_MSG,
    indentation_width: indentation_width
  )
end

def style
  style = super
  return style unless style == :auto_detection
  if target_ruby_version >= 2.3
    :squiggly
  elsif rails?
    :active_support
  end
end

def unlimited_heredoc_length?
  config.for_cop('Metrics/LineLength')['AllowHeredoc']
end