require 'base32/crockford'
require 'securerandom'
require 'bergamasco'
require 'open-uri'
require 'time'

module Cirneco
  module Utils
    # "ZZZZZZZ" decoded as number
    UPPER_LIMIT = 34359738367

    LICENSES = {
      "https://creativecommons.org/licenses/by/4.0/" => "Creative Commons Attribution (CC-BY 4.0)",
      "https://creativecommons.org/publicdomain/zero/1.0/" => "Creative Commons Public Domain Dedication (CC0 1.0)"
    }

    def get_dois_by_prefix(prefix, options={})
      response = get_dois(options)

      if response.body["data"].present?
        response.body["data"] = response.body["data"].select { |doi| doi.start_with?(prefix) }
      end
      response
    end

    def decode_doi(doi)
      prefix, string = doi.split('/', 2)
      Base32::Crockford.decode(string, checksum: true).to_i
    end

    def encode_doi(prefix, options={})
      number = options[:number].to_s.scan(/\d+/).first.to_i
      number = SecureRandom.random_number(UPPER_LIMIT) unless number > 0
      prefix.to_s + "/" + Base32::Crockford.encode(number, split: 4, length: 8, checksum: true)
    end

    def generate_accession_number(options={})
      lower_limit = options[:lower_limit] || 0
      namespace = options[:namespace] || 'MS-'
      registered_numbers = options[:registered_numbers] || []

      if options[:number]
        number = options[:number].to_s
      else
        begin
          number = SecureRandom.random_number(1000000) + lower_limit
        end while registered_numbers.include? number
        number = number.to_s
      end

      number = number.to_s.rjust(options[:length], '0') if options[:length]

      if options[:split]
        number = number.reverse
        number = number.scan(/.{1,#{options[:split]}}/).map { |x| x.reverse }
        number = number.reverse.join("-")
      end

      namespace + number
    end

    def get_accession_number(filepath)
      metadata = Bergamasco::Markdown.read_yaml_for_doi_metadata(filepath)
      metadata.fetch("accession_number", nil).to_s.scan(/\d+/).first.to_i
    end

    def get_all_accession_numbers(folderpath)
      Dir.glob("#{folderpath}/*.md").sort.map do |filepath|
        get_accession_number(filepath)
      end.select { |a| a > 0 }.sort
    end

    def update_accession_number(filepath, options={})
      filename = File.basename(filepath)
      return "File #{filename} ignored: not a markdown or html file" unless %w(.md .html .erb).include?(File.extname(filepath))

      old_metadata = Bergamasco::Markdown.read_yaml_for_doi_metadata(filepath)
      return "File #{filename} ignored: no yaml front matter" unless old_metadata.present?

      return "File #{filename} ignored: no empty accession_number" if options[:opt_in] && !old_metadata.key?("accession_number")

      return "Accession number #{old_metadata["accession_number"]} not changed for #{filename}" if old_metadata["accession_number"]

      if old_metadata["doi"].present?
        number = decode_doi(old_metadata["doi"])
        options[:number] = number if number > 0
      else
        folderpath = File.dirname(filepath)
        options[:registered_numbers] = get_all_accession_numbers(folderpath)
      end

      accession_number = generate_accession_number(options)

      new_metadata = Bergamasco::Markdown.update_file(filepath, "accession_number" => accession_number)
      "Accession number #{new_metadata["accession_number"]} generated for #{filename}"
    end

    def update_all_accession_numbers(folderpath, options={})
      Dir.glob("#{folderpath}/*.md").sort.map do |filepath|
        update_accession_number(filepath, options)
      end
    end

