require "support/jsv"

module Dolist
  class API
    CONTACT_URL = "https://apiv9.dolist.net/v1/contacts/read?AccountID=%{account_id}"
    EMAIL_LOGS_URL = "https://apiv9.dolist.net/v1/statistics/email/sendings/transactional/search?AccountID=%{account_id}"
    EMAIL_KEY = 7
    STATUS_KEY = 72
    DOLIST_WEB_DASHBOARD = "https://campaign.dolist.net/#/%{account_id}/contacts/%{contact_id}/sendings"
    EMAIL_MESSAGES_ADRESSES_REPLIES = "https://apiv9.dolist.net/v1/email/messages/addresses/replies?AccountID=%{account_id}"
    EMAIL_MESSAGES_ADRESSES_PACKSENDERS = "https://apiv9.dolist.net/v1/email/messages/addresses/packsenders?AccountID=%{account_id}"
    EMAIL_SENDING_TRANSACTIONAL = "https://apiv9.dolist.net/v1/email/sendings/transactional?AccountID=%{account_id}"
    EMAIL_SENDING_TRANSACTIONAL_ATTACHMENT = "https://apiv9.dolist.net/v1/email/sendings/transactional/attachment?AccountID=%{account_id}"
    EMAIL_SENDING_TRANSACTIONAL_SEARCH = "https://apiv9.dolist.net/v1/email/sendings/transactional/search?AccountID=%{account_id}"

    class_attribute :limit_remaining, :limit_reset_at

    # those code are just undocumented
    IGNORABLE_API_ERROR_CODE = [
      "458",
      "402"
    ]

    # see: https://usercampaign.dolist.net/wp-content/uploads/2022/12/Comprendre-les-Opt-out-tableau-v2.pdf
    IGNORABLE_CONTACT_STATUSES = [
      "4", # Le serveur distant n'accepte pas le mail car il identifie que l’adresse e-mail est en erreur.
      "7" # Suite à un envoi, le serveur distant accepte le mail dans un premier temps mais envoie une erreur définitive car l’adresse e-mail est en erreur. L'adresse e-mail n’existe pas ou n'existe plus.
    ]

    class << self
      def save_rate_limit_headers(headers)
        self.limit_remaining = headers["X-Rate-Limit-Remaining"].to_i
        self.limit_reset_at = Time.zone.at(headers["X-Rate-Limit-Reset"].to_i / 1_000)
      end

      def near_rate_limit?
        return if limit_remaining.nil?

        limit_remaining < 20 # keep 20 requests for non background API calls
      end

      def sleep_until_limit_reset
        return if limit_reset_at.nil? || limit_reset_at.past?

        sleep (limit_reset_at - Time.zone.now).ceil
      end

      def sendable?(mail)
        return false if mail.to.blank? # recipient are mandatory
        return false if mail.bcc.present? # no bcc support

        # Mail having attachments are not yet supported in our account
        mail.attachments.none? { !_1.inline? }
      end
    end

    def properly_configured?
      client_key.present?
    end

    def send_email(mail)
      if mail.attachments.any? { !_1.inline? }
        return send_email_with_attachment(mail)
      end

      body = { "TransactionalSending": prepare_mail_body(mail) }

      url = format_url(EMAIL_SENDING_TRANSACTIONAL)
      post(url, body.to_json)
    end

    def send_email_with_attachment(mail)
      uri = URI(format_url(EMAIL_SENDING_TRANSACTIONAL_ATTACHMENT))

      request = Net::HTTP::Post.new(uri)

      default_headers.each do |key, value|
        next if key.to_s == "Content-Type"
        request[key] = value
      end

      boundary = "---011000010111000001101001" # any random string not present in the body
      request.content_type = "multipart/form-data; boundary=#{boundary}"

      body = "--#{boundary}\r\n"

