#
# == Rails Twelve Hour Time Plugin
# 
# http://code.google.com/p/rails-twelve-hour-time-plugin/
# 
# ==== Authors
# * Nick Muerdter (original code)
# * Maurice Aubrey
# 
# ==== Used for
# Allows UnobtrusiveDatePicker::UnobtrusiveDatePickerHelper to use a AM/PM select of it's own, 
# and still be processed correctly by Active Record.
# 

# :enddoc:
if defined? ActiveRecord
class ActiveRecord::Base # :nodoc: all
  def extract_callstack_for_multiparameter_attributes_with_ampm(pairs)
    attributes = extract_callstack_for_multiparameter_attributes_without_ampm(pairs)
    attributes.each do |name, values|
      klass = (self.class.reflect_on_aggregation(name) ||
      column_for_attribute(name)).klass
      if klass == Time && values.length == 6
        if values[5] == ActionView::Helpers::DateHelper::AM && values[3] == 12
          values[3] = 0
        elsif values[5] == ActionView::Helpers::DateHelper::PM && values[3] != 12
          values[3] += 12
        end
      end
    end
  end

  alias_method_chain :extract_callstack_for_multiparameter_attributes, :ampm
end
end

module ActionView::Helpers::DateHelper # :nodoc: all
  AM = 'AM'
  PM = 'PM'

  def select_hour_with_ampm(datetime, options = {}, html_options = {})
    options[:twelve_hour] or return select_hour_without_ampm(datetime, options, html_options)

    val = _12_hour(datetime)

    if options[:use_hidden]
      return hidden_html(options[:field_name] || 'hour', val, options)
    end

    hour_options = []
    1.upto(12) do |hour|
      hour_options << ((val == hour) ?
        content_tag(:option, leading_zero_on_single_digits(hour), :value => leading_zero_on_single_digits(hour), :selected => "selected") :
        content_tag(:option, leading_zero_on_single_digits(hour), :value => leading_zero_on_single_digits(hour))
      )
      hour_options << "\n"
    end

    select_html(options[:field_name] || 'hour', hour_options, options, html_options)
  end

  alias_method_chain :select_hour, :ampm


  def select_ampm(datetime, options = {}, html_options = {})
    ampm = [AM, PM]
    val = datetime ? (ampm.include?(datetime) ? datetime : datetime.strftime("%p")) : ''

    if options[:use_hidden]
      return hidden_html(options[:field_name] || 'ampm', val, options)
    end

    ampm_options = []
    ampm.each do |meridiem|
      selected = (meridiem == val) ? ' selected="selected"' : ''
      ampm_options << ((meridiem == val) ? 
        content_tag(:option, meridiem, :value => meridiem, :selected => "selected") :
        content_tag(:option, meridiem, :value => meridiem)
      )
      ampm_options << "\n"
    end

    select_html(options[:field_name] || 'ampm', ampm_options, options, html_options)
  end

  def select_time_with_ampm(datetime = Time.now, options = {}, html_options = {})
    select = select_time_without_ampm(datetime, options, html_options)
    select << select_ampm(datetime, options, html_options) if options[:twelve_hour]
    select
  end

  alias_method_chain :select_time, :ampm

  private

  def _12_hour(datetime)
    return '' if datetime.blank?

    hour = datetime.kind_of?(Fixnum) ? datetime : datetime.hour
    hour = 12 if hour == 0
    hour -= 12 if hour > 12

    return hour
  end
end

class ActionView::Helpers::InstanceTag # :nodoc: all
  def date_or_time_select_with_ampm(options, html_options = {})
    options[:twelve_hour] and not options[:discard_hour] or
    return date_or_time_select_without_ampm(options, html_options)

    defaults = { :discard_type => true }
    options = defaults.merge(options)

    datetime = value(object)
    datetime ||= default_time_from_options(options[:default]) unless options[:include_blank]

    date_or_time_select_without_ampm(options, html_options) +
    select_ampm(datetime, options_with_prefix(6, options.merge(:use_hidden => options[:discard_hour], :string => true)))
  end

  alias_method_chain :date_or_time_select, :ampm

  def options_with_prefix_with_ampm(position, options)
    prefix = "#{@object_name}"
    if options[:index]
      prefix << "[#{options[:index]}]"
    elsif @auto_index
      prefix << "[#{@auto_index}]"
    end
    if options[:string]
      options.merge(:prefix => "#{prefix}[#{@method_name}(#{position}s)]")
    else
      options.merge(:prefix => "#{prefix}[#{@method_name}(#{position}i)]")
    end
  end
end