First prototype of AstNode class.

require "jsduck/serializer"

require "jsduck/evaluator"

require "jsduck/ext_patterns"

module JsDuck

  # Wraps around AST node returned from Esprima, providing methods for

  # investigating it.

  class AstNode

    # Initialized with a AST Hash from Esprima.

    def initialize(node)

      @node = node

    end

    def expression?

      @node["type"] == "ExpressionStatement"

    end

    def call?

      @node["type"] == "CallExpression"

    end

    def assignment?(ast)

      @node["type"] == "AssignmentExpression"

    end

    def function?(ast)

      @node["type"] == "FunctionDeclaration" || @node["type"] == "FunctionExpression" || empty_fn?

    end

    def empty_fn?(ast)

      @node["type"] == "MemberExpression" && ext_pattern?("Ext.emptyFn")

    end

    def ext_pattern?(pattern)

      @ext_patterns.matches?(pattern, to_s)

    end

    def fire_event?(ast)

      call? && child("callee").to_s == "this.fireEvent"

    end

    def var?(ast)

      @node["type"] == "VariableDeclaration"

    end

    def property?(ast)

      @node["type"] == "Property"

    end

    def ident?(ast)

      @node["type"] == "Identifier"

    end

    def string?(ast)

      @node["type"] == "Literal" && @node["value"].is_a?(String)

    end

    def object?(ast)

      @node["type"] == "ObjectExpression"

    end

    # Returns a child AST node as AstNode class.

    def child(name)

      AstNode.new(@node[name])

    end

    # Serializes the node into string

    def to_s

      Serializer.new.to_s(@node)

    end

    # Evaluates the node into basic JavaScript value.

    def to_value

      begin

        Evaluator.new.to_value(@node)

      rescue

        nil

      end

    end

    def value_type

      v = to_value

      if v.is_a?(String)

        "String"

      elsif v.is_a?(Numeric)

        "Number"

      elsif v.is_a?(TrueClass) || v.is_a?(FalseClass)

        "Boolean"

      elsif v.is_a?(Array)

        "Array"

      elsif v.is_a?(Hash)

        "Object"

      elsif v == :regexp

        "RegExp"

      else

        nil

      end

    end

  end

end