# frozen_string_literal: true

module Gitlab
  module Ci
    class YamlProcessor
      ValidationError = Class.new(StandardError)

      include Gitlab::Config::Entry::LegacyValidationHelpers

      attr_reader :stages, :jobs

      def initialize(config, opts = {})
        @ci_config = Gitlab::Ci::Config.new(config, **opts)
        @config = @ci_config.to_hash

        unless @ci_config.valid?
          raise ValidationError, @ci_config.errors.first
        end

        initial_parsing
      rescue Gitlab::Ci::Config::ConfigError => e
        raise ValidationError, e.message
      end

      def builds
        @jobs.map do |name, _|
          build_attributes(name)
        end
      end

      def build_attributes(name)
        job = @jobs.fetch(name.to_sym, {})

        { stage_idx: @stages.index(job[:stage]),
          stage: job[:stage],
          tag_list: job[:tags],
          name: job[:name].to_s,
          allow_failure: job[:ignore],
          when: job[:when] || 'on_success',
          environment: job[:environment_name],
          coverage_regex: job[:coverage],
          yaml_variables: transform_to_yaml_variables(job_variables(name)),
          needs_attributes: job.dig(:needs, :job),
          interruptible: job[:interruptible],
          rules: job[:rules],
          cache: job[:cache],
          options: {
            image: job[:image],
            services: job[:services],
            artifacts: job[:artifacts],
            dependencies: job[:dependencies],
            job_timeout: job[:timeout],
            before_script: job[:before_script],
            script: job[:script],
            after_script: job[:after_script],
            environment: job[:environment],
            retry: job[:retry],
            parallel: job[:parallel],
            instance: job[:instance],
            start_in: job[:start_in],
            trigger: job[:trigger],
            bridge_needs: job.dig(:needs, :bridge)&.first
          }.compact }.compact
      end

      def stage_builds_attributes(stage)
        @jobs.values
          .select { |job| job[:stage] == stage }
          .map { |job| build_attributes(job[:name]) }
      end

      def stages_attributes
        @stages.uniq.map do |stage|
          seeds = stage_builds_attributes(stage).map do |attributes|
            job = @jobs.fetch(attributes[:name].to_sym)

            attributes
              .merge(only: job.fetch(:only, {}))
              .merge(except: job.fetch(:except, {}))
          end

          { name: stage, index: @stages.index(stage), builds: seeds }
        end
      end

      def workflow_attributes
        {
          rules: @config.dig(:workflow, :rules),
          yaml_variables: transform_to_yaml_variables(@variables)
        }
      end

      def self.validation_message(content, opts = {})
        return 'Please provide content of .gitlab-ci.yml' if content.blank?

        begin
          Gitlab::Ci::YamlProcessor.new(content, opts)
          nil
        rescue ValidationError => e
          e.message
        end
      end

      private

      def initial_parsing
        ##
        # Global config
        #
        @variables = @ci_config.variables
        @stages = @ci_config.stages

        ##
        # Jobs
        #
        @jobs = Ci::Config::Normalizer.new(@ci_config.jobs).normalize_jobs

        @jobs.each do |name, job|
          # logical validation for job

          validate_job_stage!(name, job)
          validate_job_dependencies!(name, job)
          validate_job_needs!(name, job)
          validate_job_environment!(name, job)
        end
      end

      def job_variables(name)
        job_variables = @jobs.dig(name.to_sym, :variables)

        @variables.to_h
          .merge(job_variables.to_h)
      end

      def transform_to_yaml_variables(variables)
        variables.to_h.map do |key, value|
          { key: key.to_s, value: value, public: true }
        end
      end

      def validate_job_stage!(name, job)
        return unless job[:stage]

        unless job[:stage].is_a?(String) && job[:stage].in?(@stages)
          raise ValidationError, "#{name} job: stage parameter should be #{@stages.join(", ")}"
        end
      end

      def validate_job_dependencies!(name, job)
        return unless job[:dependencies]

        stage_index = @stages.index(job[:stage])

        job[:dependencies].each do |dependency|
          raise ValidationError, "#{name} job: undefined dependency: #{dependency}" unless @jobs[dependency.to_sym]

          dependency_stage_index = @stages.index(@jobs[dependency.to_sym][:stage])

          unless dependency_stage_index.present? && dependency_stage_index < stage_index
            raise ValidationError, "#{name} job: dependency #{dependency} is not defined in prior stages"
          end
        end
      end

      def validate_job_needs!(name, job)
        return unless job.dig(:needs, :job)

        stage_index = @stages.index(job[:stage])

        job.dig(:needs, :job).each do |need|
          need_job_name = need[:name]

          raise ValidationError, "#{name} job: undefined need: #{need_job_name}" unless @jobs[need_job_name.to_sym]

          needs_stage_index = @stages.index(@jobs[need_job_name.to_sym][:stage])

          unless needs_stage_index.present? && needs_stage_index < stage_index
            raise ValidationError, "#{name} job: need #{need_job_name} is not defined in prior stages"
          end
        end
      end

      def validate_job_environment!(name, job)
        return unless job[:environment]
        return unless job[:environment].is_a?(Hash)

        environment = job[:environment]
        validate_on_stop_job!(name, environment, environment[:on_stop])
      end

      def validate_on_stop_job!(name, environment, on_stop)
        return unless on_stop

        on_stop_job = @jobs[on_stop.to_sym]
        unless on_stop_job
          raise ValidationError, "#{name} job: on_stop job #{on_stop} is not defined"
        end

        unless on_stop_job[:environment]
          raise ValidationError, "#{name} job: on_stop job #{on_stop} does not have environment defined"
        end

        unless on_stop_job[:environment][:name] == environment[:name]
          raise ValidationError, "#{name} job: on_stop job #{on_stop} have different environment name"
        end

        unless on_stop_job[:environment][:action] == 'stop'
          raise ValidationError, "#{name} job: on_stop job #{on_stop} needs to have action stop defined"
        end
      end
    end
  end
end