      base64_files(mail.attachments).each do |file|
        body << "Content-Disposition: form-data; name=\"#{file.field_name}\"; filename=\"#{file.filename}\"\r\n"
        body << "Content-Type: #{file.mime_type}\r\n"
        body << "\r\n"
        body << file.content
        body << "\r\n"
      end

      body << "\r\n--#{boundary}\r\n"
      body << "Content-Disposition: form-data; name=\"TransactionalSending\"\r\n"
      body << "Content-Type: text/plain; charset=utf-8\r\n"
      body << "\r\n"
      body << prepare_mail_body(mail).to_jsv

      body << "\r\n--#{boundary}--\r\n"
      body << "\r\n"

      request.body = body

      http = Net::HTTP.new(uri.host, uri.port)
      http.use_ssl = true

      response = http.request(request)

      if response.body.empty?
        fail "Dolist API returned an empty response"
      else
        JSON.parse(response.body)
      end
    end

    def sent_mails(email_address)
      contact_id = fetch_contact_id(email_address)
      if contact_id.nil?
        Rails.logger.info "Dolist::API: no contact found for email address '#{email_address}'"
        return []
      end

      dolist_messages = fetch_dolist_messages(contact_id)

      dolist_messages.map { |m| to_sent_mail(email_address, contact_id, m) }
    rescue StandardError => e
      Rails.logger.error e.message
      []
    end

    def senders
      get format_url(EMAIL_MESSAGES_ADRESSES_PACKSENDERS)
    end

    def replies
      get format_url(EMAIL_MESSAGES_ADRESSES_REPLIES)
    end

    # Une adresse e-mail peut ne pas être adressable pour différentes raisons (injoignable, plainte pour spam, blocage d’un FAI).
    # Dans ce cas l’API d’envoi transactionnel renvoie différentes erreurs.
    # Pour connaitre exactement le statut d’une adresse, je vous invite à récupérer le champ 72 du contact à partir de son adresse e-mail avec la méthode https://api.dolist.com/documentation/index.html#/40e7751d00dc3-rechercher-un-contact
    #
    # La liste des différents statuts est disponible sur https://usercampaign.dolist.net/wp-content/uploads/2022/12/Comprendre-les-Opt-out-tableau-v2.pdf
    def fetch_contact_status(email_address)
      url = format(Dolist::API::CONTACT_URL, account_id: account_id)
      body = {
        Query: {
          FieldValueList: [{ ID: 7, Value: email_address }],
          OutputFieldIDList: [72]
        }
      }.to_json

      fields = post(url, body).fetch("FieldList", [])

      if fields.empty?
        Sentry.with_scope do |scope|
          scope.set_extra(:contact, email_address)
          Sentry.capture_message("Dolist::API: contact not found")
        end

        return nil
      end

      fields.find { _1['ID'] == 72 }.fetch('Value')
    end

    def ignorable_error?(response, mail)
      error_code = response&.dig("ResponseStatus", "ErrorCode")
      invalid_contact_status = if ignorable_api_error_code?(error_code)
        fetch_contact_status(mail.to.first)
      else
        nil
      end
      [error_code, invalid_contact_status]
    end

    private

    def ignorable_api_error_code?(api_error_code)
      IGNORABLE_API_ERROR_CODE.include?(api_error_code)
    end

    def ignorable_contact_status?(contact_status)
      IGNORABLE_CONTACT_STATUSES.include?(contact_status)
    end

    def format_url(base)
      format(base, account_id: account_id)
    end

    def sender_id
      Rails.cache.fetch("dolist_api_sender_id", expires_in: 1.hour) do
        senders.dig("ItemList", 0, "Sender", "ID")
      end
    end

    def get(url)
      response = Typhoeus.get(url, headers: default_headers).tap do
        self.class.save_rate_limit_headers(_1.headers)
      end