    # fetch schema.org metadata in JSON-LD format to mint DOI
    def mint_doi_for_url(url, options={})
      filename = File.basename(url)
      source_path = options[:source_path] || "/"
      filepath = Dir.pwd + source_path + filename + ".md"

      metadata = generate_metadata_for_work(url, options)
      return "DOI #{metadata["doi"]} not changed for #{filename}" if metadata["doi"] && metadata["date_issued"]

      response = post_metadata_for_work(metadata, options)
      return "Errors for DOI #{metadata["doi"]}: #{response.body['errors'].first['title']}\n" if response.body['errors']

      new_metadata = Bergamasco::Markdown.update_file(filepath, "doi" => metadata["doi"], "published" => true)
      "DOI #{new_metadata["doi"]} minted for #{filename}"
    end

    # fetch schema.org metadata in JSON-LD format to mint DOI
    def mint_and_hide_doi_for_url(url, options={})
      filename = File.basename(url)
      source_path = options[:source_path] || "/"
      filepath = Dir.pwd + source_path + filename + ".md"

      metadata = generate_metadata_for_work(url, options)
      return "DOI #{metadata["doi"]} not changed for #{filename}" if metadata["doi"] && metadata["date_issued"]

      response = post_metadata_for_work(metadata, options)
      return "Errors for DOI #{metadata["doi"]}: #{response.body['errors'].first['title']}\n" if response.body['errors']

      new_metadata = Bergamasco::Markdown.update_file(filepath, "doi" => metadata["doi"], "published" => false)
      "DOI #{new_metadata["doi"]} minted and hidden for #{filename}"
    end

    # fetch schema.org metadata in JSON-LD format to mint DOI
    # DOIs are never deleted, but we can remove the metadata from the DataCite index
    def hide_doi_for_url(url, options={})
      filename = File.basename(url)
      source_path = options[:source_path] || "/"
      filepath = Dir.pwd + source_path + filename + ".md"

      metadata = generate_metadata_for_work(url, options)
      return "DOI #{metadata["doi"]} not changed for #{filename}" unless metadata["doi"] && metadata["date_issued"]

      response = hide_metadata_for_work(metadata, options)
      return "Errors for DOI #{metadata["doi"]}: #{response.body['errors'].first['title']}\n" if response.body['errors']

      new_metadata = Bergamasco::Markdown.update_file(filepath, "published" => false)
      "DOI #{metadata["doi"]} hidden for #{filename}"
    end

    def mint_dois_for_all_urls(urls, options={})
      urls.map do |url|
        mint_doi_for_url(url, options)
      end.join("\n")
    end

    def mint_and_hide_dois_for_all_urls(urls, options={})
      urls.map do |url|
        mint_and_hide_doi_for_url(url, options)
      end.join("\n")
    end

    def hide_dois_for_all_urls(urls, options={})
      urls.map do |url|
        hide_doi_for_url(url, options)
      end.join("\n")
    end

    def generate_metadata_for_work(url, options={})
      doc = Nokogiri::HTML(open(url))
      json = doc.at_xpath("//script[@type='application/ld+json']")
      return "Error: no schema.org metadata found" unless json.present?

      metadata = ActiveSupport::JSON.decode(json.text)

      return "Error: required metadata missing" unless ["name", "author", "publisher", "datePublished", "@type"].all? { |k| metadata.key? k }

      # required metadata
      if /(http|https):\/\/(dx\.)?doi\.org\/(\w+)/.match(metadata["@id"])
        uri = Addressable::URI.parse(metadata["@id"])
        metadata["doi"] = uri.path[1..-1].upcase
      end

      metadata["title"] = metadata["name"]

      metadata["creators"] = format_authors(metadata["author"])

      metadata["publisher"] = metadata.fetch("publisher", {}).fetch("name", nil)
      metadata["publication_year"] = metadata.fetch("datePublished", "")[0..3].to_i

      resource_type_general = metadata["@type"] == "Dataset" ? "Dataset" : "Text"

      metadata["resource_type"] = { value: metadata["@type"],
                                    resource_type_general: resource_type_general }

      # recommended metadata

      # use alternate_identifier to generate DOI
      metadata["alternate_identifier"] = metadata["alternateName"]

      if metadata["description"].present?
        metadata["descriptions"] = [{ value: metadata["description"], description_type: "Abstract" }]
      end

