namespace Xilium.CefGlue
{
    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.Runtime.InteropServices;
    using Xilium.CefGlue.Interop;

    /// <summary>
    /// Interface that should be implemented to handle V8 function calls. The methods
    /// of this class will be called on the thread associated with the V8 function.
    /// </summary>
    public abstract unsafe partial class CefV8Accessor
    {
        private int get(cef_v8accessor_t* self, cef_string_t* name, cef_v8value_t* @object, cef_v8value_t** retval, cef_string_t* exception)
        {
            CheckSelf(self);

            var m_name = cef_string_t.ToString(name);
            var m_obj = CefV8Value.FromNative(@object); // TODO dispose?
            CefV8Value m_returnValue;
            string mException;

            var handled = Get(m_name, m_obj, out m_returnValue, out mException);

            if (handled)
            {
                if (mException != null)
                {
                    cef_string_t.Copy(mException, exception);
                }
                else if (m_returnValue != null)
                {
                    *retval = m_returnValue.ToNative();
                }
            }

            return handled ? 1 : 0;
        }

        /// <summary>
        /// Handle retrieval the accessor value identified by |name|. |object| is the
        /// receiver ('this' object) of the accessor. If retrieval succeeds set
        /// |retval| to the return value. If retrieval fails set |exception| to the
        /// exception that will be thrown. Return true if accessor retrieval was
        /// handled.
        /// </summary>
        protected abstract bool Get(string name, CefV8Value obj, out CefV8Value returnValue, out string exception);


        private int set(cef_v8accessor_t* self, cef_string_t* name, cef_v8value_t* @object, cef_v8value_t* value, cef_string_t* exception)
        {
            CheckSelf(self);

            var m_name = cef_string_t.ToString(name);
            var m_obj = CefV8Value.FromNative(@object); // TODO dispose?
            var m_value = CefV8Value.FromNative(value); // TODO dispose?
            string mException;

            var handled = this.Set(m_name, m_obj, m_value, out mException);

            if (handled)
            {
                if (mException != null)
                {
                    cef_string_t.Copy(mException, exception);
                }
            }

            return handled ? 1 : 0;
        }

        /// <summary>
        /// Handle assignment of the accessor value identified by |name|. |object| is
        /// the receiver ('this' object) of the accessor. |value| is the new value
        /// being assigned to the accessor. If assignment fails set |exception| to the
        /// exception that will be thrown. Return true if accessor assignment was
        /// handled.
        /// </summary>
        protected abstract bool Set(string name, CefV8Value obj, CefV8Value value, out string exception);
    }
}