Merge branch 'bitbucket-oauth2' into 'master'

Refactor Bitbucket importer to use BitBucket API Version 2

## What does this MR do?

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/19946

## Screenshots (if relevant)

This MR needs the following permissions in the Bitbucket OAuth settings:

![image](/uploads/a26ae5e430a724bf581a92da7028ce3c/image.png)

- [] 

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5995

20 files changed, 749 insertions, 251 deletions

diff --git a/lib/bitbucket/client.rb b/lib/bitbucket/client.rb
new file mode 100644
index 00000000000..f8ee7e0f9ae
--- /dev/null
+++ b/lib/bitbucket/client.rb
@@ -0,0 +1,58 @@
+module Bitbucket
+  class Client
+    attr_reader :connection
+
+    def initialize(options = {})
+      @connection = Connection.new(options)
+    end
+
+    def issues(repo)
+      path = "/repositories/#{repo}/issues"
+      get_collection(path, :issue)
+    end
+
+    def issue_comments(repo, issue_id)
+      path = "/repositories/#{repo}/issues/#{issue_id}/comments"
+      get_collection(path, :comment)
+    end
+
+    def pull_requests(repo)
+      path = "/repositories/#{repo}/pullrequests?state=ALL"
+      get_collection(path, :pull_request)
+    end
+
+    def pull_request_comments(repo, pull_request)
+      path = "/repositories/#{repo}/pullrequests/#{pull_request}/comments"
+      get_collection(path, :pull_request_comment)
+    end
+
+    def pull_request_diff(repo, pull_request)
+      path = "/repositories/#{repo}/pullrequests/#{pull_request}/diff"
+      connection.get(path)
+    end
+
+    def repo(name)
+      parsed_response = connection.get("/repositories/#{name}")
+      Representation::Repo.new(parsed_response)
+    end
+
+    def repos
+      path = "/repositories?role=member"
+      get_collection(path, :repo)
+    end
+
+    def user
+      @user ||= begin
+        parsed_response = connection.get('/user')
+        Representation::User.new(parsed_response)
+      end
+    end
+
+    private
+
+    def get_collection(path, type)
+      paginator = Paginator.new(connection, path, type)
+      Collection.new(paginator)
+    end
+  end
+end
diff --git a/lib/bitbucket/collection.rb b/lib/bitbucket/collection.rb
new file mode 100644
index 00000000000..3a9379ff680
--- /dev/null
+++ b/lib/bitbucket/collection.rb
@@ -0,0 +1,21 @@
+module Bitbucket
+  class Collection < Enumerator
+    def initialize(paginator)
+      super() do |yielder|
+        loop do
+          paginator.items.each { |item| yielder << item }
+        end
+      end
+
+      lazy
+    end
+
+    def method_missing(method, *args)
+      return super unless self.respond_to?(method)
+
+      self.send(method, *args) do |item|
+        block_given? ? yield(item) : item
+      end
+    end
+  end
+end
diff --git a/lib/bitbucket/connection.rb b/lib/bitbucket/connection.rb
new file mode 100644
index 00000000000..7e55cf4deab
--- /dev/null
+++ b/lib/bitbucket/connection.rb
@@ -0,0 +1,69 @@
+module Bitbucket
+  class Connection
+    DEFAULT_API_VERSION = '2.0'
+    DEFAULT_BASE_URI    = 'https://api.bitbucket.org/'
+    DEFAULT_QUERY       = {}
+
+    attr_reader :expires_at, :expires_in, :refresh_token, :token
+
+    def initialize(options = {})
+      @api_version   = options.fetch(:api_version, DEFAULT_API_VERSION)
+      @base_uri      = options.fetch(:base_uri, DEFAULT_BASE_URI)
+      @default_query = options.fetch(:query, DEFAULT_QUERY)
+
+      @token         = options[:token]
+      @expires_at    = options[:expires_at]
+      @expires_in    = options[:expires_in]
+      @refresh_token = options[:refresh_token]
+    end
+
+    def get(path, extra_query = {})
+      refresh! if expired?
+
+      response = connection.get(build_url(path), params: @default_query.merge(extra_query))
+      response.parsed
+    end
+
+    def expired?
+      connection.expired?
+    end
+
+    def refresh!
+      response = connection.refresh!
+
+      @token         = response.token
