class Lookout::PeriodCollection

def self.load_default
  instance = new
  {
    realtime: {
      label: "Realtime",
      range: -> { [1.minute.ago] },
    },
    day: {
      label: "Day",
      range: -> { [Time.current.beginning_of_day, Time.current] },
    },
    '7d': {
      label: "7 Days",
      range: -> {  [7.days.ago, Time.current] },
    },
    '30d': {
      label: "30 Days",
      range: -> { [30.days.ago, Time.current] },
    },
    mtd: {
      label: "Month-to-date",
      range: -> { [Time.current.beginning_of_month, Time.current] },
    },
    lastmonth: {
      label: "Last month",
      range: -> { [1.month.ago.beginning_of_month, 1.month.ago.end_of_month] },
    },
    ytd: {
      label: "This year",
      range: -> { [Time.current.beginning_of_year, Time.current] },
    },
    '12mo': {
      label: "12 months",
      range: -> { [12.months.ago.to_datetime, Time.current] },
    },
    all: {
      label: "All-time",
      range: -> { [Date.new(2004, 8, 1).to_datetime, Time.current] },
    },
  }.each do |param, options|
    instance.add(param, options[:label], options[:range])
  end
  instance.default = :'30d'
  instance
end

def add(param, label, range_proc)
  raise ArgumentError, "range must be a proc, or respond to .call" unless range_proc.respond_to?(:call)
  raise ArgumentError, "range.call must return a range or an array" unless range_proc.call.is_a?(Range) || range_proc.call.is_a?(Array)
  @periods[param.to_sym] = Period.new(param: param, label: label, range: range_proc)
end

def all
  @periods
end

def default=(val)
  @default = val.to_sym
end

def delete(param)
  @periods.delete(param.to_sym)
end

def each(&block)
  @periods.each(&block)
end

def find(value)
  @periods[value.try(:to_sym)]
end

def for(value)
  if value.nil?
    period = @periods[@default]
  else
    period = (@periods[value.to_sym] || @periods[@default])
  end
  if period
    period.range.call
  else
    nil
  end
end

def initialize
  @periods = {}
  @default = nil
  @max = nil
end

def max=(amount)
  @max = amount
end

def reset
  @periods = {}
  @default = nil
end