require "rails_helper"
require "email/receiver"

describe Email::Receiver do

  before do
    SiteSetting.email_in = true
    SiteSetting.reply_by_email_address = "reply+%{reply_key}@bar.com"
    SiteSetting.alternative_reply_by_email_addresses = "alt+%{reply_key}@bar.com"
  end

  def process(email_name)
    Email::Receiver.new(email(email_name)).process!
  end

  it "raises an EmptyEmailError when 'mail_string' is blank" do
    expect { Email::Receiver.new(nil) }.to raise_error(Email::Receiver::EmptyEmailError)
    expect { Email::Receiver.new("") }.to raise_error(Email::Receiver::EmptyEmailError)
  end

  it "raises a ScreenedEmailError when email address is screened" do
    ScreenedEmail.expects(:should_block?).with("screened@mail.com").returns(true)
    expect { process(:screened_email) }.to raise_error(Email::Receiver::ScreenedEmailError)
  end

  it "raises EmailNotAllowed when email address is not on whitelist" do
    SiteSetting.email_domains_whitelist = "example.com|bar.com"
    expect { process(:blacklist_whitelist_email) }.to raise_error(Email::Receiver::EmailNotAllowed)
  end

  it "raises EmailNotAllowed when email address is on blacklist" do
    SiteSetting.email_domains_blacklist = "email.com|mail.com"
    expect { process(:blacklist_whitelist_email) }.to raise_error(Email::Receiver::EmailNotAllowed)
  end

  it "raises an UserNotFoundError when staged users are disabled" do
    SiteSetting.enable_staged_users = false
    expect { process(:user_not_found) }.to raise_error(Email::Receiver::UserNotFoundError)
  end

  it "raises an AutoGeneratedEmailError when the mail is auto generated" do
    expect { process(:auto_generated_precedence) }.to raise_error(Email::Receiver::AutoGeneratedEmailError)
    expect { process(:auto_generated_header) }.to raise_error(Email::Receiver::AutoGeneratedEmailError)
  end

  it "raises a NoBodyDetectedError when the body is blank" do
    expect { process(:no_body) }.to raise_error(Email::Receiver::NoBodyDetectedError)
  end

  it "raises a NoSenderDetectedError when the From header is missing" do
    expect { process(:no_from) }.to raise_error(Email::Receiver::NoSenderDetectedError)
  end

  it "raises an InactiveUserError when the sender is inactive" do
    Fabricate(:user, email: "inactive@bar.com", active: false)
    expect { process(:inactive_sender) }.to raise_error(Email::Receiver::InactiveUserError)
  end

  it "raises a SilencedUserError when the sender has been silenced" do
    Fabricate(:user, email: "silenced@bar.com", silenced_till: 1.year.from_now)
    expect { process(:silenced_sender) }.to raise_error(Email::Receiver::SilencedUserError)
  end

  it "doesn't raise an InactiveUserError when the sender is staged" do
    user = Fabricate(:user, email: "staged@bar.com", active: false, staged: true)

    email_log = Fabricate(:email_log,
      to_address: 'reply+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa@bar.com',
      reply_key: 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
      user: user,
      post: Fabricate(:post)
    )

    expect { process(:staged_sender) }.not_to raise_error
  end

  it "raises a BadDestinationAddress when destinations aren't matching any of the incoming emails" do
    expect { process(:bad_destinations) }.to raise_error(Email::Receiver::BadDestinationAddress)
  end

  it "raises a BouncerEmailError when email is a bounced email" do
    expect { process(:bounced_email) }.to raise_error(Email::Receiver::BouncedEmailError)
    expect(IncomingEmail.last.is_bounce).to eq(true)

    expect { process(:bounced_email_multiple_status_codes) }.to raise_error(Email::Receiver::BouncedEmailError)
    expect(IncomingEmail.last.is_bounce).to eq(true)
  end

  it "logs a blank error" do
    Email::Receiver.any_instance.stubs(:process_internal).raises(RuntimeError, "")
    process(:existing_user) rescue RuntimeError
    expect(IncomingEmail.last.error).to eq("RuntimeError")
  end

  context "bounces to VERP" do

    let(:bounce_key) { "14b08c855160d67f2e0c2f8ef36e251e" }
    let(:bounce_key_2) { "b542fb5a9bacda6d28cc061d18e4eb83" }
    let!(:user) { Fabricate(:user, email: "foo@bar.com") }
    let!(:email_log) { Fabricate(:email_log, user: user, bounce_key: bounce_key) }
    let!(:email_log_2) { Fabricate(:email_log, user: user, bounce_key: bounce_key_2) }

