require "rspec/expectations"
require "aruba/runtime"
require "aruba/errors"
require "aruba/setup"

# Aruba
module Aruba
  # Api
  module Api
    # Core methods of aruba
    #
    # Those methods do not depend on any other API method of aruba
    module Core
      include ::RSpec::Matchers

      # Aruba Runtime
      def aruba
        # TODO: Check this variable being accessed inconsistently. Should only
        # be using the memo!
        # Renaming this to `aruba` causes 100's of rspec failures. Needs a
        # deeper dive, approach with caution!
        @_aruba_runtime ||= Runtime.new
      end

      # Clean the working directory of aruba
      #
      # This will only clean up aruba's working directory to remove all
      # artifacts of your tests. This does NOT clean up the current working
      # directory.
      def setup_aruba(clobber = true)
        Aruba::Setup.new(aruba).call(clobber)

        self
      end

      # Execute block in Aruba's current directory
      #
      # @yield
      #   The block which should be run in current directory
      def in_current_directory(&block)
        create_directory "." unless directory?(".")
        cd(".", &block)
      end

      # Switch to directory
      #
      # @param [String] dir
      #   The directory
      #
      # @example Normal directory
      #   cd 'dir'
      #
      # @example Move up
      #   cd '..'
      #
      # @example Run code in directory
      #   result = cd('some-dir') { Dir.getwd }
      #
      def cd(dir, &block)
        if block
          begin
            unless Aruba.platform.directory?(expand_path(dir))
              raise ArgumentError,
                    "#{expand_path(dir)} is not a directory or does not exist."
            end

            old_directory = expand_path(".")
            aruba.current_directory << dir
            new_directory = expand_path(".")

            aruba.event_bus.notify Events::ChangedWorkingDirectory.new(old: old_directory,
                                                                       new: new_directory)

            old_dir = Aruba.platform.getwd

            real_new_directory = File.expand_path(aruba.current_directory,
                                                  aruba.root_directory)
            Aruba.platform.chdir real_new_directory

            result = with_environment(
              "OLDPWD" => old_dir,
              "PWD" => real_new_directory,
              &block
            )
          ensure
            aruba.current_directory.pop
            Aruba.platform.chdir old_dir
          end

          return result
        end

        unless Aruba.platform.directory?(expand_path(dir))
          raise ArgumentError, "#{expand_path(dir)} is not a directory or does not exist."
        end

        old_directory = expand_path(".")
        aruba.current_directory << dir
        new_directory = expand_path(".")

        aruba.event_bus.notify Events::ChangedWorkingDirectory.new(old: old_directory,
                                                                   new: new_directory)

        self
      end

      # Expand file name
      #
      # @param [String] file_name
      #   Name of file
      #
      # @param [String] dir_string
      #   Name of directory to use as starting point, otherwise current directory is used.
      #
      # @return [String]
      #   The full path
      #
      # @example Single file name
      #
      #   expand_path('file')
      #   # => <path>/tmp/aruba/file
      #
      # @example Single Dot
      #
      #   expand_path('.')
      #   # => <path>/tmp/aruba
      #
      # @example using home directory
      #
      #   expand_path('~/file')
      #   # => <path>/home/<name>/file
      #
      # @example using fixtures directory
      #
      #   expand_path('%/file')
      #   # => <path>/test/fixtures/file
      #
      # @example Absolute directory (requires aruba.config.allow_absolute_paths
      # to be set)
      #
      #   expand_path('/foo/bar')
      #   # => /foo/bar
      #
      def expand_path(file_name, dir_string = nil)
        unless file_name.is_a?(String) && !file_name.empty?
          message = "Filename #{file_name} needs to be a string." \
                    " It cannot be nil or empty either." \
                    " Please use `expand_path('.')` if you want" \
                    " the current directory to be expanded."

          raise ArgumentError, message
        end

        unless Aruba.platform.directory? File.join(aruba.config.root_directory,
                                                   aruba.config.working_directory)
          raise "Aruba's working directory does not exist." \
                " Maybe you forgot to run `setup_aruba` before using its API."
        end

        prefix = file_name[0]

        if prefix == aruba.config.fixtures_path_prefix
          rest = file_name[2..]
          path = File.join(*[aruba.fixtures_directory, rest].compact)
          unless Aruba.platform.exist? path
            aruba_fixture_candidates = aruba.config.fixtures_directories
                                            .map { |p| format('"%s"', p) }.join(", ")

            raise ArgumentError,
                  "Fixture \"#{rest}\" does not exist" \
                  " in fixtures directory \"#{aruba.fixtures_directory}\"." \
                  " This was the one we found first on your system from all possible" \
                  " candidates: #{aruba_fixture_candidates}."
          end

          path
        elsif prefix == "~"
          path = with_environment do
            File.expand_path(file_name)
          end

          raise ArgumentError, 'Expanding "~/" to "/" is not allowed' if path == "/"

          unless Aruba.platform.absolute_path? path
            raise ArgumentError,
                  "Expanding \"~\" to a relative path \"#{path}\" is not allowed"
          end

          path.to_s
        elsif absolute?(file_name)
          unless aruba.config.allow_absolute_paths
            caller_location = caller_locations(1, 1).first
            caller_file_line = "#{caller_location.path}:#{caller_location.lineno}"
            message =
              "Aruba's `expand_path` method was called with an absolute path" \
              " at #{caller_file_line}, which is not recommended." \
              " The path passed was '#{file_name}'." \
              " Change the call to pass a relative path or set" \
              " `config.allow_absolute_paths = true` to silence this warning"
            raise UserError, message
          end
          file_name
        else
          with_environment do
            directory = File.expand_path(aruba.current_directory, aruba.root_directory)
            directory = File.expand_path(dir_string, directory) if dir_string
            File.expand_path(file_name, directory)
          end
        end
      end

      # Run block with environment
      #
      # @param [Hash] env (optional)
      #   The variables to be used for block.
      #
      # @yield
      #   The block of code which should be run with the changed environment variables
      def with_environment(env = {}, &block)
        aruba.environment.nest do |nested_env|
          nested_env.update(env)
          Aruba.platform.with_environment nested_env.to_h, &block
        end
      end
    end
  end
end