// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.CodeDom;
using System.Diagnostics;
using System.Reflection;

namespace System.ComponentModel.Design.Serialization
{
    /// <summary>
    ///  A MemberCodeDomSerializer for properties.
    /// </summary>
    internal sealed class PropertyMemberCodeDomSerializer : MemberCodeDomSerializer
    {
        private static PropertyMemberCodeDomSerializer s_default;

        internal static PropertyMemberCodeDomSerializer Default
        {
            get
            {
                if (s_default is null)
                {
                    s_default = new PropertyMemberCodeDomSerializer();
                }

                return s_default;
            }
        }

        /// <summary>
        ///  This retrieves the value of this property.  If the property returns false
        ///  from ShouldSerializeValue (indicating the ambient value for this property)
        ///  This will look for an AmbientValueAttribute and use it if it can.
        /// </summary>
        private object GetPropertyValue(IDesignerSerializationManager manager, PropertyDescriptor property, object value, out bool validValue)
        {
            object propertyValue = null;
            validValue = true;
            try
            {
                if (!property.ShouldSerializeValue(value))
                {
                    // We aren't supposed to be serializing this property, but we decided to do
                    // it anyway.  Check the property for an AmbientValue attribute and if we
                    // find one, use it's value to serialize.
                    AmbientValueAttribute attr = (AmbientValueAttribute)property.Attributes[typeof(AmbientValueAttribute)];

                    if (attr != null)
                    {
                        return attr.Value;
                    }
                    else
                    {
                        DefaultValueAttribute defAttr = (DefaultValueAttribute)property.Attributes[typeof(DefaultValueAttribute)];

                        if (defAttr != null)
                        {
                            return defAttr.Value;
                        }
                        else
                        {
                            // nope, we're not valid...
                            //
                            validValue = false;
                        }
                    }
                }

                propertyValue = property.GetValue(value);
            }
            catch (Exception e)
            {
                // something failed -- we don't have a valid value
                validValue = false;

                manager.ReportError(new CodeDomSerializerException(string.Format(SR.SerializerPropertyGenFailed, property.Name, e.Message), manager));
            }

            if ((propertyValue != null) && (!propertyValue.GetType().IsValueType) && !(propertyValue is Type))
            {
                // DevDiv2 (Dev11) bug 187766 : property whose type implements ISupportInitialize is not
                // serialized with Begin/EndInit.
                Type type = TypeDescriptor.GetProvider(propertyValue).GetReflectionType(typeof(object));
                if (!type.IsDefined(typeof(ProjectTargetFrameworkAttribute), false))
                {
                    // TargetFrameworkProvider is not attached
                    TypeDescriptionProvider typeProvider = CodeDomSerializerBase.GetTargetFrameworkProvider(manager, propertyValue);
                    if (typeProvider != null)
                    {
                        TypeDescriptor.AddProvider(typeProvider, propertyValue);
                    }
                }
            }

            return propertyValue;
        }

        /// <summary>
        ///  This method actually performs the serialization.  When the member is serialized
        ///  the necessary statements will be added to the statements collection.
        /// </summary>
        public override void Serialize(IDesignerSerializationManager manager, object value, MemberDescriptor descriptor, CodeStatementCollection statements)
        {
            if (manager is null)
            {
                throw new ArgumentNullException(nameof(manager));
            }

            if (value is null)
            {
                throw new ArgumentNullException(nameof(value));
            }

            if (!(descriptor is PropertyDescriptor propertyToSerialize))
            {
                throw new ArgumentNullException(nameof(descriptor));
            }

            if (statements is null)
            {
                throw new ArgumentNullException(nameof(statements));
            }

            try
            {
                ExtenderProvidedPropertyAttribute exAttr = (ExtenderProvidedPropertyAttribute)propertyToSerialize.Attributes[typeof(ExtenderProvidedPropertyAttribute)];
                bool isExtender = (exAttr != null && exAttr.Provider != null);
                bool serializeContents = propertyToSerialize.Attributes.Contains(DesignerSerializationVisibilityAttribute.Content);

