# Copyright 2015 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


require "time"
require "gcloud/resource_manager/project/list"
require "gcloud/resource_manager/project/updater"
require "gcloud/resource_manager/policy"

module Gcloud
  module ResourceManager
    ##
    # # Project
    #
    # Project is a high-level Google Cloud Platform entity. It is a container
    # for ACLs, APIs, AppEngine Apps, VMs, and other Google Cloud Platform
    # resources.
    #
    # @example
    #   require "gcloud"
    #
    #   gcloud = Gcloud.new
    #   resource_manager = gcloud.resource_manager
    #   project = resource_manager.project "tokyo-rain-123"
    #   project.update do |p|
    #     p.name = "My Project"
    #     p.labels["env"] = "production"
    #   end
    #
    class Project
      ##
      # @private The Service object.
      attr_accessor :service

      ##
      # @private The Google API Client object.
      attr_accessor :gapi

      ##
      # @private Create an empty Project object.
      def initialize
        @service = nil
        @gapi = Gcloud::ResourceManager::Service::API::Project.new
      end

      ##
      # The unique, user-assigned ID of the project. It must be 6 to 30
      # lowercase letters, digits, or hyphens. It must start with a letter.
      # Trailing hyphens are prohibited. e.g. tokyo-rain-123
      #
      def project_id
        @gapi.project_id
      end

      ##
      # The number uniquely identifying the project. e.g. 415104041262
      #
      def project_number
        @gapi.project_number
      end

      ##
      # The user-assigned name of the project.
      #
      def name
        @gapi.name
      end

      ##
      # Updates the user-assigned name of the project. This field is optional
      # and can remain unset.
      #
      # Allowed characters are: lowercase and uppercase letters, numbers,
      # hyphen, single-quote, double-quote, space, and exclamation point.
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.name = "My Project"
      #
      def name= new_name
        ensure_service!
        @gapi.name = new_name
        @gapi = service.update_project @gapi
      end

      ##
      # The labels associated with this project.
      #
      # Label keys must be between 1 and 63 characters long and must conform to
      # the regular expression <code>[a-z]([-a-z0-9]*[a-z0-9])?</code>.
      #
      # Label values must be between 0 and 63 characters long and must conform
      # to the regular expression <code>([a-z]([-a-z0-9]*[a-z0-9])?)?</code>.
      #
      # No more than 256 labels can be associated with a given resource.
      # (`Hash`)
      #
      # @yield [labels] a block for setting labels
      # @yieldparam [Hash] labels the hash accepting labels
      #
      # @example Labels are read-only and cannot be changed:
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.labels["env"] #=> "dev" # read only
      #   project.labels["env"] = "production" # raises error
      #
      # @example Labels can be updated by passing a block, or with {#labels=}:
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.labels do |labels|
      #     labels["env"] = "production"
      #   end
      #
      def labels
        labels = @gapi.labels.to_h
        if block_given?
          yielded_labels = labels.dup
          yield yielded_labels
          self.labels = yielded_labels if yielded_labels != labels # changed
        else
          labels.freeze
        end
      end

      ##
      # Updates the labels associated with this project.
      #
      # Label keys must be between 1 and 63 characters long and must conform to
      # the regular expression <code>[a-z]([-a-z0-9]*[a-z0-9])?</code>.
      #
      # Label values must be between 0 and 63 characters long and must conform
      # to the regular expression <code>([a-z]([-a-z0-9]*[a-z0-9])?)?</code>.
      #
      # No more than 256 labels can be associated with a given resource.
      # (`Hash`)
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.labels = { "env" => "production" }
      #
      def labels= new_labels
        ensure_service!
        @gapi.labels = new_labels
        @gapi = service.update_project @gapi
      end

      ##
      # The time that this project was created.
      #
      def created_at
        Time.parse @gapi.create_time
      rescue
        nil
      end

