module Phonelib
  # @private phone analyzing methods module
  module PhoneAnalyzer
    # extending with helper methods for analyze
    include Phonelib::PhoneAnalyzerHelper

    # array of types not included for validation check in cycle
    NOT_FOR_CHECK = [:general_desc, :fixed_line, :mobile, :fixed_or_mobile]

    # parses provided phone if it is valid for  country data and
    # returns result of analyze
    #
    # ==== Attributes
    #
    # * +phone+ - Phone number for parsing
    # * +passed_country+ - Country provided for parsing. Must be ISO code of
    #   country (2 letters) like 'US', 'us' or :us for United States
    def analyze(phone, passed_country)
      countries = country_or_default_country passed_country

      return analyze_single_country(phone, countries.first, passed_country) if countries.size == 1

      results = {}
      countries.map do |country|
        results.merge! analyze_single_country(phone, country, passed_country)
      end

      pick_results(results)
    end

    private

    # pick best result when several countries specified
    def pick_results(results)
      [:valid, :possible].each do |key|
        final = results.select { |_k, v| v[key].any? }
        return decorate_analyze_result(final) if final.size > 0
      end

      decorate_analyze_result(results)
    end

    def analyze_single_country(phone, country, passed_country)
      result = parse_country(phone, country)
      d_result = case
                 when result && result.values.find { |e| e[:valid].any? }
                   # all is good, return result
                 when passed_country.nil?
                   # trying for all countries if no country was passed
                   detect_and_parse(phone, country)
                 when country_can_dp?(country)
                   # if country allows double prefix trying modified phone
                   parse_country(changed_dp_phone(country, phone), country)
                 end
      better_result(result, d_result)
    end

    # method checks which result is better to return
    def better_result(base_result, result = nil)
      base_result ||= {}
      return base_result unless result

      return result unless base_result.values.find { |e| e[:possible].any? }

      return result if result.values.find { |e| e[:valid].any? }

      base_result
    end

    # replacing national prefix to simplified format
    def with_replaced_national_prefix(phone, data)
      return phone unless data[Core::NATIONAL_PREFIX_TRANSFORM_RULE]
      pattern = cr("^(?:#{data[Core::NATIONAL_PREFIX_FOR_PARSING]})")
      match = phone.match pattern
      if match && match.captures.compact.size > 0
        phone.gsub(pattern, data[Core::NATIONAL_PREFIX_TRANSFORM_RULE])
      else
        phone
      end
    end

    # trying to parse phone for single country including international prefix
    # check for provided country
    #
    # ==== Attributes
    #
    # * +phone+ - phone for parsing
    # * +country+ - country to parse phone with
    def parse_country(phone, country)
      data = Phonelib.phone_data[country]
      return nil unless data

      # if country was provided and it's a valid country, trying to
      # create e164 representation of phone number,
      # kind of normalization for parsing
      e164 = convert_to_e164 with_replaced_national_prefix(phone, data), data
      # if phone starts with international prefix of provided
      # country try to reanalyze without international prefix for
      # all countries
      return analyze(e164[1..-1], nil) if Core::PLUS_SIGN == e164[0]
      # trying to parse number for provided country
      parse_single_country e164, data
    end

    # method checks if phone is valid against single provided country data
    #
    # ==== Attributes
    #
    # * +e164+ - e164 representation of phone for parsing
    # * +data+ - country data for single country for parsing
    def parse_single_country(e164, data)
      valid_match = phone_match_data?(e164, data)
      if valid_match
        national_and_data(data, valid_match)
      else
        possible_match = phone_match_data?(e164, data, true)
        possible_match && national_and_data(data, possible_match, true)
      end
    end