    before do
      $redis.del("bounce_score:#{user.email}:#{Date.today}")
      $redis.del("bounce_score:#{user.email}:#{2.days.from_now.to_date}")
    end

    it "deals with soft bounces" do
      expect { process(:soft_bounce_via_verp) }.to raise_error(Email::Receiver::BouncedEmailError)

      email_log.reload
      expect(email_log.bounced).to eq(true)
      expect(email_log.user.user_stat.bounce_score).to eq(1)
    end

    it "deals with hard bounces" do
      expect { process(:hard_bounce_via_verp) }.to raise_error(Email::Receiver::BouncedEmailError)

      email_log.reload
      expect(email_log.bounced).to eq(true)
      expect(email_log.user.user_stat.bounce_score).to eq(2)

      freeze_time 2.days.from_now

      expect { process(:hard_bounce_via_verp_2) }.to raise_error(Email::Receiver::BouncedEmailError)

      email_log_2.reload
      expect(email_log_2.user.user_stat.bounce_score).to eq(4)
      expect(email_log_2.bounced).to eq(true)
    end

  end

  context "reply" do

    let(:reply_key) { "4f97315cc828096c9cb34c6f1a0d6fe8" }
    let(:category) { Fabricate(:category) }
    let(:user) { Fabricate(:user, email: "discourse@bar.com") }
    let(:topic) { create_topic(category: category, user: user) }
    let(:post) { create_post(topic: topic, user: user) }
    let!(:email_log) { Fabricate(:email_log, reply_key: reply_key, user: user, topic: topic, post: post) }

    it "uses MD5 of 'mail_string' there is no message_id" do
      mail_string = email(:missing_message_id)
      expect { Email::Receiver.new(mail_string).process! }.to change { IncomingEmail.count }
      expect(IncomingEmail.last.message_id).to eq(Digest::MD5.hexdigest(mail_string))
    end

    it "raises a ReplyUserNotMatchingError when the email address isn't matching the one we sent the notification to" do
      expect { process(:reply_user_not_matching) }.to raise_error(Email::Receiver::ReplyUserNotMatchingError)
    end

    it "raises a TopicNotFoundError when the topic was deleted" do
      topic.update_columns(deleted_at: 1.day.ago)
      expect { process(:reply_user_matching) }.to raise_error(Email::Receiver::TopicNotFoundError)
    end

    it "raises a TopicClosedError when the topic was closed" do
      topic.update_columns(closed: true)
      expect { process(:reply_user_matching) }.to raise_error(Email::Receiver::TopicClosedError)
    end

    it "does not raise TopicClosedError when performing a like action" do
      topic.update_columns(closed: true)
      expect { process(:like) }.to change(PostAction, :count)
    end

    it "raises an InvalidPost when there was an error while creating the post" do
      expect { process(:too_small) }.to raise_error(Email::Receiver::InvalidPost)
    end

    it "raises an InvalidPost when there are too may mentions" do
      SiteSetting.max_mentions_per_post = 1
      Fabricate(:user, username: "user1")
      Fabricate(:user, username: "user2")
      expect { process(:too_many_mentions) }.to raise_error(Email::Receiver::InvalidPost)
    end

    it "raises an InvalidPostAction when they aren't allowed to like a post" do
      topic.update_columns(archived: true)
      expect { process(:like) }.to raise_error(Email::Receiver::InvalidPostAction)
    end

    it "works" do
      expect { process(:text_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is a text reply :)")
      expect(topic.posts.last.via_email).to eq(true)
      expect(topic.posts.last.cooked).not_to match(/<br/)

      expect { process(:html_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is a **HTML** reply ;)")
    end

    it "automatically elides gmail quotes" do
      SiteSetting.always_show_trimmed_content = true
      expect { process(:gmail_html_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is a **GMAIL** reply ;)\n\n<details class='elided'>\n<summary title='Show trimmed content'>&#183;&#183;&#183;</summary>\n\nThis is the *elided* part!\n\n</details>")
    end

    it "doesn't process email with same message-id more than once" do
      expect do
        process(:text_reply)
        process(:text_reply)
      end.to change { topic.posts.count }.by(1)
    end

    it "handles different encodings correctly" do
      expect { process(:hebrew_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("שלום! מה שלומך היום?")