      ##
      # The project lifecycle state.
      #
      # Possible values are:
      # * `ACTIVE` - The normal and active state.
      # * `DELETE_REQUESTED` - The project has been marked for deletion by the
      #   user (by invoking ##delete) or by the system (Google Cloud
      #   Platform). This can generally be reversed by invoking {#undelete}.
      # * `DELETE_IN_PROGRESS` - The process of deleting the project has begun.
      #   Reversing the deletion is no longer possible.
      # * `LIFECYCLE_STATE_UNSPECIFIED` - Unspecified state. This is only
      #   used/useful for distinguishing unset values.
      #
      def state
        @gapi.lifecycle_state
      end

      ##
      # Checks if the state is `ACTIVE`.
      def active?
        return false if state.nil?
        "ACTIVE".casecmp(state).zero?
      end

      ##
      # Checks if the state is `LIFECYCLE_STATE_UNSPECIFIED`.
      def unspecified?
        return false if state.nil?
        "LIFECYCLE_STATE_UNSPECIFIED".casecmp(state).zero?
      end

      ##
      # Checks if the state is `DELETE_REQUESTED`.
      def delete_requested?
        return false if state.nil?
        "DELETE_REQUESTED".casecmp(state).zero?
      end

      ##
      # Checks if the state is `DELETE_IN_PROGRESS`.
      def delete_in_progress?
        return false if state.nil?
        "DELETE_IN_PROGRESS".casecmp(state).zero?
      end

      ##
      # Updates the project in a single API call. See {Project::Updater}
      #
      # @yield [project] a block yielding a project delegate
      # @yieldparam [Project::Updater] project the delegate object for updating
      #   the project
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.update do |p|
      #     p.name = "My Project"
      #     p.labels["env"] = "production"
      #   end
      #
      def update
        updater = Updater.from_project self
        yield updater
        if updater.gapi.to_h != @gapi.to_h # changed
          @gapi = service.update_project updater.gapi
        end
        self
      end

      ##
      # Reloads the project (with updated state) from the Google Cloud Resource
      # Manager service.
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.reload!
      #
      def reload!
        @gapi = service.get_project project_id
      end
      alias_method :refresh!, :reload!

      ##
      # Marks the project for deletion. This method will only affect the project
      # if the following criteria are met:
      #
      # * The project does not have a billing account associated with it.
      # * The project has a lifecycle state of `ACTIVE`.
      # * This method changes the project's lifecycle state from `ACTIVE` to
      #   `DELETE_REQUESTED`. The deletion starts at an unspecified time, at
      #   which point the lifecycle state changes to `DELETE_IN_PROGRESS`.
      #
      # Until the deletion completes, you can check the lifecycle state by
      # calling #reload!, or by retrieving the project with Manager#project. The
      # project remains visible to Manager#project and Manager#projects, but
      # cannot be updated.
      #
      # After the deletion completes, the project is not retrievable by the
      # Manager#project and Manager#projects methods.
      #
      # The caller must have modify permissions for this project.
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.active? #=> true
      #   project.delete
      #   project.active? #=> false
      #   project.delete_requested? #=> true
      #
      def delete
        service.delete_project project_id
        reload!
        true
      end

      ##
      # Restores the project. You can only use this method for a project that
      # has a lifecycle state of `DELETE_REQUESTED`. After deletion starts, as
      # indicated by a lifecycle state of `DELETE_IN_PROGRESS`, the project
      # cannot be restored.
      #
      # The caller must have modify permissions for this project.
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   project.delete_requested? #=> true
      #   project.undelete
      #   project.delete_requested? #=> false
      #   project.active? #=> true
      #
      def undelete
        service.undelete_project project_id
        reload!
        true
      end

