# frozen_string_literal: true

require 'rails_helper'
require 'imap/sync'
require_relative 'imap_helper'

describe Imap::Sync do

  before do
    SiteSetting.tagging_enabled = true
    SiteSetting.allow_staff_to_tag_pms = true

    SiteSetting.enable_imap = true

    Jobs.run_immediately!
  end

  let(:group) do
    Fabricate(
      :group,
      imap_server: 'imap.gmail.com',
      imap_port: 993,
      email_username: 'discourse@example.com',
      email_password: 'discourse@example.com',
      imap_mailbox_name: '[Gmail]/All Mail'
    )
  end

  let(:sync_handler) { Imap::Sync.new(group) }

  before do
    mocked_imap_provider = MockedImapProvider.new(
      group.imap_server,
      port: group.imap_port,
      ssl: group.imap_ssl,
      username: group.email_username,
      password: group.email_password
    )
    Imap::Providers::Detector.stubs(:init_with_detected_provider).returns(
      mocked_imap_provider
    )
  end

  context 'no previous sync' do
    let(:from) { 'john@free.fr' }
    let(:subject) { 'Testing email post' }
    let(:message_id) { "#{SecureRandom.hex}@example.com" }

    let(:email) do
      EmailFabricator(
        from: from,
        to: group.email_username,
        subject: subject,
        message_id: message_id)
    end

    before do
      provider = MockedImapProvider.any_instance
      provider.stubs(:open_mailbox).returns(uid_validity: 1)
      provider.stubs(:uids).with.returns([100])
      provider.stubs(:uids).with(to: 100).returns([100])
      provider.stubs(:uids).with(from: 101).returns([])
      provider.stubs(:emails).returns(
        [
          {
            'UID' => 100,
            'LABELS' => %w[\\Important test-label],
            'FLAGS' => %i[Seen],
            'RFC822' => email
          }
        ]
      )
    end

    it 'creates a topic from an incoming email' do
      expect { sync_handler.process }
        .to change { Topic.count }.by(1)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(1)
        .and change { IncomingEmail.count }.by(1)

      expect(group.imap_uid_validity).to eq(1)
      expect(group.imap_last_uid).to eq(100)

      topic = Topic.last
      expect(topic.title).to eq(subject)
      expect(topic.user.email).to eq(from)
      expect(topic.tags.pluck(:name)).to eq(%w[seen important test-label])

      post = topic.first_post
      expect(post.raw).to eq('This is an email *body*. :smile:')

      incoming_email = post.incoming_email
      expect(incoming_email.raw.lines.map(&:strip)).to eq(email.lines.map(&:strip))
      expect(incoming_email.message_id).to eq(message_id)
      expect(incoming_email.from_address).to eq(from)
      expect(incoming_email.to_addresses).to eq(group.email_username)
      expect(incoming_email.imap_uid_validity).to eq(1)
      expect(incoming_email.imap_uid).to eq(100)
      expect(incoming_email.imap_sync).to eq(false)
      expect(incoming_email.imap_group_id).to eq(group.id)
    end

    it 'does not duplicate topics' do
      expect { sync_handler.process }
        .to change { Topic.count }.by(1)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(1)
        .and change { IncomingEmail.count }.by(1)

      expect { sync_handler.process }
        .to change { Topic.count }.by(0)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(0)
        .and change { IncomingEmail.count }.by(0)
    end

    it 'creates a new incoming email if the message ID does not match the receiver post id regex' do
      incoming_email = Fabricate(:incoming_email, message_id: message_id)

      expect { sync_handler.process }
        .to change { Topic.count }.by(1)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(1)
        .and change { IncomingEmail.count }.by(1)

      last_incoming = IncomingEmail.where(message_id: message_id).last
      expect(last_incoming.message_id).to eq(message_id)
      expect(last_incoming.imap_uid_validity).to eq(1)
      expect(last_incoming.imap_uid).to eq(100)
      expect(last_incoming.imap_sync).to eq(false)
      expect(last_incoming.imap_group_id).to eq(group.id)
    end

    context "when the message id matches the receiver post id regex" do
      let(:message_id) { "topic/999/324@test.localhost" }
      it 'does not duplicate incoming email' do
        incoming_email = Fabricate(:incoming_email, message_id: message_id)

        expect { sync_handler.process }
          .to change { Topic.count }.by(0)
          .and change { Post.where(post_type: Post.types[:regular]).count }.by(0)
          .and change { IncomingEmail.count }.by(0)

        incoming_email.reload
        expect(incoming_email.message_id).to eq(message_id)
        expect(incoming_email.imap_uid_validity).to eq(1)
        expect(incoming_email.imap_uid).to eq(100)
        expect(incoming_email.imap_sync).to eq(false)
        expect(incoming_email.imap_group_id).to eq(group.id)
      end
    end
  end