                CodeDomSerializer.Trace("Serializing property {0}", propertyToSerialize.Name);
                if (serializeContents)
                {
                    SerializeContentProperty(manager, value, propertyToSerialize, isExtender, statements);
                }
                else if (isExtender)
                {
                    SerializeExtenderProperty(manager, value, propertyToSerialize, statements);
                }
                else
                {
                    SerializeNormalProperty(manager, value, propertyToSerialize, statements);
                }
            }
            catch (Exception e)
            {
                // Since we usually go through reflection, don't
                // show what our engine does, show what caused
                // the problem.
                if (e is TargetInvocationException)
                {
                    e = e.InnerException;
                }

                manager.ReportError(new CodeDomSerializerException(string.Format(SR.SerializerPropertyGenFailed, propertyToSerialize.Name, e.Message), manager));
            }
        }

        /// <summary>
        ///  This serializes the given property on this object as a content property.
        /// </summary>
        private void SerializeContentProperty(IDesignerSerializationManager manager, object value, PropertyDescriptor property, bool isExtender, CodeStatementCollection statements)
        {
            CodeDomSerializer.Trace("Property is marked as Visibility.Content.  Recursing.");

            object propertyValue = GetPropertyValue(manager, property, value, out bool validValue);

            // For persist contents objects, we don't just serialize the properties on the object; we
            // serialize everything.
            //
            if (propertyValue is null)
            {
                CodeDomSerializer.TraceError("Property {0} is marked as Visibility.Content but it is returning null.", property.Name);

                string name = manager.GetName(value);

                if (name is null)
                {
                    name = value.GetType().FullName;
                }

                manager.ReportError(new CodeDomSerializerException(string.Format(SR.SerializerNullNestedProperty, name, property.Name), manager));
            }
            else
            {
                var serializer = (CodeDomSerializer)manager.GetSerializer(propertyValue.GetType(), typeof(CodeDomSerializer));
                if (serializer != null)
                {
                    // Create a property reference expression and push it on the context stack.
                    // This allows the serializer to gain some context as to what it should be
                    // serializing.
                    CodeExpression target = SerializeToExpression(manager, value);

                    if (target is null)
                    {
                        CodeDomSerializer.TraceWarning("Unable to convert value to expression object");
                    }
                    else
                    {
                        CodeExpression propertyRef = null;

                        if (isExtender)
                        {
                            CodeDomSerializer.Trace("Content property is an extender.");
                            ExtenderProvidedPropertyAttribute exAttr = (ExtenderProvidedPropertyAttribute)property.Attributes[typeof(ExtenderProvidedPropertyAttribute)];

                            // Extender properties are method invokes on a target "extender" object.
                            //
                            CodeExpression extender = SerializeToExpression(manager, exAttr.Provider);
                            CodeExpression extended = SerializeToExpression(manager, value);

                            CodeDomSerializer.TraceWarningIf(extender is null, "Extender object {0} could not be serialized.", manager.GetName(exAttr.Provider));
                            CodeDomSerializer.TraceWarningIf(extended is null, "Extended object {0} could not be serialized.", manager.GetName(value));
                            if (extender != null && extended != null)
                            {
                                CodeMethodReferenceExpression methodRef = new CodeMethodReferenceExpression(extender, "Get" + property.Name);
                                CodeMethodInvokeExpression methodInvoke = new CodeMethodInvokeExpression
                                {
                                    Method = methodRef
                                };
                                methodInvoke.Parameters.Add(extended);
                                propertyRef = methodInvoke;
                            }
                        }
                        else
                        {
                            propertyRef = new CodePropertyReferenceExpression(target, property.Name);
                        }

                        if (propertyRef != null)
                        {
                            ExpressionContext tree = new ExpressionContext(propertyRef, property.PropertyType, value, propertyValue);
                            manager.Context.Push(tree);

                            object result = null;

                            try
                            {
                                SerializeAbsoluteContext absolute = (SerializeAbsoluteContext)manager.Context[typeof(SerializeAbsoluteContext)];