      ##
      # Gets and updates the [Cloud IAM](https://cloud.google.com/iam/) access
      # control policy for this project.
      #
      # @see https://cloud.google.com/iam/docs/managing-policies Managing
      #   Policies
      # @see https://cloud.google.com/resource-manager/reference/rest/v1beta1/projects/setIamPolicy
      #   projects.setIamPolicy
      #
      # @param [Boolean] force Force load the latest policy when `true`.
      #   Otherwise the policy will be memoized to reduce the number of API
      #   calls made. The default is `false`.
      #
      # @yield [policy] A block for updating the policy. The latest policy will
      #   be read from the service and passed to the block. After the block
      #   completes, the modified policy will be written to the service.
      # @yieldparam [Policy] policy the current Cloud IAM Policy for this
      #   project
      #
      # @return [Policy] the current Cloud IAM Policy for this project
      #
      # @example Policy values are memoized to reduce the number of API calls:
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #
      #   policy = project.policy # API call
      #   policy_2 = project.policy # No API call
      #
      # @example Use `force` to retrieve the latest policy from the service:
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #
      #   policy = project.policy force: true # API call
      #   policy_2 = project.policy force: true # API call
      #
      # @example Update the policy by passing a block:
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #
      #   policy = project.policy do |p|
      #     p.add "roles/owner", "user:owner@example.com"
      #   end # 2 API calls
      #
      def policy force: false
        @policy = nil if force || block_given?
        @policy ||= begin
          ensure_service!
          gapi = service.get_policy project_id
          Policy.from_gapi gapi
        end
        return @policy unless block_given?
        p = @policy.deep_dup
        yield p
        self.policy = p
      end

      ##
      # Updates the [Cloud IAM](https://cloud.google.com/iam/) access control
      # policy for this project. The policy should be read from {#policy}.
      # See {Gcloud::ResourceManager::Policy} for an explanation of the policy
      # `etag` property and how to modify policies.
      #
      # You can also update the policy by passing a block to {#policy}, which
      # will call this method internally after the block completes.
      #
      # @see https://cloud.google.com/iam/docs/managing-policies Managing
      #   Policies
      # @see https://cloud.google.com/resource-manager/reference/rest/v1beta1/projects/setIamPolicy
      #   projects.setIamPolicy
      #
      # @param [Policy] new_policy a new or modified Cloud IAM Policy for this
      #   project
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #
      #   policy = project.policy # API call
      #
      #   policy.add "roles/owner", "user:owner@example.com"
      #
      #   project.policy = policy # API call
      #
      def policy= new_policy
        ensure_service!
        gapi = service.set_policy project_id, new_policy.to_gapi
        # Convert symbols to strings for backwards compatibility.
        # This will go away when we add a ResourceManager::Policy class.
        @policy = Policy.from_gapi gapi
      end

      ##
      # Tests the specified permissions against the [Cloud
      # IAM](https://cloud.google.com/iam/) access control policy.
      #
      # @see https://cloud.google.com/iam/docs/managing-policies Managing
      #   Policies
      #
      # @param [String, Array<String>] permissions The set of permissions to
      #   check access for. Permissions with wildcards (such as `*` or
      #   `storage.*`) are not allowed.
      #
      # @return [Array<String>] The permissions that have access
      #
      # @example
      #   require "gcloud"
      #
      #   gcloud = Gcloud.new
      #   resource_manager = gcloud.resource_manager
      #   project = resource_manager.project "tokyo-rain-123"
      #   perms = project.test_permissions "resourcemanager.projects.get",
      #                                    "resourcemanager.projects.delete"
      #   perms.include? "resourcemanager.projects.get"    #=> true
      #   perms.include? "resourcemanager.projects.delete" #=> false
      #
      def test_permissions *permissions
        permissions = Array(permissions).flatten
        ensure_service!
        gapi = service.test_permissions project_id, permissions
        gapi.permissions
      end

      ##
      # @private New Change from a Google API Client object.
      def self.from_gapi gapi, service
        new.tap do |p|
          p.gapi = gapi
          p.service = service
        end
      end

      protected

      ##
      # Raise an error unless an active service is available.
      def ensure_service!
        fail "Must have active connection" unless service
      end
    end
  end
end