      # use default version 1.0
      metadata["version"] ||= "1.0"

      # fetch reference metadata if available
      metadata["related_identifiers"] = get_related_identifiers(metadata)

      if metadata["license"].present?
        value = LICENSES.fetch(metadata["license_url"], nil)
        metadata["rights_list"] = [{ value: value, rights_uri: metadata["license"] }] if value.present?
      end

      if metadata["keywords"].present?
        metadata["subjects"] = Array(metadata["keywords"].split(", ")).select { |k| k != "featured" }
      end

      metadata["date_created"] = metadata["dateCreated"]
      metadata["date_issued"] = metadata["datePublished"]
      metadata["date_updated"] = metadata["dateModified"]

      metadata = metadata.extract!(*%w(doi alternate_identifier url creators title
        publisher publication_year resource_type descriptions version rights_list
        subjects date_issued date_created date_updated related_identifiers))
    end

    def post_metadata_for_work(metadata, options={})
      prefix = options[:prefix] || ENV['PREFIX']
      metadata["doi"] ||= encode_doi(prefix, number: metadata["alternate_identifier"])

      work = Cirneco::Work.new(metadata)
      return work.validation_errors if work.validation_errors.body["errors"].present?

      response = work.post_metadata(work.data, options)
      return response unless response.status == 201

      work.put_doi(metadata["doi"], options.merge(url: metadata["url"]))
    end

    def post_and_hide_metadata_for_work(metadata, options={})
      prefix = options[:prefix] || ENV['PREFIX']
      metadata["doi"] ||= encode_doi(prefix, number: metadata["alternate_identifier"])

      work = Cirneco::Work.new(metadata)
      return work.validation_errors if work.validation_errors.body["errors"].present?

      response = work.post_metadata(work.data, options)
      return response unless response.status == 201

      response = work.put_doi(metadata["doi"], options.merge(url: metadata["url"]))
      return response unless response.status == 201

      work.delete_metadata(metadata["doi"], options)
    end

    def hide_metadata_for_work(metadata, options={})
      prefix = options[:prefix] || ENV['PREFIX']
      metadata["doi"] ||= encode_doi(prefix, number: metadata["alternate_identifier"])

      work = Cirneco::Work.new(metadata)
      return work.validation_errors if work.validation_errors.body["errors"].present?

      work.delete_metadata(metadata["doi"], options)
    end

    def generate_jats(filepath, options={})
      Bergamasco::Pandoc.write_jats(filepath, options)
    end

    def url_from_path(site_url, filepath)
      site_url.to_s.chomp("\\") + "/" + File.basename(filepath)[0..-9] + "/"
    end

    def format_authors(authors)
      Array(authors).map do |author|
        orcid = orcid_from_url(author["@id"])
        name = (author["givenName"].present? || author["familyName"].present?) ? nil : author["name"]

        { given_name: author["givenName"],
          family_name: author["familyName"],
          name: name,
          orcid: orcid }.compact
      end
    end

    def get_related_identifiers(metadata)
      citations = Array(metadata["citation"])
      parts = Array(metadata["IsPartOf"]).map { |r| r["relation_type"] = "IsPartOf" }

      (citations + parts).map do |r|
        id = r.fetch("@id", "")
        relation_type = r.fetch("relation_type", "References")

        if /(http|https):\/\/(dx\.)?doi\.org\/(\w+)/.match(id)
          uri = Addressable::URI.parse(id)
          value = uri.path[1..-1].upcase
          type = "DOI"
        elsif /(http|https):\/\//.match(id)
          uri = Addressable::URI.parse(id)
          value = uri.normalize.to_s
          type = "URL"
        else
          type = nil
        end

        {
          value: value,
          related_identifier_type: type,
          relation_type: relation_type
        }
      end.select { |t| t[:related_identifier_type].present? }
    end

    def orcid_from_url(url)
      return nil unless url.present?

      Array(/\Ahttp:\/\/orcid\.org\/(.+)/.match(url)).last
    end
  end
end