      expect { process(:chinese_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("您好！ 你今天好吗？")

      expect { process(:reply_with_weird_encoding) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is a reply with a weird encoding.")

      expect { process(:reply_with_8bit_encoding) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("hab vergessen kritische zeichen einzufügen:\näöüÄÖÜß")
    end

    it "prefers text over html when site setting is disabled" do
      SiteSetting.incoming_email_prefer_html = false
      expect { process(:text_and_html_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is the *text* part.")
    end

    it "prefers html over text when site setting is enabled" do
      SiteSetting.incoming_email_prefer_html = true
      expect { process(:text_and_html_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq('This is the **html** part.')
    end

    it "uses text when prefer_html site setting is enabled but no html is available" do
      SiteSetting.incoming_email_prefer_html = true
      expect { process(:text_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is a text reply :)")
    end

    it "removes the 'on <date>, <contact> wrote' quoting line" do
      expect { process(:on_date_contact_wrote) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is the actual reply.")
    end

    it "removes the 'Previous Replies' marker" do
      expect { process(:previous_replies) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This will not include the previous discussion that is present in this email.")
    end

    it "handles multiple paragraphs" do
      expect { process(:paragraphs) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("Do you like liquorice?\n\nI really like them. One could even say that I am *addicted* to liquorice. Anf if\nyou can mix it up with some anise, then I'm in heaven ;)")
    end

    it "handles invalid from header" do
      expect { process(:invalid_from_1) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This email was sent with an invalid from header field.")
    end

    it "raises a NoSenderDetectedError when the From header doesn't contain an email address" do
      expect { process(:invalid_from_2) }.to raise_error(Email::Receiver::NoSenderDetectedError)
    end

    it "doesn't raise an AutoGeneratedEmailError when the mail is auto generated but is whitelisted" do
      SiteSetting.auto_generated_whitelist = "foo@bar.com|discourse@bar.com"
      expect { process(:auto_generated_whitelisted) }.to change { topic.posts.count }
    end

    it "doesn't raise an AutoGeneratedEmailError when block_auto_generated_emails is disabled" do
      SiteSetting.block_auto_generated_emails = false
      expect { process(:auto_generated_unblocked) }.to change { topic.posts.count }
    end

    it "allows staged users to reply to a restricted category" do
      user.update_columns(staged: true)

      category.email_in = "category@bar.com"
      category.email_in_allow_strangers = true
      category.set_permissions(Group[:trust_level_4] => :full)
      category.save

      expect { process(:staged_reply_restricted) }.to change { topic.posts.count }
    end

    describe 'Unsubscribing via email' do
      let(:last_email) { ActionMailer::Base.deliveries.last }

      describe 'unsubscribe_subject.eml' do
        it 'sends an email asking the user to confirm the unsubscription' do
          expect { process("unsubscribe_subject") }.to change { ActionMailer::Base.deliveries.count }.by(1)
          expect(last_email.to.length).to eq 1
          expect(last_email.from.length).to eq 1
          expect(last_email.from).to include "noreply@#{Discourse.current_hostname}"
          expect(last_email.to).to include "discourse@bar.com"
          expect(last_email.subject).to eq I18n.t(:"unsubscribe_mailer.subject_template").gsub("%{site_title}", SiteSetting.title)
        end

        it 'does nothing unless unsubscribe_via_email is turned on' do
          SiteSetting.unsubscribe_via_email = false
          before_deliveries = ActionMailer::Base.deliveries.count
          expect { process("unsubscribe_subject") }.to raise_error { Email::Receiver::BadDestinationAddress }
          expect(before_deliveries).to eq ActionMailer::Base.deliveries.count
        end
      end

      describe 'unsubscribe_body.eml' do
        it 'sends an email asking the user to confirm the unsubscription' do
          expect { process("unsubscribe_body") }.to change { ActionMailer::Base.deliveries.count }.by(1)
          expect(last_email.to.length).to eq 1
          expect(last_email.from.length).to eq 1
          expect(last_email.from).to include "noreply@#{Discourse.current_hostname}"
          expect(last_email.to).to include "discourse@bar.com"
          expect(last_email.subject).to eq I18n.t(:"unsubscribe_mailer.subject_template").gsub("%{site_title}", SiteSetting.title)
        end

        it 'does nothing unless unsubscribe_via_email is turned on' do
          SiteSetting.unsubscribe_via_email = false
          before_deliveries = ActionMailer::Base.deliveries.count
          expect { process("unsubscribe_body") }.to raise_error { Email::Receiver::InvalidPost }
          expect(before_deliveries).to eq ActionMailer::Base.deliveries.count
        end
      end