+      @expires_at    = response.expires_at
+      @expires_in    = response.expires_in
+      @refresh_token = response.refresh_token
+      @connection    = nil
+    end
+
+    private
+
+    def client
+      @client ||= OAuth2::Client.new(provider.app_id, provider.app_secret, options)
+    end
+
+    def connection
+      @connection ||= OAuth2::AccessToken.new(client, @token, refresh_token: @refresh_token, expires_at: @expires_at, expires_in: @expires_in)
+    end
+
+    def build_url(path)
+      return path if path.starts_with?(root_url)
+
+      "#{root_url}#{path}"
+    end
+
+    def root_url
+      @root_url ||= "#{@base_uri}#{@api_version}"
+    end
+
+    def provider
+      Gitlab::OAuth::Provider.config_for('bitbucket')
+    end
+
+    def options
+      OmniAuth::Strategies::Bitbucket.default_options[:client_options].deep_symbolize_keys
+    end
+  end
+end
diff --git a/lib/bitbucket/error/unauthorized.rb b/lib/bitbucket/error/unauthorized.rb
new file mode 100644
index 00000000000..5e2eb57bb0e
--- /dev/null
+++ b/lib/bitbucket/error/unauthorized.rb
@@ -0,0 +1,6 @@
+module Bitbucket
+  module Error
+    class Unauthorized < StandardError
+    end
+  end
+end
diff --git a/lib/bitbucket/page.rb b/lib/bitbucket/page.rb
new file mode 100644
index 00000000000..2b0a3fe7b1a
--- /dev/null
+++ b/lib/bitbucket/page.rb
@@ -0,0 +1,34 @@
+module Bitbucket
+  class Page
+    attr_reader :attrs, :items
+
+    def initialize(raw, type)
+      @attrs = parse_attrs(raw)
+      @items = parse_values(raw, representation_class(type))
+    end
+
+    def next?
+      attrs.fetch(:next, false)
+    end
+
+    def next
+      attrs.fetch(:next)
+    end
+
+    private
+
+    def parse_attrs(raw)
+      raw.slice(*%w(size page pagelen next previous)).symbolize_keys
+    end
+
+    def parse_values(raw, bitbucket_rep_class)
+      return [] unless raw['values'] && raw['values'].is_a?(Array)
+
+      bitbucket_rep_class.decorate(raw['values'])
+    end
+
+    def representation_class(type)
+      Bitbucket::Representation.const_get(type.to_s.camelize)
+    end
+  end
+end
diff --git a/lib/bitbucket/paginator.rb b/lib/bitbucket/paginator.rb
new file mode 100644
index 00000000000..135d0d55674
--- /dev/null
+++ b/lib/bitbucket/paginator.rb
@@ -0,0 +1,36 @@
+module Bitbucket
+  class Paginator
+    PAGE_LENGTH = 50 # The minimum length is 10 and the maximum is 100.
+
+    def initialize(connection, url, type)
+      @connection = connection
+      @type = type
+      @url = url
+      @page = nil
+    end
+
+    def items
+      raise StopIteration unless has_next_page?
+
+      @page = fetch_next_page
+      @page.items
+    end
+
+    private
+
+    attr_reader :connection, :page, :url, :type
+
+    def has_next_page?
+      page.nil? || page.next?
+    end
+
+    def next_url
+      page.nil? ? url : page.next
+    end
+
+    def fetch_next_page
+      parsed_response = connection.get(next_url, pagelen: PAGE_LENGTH, sort: :created_on)
+      Page.new(parsed_response, type)
+    end
+  end
+end
diff --git a/lib/bitbucket/representation/base.rb b/lib/bitbucket/representation/base.rb
new file mode 100644
index 00000000000..94adaacc9b5
--- /dev/null
+++ b/lib/bitbucket/representation/base.rb
@@ -0,0 +1,17 @@
+module Bitbucket
+  module Representation
+    class Base
+      def initialize(raw)
+        @raw = raw
+      end
+
+      def self.decorate(entries)
+        entries.map { |entry| new(entry)}
+      end
+
+      private
+
+      attr_reader :raw
+    end
+  end
+end
diff --git a/lib/bitbucket/representation/comment.rb b/lib/bitbucket/representation/comment.rb
new file mode 100644
index 00000000000..4937aa9728f
--- /dev/null
+++ b/lib/bitbucket/representation/comment.rb
@@ -0,0 +1,27 @@
+module Bitbucket
+  module Representation
+    class Comment < Representation::Base
+      def author
+        user['username']
+      end
+
+      def note
