module FindNearDate

Constants

VERSION

Public Instance Methods

find_near_date(date, date_column = :created_at, key_column: primary_key, period: 0, log: false) click to toggle source

find record by date from DB tables that is not indexed by date column @param [Time] date date to find @param [Symbol] date_column date column name @param [Symbol] key_column primary_key column @param [Number] period acceptable defference period. if this is 0, find most near date @param [Boolean] log print log or not

# File lib/find_near_date.rb, line 10
def find_near_date(date, date_column = :created_at, key_column: primary_key, period: 0, log: false)
  _first = select(key_column, date_column).order(key_column => :asc).first
  _last = select(key_column, date_column).order(key_column => :desc).first
  find_near_date_iteration(_first, _last, _last, date, date_column, key_column, period, log)
end

find_near_date_iteration(_first, _last, _previous, date, date_column, key_column, period, log) click to toggle source

# File lib/find_near_date.rb, line 16
def find_near_date_iteration(_first, _last, _previous, date, date_column, key_column, period, log) # rubocop:disable Metrics/AbcSize, Metrics/ParameterLists, Metrics/LineLength
  start_key = _first.public_send(key_column)
  end_key = _last.public_send(key_column)
  key_period = end_key - start_key
  start_date = _first.public_send(date_column)
  end_date = _last.public_send(date_column)
  date_period = end_date - start_date
  rate = 1.0 * (date - start_date) / date_period
  target_key = (key_period * rate).round + start_key
  _next = where("#{key_column} >= ?", target_key).order(key_column => :asc).first # id may not be exists
  return _next if _next.public_send(key_column) == _previous.public_send(key_column)

  next_date = _next.public_send(date_column)
  date_diff = next_date - date
  return _next if date_diff == 0 || date_diff.abs <= period

  if date_diff > 0
    _last = _next
  else
    _first = _next
  end
  puts "find_date_id> diff=#{date_diff} target=#{date} current #{key_column}=#{target_key} [#{start_key}=#{start_date} - #{end_key}=#{end_date}]" if log
  find_near_date_iteration(_first, _last, _next, date, date_column, key_column, period, log)
end