      it "raises an UnsubscribeNotAllowed and does not send an unsubscribe email" do
        before_deliveries = ActionMailer::Base.deliveries.count
        expect { process(:unsubscribe_new_user) }.to raise_error { Email::Receiver::UnsubscribeNotAllowed }
        expect(before_deliveries).to eq ActionMailer::Base.deliveries.count
      end
    end

    it "handles inline reply" do
      expect { process(:inline_reply) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("And this is *my* reply :+1:")
    end

    it "retrieves the first part of multiple replies" do
      expect { process(:inline_mixed_replies) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("> WAT <https://bar.com/users/wat> November 28\n>\n> This is the previous post.\n\nAnd this is *my* reply :+1:\n\n> This is another post.\n\nAnd this is **another** reply.")
    end

    it "strips mobile/webmail signatures" do
      expect { process(:iphone_signature) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is not the signature you're looking for.")
    end

    it "strips 'original message' context" do
      expect { process(:original_message) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is a reply :)")
    end

    it "add the 'elided' part of the original message only for private messages" do
      topic.update_columns(category_id: nil, archetype: Archetype.private_message)
      topic.allowed_users << user
      topic.save

      expect { process(:original_message) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to eq("This is a reply :)\n\n<details class='elided'>\n<summary title='Show trimmed content'>&#183;&#183;&#183;</summary>\n\n---Original Message---\nThis part should not be included\n\n</details>")
    end

    it "doesn't include the 'elided' part of the original message when always_show_trimmed_content is disabled" do
      SiteSetting.always_show_trimmed_content = false
      expect { process(:original_message) }.to change { topic.posts.count }.from(1).to(2)
      expect(topic.posts.last.raw).to eq("This is a reply :)")
    end

    it "adds the 'elided' part of the original message for public replies when always_show_trimmed_content is enabled" do
      SiteSetting.always_show_trimmed_content = true
      expect { process(:original_message) }.to change { topic.posts.count }.from(1).to(2)
      expect(topic.posts.last.raw).to eq("This is a reply :)\n\n<details class='elided'>\n<summary title='Show trimmed content'>&#183;&#183;&#183;</summary>\n\n---Original Message---\nThis part should not be included\n\n</details>")
    end

    it "supports attached images in TEXT part" do
      SiteSetting.incoming_email_prefer_html = false
      SiteSetting.queue_jobs = true

      expect { process(:no_body_with_image) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to match(/<img/)

      expect { process(:inline_image) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to match(/Before\s+<img.+>\s+After/)
    end

    it "supports attached images in HTML part" do
      SiteSetting.queue_jobs = true
      SiteSetting.incoming_email_prefer_html = true

      expect { process(:inline_image) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to match(/\*\*Before\*\*\s+<img.+>\s+\*After\*/)
    end

    it "supports attachments" do
      SiteSetting.authorized_extensions = "txt"
      expect { process(:attached_txt_file) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to match(/text\.txt/)

      SiteSetting.authorized_extensions = "csv"
      expect { process(:attached_txt_file_2) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to_not match(/text\.txt/)
    end

    it "supports emails with just an attachment" do
      SiteSetting.authorized_extensions = "pdf"
      expect { process(:attached_pdf_file) }.to change { topic.posts.count }
      expect(topic.posts.last.raw).to match(/discourse\.pdf/)
    end

    it "supports liking via email" do
      expect { process(:like) }.to change(PostAction, :count)
    end

    it "ensures posts aren't dated in the future" do
      expect { process(:from_the_future) }.to change { topic.posts.count }
      expect(topic.posts.last.created_at).to be_within(1.minute).of(DateTime.now)
    end

    it "accepts emails with wrong reply key if the system knows about the forwarded email" do
      Fabricate(:incoming_email,
                raw: <<~RAW,
                  Return-Path: <discourse@bar.com>
                  From: Alice <discourse@bar.com>
                  To: dave@bar.com, reply+4f97315cc828096c9cb34c6f1a0d6fe8@bar.com
                  CC: carol@bar.com, bob@bar.com
                  Subject: Hello world
                  Date: Fri, 15 Jan 2016 00:12:43 +0100
                  Message-ID: <10@foo.bar.mail>
                  Mime-Version: 1.0
                  Content-Type: text/plain; charset=UTF-8
                  Content-Transfer-Encoding: quoted-printable