  context 'previous sync' do
    let(:subject) { 'Testing email post' }

    let(:first_from) { 'john@free.fr' }
    let(:first_message_id) { SecureRandom.hex }
    let(:first_body) { 'This is the first message of this exchange.' }

    let(:second_from) { 'sam@free.fr' }
    let(:second_message_id) { SecureRandom.hex }
    let(:second_body) { '<p>This is an <b>answer</b> to this message.</p>' }

    it 'continues with new emails' do
      provider = MockedImapProvider.any_instance
      provider.stubs(:open_mailbox).returns(uid_validity: 1)

      provider.stubs(:uids).with.returns([100])
      provider.stubs(:emails).with([100], ['UID', 'FLAGS', 'LABELS', 'RFC822'], anything).returns(
        [
          {
            'UID' => 100,
            'LABELS' => %w[\\Inbox],
            'FLAGS' => %i[Seen],
            'RFC822' => EmailFabricator(
              message_id: first_message_id,
              from: first_from,
              to: group.email_username,
              cc: second_from,
              subject: subject,
              body: first_body
            )
          }
        ]
      )

      expect { sync_handler.process }
        .to change { Topic.count }.by(1)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(1)
        .and change { IncomingEmail.count }.by(1)

      topic = Topic.last
      expect(topic.title).to eq(subject)
      expect(GroupArchivedMessage.where(topic_id: topic.id).exists?).to eq(false)

      post = Post.where(post_type: Post.types[:regular]).last
      expect(post.user.email).to eq(first_from)
      expect(post.raw).to eq(first_body)
      expect(group.imap_uid_validity).to eq(1)
      expect(group.imap_last_uid).to eq(100)

      provider.stubs(:uids).with(to: 100).returns([100])
      provider.stubs(:uids).with(from: 101).returns([200])
      provider.stubs(:emails).with([100], ['UID', 'FLAGS', 'LABELS', 'ENVELOPE'], anything).returns(
        [
          {
            'UID' => 100,
            'LABELS' => %w[\\Inbox],
            'FLAGS' => %i[Seen]
          }
        ]
      )
      provider.stubs(:emails).with([200], ['UID', 'FLAGS', 'LABELS', 'RFC822'], anything).returns(
        [
          {
            'UID' => 200,
            'LABELS' => %w[\\Inbox],
            'FLAGS' => %i[Recent],
            'RFC822' => EmailFabricator(
              message_id: SecureRandom.hex,
              in_reply_to: first_message_id,
              from: second_from,
              to: group.email_username,
              subject: "Re: #{subject}",
              body: second_body
            )
          }
        ]
      )

      expect { sync_handler.process }
        .to change { Topic.count }.by(0)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(1)
        .and change { IncomingEmail.count }.by(1)

      post = Post.where(post_type: Post.types[:regular]).last
      expect(post.user.email).to eq(second_from)
      expect(post.raw).to eq(second_body)
      expect(group.imap_uid_validity).to eq(1)
      expect(group.imap_last_uid).to eq(200)

      provider.stubs(:uids).with(to: 200).returns([100, 200])
      provider.stubs(:uids).with(from: 201).returns([])
      provider.stubs(:emails).with([100, 200], ['UID', 'FLAGS', 'LABELS', 'ENVELOPE'], anything).returns(
        [
          {
            'UID' => 100,
            'LABELS' => %w[],
            'FLAGS' => %i[Seen]
          },
          {
            'UID' => 200,
            'LABELS' => %w[],
            'FLAGS' => %i[Recent],
          }
        ]
      )

      expect { sync_handler.process }
        .to change { Topic.count }.by(0)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(0)
        .and change { IncomingEmail.count }.by(0)

      topic = Topic.last
      expect(topic.title).to eq(subject)
      expect(GroupArchivedMessage.where(topic_id: topic.id).exists?).to eq(true)

      expect(Topic.last.posts.where(post_type: Post.types[:regular]).count).to eq(2)
    end

    describe "archiving emails" do
      let(:provider) { MockedImapProvider.any_instance }
      before do
        SiteSetting.enable_imap_write = true
        provider.stubs(:open_mailbox).returns(uid_validity: 1)

        provider.stubs(:uids).with.returns([100])
        provider.stubs(:emails).with([100], ['UID', 'FLAGS', 'LABELS', 'RFC822'], anything).returns(
          [
            {
              'UID' => 100,
              'LABELS' => %w[\\Inbox],
              'FLAGS' => %i[Seen],
              'RFC822' => EmailFabricator(
                message_id: first_message_id,
                from: first_from,
                to: group.email_username,
                cc: second_from,
                subject: subject,
                body: first_body
              )
            }
          ]
        )

        sync_handler.process
        @incoming_email = IncomingEmail.find_by(message_id: first_message_id)
        @topic = @incoming_email.topic

