module ChartsReport

# File lib/charts_report.rb, line 28
def build(country_name:, chart_date:, entries:)
  if entries.empty?
    return IrcReply.card(
      tag: TAG,
      title: "#{country_name} · weekly chart",
      body_lines: ["No chart entries found."],
      footer_parts: [SOURCE]
    )
  end

  title = "#{country_name} · weekly top #{entries.length}"
  title = "#{title} · #{chart_date}" if chart_date

  IrcReply.card(
    tag: TAG,
    title: title,
    body_lines: entries.map { |entry| format_entry_line(**entry) },
    footer_parts: [entries.length.to_s, "tracks", SOURCE]
  )
end

# File lib/charts_report.rb, line 49
def error(message)
  IrcReply.error(tag: TAG, message: message)
end

# File lib/charts_report.rb, line 20
def format_change(change)
  value = change.to_s.strip
  return "NEW" if value.match?(/\ANEW\z/i)
  return value if value.match?(/\A[+-]\d+\z/)

  value.empty? ? "=" : value
end

# File lib/charts_report.rb, line 15
def format_entry_line(position:, change:, label:)
  move = format_change(change)
  "#{position}. #{label} · #{move}"
end