+        raw.fetch('content', {}).fetch('raw', nil)
+      end
+
+      def created_at
+        raw['created_on']
+      end
+
+      def updated_at
+        raw['updated_on'] || raw['created_on']
+      end
+
+      private
+
+      def user
+        raw.fetch('user', {})
+      end
+    end
+  end
+end
diff --git a/lib/bitbucket/representation/issue.rb b/lib/bitbucket/representation/issue.rb
new file mode 100644
index 00000000000..054064395c3
--- /dev/null
+++ b/lib/bitbucket/representation/issue.rb
@@ -0,0 +1,53 @@
+module Bitbucket
+  module Representation
+    class Issue < Representation::Base
+      CLOSED_STATUS = %w(resolved invalid duplicate wontfix closed).freeze
+
+      def iid
+        raw['id']
+      end
+
+      def kind
+        raw['kind']
+      end
+
+      def author
+        raw.fetch('reporter', {}).fetch('username', nil)
+      end
+
+      def description
+        raw.fetch('content', {}).fetch('raw', nil)
+      end
+
+      def state
+        closed? ? 'closed' : 'opened'
+      end
+
+      def title
+        raw['title']
+      end
+
+      def milestone
+        raw['milestone']['name'] if raw['milestone'].present?
+      end
+
+      def created_at
+        raw['created_on']
+      end
+
+      def updated_at
+        raw['edited_on']
+      end
+
+      def to_s
+        iid
+      end
+
+      private
+
+      def closed?
+        CLOSED_STATUS.include?(raw['state'])
+      end
+    end
+  end
+end
diff --git a/lib/bitbucket/representation/pull_request.rb b/lib/bitbucket/representation/pull_request.rb
new file mode 100644
index 00000000000..eebf8093380
--- /dev/null
+++ b/lib/bitbucket/representation/pull_request.rb
@@ -0,0 +1,65 @@
+module Bitbucket
+  module Representation
+    class PullRequest < Representation::Base
+      def author
+        raw.fetch('author', {}).fetch('username', nil)
+      end
+
+      def description
+        raw['description']
+      end
+
+      def iid
+        raw['id']
+      end
+
+      def state
+        if raw['state'] == 'MERGED'
+          'merged'
+        elsif raw['state'] == 'DECLINED'
+          'closed'
+        else
+          'opened'
+        end
+      end
+
+      def created_at
+        raw['created_on']
+      end
+
+      def updated_at
+        raw['updated_on']
+      end
+
+      def title
+        raw['title']
+      end
+
+      def source_branch_name
+        source_branch.fetch('branch', {}).fetch('name', nil)
+      end
+
+      def source_branch_sha
+        source_branch.fetch('commit', {}).fetch('hash', nil)
+      end
+
+      def target_branch_name
+        target_branch.fetch('branch', {}).fetch('name', nil)
+      end
+
+      def target_branch_sha
+        target_branch.fetch('commit', {}).fetch('hash', nil)
+      end
+
+      private
+
+      def source_branch
+        raw['source']
+      end
+
+      def target_branch
+        raw['destination']
+      end
+    end
+  end
+end
diff --git a/lib/bitbucket/representation/pull_request_comment.rb b/lib/bitbucket/representation/pull_request_comment.rb
new file mode 100644
index 00000000000..4f8efe03bae
--- /dev/null
+++ b/lib/bitbucket/representation/pull_request_comment.rb
@@ -0,0 +1,39 @@
+module Bitbucket
+  module Representation
+    class PullRequestComment < Comment
+      def iid
+        raw['id']
+      end
+
+      def file_path
+        inline.fetch('path')
+      end
+
+      def old_pos
+        inline.fetch('from')
+      end
+
+      def new_pos
+        inline.fetch('to')
+      end
+
+      def parent_id
+        raw.fetch('parent', {}).fetch('id', nil)
+      end
+
+      def inline?
+        raw.has_key?('inline')
+      end
+
+      def has_parent?
+        raw.has_key?('parent')
+      end
+
+      private
+
+      def inline
+        raw.fetch('inline', {})
+      end
+    end
+  end
+end
diff --git a/lib/bitbucket/representation/repo.rb b/lib/bitbucket/representation/repo.rb
new file mode 100644
index 00000000000..8969ecd1c19