        provider.stubs(:uids).with(to: 100).returns([100])
        provider.stubs(:uids).with(from: 101).returns([101])
        provider.stubs(:emails).with([100], ['UID', 'FLAGS', 'LABELS', 'ENVELOPE'], anything).returns(
          [
            {
              'UID' => 100,
              'LABELS' => %w[\\Inbox],
              'FLAGS' => %i[Seen]
            }
          ]
        )
        provider.stubs(:emails).with([101], ['UID', 'FLAGS', 'LABELS', 'RFC822'], anything).returns(
          []
        )
        provider.stubs(:emails).with(100, ['FLAGS', 'LABELS']).returns(
          [
            {
              'LABELS' => %w[\\Inbox],
              'FLAGS' => %i[Seen]
            }
          ]
        )
      end

      it "archives an email on the IMAP server when archived in discourse" do
        GroupArchivedMessage.archive!(group.id, @topic, skip_imap_sync: false)
        @incoming_email.update(imap_sync: true)

        provider.stubs(:store).with(100, 'FLAGS', anything, anything)
        provider.stubs(:store).with(100, 'LABELS', ["\\Inbox"], ["seen"])

        provider.expects(:archive).with(100)
        sync_handler.process
      end

      it "does not archive email if not archived in discourse" do
        @incoming_email.update(imap_sync: true)
        provider.stubs(:store).with(100, 'FLAGS', anything, anything)
        provider.stubs(:store).with(100, 'LABELS', ["\\Inbox"], ["seen", "\\Inbox"])

        provider.expects(:archive).with(100).never
        sync_handler.process
      end
    end

  end

  context 'invaidated previous sync' do
    let(:subject) { 'Testing email post' }

    let(:first_from) { 'john@free.fr' }
    let(:first_message_id) { SecureRandom.hex }
    let(:first_body) { 'This is the first message of this exchange.' }

    let(:second_from) { 'sam@free.fr' }
    let(:second_message_id) { SecureRandom.hex }
    let(:second_body) { '<p>This is an <b>answer</b> to this message.</p>' }

    # TODO: Improve the invalidating flow for mailbox change. This is a destructive
    # action so it should not be done often.
    xit 'is updated' do
      provider = MockedImapProvider.any_instance

      provider.stubs(:open_mailbox).returns(uid_validity: 1)
      provider.stubs(:uids).with.returns([100, 200])
      provider.stubs(:emails).with([100, 200], ['UID', 'FLAGS', 'LABELS', 'RFC822'], anything).returns(
        [
          {
            'UID' => 100,
            'LABELS' => %w[\\Inbox],
            'FLAGS' => %i[Seen],
            'RFC822' => EmailFabricator(
              message_id: first_message_id,
              from: first_from,
              to: group.email_username,
              cc: second_from,
              subject: subject,
              body: first_body
            )
          },
          {
            'UID' => 200,
            'LABELS' => %w[\\Inbox],
            'FLAGS' => %i[Recent],
            'RFC822' => EmailFabricator(
              message_id: second_message_id,
              in_reply_to: first_message_id,
              from: second_from,
              to: group.email_username,
              subject: "Re: #{subject}",
              body: second_body
            )
          }
        ]
      )

      expect { sync_handler.process }
        .to change { Topic.count }.by(1)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(2)
        .and change { IncomingEmail.count }.by(2)

      imap_data = Topic.last.incoming_email.pluck(:imap_uid_validity, :imap_uid, :imap_group_id)
      expect(imap_data).to contain_exactly([1, 100, group.id], [1, 200, group.id])

      provider.stubs(:open_mailbox).returns(uid_validity: 2)
      provider.stubs(:uids).with.returns([111, 222])
      provider.stubs(:emails).with([111, 222], ['UID', 'FLAGS', 'LABELS', 'RFC822'], anything).returns(
        [
          {
            'UID' => 111,
            'LABELS' => %w[\\Inbox],
            'FLAGS' => %i[Seen],
            'RFC822' => EmailFabricator(
              message_id: first_message_id,
              from: first_from,
              to: group.email_username,
              cc: second_from,
              subject: subject,
              body: first_body
            )
          },
          {
            'UID' => 222,
            'LABELS' => %w[\\Inbox],
            'FLAGS' => %i[Recent],
            'RFC822' => EmailFabricator(
              message_id: second_message_id,
              in_reply_to: first_message_id,
              from: second_from,
              to: group.email_username,
              subject: "Re: #{subject}",
              body: second_body
            )
          }
        ]
      )

      expect { sync_handler.process }
        .to change { Topic.count }.by(0)
        .and change { Post.where(post_type: Post.types[:regular]).count }.by(0)
        .and change { IncomingEmail.count }.by(0)

      imap_data = Topic.last.incoming_email.pluck(:imap_uid_validity, :imap_uid, :imap_group_id)
      expect(imap_data).to contain_exactly([2, 111, group.id], [2, 222, group.id])
    end
  end
end