                  This post was created by email.
                RAW
                from_address: "discourse@bar.com",
                to_addresses: "dave@bar.com;reply+4f97315cc828096c9cb34c6f1a0d6fe8@bar.com",
                cc_addresses: "carol@bar.com;bob@bar.com",
                topic: topic,
                post: post,
                user: user)

      expect { process(:reply_user_not_matching_but_known) }.to change { topic.posts.count }
    end
  end

  context "new message to a group" do

    let!(:group) { Fabricate(:group, incoming_email: "team@bar.com|meat@bar.com") }

    it "handles encoded display names" do
      expect { process(:encoded_display_name) }.to change(Topic, :count)

      topic = Topic.last
      expect(topic.title).to eq("I need help")
      expect(topic.private_message?).to eq(true)
      expect(topic.allowed_groups).to include(group)

      user = topic.user
      expect(user.staged).to eq(true)
      expect(user.username).to eq("random.name")
      expect(user.name).to eq("Случайная Имя")
    end

    it "handles email with no subject" do
      expect { process(:no_subject) }.to change(Topic, :count)
      expect(Topic.last.title).to eq("This topic needs a title")
    end

    it "invites everyone in the chain but emails configured as 'incoming' (via reply, group or category)" do
      expect { process(:cc) }.to change(Topic, :count)

      topic = Topic.last

      emails = topic.allowed_users.joins(:user_emails).pluck(:"user_emails.email")
      expect(emails).to contain_exactly("someone@else.com", "discourse@bar.com", "wat@bar.com")

      expect(topic.topic_users.count).to eq(3)
    end

    it "cap the number of staged users created per email" do
      SiteSetting.maximum_staged_users_per_email = 1
      expect { process(:cc) }.to change(Topic, :count)
      expect(Topic.last.ordered_posts[-1].post_type).to eq(Post.types[:moderator_action])
    end

    it "associates email replies using both 'In-Reply-To' and 'References' headers when 'find_related_post_with_key' is disabled" do
      SiteSetting.find_related_post_with_key = false

      expect { process(:email_reply_1) }.to change(Topic, :count)

      topic = Topic.last

      expect { process(:email_reply_2) }.to change { topic.posts.count }
      expect { process(:email_reply_3) }.to change { topic.posts.count }

      # Why 5 when we only processed 3 emails?
      #   - 3 of them are indeed "regular" posts generated from the emails
      #   - The 2 others are "small action" posts automatically added because
      #     we invited 2 users (two@foo.com and three@foo.com)
      expect(topic.posts.count).to eq(5)

      # trash all but the 1st post
      topic.ordered_posts[1..-1].each(&:trash!)

      expect { process(:email_reply_4) }.to change { topic.posts.count }
    end

    it "supports any kind of attachments when 'allow_all_attachments_for_group_messages' is enabled" do
      SiteSetting.allow_all_attachments_for_group_messages = true
      expect { process(:attached_rb_file) }.to change(Topic, :count)
      expect(Post.last.raw).to match(/discourse\.rb/)
    end

    context "with forwarded emails enabled" do
      before { SiteSetting.enable_forwarded_emails = true }

      it "handles forwarded emails" do
        expect { process(:forwarded_email_1) }.to change(Topic, :count)

        forwarded_post, last_post = *Post.last(2)

        expect(forwarded_post.user.email).to eq("some@one.com")
        expect(last_post.user.email).to eq("ba@bar.com")

        expect(forwarded_post.raw).to match(/XoXo/)
        expect(last_post.raw).to match(/can you have a look at this email below/)

        expect(last_post.post_type).to eq(Post.types[:regular])
      end

      it "handles weirdly forwarded emails" do
        group.add(Fabricate(:user, email: "ba@bar.com"))
        group.save