--- /dev/null
+++ b/lib/bitbucket/representation/repo.rb
@@ -0,0 +1,67 @@
+module Bitbucket
+  module Representation
+    class Repo < Representation::Base
+      attr_reader :owner, :slug
+
+      def initialize(raw)
+        super(raw)
+      end
+
+      def owner_and_slug
+        @owner_and_slug ||= full_name.split('/', 2)
+      end
+
+      def owner
+        owner_and_slug.first
+      end
+
+      def slug
+        owner_and_slug.last
+      end
+
+      def clone_url(token = nil)
+        url = raw['links']['clone'].find { |link| link['name'] == 'https' }.fetch('href')
+
+        if token.present?
+          clone_url = URI::parse(url)
+          clone_url.user = "x-token-auth:#{token}"
+          clone_url.to_s
+        else
+          url
+        end
+      end
+
+      def description
+        raw['description']
+      end
+
+      def full_name
+        raw['full_name']
+      end
+
+      def issues_enabled?
+        raw['has_issues']
+      end
+
+      def name
+        raw['name']
+      end
+
+      def valid?
+        raw['scm'] == 'git'
+      end
+
+      def visibility_level
+        if raw['is_private']
+          Gitlab::VisibilityLevel::PRIVATE
+        else
+          Gitlab::VisibilityLevel::PUBLIC
+        end
+      end
+
+      def to_s
+        full_name
+      end
+    end
+  end
+end
diff --git a/lib/bitbucket/representation/user.rb b/lib/bitbucket/representation/user.rb
new file mode 100644
index 00000000000..ba6b7667b49
--- /dev/null
+++ b/lib/bitbucket/representation/user.rb
@@ -0,0 +1,9 @@
+module Bitbucket
+  module Representation
+    class User < Representation::Base
+      def username
+        raw['username']
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/bitbucket_import.rb b/lib/gitlab/bitbucket_import.rb
deleted file mode 100644
index 7298152e7e9..00000000000
--- a/lib/gitlab/bitbucket_import.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-module Gitlab
-  module BitbucketImport
-    mattr_accessor :public_key
-    @public_key = nil
-  end
-end
diff --git a/lib/gitlab/bitbucket_import/client.rb b/lib/gitlab/bitbucket_import/client.rb
deleted file mode 100644
index 8d1ad62fae0..00000000000
--- a/lib/gitlab/bitbucket_import/client.rb
+++ /dev/null
@@ -1,142 +0,0 @@
-module Gitlab
-  module BitbucketImport
-    class Client
-      class Unauthorized < StandardError; end
-
-      attr_reader :consumer, :api
-
-      def self.from_project(project)
-        import_data_credentials = project.import_data.credentials if project.import_data
-        if import_data_credentials && import_data_credentials[:bb_session]
-          token = import_data_credentials[:bb_session][:bitbucket_access_token]
-          token_secret = import_data_credentials[:bb_session][:bitbucket_access_token_secret]
-          new(token, token_secret)
-        else
-          raise Projects::ImportService::Error, "Unable to find project import data credentials for project ID: #{project.id}"
-        end
-      end
-
-      def initialize(access_token = nil, access_token_secret = nil)
-        @consumer = ::OAuth::Consumer.new(
-          config.app_id,
-          config.app_secret,
-          bitbucket_options
-        )
-
-        if access_token && access_token_secret
-          @api = ::OAuth::AccessToken.new(@consumer, access_token, access_token_secret)
-        end
-      end
-
-      def request_token(redirect_uri)
-        request_token = consumer.get_request_token(oauth_callback: redirect_uri)
-
-        {
-          oauth_token:              request_token.token,
-          oauth_token_secret:       request_token.secret,
-          oauth_callback_confirmed: request_token.callback_confirmed?.to_s
-        }
-      end
-
-      def authorize_url(request_token, redirect_uri)
-        request_token = ::OAuth::RequestToken.from_hash(consumer, request_token) if request_token.is_a?(Hash)
-
-        if request_token.callback_confirmed?
