module SnowmanIO
  # Helpfull class to seed data and update DB
  class Migration
    def initialize
      @db = Mongoid::Sessions.default
      @done_versions = @db[:snowman_io_schema].find.map { |c| c["version"] }
      @migration_versions = []
    end

    def migrate
      SnowmanIO.logger.info "Migration start"

      migration "Set boundary template for all checks" do
        @db[:snowman_io_checks].find().update_all("$set" => {"template" => "boundary"})
      end

      migration "boundary => last_value_limit" do
        @db[:snowman_io_checks].find({template: "boundary"}).update_all("$set" => {"template" => "last_value_limit"})
      end

      migration "daily_datapoints => prev_day_datapoints_limit" do
        @db[:snowman_io_checks].find({template: "daily_datapoints"}).update_all("$set" => {"template" => "prev_day_datapoints_limit"})
      end

      migration "set owner to each check" do
        if user = @db[:snowman_io_users].find.first
          @db[:snowman_io_checks].find.update_all("$set" => {"user_id" => user["_id"]})
        end
      end

      migration "users timestamps" do
        @db[:snowman_io_users].find.update_all("$set" => {"created_at" => Time.now})
        @db[:snowman_io_users].find.update_all("$set" => {"updated_at" => Time.now})
      end

      migration "users daily_report" do
        @db[:snowman_io_users].find.update_all("$set" => {"daily_report" => true})
      end

      migration "users invite_token" do
        @db[:snowman_io_users].find.update_all("$set" => {"invite_token" => ""})
      end

      migration "users invite_send_count" do
        @db[:snowman_io_users].find.update_all("$set" => {"invite_send_count" => 0})
      end

      migration "users status" do
        @db[:snowman_io_users].find.update_all("$set" => {"status" => "wait_invite"})
        @db[:snowman_io_users].where(invite_token: "").update_all("$set" => {"status" => "active"})
      end

      migration "users name" do
        @db[:snowman_io_users].where(status: "active").each do |record|
          @db[:snowman_io_users].where(_id: record["_id"]).update_all("$set" => {"name" => record["email"]})
        end
      end

      migration "remove next_report_date setting" do
        @db[:snowman_io_settings].where(name: "next_report_date").remove_all
      end

      migration "user daily_report" do
        @db[:snowman_io_users].find.update_all("$unset" => {"daily_report" => 1})
      end

      migration "add sys app" do
        @db[:snowman_io_apps].find.update_all("$set" => {"system" => false})
        @db[:snowman_io_apps].insert(name: "Snowman", system: true)
      end

      SnowmanIO.logger.info "Migration done"
    end

    private

    def migration(version, &block)
      if @migration_versions.include?(version)
        raise "Duplicate migration version '#{version}'"
      end
      @migration_versions.push version

      return if @done_versions.include?(version)

      SnowmanIO.logger.info "Apply: #{version} ..."
      yield
      @db[:snowman_io_schema].insert(version: version)
      SnowmanIO.logger.info "Apply: #{version} ... OK"
    end
  end
end