        SiteSetting.enable_forwarded_emails = true
        expect { process(:forwarded_email_2) }.to change(Topic, :count)

        forwarded_post, last_post = *Post.last(2)

        expect(forwarded_post.user.email).to eq("some@one.com")
        expect(last_post.user.email).to eq("ba@bar.com")

        expect(forwarded_post.raw).to match(/XoXo/)
        expect(last_post.raw).to match(/can you have a look at this email below/)

        expect(last_post.post_type).to eq(Post.types[:whisper])
      end

      # Who thought this was a good idea?!
      it "doesn't blow up with localized email headers" do
        expect { process(:forwarded_email_3) }.to change(Topic, :count)
      end

    end

    context "when message sent to a group has no key and find_related_post_with_key is enabled" do
      let!(:topic) do
        SiteSetting.find_related_post_with_key = true
        process(:email_reply_1)
        Topic.last
      end

      it "creates a reply when the sender and referenced message id are known" do
        expect { process(:email_reply_2) }.to change { topic.posts.count }.by(1).and change { Topic.count }.by(0)
      end

      it "creates a new topic when the sender is not known" do
        IncomingEmail.where(message_id: '34@foo.bar.mail').update(cc_addresses: 'three@foo.com')
        expect { process(:email_reply_2) }.to change { topic.posts.count }.by(0).and change { Topic.count }.by(1)
      end

      it "creates a new topic when the referenced message id is not known" do
        IncomingEmail.where(message_id: '34@foo.bar.mail').update(message_id: '99@foo.bar.mail')
        expect { process(:email_reply_2) }.to change { topic.posts.count }.by(0).and change { Topic.count }.by(1)
      end
    end
  end

  context "new topic in a category" do

    let!(:category) { Fabricate(:category, email_in: "category@bar.com|category@foo.com", email_in_allow_strangers: false) }

    it "raises a StrangersNotAllowedError when 'email_in_allow_strangers' is disabled" do
      expect { process(:new_user) }.to raise_error(Email::Receiver::StrangersNotAllowedError)
    end

    it "raises an InsufficientTrustLevelError when user's trust level isn't enough" do
      Fabricate(:user, email: "existing@bar.com", trust_level: 3)
      SiteSetting.email_in_min_trust = 4
      expect { process(:existing_user) }.to raise_error(Email::Receiver::InsufficientTrustLevelError)
    end

    it "works" do
      user = Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
      group = Fabricate(:group)

      group.add(user)
      group.save

      category.set_permissions(group => :create_post)
      category.save

      # raises an InvalidAccess when the user doesn't have the privileges to create a topic
      expect { process(:existing_user) }.to raise_error(Discourse::InvalidAccess)

      category.update_columns(email_in_allow_strangers: true)

      # allows new user to create a topic
      expect { process(:new_user) }.to change(Topic, :count)
    end

    it "adds the 'elided' part of the original message when always_show_trimmed_content is enabled" do
      SiteSetting.always_show_trimmed_content = true

      Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
      expect { process(:forwarded_email_to_category) }.to change { Topic.count }.by(1) # Topic created

      new_post, = Post.last
      expect(new_post.raw).to include("Hi everyone, can you have a look at the email below?", "<summary title='Show trimmed content'>&#183;&#183;&#183;</summary>", "Discoursing much today?")
    end

    it "works when approving is enabled" do
      SiteSetting.approve_unless_trust_level = 4

      Fabricate(:user, email: "tl3@bar.com", trust_level: TrustLevel[3])
      Fabricate(:user, email: "tl4@bar.com", trust_level: TrustLevel[4])

      category.set_permissions(Group[:trust_level_4] => :full)
      category.save

      Group.refresh_automatic_group!(:trust_level_4)

      expect { process(:tl3_user) }.to_not change(Topic, :count)
      expect { process(:tl4_user) }.to change(Topic, :count)
    end

    it "ignores by case-insensitive title" do
      SiteSetting.ignore_by_title = "foo"
      expect { process(:ignored) }.to_not change(Topic, :count)
    end
  end

  context "new topic in a category that allows strangers" do

    let!(:category) { Fabricate(:category, email_in: "category@bar.com|category@foo.com", email_in_allow_strangers: true) }

    it "lets an email in from a stranger" do
      expect { process(:new_user) }.to change(Topic, :count)
    end

    it "lets an email in from a high-TL user" do
      Fabricate(:user, email: "tl4@bar.com", trust_level: TrustLevel[4])
      expect { process(:tl4_user) }.to change(Topic, :count)
    end

    it "fails on email from a low-TL user" do
      SiteSetting.email_in_min_trust = 4
      Fabricate(:user, email: "tl3@bar.com", trust_level: TrustLevel[3])
      expect { process(:tl3_user) }.to raise_error(Email::Receiver::InsufficientTrustLevelError)
    end

  end

  context "#reply_by_email_address_regex" do

    before do
      SiteSetting.reply_by_email_address = nil
      SiteSetting.alternative_reply_by_email_addresses = nil
    end

    it "is empty by default" do
      expect(Email::Receiver.reply_by_email_address_regex).to eq(//)
    end