-          request_token.authorize_url
-        else
-          request_token.authorize_url(oauth_callback: redirect_uri)
-        end
-      end
-
-      def get_token(request_token, oauth_verifier, redirect_uri)
-        request_token = ::OAuth::RequestToken.from_hash(consumer, request_token) if request_token.is_a?(Hash)
-
-        if request_token.callback_confirmed?
-          request_token.get_access_token(oauth_verifier: oauth_verifier)
-        else
-          request_token.get_access_token(oauth_callback: redirect_uri)
-        end
-      end
-
-      def user
-        JSON.parse(get("/api/1.0/user").body)
-      end
-
-      def issues(project_identifier)
-        all_issues = []
-        offset = 0
-        per_page = 50 # Maximum number allowed by Bitbucket
-        index = 0
-
-        begin
-          issues = JSON.parse(get(issue_api_endpoint(project_identifier, per_page, offset)).body)
-          # Find out how many total issues are present
-          total = issues["count"] if index == 0
-          all_issues.concat(issues["issues"])
-          offset += issues["issues"].count
-          index += 1
-        end while all_issues.count < total
-
-        all_issues
-      end
-
-      def issue_comments(project_identifier, issue_id)
-        comments = JSON.parse(get("/api/1.0/repositories/#{project_identifier}/issues/#{issue_id}/comments").body)
-        comments.sort_by { |comment| comment["utc_created_on"] }
-      end
-
-      def project(project_identifier)
-        JSON.parse(get("/api/1.0/repositories/#{project_identifier}").body)
-      end
-
-      def find_deploy_key(project_identifier, key)
-        JSON.parse(get("/api/1.0/repositories/#{project_identifier}/deploy-keys").body).find do |deploy_key|
-          deploy_key["key"].chomp == key.chomp
-        end
-      end
-
-      def add_deploy_key(project_identifier, key)
-        deploy_key = find_deploy_key(project_identifier, key)
-        return if deploy_key
-
-        JSON.parse(api.post("/api/1.0/repositories/#{project_identifier}/deploy-keys", key: key, label: "GitLab import key").body)
-      end
-
-      def delete_deploy_key(project_identifier, key)
-        deploy_key = find_deploy_key(project_identifier, key)
-        return unless deploy_key
-
-        api.delete("/api/1.0/repositories/#{project_identifier}/deploy-keys/#{deploy_key["pk"]}").code == "204"
-      end
-
-      def projects
-        JSON.parse(get("/api/1.0/user/repositories").body).select { |repo| repo["scm"] == "git" }
-      end
-
-      def incompatible_projects
-        JSON.parse(get("/api/1.0/user/repositories").body).reject { |repo| repo["scm"] == "git" }
-      end
-
-      private
-
-      def get(url)
-        response = api.get(url)
-        raise Unauthorized if (400..499).cover?(response.code.to_i)
-
-        response
-      end
-
-      def issue_api_endpoint(project_identifier, per_page, offset)
-        "/api/1.0/repositories/#{project_identifier}/issues?sort=utc_created_on&limit=#{per_page}&start=#{offset}"
-      end
-
-      def config
-        Gitlab.config.omniauth.providers.find { |provider| provider.name == "bitbucket" }
-      end
-
-      def bitbucket_options
-        OmniAuth::Strategies::Bitbucket.default_options[:client_options].symbolize_keys
-      end
-    end
-  end
-end
diff --git a/lib/gitlab/bitbucket_import/importer.rb b/lib/gitlab/bitbucket_import/importer.rb
index f4b5097adb1..7d2f92d577a 100644
--- a/lib/gitlab/bitbucket_import/importer.rb
+++ b/lib/gitlab/bitbucket_import/importer.rb
@@ -1,84 +1,234 @@
 module Gitlab
   module BitbucketImport
     class Importer
-      attr_reader :project, :client
+      LABELS = [{ title: 'bug', color: '#FF0000' },
+                { title: 'enhancement', color: '#428BCA' },
+                { title: 'proposal', color: '#69D100' },
+                { title: 'task', color: '#7F8C8D' }].freeze
+
+      attr_reader :project, :client, :errors, :users
 
