# frozen_string_literal: true

# require 'isobib/iso_bibliographic_item'
require "relaton_iec/scrapper"
require "relaton_iec/hit_collection"
require "date"

module RelatonIec
  # Class methods for search ISO standards.
  class IecBibliography
    class << self
      # @param text [String]
      # @return [RelatonIec::HitCollection]
      def search(text, year = nil)
        HitCollection.new text, year
      rescue SocketError, OpenURI::HTTPError, OpenSSL::SSL::SSLError
        raise RelatonBib::RequestError, "Could not access http://www.iec.ch"
      end

      # @param code [String] the ISO standard Code to look up (e..g "ISO 9000")
      # @param year [String] the year the standard was published (optional)
      # @param opts [Hash] options; restricted to :all_parts if all-parts
      #   reference is required
      # @return [String] Relaton XML serialisation of reference
      def get(code, year = nil, opts = {})
        if year.nil?
          /^(?<code1>[^:]+):(?<year1>[^:]+)/ =~ code
          unless code1.nil?
            code = code1
            year = year1
          end
        end

        return iev if code.casecmp("IEV").zero?

        opts[:all_parts] ||= !(code =~ / \(all parts\)/).nil?
        code = code.sub(/ \(all parts\)/, "")
        ret = iecbib_get1(code, year, opts)
        return nil if ret.nil?

        ret = ret.to_most_recent_reference unless year || opts[:keep_year]
        ret = ret.to_all_parts if opts[:all_parts]
        ret
      end

      private

      def fetch_ref_err(code, year, missed_years)
        id = year ? "#{code}:#{year}" : code
        warn "[relaton-iec] WARNING: no match found online for #{id}. "\
          "The code must be exactly like it is on the standards website."
        warn "[relaton-iec] (There was no match for #{year}, though there were matches "\
          "found for #{missed_years.join(', ')}.)" unless missed_years.empty?
        if /\d-\d/ =~ code
          warn "[relaton-iec] The provided document part may not exist, or the document "\
            "may no longer be published in parts."
        else
          warn "[relaton-iec] If you wanted to cite all document parts for the reference, "\
            "use \"#{code} (all parts)\".\nIf the document is not a standard, "\
            "use its document type abbreviation (TS, TR, PAS, Guide)."
        end
        nil
      end

      def fetch_pages(s, n)
        workers = RelatonBib::WorkersPool.new n
        workers.worker { |w| { i: w[:i], hit: w[:hit].fetch } }
        s.each_with_index { |hit, i| workers << { i: i, hit: hit } }
        workers.end
        workers.result.sort_by { |a| a[:i] }.map { |x| x[:hit] }
      end

      def isobib_search_filter(code)
        docidrx = %r{^(ISO|IEC)[^0-9]*\s[0-9-]+}
        corrigrx = %r{^(ISO|IEC)[^0-9]*\s[0-9-]+:[0-9]+/}
        warn "[relaton-iec] (\"#{code}\") fetching..."
        result = search(code)
        result.select do |i|
          i.hit[:code] &&
            i.hit[:code].match(docidrx).to_s.include?(code) &&
            corrigrx !~ i.hit[:code]
        end
      end

      def iev(code = "IEC 60050")
        RelatonIsoBib::XMLParser.from_xml(<<~"END")
<bibitem>
  <fetched>#{Date.today}</fetched>
  <title format="text/plain" language="en" script="Latn">International Electrotechnical Vocabulary</title>
  <link type="src">http://www.electropedia.org</link>
  <docidentifier>#{code}:2011</docidentifier>
  <date type="published"><on>2011</on></date>
  <contributor>
    <role type="publisher"/>
    <organization>
      <name>International Electrotechnical Commission</name>
      <abbreviation>IEC</abbreviation>
      <uri>www.iec.ch</uri>
    </organization>
  </contributor>
  <language>en</language> <language>fr</language>
  <script>Latn</script>
  <status> <stage>60</stage> </status>
  <copyright>
    <from>2018</from>
    <owner>
      <organization>
      <name>International Electrotechnical Commission</name>
      <abbreviation>IEC</abbreviation>
      <uri>www.iec.ch</uri>
      </organization>
    </owner>
  </copyright>
</bibitem>
        END
      end

      # Sort through the results from Isobib, fetching them three at a time,
      # and return the first result that matches the code,
      # matches the year (if provided), and which # has a title (amendments do not).
      # Only expects the first page of results to be populated.
      # Does not match corrigenda etc (e.g. ISO 3166-1:2006/Cor 1:2007)
      # If no match, returns any years which caused mismatch, for error reporting
      def isobib_results_filter(result, year)
        missed_years = []
        result.each_slice(3) do |s| # ISO website only allows 3 connections
          fetch_pages(s, 3).each_with_index do |r, _i|
            return { ret: r } if !year

            r.date.select { |d| d.type == "published" }.each do |d|
              return { ret: r } if year.to_i == d.on.year

              missed_years << d.on.year
            end
          end
        end
        { years: missed_years }
      end

      def iecbib_get1(code, year, _opts)
        return iev if code.casecmp("IEV").zero?

        result = isobib_search_filter(code) || return
        ret = isobib_results_filter(result, year)
        if ret[:ret]
          warn "[relaton-iec] (\"#{code}\") found #{ret[:ret].docidentifier.first.id}"
          ret[:ret]
        else
          fetch_ref_err(code, year, ret[:years])
        end
      end
    end
  end
end