require 'concurrent'
require 'hanami/application'
require 'hanami/utils/class'
require 'hanami/utils/string'

module Hanami
  # @api private
  class Configuration
    require "hanami/configuration/app"
    require "hanami/configuration/middleware"

    # @api private
    def initialize(&blk)
      @settings = Concurrent::Map.new
      instance_eval(&blk)
    end

    # Mount a Hanami::Application or a Rack app
    #
    # @param app [#call] an application compatible with Rack SPEC
    # @param options [Hash] a set of options
    # @option :at [String] options the mount point
    #
    # @since 0.9.0
    #
    # @example
    #   # config/environment.rb
    #   # ...
    #   Hanami.configure do
    #     mount Web::Application, at: '/'
    #
    #     # ...
    #   end
    def mount(app, options)
      mounted[app] = App.new(app, options.fetch(:at))
    end

    # Configure database
    #
    # @param blk [Proc] the database configuration
    #
    # @see Hanami::Model.configure
    #
    # @example
    #   # config/environment.rb
    #   # ...
    #   Hanami.configure do
    #     model do
    #       adapter :sql, ENV['DATABASE_URL']
    #
    #       migrations 'db/migrations'
    #       schema     'db/schema.sql'
    #     end
    #
    #     # ...
    #   end
    def model(&blk)
      if block_given?
        settings.put_if_absent(:model, blk)
      else
        settings.fetch(:model)
      end
    end

    # Configure mailer
    #
    # @param blk [Proc] the mailer configuration
    #
    # @see Hanami::Mailer.configure
    #
    # @example
    #   # config/environment.rb
    #   # ...
    #   Hanami.configure do
    #     mailer do
    #       root 'lib/bookshelf/mailers'
    #
    #       # See https://guides.hanamirb.org/mailers/delivery
    #       delivery :test
    #     end
    #
    #     # ...
    #   end
    def mailer(&blk)
      mailer_settings.push(blk) if block_given?
    end

    # @since next
    # @api private
    def mailer_settings
      settings.fetch_or_store(:mailers, [])
    end

    # @since 0.9.0
    # @api private
    def mounted
      settings.fetch_or_store(:mounted, {})
    end

    # @since 1.2.0
    #
    # @example
    #   # config/environment.rb
    #   # ...
    #   Hanami.configure do
    #     middleware.use MyRackMiddleware
    #   end
    def middleware
      settings.fetch_or_store(:middleware, Configuration::Middleware.new)
    end

    # Setup Early Hints feature
    #
    # @since 1.2.0
    #
    # @example Enable for all the environments
    #   # config/environment.rb
    #   Hanami.configure do
    #     early_hints true
    #   end
    #
    # @example Enable only for production
    #   # config/environment.rb
    #   Hanami.configure do
    #     environment :production do
    #       early_hints true
    #     end
    #   end
    def early_hints(value = nil)
      if value.nil?
        settings.fetch(:early_hints, false)
      else
        settings[:early_hints] = value
      end
    end

    # @since 0.9.0
    # @api private
    def apps
      mounted.each_pair do |klass, app|
        yield(app) if klass <= Hanami::Application
      end
    end

    # Configure logger
    #
    # @since 1.0.0
    #
    # @param options [Array] a set of options
    #
    # @see Hanami.logger
    # @see Hanami::Logger
    #
    # @see https://guides.hanamirb.org/projects/logging
    #
    # @example Basic Usage
    #   # config/environment.rb
    #   # ...
    #   Hanami.configure do
    #     # ...
    #     environment :development do
    #       logger level: :debug
    #     end
    #   end
    #
    # @example Daily Rotation
    #   # config/environment.rb
    #   # ...
    #   Hanami.configure do
    #     # ...
    #     environment :development do
    #       logger 'daily', level: :debug
    #     end
    #   end
    def logger(*options)
      if options.empty?
        settings.fetch(:logger, nil)
      else
        settings[:logger] = options
      end
    end

    # Configure settings for the current environment
    # @since 1.0.0
    #
    # @param name [Symbol] the name of the Hanami environment
    #
    # @see Hanami.env
    #
    # @example Configure Logging for Different Environments
    #   # config/environment.rb
    #   # ...
    #   Hanami.configure do
    #     # ...
    #     environment :development do
    #       logger level: :debug
    #     end
    #
    #     environment :production do
    #       logger level: :info, formatter: :json
    #     end
    #   end
    def environment(name)
      yield if ENV['HANAMI_ENV'] == name.to_s
    end

    private

    # @api private
    attr_reader :settings
  end
end