       def initialize(project)
         @project = project
-        @client = Client.from_project(@project)
+        @client = Bitbucket::Client.new(project.import_data.credentials)
         @formatter = Gitlab::ImportFormatter.new
+        @labels = {}
+        @errors = []
+        @users = {}
       end
 
       def execute
-        import_issues if has_issues?
+        import_issues
+        import_pull_requests
+        handle_errors
 
         true
-      rescue ActiveRecord::RecordInvalid => e
-        raise Projects::ImportService::Error.new, e.message
-      ensure
-        Gitlab::BitbucketImport::KeyDeleter.new(project).execute
       end
 
       private
 
-      def gitlab_user_id(project, bitbucket_id)
-        if bitbucket_id
-          user = User.joins(:identities).find_by("identities.extern_uid = ? AND identities.provider = 'bitbucket'", bitbucket_id.to_s)
-          (user && user.id) || project.creator_id
-        else
-          project.creator_id
-        end
+      def handle_errors
+        return unless errors.any?
+
+        project.update_column(:import_error, {
+          message: 'The remote data could not be fully imported.',
+          errors: errors
+        }.to_json)
       end
 
-      def identifier
-        project.import_source
+      def gitlab_user_id(project, username)
+        find_user_id(username) || project.creator_id
       end
 
-      def has_issues?
-        client.project(identifier)["has_issues"]
+      def find_user_id(username)
+        return nil unless username
+
+        return users[username] if users.key?(username)
+
+        users[username] = User.select(:id)
+                              .joins(:identities)
+                              .find_by("identities.extern_uid = ? AND identities.provider = 'bitbucket'", username)
+                              .try(:id)
+      end
+
+      def repo
+        @repo ||= client.repo(project.import_source)
       end
 
       def import_issues
-        issues = client.issues(identifier)
+        return unless repo.issues_enabled?
+
+        create_labels
+
+        client.issues(repo).each do |issue|
+          begin
+            description = ''
+            description += @formatter.author_line(issue.author) unless find_user_id(issue.author)
+            description += issue.description
+
+            label_name = issue.kind
+            milestone = issue.milestone ? project.milestones.find_or_create_by(title: issue.milestone) : nil
+
+            gitlab_issue = project.issues.create!(
+              iid: issue.iid,
+              title: issue.title,
+              description: description,
+              state: issue.state,
+              author_id: gitlab_user_id(project, issue.author),
+              milestone: milestone,
+              created_at: issue.created_at,
+              updated_at: issue.updated_at
+            )
+
+            gitlab_issue.labels << @labels[label_name]
+
+            import_issue_comments(issue, gitlab_issue) if gitlab_issue.persisted?
+          rescue StandardError => e
+            errors << { type: :issue, iid: issue.iid, errors: e.message }
+          end
+        end
+      end
+
+      def import_issue_comments(issue, gitlab_issue)
+        client.issue_comments(repo, issue.iid).each do |comment|
+          # The note can be blank for issue service messages like "Changed title: ..."
+          # We would like to import those comments as well but there is no any
+          # specific parameter that would allow to process them, it's just an empty comment.
+          # To prevent our importer from just crashing or from creating useless empty comments
+          # we do this check.
+          next unless comment.note.present?
+
+          note = ''
+          note += @formatter.author_line(comment.author) unless find_user_id(comment.author)
+          note += comment.note
+
+          begin
+            gitlab_issue.notes.create!(
+              project: project,
+              note: note,
+              author_id: gitlab_user_id(project, comment.author),
+              created_at: comment.created_at,
+              updated_at: comment.updated_at
+            )
+          rescue StandardError => e
+            errors << { type: :issue_comment, iid: issue.iid, errors: e.message }
+          end
+        end
+      end
 
-        issues.each do |issue|
-          body = ''
-          reporter = nil
-          author = 'Anonymous'
+      def create_labels
+        LABELS.each do |label|
+          @labels[label[:title]] = project.labels.create!(label)
+        end
+      end
 
-          if issue["reported_by"] && issue["reported_by"]["username"]
-            reporter = issue["reported_by"]["username"]
-            author = reporter
+      def import_pull_requests
+        pull_requests = client.pull_requests(repo)
+
+        pull_requests.each do |pull_request|
+          begin
+            description = ''
+            description += @formatter.author_line(pull_request.author) unless find_user_id(pull_request.author)
+            description += pull_request.description
+
+            merge_request = project.merge_requests.create(
+              iid: pull_request.iid,
+              title: pull_request.title,
+              description: description,
+              source_project: project,
+              source_branch: pull_request.source_branch_name,
+              source_branch_sha: pull_request.source_branch_sha,
+              target_project: project,
+              target_branch: pull_request.target_branch_name,
+              target_branch_sha: pull_request.target_branch_sha,
+              state: pull_request.state,
+              author_id: gitlab_user_id(project, pull_request.author),
+              assignee_id: nil,
+              created_at: pull_request.created_at,
+              updated_at: pull_request.updated_at
+            )
+
+            import_pull_request_comments(pull_request, merge_request) if merge_request.persisted?
+          rescue StandardError => e
+            errors << { type: :pull_request, iid: pull_request.iid, errors: e.message }
           end
+        end
+      end
 
-          body = @formatter.author_line(author)
-          body += issue["content"]
+      def import_pull_request_comments(pull_request, merge_request)
+        comments = client.pull_request_comments(repo, pull_request.iid)
 
-          comments = client.issue_comments(identifier, issue["local_id"])
+        inline_comments, pr_comments = comments.partition(&:inline?)
 
