require "colorize"
require "option_parser"

module Spec
  # :nodoc:
  # The default spec runner.
  class_getter cli = CLI.new

  # :nodoc:
  enum InfoKind
    Comment
    Focus
    Order

    def color : Colorize::Color
      Colorize::ColorANSI::Cyan
    end
  end

  # :nodoc:
  class SpecError < Exception
    getter file : String
    getter line : Int32

    def initialize(message, @file, @line)
      super(message)
    end
  end

  # :nodoc:
  class AssertionFailed < SpecError
  end

  # :nodoc:
  class ExamplePending < SpecError
  end

  # :nodoc:
  class NestingSpecError < SpecError
  end

  # :nodoc:
  def self.to_human(span : Time::Span)
    total_milliseconds = span.total_milliseconds
    if total_milliseconds < 1
      return "#{(span.total_milliseconds * 1000).round.to_i} microseconds"
    end

    total_seconds = span.total_seconds
    if total_seconds < 1
      return "#{span.total_milliseconds.round(2)} milliseconds"
    end

    if total_seconds < 60
      return "#{total_seconds.round(2)} seconds"
    end

    minutes = span.minutes
    seconds = span.seconds
    "#{minutes}:#{seconds < 10 ? "0" : ""}#{seconds} minutes"
  end

  record SplitFilter, remainder : Int32, quotient : Int32

  # Instructs the spec runner to execute the given block
  # before each spec in the spec suite.
  #
  # If multiple blocks are registered they run in the order
  # that they are given.
  #
  # For example:
  #
  # ```
  # Spec.before_each { puts 1 }
  # Spec.before_each { puts 2 }
  # ```
  #
  # will print, just before each spec, 1 and then 2.
  def self.before_each(&block)
    @@cli.root_context.before_each(&block)
  end

  # Instructs the spec runner to execute the given block
  # after each spec in the spec suite.
  #
  # If multiple blocks are registered they run in the reversed
  # order that they are given.
  #
  # For example:
  #
  # ```
  # Spec.after_each { puts 1 }
  # Spec.after_each { puts 2 }
  # ```
  #
  # will print, just after each spec, 2 and then 1.
  def self.after_each(&block)
    @@cli.root_context.after_each(&block)
  end

  # Instructs the spec runner to execute the given block
  # before the entire spec suite.
  #
  # If multiple blocks are registered they run in the order
  # that they are given.
  #
  # For example:
  #
  # ```
  # Spec.before_suite { puts 1 }
  # Spec.before_suite { puts 2 }
  # ```
  #
  # will print, just before the spec suite starts, 1 and then 2.
  def self.before_suite(&block)
    @@cli.root_context.before_all(&block)
  end

  # Instructs the spec runner to execute the given block
  # after the entire spec suite.
  #
  # If multiple blocks are registered they run in the reversed
  # order that they are given.
  #
  # For example:
  #
  # ```
  # Spec.after_suite { puts 1 }
  # Spec.after_suite { puts 2 }
  # ```
  #
  # will print, just after the spec suite ends, 2 and then 1.
  def self.after_suite(&block)
    @@cli.root_context.after_all(&block)
  end

  # Instructs the spec runner to execute the given block when each spec in the
  # spec suite runs.
  #
  # The block must call `run` on the given `Example::Procsy` object.
  #
  # If multiple blocks are registered they run in the reversed
  # order that they are given.
  #
  # ```
  # require "spec"
  #
  # Spec.around_each do |example|
  #   puts "runs before each sample"
  #   example.run
  #   puts "runs after each sample"
  # end
  #
  # it { }
  # it { }
  # ```
  def self.around_each(&block : Example::Procsy ->)
    @@cli.root_context.around_each(&block)
  end

  # :nodoc:
  class CLI
    @aborted = false

    def abort!
      @aborted = true
      finish_run
    end

    @split_filter : SplitFilter? = nil

    def add_split_filter(filter)
      if filter
        r, _, m = filter.partition('%')
        @split_filter = SplitFilter.new(remainder: r.to_i, quotient: m.to_i)
      else
        @split_filter = nil
      end
    end

    @start_time : Time::Instant? = nil

    def run
      @start_time = Time.instant

      at_exit do |status|
        # Do not run specs if the process is exiting on an error
        next unless status == 0

        begin
          if list_tags?
            execute_list_tags
          else
            execute_examples
          end
        rescue ex
          @stderr.print "Unhandled exception: "
          ex.inspect_with_backtrace(@stderr)
          @stderr.flush
          @aborted = true
        ensure
          finish_run unless list_tags?
        end
      end
    end

    def colorize(str, status : Status)
      str.colorize(status.color).toggle(@color)
    end

    def colorize(str, kind : InfoKind)
      str.colorize(kind.color).toggle(@color)
    end

    def execute_examples
      log_setup
      maybe_randomize
      run_filters
      root_context.run
    end

    def execute_list_tags
      run_filters
      tag_counts = collect_tags(root_context)
      print_list_tags(tag_counts)
    end

    private def collect_tags(context) : Hash(String, Int32)
      tag_counts = Hash(String, Int32).new(0)
      collect_tags(tag_counts, context, Set(String).new)
      tag_counts
    end

    private def collect_tags(tag_counts, context : Context, tags)
      if context.responds_to?(:tags) && (context_tags = context.tags)
        tags += context_tags
      end
      context.children.each do |child|
        collect_tags(tag_counts, child, tags)
      end
    end

    private def collect_tags(tag_counts, example : Example, tags)
      if example_tags = example.tags
        tags += example_tags
      end
      if tags.empty?
        tag_counts.update("untagged") { |count| count + 1 }
      else
        tags.tally(tag_counts)
      end
    end

    private def print_list_tags(tag_counts : Hash(String, Int32)) : Nil
      return if tag_counts.empty?
      longest_name_size = tag_counts.keys.max_of(&.size)
      tag_counts.to_a.sort_by! { |k, v| {-v, k} }.each do |tag_name, count|
        @stdout.puts "#{tag_name.rjust(longest_name_size)}: #{count}"
      end
    end

    # :nodoc:
    #
    # Workaround for #8914
    private macro defined?(t)
      {% if t.resolve? %}
        {{ yield }}
      {% end %}
    end

    # :nodoc:
    def log_setup
    end

    # :nodoc:
    macro finished
      # :nodoc:
      #
      # Initialized the log module for the specs.
      # If the "log" module is required it is configured to emit no entries by default.
      def log_setup
        defined?(::Log) do
          if ::Log.responds_to?(:setup)
            ::Log.setup_from_env(default_level: :none)
          end
        end
      end
    end

    def finish_run
      elapsed_time = @start_time.not_nil!.elapsed
      root_context.finish(elapsed_time, @aborted)
      exit 1 if !root_context.succeeded || @aborted || (focus? && ENV["SPEC_FOCUS_NO_FAIL"]? != "1")
    end

    # :nodoc:
    def maybe_randomize
      if randomizer = @randomizer
        root_context.randomize(randomizer)
      end
    end

    # :nodoc:
    def run_filters
      root_context.run_filters(@pattern, @line, @locations, @split_filter, @focus, @tags, @anti_tags)
    end
  end

  @[Deprecated("This is an internal API.")]
  def self.finish_run
    @@cli.finish_run
  end

  @[Deprecated("This is an internal API.")]
  def self.add_split_filter(filter)
    @@cli.add_split_filter(filter)
  end
end

require "./*"
