require "assert/cli"

module Assert

  class AssertRunner
    USER_SETTINGS_FILE  = ".assert/init.rb"
    LOCAL_SETTINGS_FILE = ".assert.rb"

    attr_reader :config

    def initialize(config, test_paths, test_options)
      @config = config
      Assert::CLI.bench("Applying settings") do
        apply_user_settings
        apply_local_settings
        apply_env_settings
        apply_option_settings(test_options)
      end

      paths = test_paths.empty? ? [*self.config.test_dir] : test_paths
      files = lookup_test_files(paths)
      init(files, path_of(self.config.test_dir, files.first))
    end

    def init(test_files, test_dir)
      # load any test helper file
      if test_dir && (h = File.join(test_dir, self.config.test_helper)) && File.exists?(h)
        Assert::CLI.bench("Requiring test helper"){ require h }
      end

      if self.config.list
        $stdout.puts test_files
        halt
      end

      # load the test files
      runner, suite, view = self.config.runner, self.config.suite, self.config.view
      runner.before_load(test_files)
      suite.before_load(test_files)
      view.before_load(test_files)
      Assert::CLI.bench("Requiring #{test_files.size} test files") do
        test_files.each{ |p| require p }
      end
      if self.config.debug
        puts Assert::CLI.debug_msg("Test files:")
        test_files.each{ |f| puts Assert::CLI.debug_msg("  #{f}") }
      end
      runner.after_load
      suite.after_load
      view.after_load
    end

    def run
      self.config.runner.run
    end

    private

    def halt
      throw(:halt)
    end

    def apply_user_settings
      safe_require("#{ENV["HOME"]}/#{USER_SETTINGS_FILE}") if ENV["HOME"]
    end

    def apply_local_settings
      safe_require(ENV["ASSERT_LOCALFILE"] || path_of(LOCAL_SETTINGS_FILE, Dir.pwd))
    end

    def apply_env_settings
      self.config.runner_seed ENV["ASSERT_RUNNER_SEED"].to_i if ENV["ASSERT_RUNNER_SEED"]
    end

    def apply_option_settings(options)
      self.config.apply(options)
    end

    def lookup_test_files(test_paths)
      file_paths = if self.config.changed_only
        changed_test_files(test_paths)
      elsif self.config.single_test?
        globbed_test_files([self.config.single_test_file_path])
      else
        globbed_test_files(test_paths)
      end

      file_paths.select{ |p| is_test_file?(p) }.sort
    end

    def changed_test_files(test_paths)
      globbed_test_files(self.config.changed_proc.call(self.config, test_paths))
    end

    def globbed_test_files(test_paths)
      test_paths.inject(Set.new) do |paths, path|
        p = File.expand_path(path, Dir.pwd)
        paths += Dir.glob("#{p}*") + Dir.glob("#{p}*/**/*")
      end
    end

    def is_test_file?(path)
      self.config.test_file_suffixes.inject(false) do |result, suffix|
        result || path =~ /#{suffix}$/
      end
    end

    def safe_require(settings_file)
      require settings_file if File.exists?(settings_file)
    end

    def path_of(segment, a_path)
      # this method inspects a test path and finds the test dir path.
      full_path = File.expand_path(a_path || ".", Dir.pwd)
      seg_pos = full_path.index(segment_regex(segment))
      File.join(seg_pos && (seg_pos > 0) ? full_path[0..(seg_pos-1)] : full_path, segment)
    end

    def segment_regex(seg); /^#{seg}$|^#{seg}\/|\/#{seg}\/|\/#{seg}$/; end

  end

end