                                if (IsSerialized(manager, propertyValue, absolute != null))
                                {
                                    result = GetExpression(manager, propertyValue);
                                }
                                else
                                {
                                    result = serializer.Serialize(manager, propertyValue);
                                }
                            }
                            finally
                            {
                                Debug.Assert(manager.Context.Current == tree, "Serializer added a context it didn't remove.");
                                manager.Context.Pop();
                            }

                            if (result is CodeStatementCollection csc)
                            {
                                foreach (CodeStatement statement in csc)
                                {
                                    statements.Add(statement);
                                }
                            }
                            else
                            {
                                if (result is CodeStatement cs)
                                {
                                    statements.Add(cs);
                                }
                            }
                        }
                    }
                }
                else
                {
                    CodeDomSerializer.TraceError("Property {0} is marked as Visibilty.Content but there is no serializer for it.", property.Name);

                    manager.ReportError(new CodeDomSerializerException(string.Format(SR.SerializerNoSerializerForComponent, property.PropertyType.FullName), manager));
                }
            }
        }

        /// <summary>
        ///  This serializes the given property on this object.
        /// </summary>
        private void SerializeExtenderProperty(IDesignerSerializationManager manager, object value, PropertyDescriptor property, CodeStatementCollection statements)
        {
            AttributeCollection attributes = property.Attributes;

            using (CodeDomSerializer.TraceScope("PropertyMemberCodeDomSerializer::" + nameof(SerializeExtenderProperty)))
            {
                ExtenderProvidedPropertyAttribute exAttr = (ExtenderProvidedPropertyAttribute)attributes[typeof(ExtenderProvidedPropertyAttribute)];

                // Extender properties are method invokes on a target "extender" object.
                //
                CodeExpression extender = SerializeToExpression(manager, exAttr.Provider);
                CodeExpression extended = SerializeToExpression(manager, value);

                CodeDomSerializer.TraceWarningIf(extender is null, "Extender object {0} could not be serialized.", manager.GetName(exAttr.Provider));
                CodeDomSerializer.TraceWarningIf(extended is null, "Extended object {0} could not be serialized.", manager.GetName(value));
                if (extender != null && extended != null)
                {
                    CodeMethodReferenceExpression methodRef = new CodeMethodReferenceExpression(extender, "Set" + property.Name);
                    object propValue = GetPropertyValue(manager, property, value, out bool validValue);
                    CodeExpression serializedPropertyValue = null;

                    // Serialize the value of this property into a code expression.  If we can't get one,
                    // then we won't serialize the property.
                    if (validValue)
                    {
                        ExpressionContext tree = null;

                        if (propValue != value)
                        {
                            // make sure the value isn't the object or we'll end up printing
                            // this property instead of the value.
                            tree = new ExpressionContext(methodRef, property.PropertyType, value);
                            manager.Context.Push(tree);
                        }

                        try
                        {
                            serializedPropertyValue = SerializeToExpression(manager, propValue);
                        }
                        finally
                        {
                            if (tree != null)
                            {
                                Debug.Assert(manager.Context.Current == tree, "Context stack corrupted.");
                                manager.Context.Pop();
                            }
                        }
                    }

                    if (serializedPropertyValue != null)
                    {
                        CodeMethodInvokeExpression methodInvoke = new CodeMethodInvokeExpression
                        {
                            Method = methodRef
                        };
                        methodInvoke.Parameters.Add(extended);
                        methodInvoke.Parameters.Add(serializedPropertyValue);
                        statements.Add(methodInvoke);
                    }
                }
            }
        }

        /// <summary>
        ///  This serializes the given property on this object.
        /// </summary>
        private void SerializeNormalProperty(IDesignerSerializationManager manager, object value, PropertyDescriptor property, CodeStatementCollection statements)
        {
            using (CodeDomSerializer.TraceScope("CodeDomSerializer::" + nameof(SerializeProperty)))
            {
                CodeExpression target = SerializeToExpression(manager, value);

                CodeDomSerializer.TraceWarningIf(target is null, "Unable to serialize target for property {0}", property.Name);
                if (target != null)
                {
                    CodeExpression propertyRef = new CodePropertyReferenceExpression(target, property.Name);

                    CodeExpression serializedPropertyValue = null;

