module Caricature

  class BlockCallRecording
    attr_accessor :call_number
    attr_reader :args

    def initialize(*args)
      @call_number = 1
      @args = args
    end

    # compares one block variation to another.
    # Also takes an array as an argument
    def ==(other)
      other = self.class.new(other) if other.respond_to?(:each)
      return true if other.args.first.is_a?(Symbol) and other.args.first == :any
      other.args == args
    end

  end

  # A recording of an argument variation.
  # Every time a method is called with different arguments
  # the method call recorder will create an ArgumentVariation
  # these variations are used later in the assertion
  # to verify against specific argument values
  class ArgumentRecording

    # contains the arguments of the recorded parameters
    attr_accessor :args

    # contains the block for the recorded parameters
    attr_accessor :block

    # the number of the call that has the following parameters
    attr_accessor :call_number

    # the collection of block calls variations on this argument variation 
    attr_reader :blocks

    # initializes a new instance of an argument recording.
    # configures it with 1 call count and the args as an +Array+
    def initialize(args=[], call_number=1, block=nil)
      @args = args
      @block = block
      @blocks = []
      @call_number = call_number
    end

    def add_block_variation(*args)
      bv = find_block_variation(*args)
      if bv.empty?
        blocks << BlockCallRecording.new(*args)
      else
        bv.first.call_number += 1
      end
    end

    def find_block_variation(*args)
      return @blocks if args.last.is_a?(Symbol) and args.last == :any
      @blocks.select { |bv| bv.args == args }
    end

    # compares one argument variation to another.
    # Also takes an array as an argument
    def ==(other)
      other = self.class.new(other) if other.respond_to?(:each)
      return true if other.args.first.is_a?(Symbol) and other.args.first == :any 
      other.args == args
    end   
    
    def to_s
      "<ArgumentRecording @args=#{args}, @block= #{block}, @call_number=#{call_number}"
    end
    alias_method :inspect, :to_s
  end

  # A recording that represents a method call
  # it contains argument variations that can be matched too
  class MethodCallRecording

    # gets or sets the method name
    attr_accessor :method_name

    # gets or sets the amount of times the method was called
    attr_accessor :count

    # gets or sets the arguments for this method call
    attr_accessor :args

    # gets or sets the block for this method call
    attr_accessor :block

    # Initializes a new instance of a method call recording
    # every time a method gets called in an isolated object
    # this gets stored in the method call recorder
    # It expects a +method_name+ at the very least.
    def initialize(method_name, count=0)
      @method_name = method_name
      @count = count
      @variations = []
    end

    # add args
    def args
      @variations
    end

    # indicates if it has an argument variation
    def has_argument_variations?
      @variations.size > 1
    end

    # add an argument variation
    def add_argument_variation(args, block)
      variation = find_argument_variations args, nil
      if variation.empty?
        @variations << ArgumentRecording.new(args, @variations.size+1, block) if variation == []
      else
        variation.first.call_number += 1
      end
    end

    # finds an argument variation that matches the provided +args+
    def find_argument_variations(args, block_args)
      return @variations if args.first.is_a?(Symbol) and args.last == :any
      return @variations.select { |ar| ar.args == args } if block_args.nil?
      return @variations.select { |ar| ar.args == args and ar.block } if block_args.last == :any
      return @variations.select do |ar|
        av = ar.args == args
        av and not ar.find_block_variation(*block_args).empty?
      end
    end
  end

  # The recorder that will collect method calls and provides an interface for finding those recordings
  class MethodCallRecorder

    # gets the collection of method calls. This is a hash with the method name as key
    attr_reader :method_calls


    # Initializes a new instance of a method call recorder
    # every time a method gets called in an isolated object
    # this gets stored in the method call recorder
    def initialize
      @method_calls = {:instance => {}, :class => {} }      
    end

    # records a method call or increments the count of how many times this method was called.
    def record_call(method_name, mode=:instance, expectation=nil, *args, &block)
      mn_sym = method_name.to_s.to_sym
      method_calls[mode][mn_sym] ||= MethodCallRecording.new method_name
      mc = method_calls[mode][mn_sym]
      mc.count += 1
      agc = mc.add_argument_variation args, block
      b = (expectation && expectation.block) ? (expectation.block||block) : block
      expectation.block = lambda do |*ags|
        res = nil
        res = b.call *ags if b
        agc.first.add_block_variation *ags
        res
      end if expectation
      block.nil? ? nil : (lambda { |*ags|
        res = nil
        res = block.call *ags if block
        agc.first.add_block_variation *ags
        res
      })
      end

    # returns whether the method was actually called with the specified constraints
    def was_called?(method_name, block_args, mode=:instance, *args)
      mc = method_calls[mode][method_name.to_s.to_sym]  
      if mc
         result = mc.find_argument_variations(args, block_args).first == args
         raise ArgumentError, "Arguments don't match.\nYou expected: #{args.join(", ")}.\nI did find the following variations: #{mc.args.collect {|ar| ar.args.join(', ') }.join(' and ')}" unless result
         result
      else
        return !!mc
      end
    end

#    # indexer that gives you access to the recorded method by method name
#    def [](method_name)
#      method_calls[:instance][method_name.to_s.to_sym]
#    end

    # returns the number of different methods that has been recorderd
    def size
      @method_calls.size
    end
  end


end