//  This file is part of YamlDotNet - A .NET library for YAML.
//  Copyright (c) Antoine Aubry and contributors
    
//  Permission is hereby granted, free of charge, to any person obtaining a copy of
//  this software and associated documentation files (the "Software"), to deal in
//  the Software without restriction, including without limitation the rights to
//  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
//  of the Software, and to permit persons to whom the Software is furnished to do
//  so, subject to the following conditions:
    
//  The above copyright notice and this permission notice shall be included in all
//  copies or substantial portions of the Software.
    
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//  SOFTWARE.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using YamlDotNet.Core;

namespace YamlDotNet.Serialization.TypeInspectors
{
    /// <summary>
    /// Returns the properties of a type that are readable.
    /// </summary>
    public sealed class ReadablePropertiesTypeInspector : TypeInspectorSkeleton
    {
        private readonly ITypeResolver _typeResolver;

        public ReadablePropertiesTypeInspector(ITypeResolver typeResolver)
        {
            if (typeResolver == null)
            {
                throw new ArgumentNullException("typeResolver");
            }

            _typeResolver = typeResolver;
        }

        private static bool IsValidProperty(PropertyInfo property)
        {
            return property.CanRead
                && property.GetGetMethod().GetParameters().Length == 0;
        }

        public override IEnumerable<IPropertyDescriptor> GetProperties(Type type, object container)
        {
            return type
                .GetPublicProperties()
                .Where(IsValidProperty)
                .Select(p => (IPropertyDescriptor)new ReflectionPropertyDescriptor(p, _typeResolver));
        }

        private sealed class ReflectionPropertyDescriptor : IPropertyDescriptor
        {
            private readonly PropertyInfo _propertyInfo;
            private readonly ITypeResolver _typeResolver;

            public ReflectionPropertyDescriptor(PropertyInfo propertyInfo, ITypeResolver typeResolver)
            {
                _propertyInfo = propertyInfo;
                _typeResolver = typeResolver;
                ScalarStyle = ScalarStyle.Any;
            }

            public string Name { get { return _propertyInfo.Name; } }
            public Type Type { get { return _propertyInfo.PropertyType; } }
            public Type TypeOverride { get; set; }
            public int Order { get; set; }
            public bool CanWrite { get { return _propertyInfo.CanWrite; } }
            public ScalarStyle ScalarStyle { get; set; }

            public void Write(object target, object value)
            {
                _propertyInfo.SetValue(target, value, null);
            }

            public T GetCustomAttribute<T>() where T : Attribute
            {
                var attributes = _propertyInfo.GetCustomAttributes(typeof(T), true);
                return (T)attributes.FirstOrDefault();
            }

            public IObjectDescriptor Read(object target)
            {
                var propertyValue = _propertyInfo.ReadValue(target);
                var actualType = TypeOverride ?? _typeResolver.Resolve(Type, propertyValue);
                return new ObjectDescriptor(propertyValue, actualType, Type, ScalarStyle);
            }
        }
    }
}