    it "uses 'reply_by_email_address' site setting" do
      SiteSetting.reply_by_email_address = "foo+%{reply_key}@bar.com"
      expect(Email::Receiver.reply_by_email_address_regex).to eq(/foo\+(\h{32})@bar\.com/)
    end

    it "uses 'alternative_reply_by_email_addresses' site setting" do
      SiteSetting.alternative_reply_by_email_addresses = "alt.foo+%{reply_key}@bar.com"
      expect(Email::Receiver.reply_by_email_address_regex).to eq(/alt\.foo\+(\h{32})@bar\.com/)
    end

    it "combines both 'reply_by_email' settings" do
      SiteSetting.reply_by_email_address = "foo+%{reply_key}@bar.com"
      SiteSetting.alternative_reply_by_email_addresses = "alt.foo+%{reply_key}@bar.com"
      expect(Email::Receiver.reply_by_email_address_regex).to eq(/foo\+(\h{32})@bar\.com|alt\.foo\+(\h{32})@bar\.com/)
    end

  end

  context "check_address" do
    before do
      SiteSetting.reply_by_email_address = "foo+%{reply_key}@bar.com"
    end

    it "returns nil when the key is invalid" do
      expect(Email::Receiver.check_address('fake@fake.com')).to be_nil
      expect(Email::Receiver.check_address('foo+4f97315cc828096c9cb34c6f1a0d6fe8@bar.com')).to be_nil
    end

    context "with a valid reply" do
      it "returns the destination when the key is valid" do
        Fabricate(:email_log, reply_key: '4f97315cc828096c9cb34c6f1a0d6fe8')

        dest = Email::Receiver.check_address('foo+4f97315cc828096c9cb34c6f1a0d6fe8@bar.com')
        expect(dest).to be_present
        expect(dest[:type]).to eq(:reply)
        expect(dest[:obj]).to be_present
      end
    end
  end

  context "staged users" do
    before do
      SiteSetting.enable_staged_users = true
    end

    shared_examples "no staged users" do |email_name, expected_exception|
      it "does not create staged users" do
        staged_user_count = User.where(staged: true).count
        expect { process(email_name) }.to raise_error(expected_exception)
        expect(User.where(staged: true).count).to eq(staged_user_count)
      end
    end

    context "when email address is screened" do
      before do
        ScreenedEmail.expects(:should_block?).with("screened@mail.com").returns(true)
      end

      include_examples "no staged users", :screened_email, Email::Receiver::ScreenedEmailError
    end

    context "when the mail is auto generated" do
      include_examples "no staged users", :auto_generated_header, Email::Receiver::AutoGeneratedEmailError
    end

    context "when email is a bounced email" do
      include_examples "no staged users", :bounced_email, Email::Receiver::BouncedEmailError
    end

    context "when the body is blank" do
      include_examples "no staged users", :no_body, Email::Receiver::NoBodyDetectedError
    end

    context "when unsubscribe via email is not allowed" do
      include_examples "no staged users", :unsubscribe_new_user, Email::Receiver::UnsubscribeNotAllowed
    end

    context "when From email address is not on whitelist" do
      before do
        SiteSetting.email_domains_whitelist = "example.com|bar.com"
      end

      include_examples "no staged users", :blacklist_whitelist_email, Email::Receiver::EmailNotAllowed
    end

    context "when From email address is on blacklist" do
      before do
        SiteSetting.email_domains_blacklist = "email.com|mail.com"
      end

      include_examples "no staged users", :blacklist_whitelist_email, Email::Receiver::EmailNotAllowed
    end

    context "blacklist and whitelist for To and Cc" do
      before do
        Fabricate(:group, incoming_email: "some_group@bar.com")
      end

      it "does not create staged users for email addresses not on whitelist" do
        SiteSetting.email_domains_whitelist = "mail.com|example.com"
        process(:blacklist_whitelist_email)

        expect(User.find_by_email("alice@foo.com")).to be_nil
        expect(User.find_by_email("bob@foo.com")).to be_nil
        expect(User.find_by_email("carol@example.com")).to be_present
      end

      it "does not create staged users for email addresses on blacklist" do
        SiteSetting.email_domains_blacklist = "email.com|foo.com"
        process(:blacklist_whitelist_email)

        expect(User.find_by_email("alice@foo.com")).to be_nil
        expect(User.find_by_email("bob@foo.com")).to be_nil
        expect(User.find_by_email("carol@example.com")).to be_present
      end
    end