                    // First check for a member relationship service to see if this property
                    // is related to another member.  If it is, then we will use that
                    // relationship to construct the property assign statement.  if
                    // it isn't, then we're serialize ourselves.

                    if (manager.GetService(typeof(MemberRelationshipService)) is MemberRelationshipService relationships)
                    {
                        MemberRelationship relationship = relationships[value, property];

                        if (relationship != MemberRelationship.Empty)
                        {
                            CodeExpression rhsTarget = SerializeToExpression(manager, relationship.Owner);

                            if (rhsTarget != null)
                            {
                                serializedPropertyValue = new CodePropertyReferenceExpression(rhsTarget, relationship.Member.Name);
                            }
                        }
                    }

                    if (serializedPropertyValue is null)
                    {
                        // Serialize the value of this property into a code expression.  If we can't get one,
                        // then we won't serialize the property.
                        //
                        object propValue = GetPropertyValue(manager, property, value, out bool validValue);

                        if (validValue)
                        {
                            ExpressionContext tree = null;

                            if (propValue != value)
                            {
                                // make sure the value isn't the object or we'll end up printing
                                // this property instead of the value.
                                tree = new ExpressionContext(propertyRef, property.PropertyType, value);
                                manager.Context.Push(tree);
                            }

                            try
                            {
                                serializedPropertyValue = SerializeToExpression(manager, propValue);
                            }
                            finally
                            {
                                if (tree != null)
                                {
                                    Debug.Assert(manager.Context.Current == tree, "Context stack corrupted.");
                                    manager.Context.Pop();
                                }
                            }
                        }
                    }

                    if (serializedPropertyValue != null)
                    {
                        CodeAssignStatement assign = new CodeAssignStatement(propertyRef, serializedPropertyValue);
                        statements.Add(assign);
                    }
                }
            }
        }

        /// <summary>
        ///  This method returns true if the given member descriptor should be serialized,
        ///  or false if there is no need to serialize the member.
        /// </summary>
        public override bool ShouldSerialize(IDesignerSerializationManager manager, object value, MemberDescriptor descriptor)
        {
            if (manager is null)
            {
                throw new ArgumentNullException(nameof(manager));
            }

            if (value is null)
            {
                throw new ArgumentNullException(nameof(value));
            }

            if (!(descriptor is PropertyDescriptor propertyToSerialize))
            {
                throw new ArgumentNullException(nameof(descriptor));
            }

            bool shouldSerializeProperty = propertyToSerialize.ShouldSerializeValue(value);

            if (!shouldSerializeProperty)
            {
                SerializeAbsoluteContext absolute = (SerializeAbsoluteContext)manager.Context[typeof(SerializeAbsoluteContext)];

                if (absolute != null && absolute.ShouldSerialize(propertyToSerialize))
                {
                    // For ReadOnly properties, we only want to override the value returned from
                    // ShouldSerializeValue() if the property is marked with DesignerSerializationVisibilityAttribute(Content).
                    // Consider the case of a property with just a getter - we only want to serialize those
                    // if they're marked in this way (see ReflectPropertyDescriptor::ShouldSerializeValue())
                    if (!propertyToSerialize.Attributes.Contains(DesignerSerializationVisibilityAttribute.Content))
                    {
                        shouldSerializeProperty = false; // it's already false at this point, but this is clearer.
                    }
                    else
                    {
                        shouldSerializeProperty = true; // Always serialize difference properties
                    }
                }
            }

            if (shouldSerializeProperty)
            {
                bool isDesignTime = propertyToSerialize.Attributes.Contains(DesignOnlyAttribute.Yes);
                if (!isDesignTime)
                {
                    return true;
                }
            }

            // If we don't have to serialize, we need to make sure there isn't a member
            // relationship with this property.  If there is, we still need to serialize.

            if (manager.GetService(typeof(MemberRelationshipService)) is MemberRelationshipService relationships)
            {
                MemberRelationship relationship = relationships[value, descriptor];

                if (relationship != MemberRelationship.Empty)
                {
                    return true;
                }
            }

            return false;
        }
    }
}