-          if comments.any?
-            body += @formatter.comments_header
-          end
+        import_inline_comments(inline_comments, pull_request, merge_request)
+        import_standalone_pr_comments(pr_comments, merge_request)
+      end
 
-          comments.each do |comment|
-            author = 'Anonymous'
+      def import_inline_comments(inline_comments, pull_request, merge_request)
+        line_code_map = {}
 
-            if comment["author_info"] && comment["author_info"]["username"]
-              author = comment["author_info"]["username"]
-            end
+        children, parents = inline_comments.partition(&:has_parent?)
+
+        # The Bitbucket API returns threaded replies as parent-child
+        # relationships. We assume that the child can appear in any order in
+        # the JSON.
+        parents.each do |comment|
+          line_code_map[comment.iid] = generate_line_code(comment)
+        end
 
-            body += @formatter.comment(author, comment["utc_created_on"], comment["content"])
+        children.each do |comment|
+          line_code_map[comment.iid] = line_code_map.fetch(comment.parent_id, nil)
+        end
+
+        inline_comments.each do |comment|
+          begin
+            attributes = pull_request_comment_attributes(comment)
+            attributes.merge!(
+              position: build_position(merge_request, comment),
+              line_code: line_code_map.fetch(comment.iid),
+              type: 'DiffNote')
+
+            merge_request.notes.create!(attributes)
+          rescue StandardError => e
+            errors << { type: :pull_request, iid: comment.iid, errors: e.message }
           end
+        end
+      end
 
-          project.issues.create!(
-            description: body,
-            title: issue["title"],
-            state: %w(resolved invalid duplicate wontfix closed).include?(issue["status"]) ? 'closed' : 'opened',
-            author_id: gitlab_user_id(project, reporter)
-          )
+      def build_position(merge_request, pr_comment)
+        params = {
+          diff_refs: merge_request.diff_refs,
+          old_path: pr_comment.file_path,
+          new_path: pr_comment.file_path,
+          old_line: pr_comment.old_pos,
+          new_line: pr_comment.new_pos
+        }
+
+        Gitlab::Diff::Position.new(params)
+      end
+
+      def import_standalone_pr_comments(pr_comments, merge_request)
+        pr_comments.each do |comment|
+          begin
+            merge_request.notes.create!(pull_request_comment_attributes(comment))
+          rescue StandardError => e
+            errors << { type: :pull_request, iid: comment.iid, errors: e.message }
+          end
         end
-      rescue ActiveRecord::RecordInvalid => e
-        raise Projects::ImportService::Error, e.message
+      end
+
+      def generate_line_code(pr_comment)
+        Gitlab::Diff::LineCode.generate(pr_comment.file_path, pr_comment.new_pos, pr_comment.old_pos)
+      end
+
+      def pull_request_comment_attributes(comment)
+        {
+          project: project,
+          note: comment.note,
+          author_id: gitlab_user_id(project, comment.author),
+          created_at: comment.created_at,
+          updated_at: comment.updated_at
+        }
       end
     end
   end
diff --git a/lib/gitlab/bitbucket_import/key_adder.rb b/lib/gitlab/bitbucket_import/key_adder.rb
deleted file mode 100644
index 0b63f025d0a..00000000000
--- a/lib/gitlab/bitbucket_import/key_adder.rb
+++ /dev/null
@@ -1,24 +0,0 @@
-module Gitlab
-  module BitbucketImport
-    class KeyAdder
-      attr_reader :repo, :current_user, :client
-
-      def initialize(repo, current_user, access_params)
-        @repo, @current_user = repo, current_user
-        @client = Client.new(access_params[:bitbucket_access_token],
-                             access_params[:bitbucket_access_token_secret])
-      end
-
-      def execute
-        return false unless BitbucketImport.public_key.present?
-
-        project_identifier = "#{repo["owner"]}/#{repo["slug"]}"
-        client.add_deploy_key(project_identifier, BitbucketImport.public_key)
-
-        true
-      rescue
-        false
-      end
-    end
-  end
-end
diff --git a/lib/gitlab/bitbucket_import/key_deleter.rb b/lib/gitlab/bitbucket_import/key_deleter.rb
deleted file mode 100644
index e03c3155b3e..00000000000
--- a/lib/gitlab/bitbucket_import/key_deleter.rb
+++ /dev/null
@@ -1,23 +0,0 @@
-module Gitlab
-  module BitbucketImport
-    class KeyDeleter
-      attr_reader :project, :current_user, :client
-
-      def initialize(project)
-        @project = project
-        @current_user = project.creator
-        @client = Client.from_project(@project)
-      end
-
-      def execute
-        return false unless BitbucketImport.public_key.present?
-
-        client.delete_deploy_key(project.import_source, BitbucketImport.public_key)
-
-        true
-      rescue
-        false
-      end
-    end
-  end
-end
diff --git a/lib/gitlab/bitbucket_import/project_creator.rb b/lib/gitlab/bitbucket_import/project_creator.rb
index b90ef0b0fba..eb03882ab26 100644
--- a/lib/gitlab/bitbucket_import/project_creator.rb
+++ b/lib/gitlab/bitbucket_import/project_creator.rb
@@ -1,10 +1,11 @@
 module Gitlab
   module BitbucketImport
     class ProjectCreator
-      attr_reader :repo, :namespace, :current_user, :session_data
+      attr_reader :repo, :name, :namespace, :current_user, :session_data
 