    context "when destinations aren't matching any of the incoming emails" do
      include_examples "no staged users", :bad_destinations, Email::Receiver::BadDestinationAddress
    end

    context "when email is sent to category" do
      context "when email is sent by a new user and category does not allow strangers" do
        let!(:category) { Fabricate(:category, email_in: "category@foo.com", email_in_allow_strangers: false) }

        include_examples "no staged users", :new_user, Email::Receiver::StrangersNotAllowedError
      end

      context "when email has no date" do
        let!(:category) { Fabricate(:category, email_in: "category@foo.com", email_in_allow_strangers: true) }

        include_examples "no staged users", :no_date, Email::Receiver::InvalidPost
      end
    end

    context "email is a reply" do
      let(:reply_key) { "4f97315cc828096c9cb34c6f1a0d6fe8" }
      let(:category) { Fabricate(:category) }
      let(:user) { Fabricate(:user, email: "discourse@bar.com") }
      let(:topic) { create_topic(category: category, user: user) }
      let(:post) { create_post(topic: topic, user: user) }
      let!(:email_log) { Fabricate(:email_log, reply_key: reply_key, user: user, topic: topic, post: post) }

      context "when the email address isn't matching the one we sent the notification to" do
        include_examples "no staged users", :reply_user_not_matching, Email::Receiver::ReplyUserNotMatchingError
      end
    end

    context "replying without key is allowed" do
      let!(:group) { Fabricate(:group, incoming_email: "team@bar.com") }
      let!(:topic) do
        SiteSetting.find_related_post_with_key = false
        process(:email_reply_1)
        Topic.last
      end

      context "when the topic was deleted" do
        before do
          topic.update_columns(deleted_at: 1.day.ago)
        end

        include_examples "no staged users", :email_reply_staged, Email::Receiver::TopicNotFoundError
      end

      context "when the topic was closed" do
        before do
          topic.update_columns(closed: true)
        end

        include_examples "no staged users", :email_reply_staged, Email::Receiver::TopicClosedError
      end

      context "when they aren't allowed to like a post" do
        before do
          topic.update_columns(archived: true)
        end

        include_examples "no staged users", :email_reply_like, Email::Receiver::InvalidPostAction
      end
    end

    it "does not remove the incoming email record when staged users are deleted" do
      expect { process(:bad_destinations) }.to change { IncomingEmail.count }
        .and raise_error(Email::Receiver::BadDestinationAddress)
      expect(IncomingEmail.last.message_id).to eq("9@foo.bar.mail")
    end
  end

  context "mailing list mirror" do
    let!(:category) { Fabricate(:mailinglist_mirror_category) }

    before do
      SiteSetting.block_auto_generated_emails = true
      SiteSetting.find_related_post_with_key = true
    end

    it "should allow creating topic even when email is autogenerated" do
      expect { process(:mailinglist) }.to change { Topic.count }
      expect(IncomingEmail.last.is_auto_generated).to eq(false)
    end

    it "should allow replying without reply key" do
      process(:mailinglist)
      topic = Topic.last

      expect { process(:mailinglist_reply) }.to change { topic.posts.count }
    end

    it "should skip validations for staged users" do
      Fabricate(:user, email: "alice@foo.com", staged: true)
      expect { process(:mailinglist_short_message) }.to change { Topic.count }
    end

    it "should skip validations for regular users" do
      Fabricate(:user, email: "alice@foo.com")
      expect { process(:mailinglist_short_message) }.to change { Topic.count }
    end

    context "read-only category" do
      before do
        category.set_permissions(everyone: :readonly)
        category.save

        Fabricate(:user, email: "alice@foo.com")
        Fabricate(:user, email: "bob@bar.com")
      end

      it "should allow creating topic within read-only category" do
        expect { process(:mailinglist) }.to change { Topic.count }
      end

      it "should allow replying within read-only category" do
        process(:mailinglist)
        topic = Topic.last

        expect { process(:mailinglist_reply) }.to change { topic.posts.count }
      end
    end
  end

  it "tries to fix unparsable email addresses in To and CC headers" do
    expect { process(:unparsable_email_addresses) }.to raise_error(Email::Receiver::BadDestinationAddress)

    email = IncomingEmail.last
    expect(email.to_addresses).to eq("foo@bar.com")
    expect(email.cc_addresses).to eq("bob@example.com;carol@example.com")
  end
end