    # method tries to detect what is the country for provided phone
    #
    # ==== Attributes
    #
    # * +phone+ - phone number for parsing
    def detect_and_parse(phone, country)
      countries_data = country_code_candidates_for(phone).flat_map { |code|
        Phonelib.data_by_country_codes[code] || []
      }
      countries_data.each_with_object({}) do |data, result|
        key = data[:id]
        parsed = parse_single_country(phone, data)
        if (!Phonelib.strict_double_prefix_check || key == country) && double_prefix_allowed?(data, phone, parsed && parsed[key])
          parsed = parse_single_country(changed_dp_phone(key, phone), data)
        end
        result.merge!(parsed) unless parsed.nil?
      end.compact
    end

    def country_code_candidates_for(phone)
      stripped_phone = phone.gsub(/^(#{Phonelib.phone_data_int_prefixes})/, '')
      ((1..3).map { |length| phone[0, length] } + (1..3).map { |length| stripped_phone[0, length] }).uniq
    end

    # Create phone representation in e164 format
    #
    # ==== Attributes
    #
    # * +phone+ - phone number for parsing
    # * +data+  - country data to be based on for creating e164 representation
    def convert_to_e164(phone, data)
      match = phone.match full_regex_for_data(data, Core::VALID_PATTERN, !original_starts_with_plus?)
      case
      when match
        "#{data[Core::COUNTRY_CODE]}#{match.to_a.last}"
      when phone.match(cr("^#{data[Core::INTERNATIONAL_PREFIX]}"))
        phone.sub(cr("^#{data[Core::INTERNATIONAL_PREFIX]}"), Core::PLUS_SIGN)
      when original_starts_with_plus? && phone.start_with?(data[Core::COUNTRY_CODE])
        phone
      else
        "#{data[Core::COUNTRY_CODE]}#{phone}"
      end
    end

    # returns national number and analyzing results for provided phone number
    #
    # ==== Attributes
    #
    # * +data+ - country data
    # * +country_match+ - result of match of phone within full regex
    # * +not_valid+ - specifies that number is not valid by general desc pattern
    def national_and_data(data, country_match, not_valid = false)
      result = data.select { |k, _v| k != :types && k != :formats }
      phone = country_match.to_a.last
      result[:national] = phone
      result[:format] = number_format(phone, data[Core::FORMATS])
      result.merge! all_number_types(phone, data[Core::TYPES], not_valid)
      result[:valid] = [] if not_valid

      { result[:id] => result }
    end

    # Returns all valid and possible phone number types for currently parsed
    # phone for provided data hash.
    #
    # ==== Attributes
    #
    # * +phone+ - phone number for parsing
    # * +data+  - country data
    # * +not_valid+ - specifies that number is not valid by general desc pattern
    def all_number_types(phone, data, not_valid = false)
      response = { valid: [], possible: [] }

      types_for_check(data).each do |type|
        possible, valid = get_patterns(data, type)

        valid_and_possible, possible_result =
            number_valid_and_possible?(phone, possible, valid, not_valid)
        response[:possible] << type if possible_result
        response[:valid] << type if valid_and_possible
      end

      sanitize_fixed_mobile(response)
    end

    # Gets matched number formatting rule or default one
    #
    # ==== Attributes
    #
    # * +national+ - national phone number
    # * +format_data+  - formatting data from country data
    def number_format(national, format_data)
      format_data && format_data.find do |format|
        (format[Core::LEADING_DIGITS].nil? || \
            national.match(cr("^(#{format[Core::LEADING_DIGITS]})"))) && \
          national.match(cr("^(#{format[Core::PATTERN]})$"))
      end || Core::DEFAULT_NUMBER_FORMAT
    end

    # Returns possible and valid patterns for validation for provided type
    #
    # ==== Attributes
    #
    # * +all_patterns+ - hash of all patterns for validation
    # * +type+ - type of phone to get patterns for
    def get_patterns(all_patterns, type)
      type = Core::FIXED_LINE if type == Core::FIXED_OR_MOBILE
      patterns = all_patterns[type]

      if patterns
        [
          type_regex(patterns, Core::POSSIBLE_PATTERN),
          type_regex(patterns, Core::VALID_PATTERN)
        ]
      else
        [nil, nil]
      end
    end
  end
end