-      def initialize(repo, namespace, current_user, session_data)
+      def initialize(repo, name, namespace, current_user, session_data)
         @repo = repo
+        @name = name
         @namespace = namespace
         @current_user = current_user
         @session_data = session_data
@@ -13,15 +14,15 @@ module Gitlab
       def execute
         ::Projects::CreateService.new(
           current_user,
-          name: repo["name"],
-          path: repo["slug"],
-          description: repo["description"],
+          name: name,
+          path: name,
+          description: repo.description,
           namespace_id: namespace.id,
-          visibility_level: repo["is_private"] ? Gitlab::VisibilityLevel::PRIVATE : Gitlab::VisibilityLevel::PUBLIC,
-          import_type: "bitbucket",
-          import_source: "#{repo["owner"]}/#{repo["slug"]}",
-          import_url: "ssh://git@bitbucket.org/#{repo["owner"]}/#{repo["slug"]}.git",
-          import_data: { credentials: { bb_session: session_data } }
+          visibility_level: repo.visibility_level,
+          import_type: 'bitbucket',
+          import_source: repo.full_name,
+          import_url: repo.clone_url(session_data[:token]),
+          import_data: { credentials: session_data }
         ).execute
       end
     end
diff --git a/lib/omniauth/strategies/bitbucket.rb b/lib/omniauth/strategies/bitbucket.rb
new file mode 100644
index 00000000000..5a7d67c2390
--- /dev/null
+++ b/lib/omniauth/strategies/bitbucket.rb
@@ -0,0 +1,41 @@
+require 'omniauth-oauth2'
+
+module OmniAuth
+  module Strategies
+    class Bitbucket < OmniAuth::Strategies::OAuth2
+      option :name, 'bitbucket'
+
+      option :client_options, {
+        site: 'https://bitbucket.org',
+        authorize_url: 'https://bitbucket.org/site/oauth2/authorize',
+        token_url: 'https://bitbucket.org/site/oauth2/access_token'
+      }
+
+      uid do
+        raw_info['username']
+      end
+
+      info do
+        {
+          name: raw_info['display_name'],
+          avatar: raw_info['links']['avatar']['href'],
+          email: primary_email
+        }
+      end
+
+      def raw_info
+        @raw_info ||= access_token.get('api/2.0/user').parsed
+      end
+
+      def primary_email
+        primary = emails.find { |i| i['is_primary'] && i['is_confirmed'] }
+        primary && primary['email'] || nil
+      end
+
+      def emails
+        email_response = access_token.get('api/2.0/user/emails').parsed
+        @emails ||= email_response && email_response['values'] || nil
+      end
+    end
+  end
+end