      JSON.parse(response.response_body)
    end

    def post(url, body)
      response = Typhoeus.post(url, body:, headers: default_headers).tap do
        self.class.save_rate_limit_headers(_1.headers)
      end

      if response.response_body.empty?
        fail "Empty response from Dolist API"
      else
        JSON.parse(response.response_body)
      end
    end

    def default_headers
      {
        "Content-Type": 'application/json',
        "Accept": 'application/json',
        "X-API-Key": client_key
      }
    end

    def client_key
      Rails.application.secrets.dolist[:api_key]
    end

    def account_id
      Rails.application.secrets.dolist[:account_id]
    end

    # https://api.dolist.com/documentation/index.html#/b3A6Mzg0MTQ0MDc-rechercher-un-contact
    def fetch_contact_id(email_address)
      url = format(CONTACT_URL, account_id: account_id)

      body = {
        Query: { FieldValueList: [{ ID: EMAIL_KEY, Value: email_address }] }
      }.to_json

      post(url, body)["ID"]
    end

    # https://api.dolist.com/documentation/index.html#/b3A6Mzg0MTQ4MDk-recuperer-les-statistiques-des-envois-pour-un-contact
    def fetch_dolist_messages(contact_id)
      url = format(EMAIL_LOGS_URL, account_id: account_id)

      body = { SearchQuery: { ContactID: contact_id } }.to_json

      post(url, body)["ItemList"]
    end

    # see: https://api.dolist.com/documentation/index.html#/7edc2948ba01f-creer-un-envoi-transactionnel
    def prepare_mail_body(mail)
      {
        "Type": "TransactionalService",
        "Contact": {
          "FieldList": [
            {
              "ID": EMAIL_KEY,
              "Value": mail.to.first
            }
          ]
        },
        "Message": {
          "Name": mail['X-Dolist-Message-Name'].value,
          "Subject": mail.subject,
          "SenderID": sender_id,
          "ForceHttp": false, # ForceHttp : force le tracking http non sécurisé (True/False).
          "Format": "html",
          "DisableOpenTracking": true, # DisableOpenTracking : désactivation du tracking d'ouverture (True/False).
          "IsTrackingValidated": true # IsTrackingValidated : est-ce que le tracking de ce message est validé ? (True/False). Passez la valeur True pour un envoi transactionnel.
        },
        "MessageContent": {
          "SourceCode":  mail_source_code(mail),
          "EncodingType": "UTF8",
          "EnableTrackingDetection": false # EnableTrackingDetection : booléen pour l’activation du tracking personnalisé des liens des messages utilisés lors des précédents envois (True/False).
        }
      }
    end

    def to_sent_mail(email_address, contact_id, dolist_message)
      SentMail.new(
        from: ENV['DOLIST_NO_REPLY_EMAIL'],
        to: email_address,
        subject: dolist_message['SendingName'],
        delivered_at: Time.zone.parse(dolist_message['SendDate']),
        status: status(dolist_message),
        service_name: 'Dolist',
        external_url: format(DOLIST_WEB_DASHBOARD, account_id: account_id, contact_id: contact_id)
      )
    end

    def status(dolist_message)
      case dolist_message.fetch_values('Status', 'IsDelivered')
      in ['Sent', true]
        "delivered"
      in ['Sent', false]
        "sent (delivered ?)"
      in [status, _]
        status
      end
    end

    def mail_source_code(mail)
      if mail.html_part.nil? && mail.text_part.nil?
        mail.decoded
      else
        mail.html_part.body.decoded
      end
    end

    def base64_files(attachments)
      attachments.map do |attachment|
        raise ArgumentError, "Dolist API does not support non PDF attachments. Given #{attachment.filename} which has mime_type=#{attachment.mime_type}" unless attachment.mime_type == "application/pdf"

        field_name = File.basename(attachment.filename, File.extname(attachment.filename))
        attachment_content = attachment.body.decoded
        attachment_base64 = Base64.strict_encode64(attachment_content)

        Dolist::Base64File.new(field_name:, filename: attachment.filename, mime_type: attachment.mime_type, content: attachment_base64)
      end
    end
  end
end