#!/usr/bin/env ruby

require 'gitlab'

#
# Configure credentials to be used with gitlab gem
#
Gitlab.configure do |config|
  config.endpoint      = 'https://gitlab.com/api/v4'
  config.private_token = ENV['GITLAB_QA_ACCESS_TOKEN'] # gitlab-qa bot access token
end

module Trigger
  TOKEN = ENV['BUILD_TRIGGER_TOKEN']

  def self.ee?
    ENV['CI_PROJECT_NAME'] == 'gitlab-ee' || File.exist?('CHANGELOG-EE.md')
  end

  class Base
    def initialize(api_token)
      Gitlab.private_token = api_token
    end

    def invoke!(post_comment: false)
      pipeline = Gitlab.run_trigger(
        downstream_project_path,
        Trigger::TOKEN,
        ref,
        variables)

      puts "Triggered #{pipeline.web_url}"
      puts "Waiting for downstream pipeline status"

      begin
        Trigger::CommitComment.post!(downstream_project_path, pipeline) if post_comment
      rescue Gitlab::Error::Error => error
        puts "Ignoring the following error: #{error}"
      end
      Trigger::Pipeline.new(downstream_project_path, pipeline.id)
    end

    private

    # Must be overriden
    def downstream_project_path
      raise NotImplementedError
    end

    # Must be overriden
    def ref
      raise NotImplementedError
    end

    # Can be overriden
    def extra_variables
      {}
    end

    # Can be overriden
    def version_param_value(version_file)
      File.read(version_file).strip
    end

    def variables
      base_variables.merge(extra_variables).merge(version_file_variables)
    end

    def base_variables
      {
        'TRIGGERED_USER' => ENV['GITLAB_USER_NAME'],
        'TRIGGER_SOURCE' => ENV['CI_JOB_URL']
      }
    end

    # Read version files from all components
    def version_file_variables
      Dir.glob("*_VERSION").each_with_object({}) do |version_file, params|
        params[version_file] = version_param_value(version_file)
      end
    end
  end

  class Omnibus < Base
    private

    def downstream_project_path
      'gitlab-org/omnibus-gitlab'.freeze
    end

    def ref
      ENV['OMNIBUS_BRANCH'] || 'master'
    end

    def extra_variables
      {
        'GITLAB_VERSION' => ENV['CI_COMMIT_SHA'],
        'ALTERNATIVE_SOURCES' => 'true',
        'ee' => Trigger.ee? ? 'true' : 'false'
      }
    end
  end

  class CNG < Base
    private

    def downstream_project_path
      ENV['CNG_PROJECT_PATH'] || 'gitlab-org/build/CNG-mirror'
    end

    def ref
      ENV['CNG_BRANCH'] || 'master'
    end

    def extra_variables
      edition = Trigger.ee? ? 'EE' : 'CE'

      {
        "GITLAB_#{edition}_VERSION" => ENV['CI_COMMIT_REF_NAME'],
        "#{edition}_PIPELINE" => 'true'
      }
    end

    def version_param_value(_version_file)
      raw_version = super

      # if the version matches semver format, treat it as a tag and prepend `v`
      if raw_version =~ Regexp.compile(/^\d+\.\d+\.\d+(-rc\d+)?(-ee)?$/)
        "v#{raw_version}"
      else
        raw_version
      end
    end
  end

  class CommitComment
    def self.post!(downstream_project_path, downstream_pipeline)
      Gitlab.create_commit_comment(
        ENV['CI_PROJECT_PATH'],
        ENV['CI_COMMIT_SHA'],
        "The [`#{ENV['CI_JOB_NAME']}`](#{ENV['CI_JOB_URL']}) job from pipeline #{ENV['CI_PIPELINE_URL']} triggered #{downstream_pipeline.web_url} downstream.")
    end
  end

  class Pipeline
    INTERVAL = 60 # seconds
    MAX_DURATION = 3600 * 3 # 3 hours

    attr_reader :project, :id

    def initialize(project, id)
      @project = project
      @id = id
      @start = Time.now.to_i

      # gitlab-bot's token "GitLab multi-project pipeline polling"
      Gitlab.private_token = ENV['GITLAB_BOT_MULTI_PROJECT_PIPELINE_POLLING_TOKEN']
    end

    def wait!
      loop do
        raise "Pipeline timed out after waiting for #{duration} minutes!" if timeout?

        case status
        when :created, :pending, :running
          print "."
          sleep INTERVAL
        when :success
          puts "Pipeline succeeded in #{duration} minutes!"
          break
        else
          raise "Pipeline did not succeed!"
        end

        STDOUT.flush
      end
    end

    def timeout?
      Time.now.to_i > (@start + MAX_DURATION)
    end

    def duration
      (Time.now.to_i - @start) / 60
    end

    def status
      Gitlab.pipeline(project, id).status.to_sym
    rescue Gitlab::Error::Error => error
      puts "Ignoring the following error: #{error}"
      # Ignore GitLab API hiccups. If GitLab is really down, we'll hit the job
      # timeout anyway.
      :running
    end
  end
end

case ARGV[0]
when 'omnibus'
  Trigger::Omnibus.new(ENV['GITLAB_QA_ACCESS_TOKEN']).invoke!(post_comment: true).wait!
when 'cng'
  Trigger::CNG.new(ENV['GITLAB_QA_ACCESS_TOKEN']).invoke!.wait!
else
  puts "Please provide a valid option:
  omnibus - Triggers a pipeline that builds the omnibus-gitlab package
  cng - Triggers a pipeline that builds images used by the GitLab helm chart"
end