// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Text.Json;
using Microsoft.AspNetCore.DataProtection;
 
namespace Microsoft.AspNetCore.Components.Endpoints;
 
// See the details of the component serialization protocol in ServerComponentDeserializer.cs on the Components solution.
internal sealed class ServerComponentSerializer
{
    private readonly ITimeLimitedDataProtector _dataProtector;
 
    public ServerComponentSerializer(IDataProtectionProvider dataProtectionProvider) =>
        _dataProtector = dataProtectionProvider
            .CreateProtector(ServerComponentSerializationSettings.DataProtectionProviderPurpose)
            .ToTimeLimitedDataProtector();
 
    public void SerializeInvocation(
        ref ComponentMarker marker,
        ServerComponentInvocationSequence invocationId,
        Type type,
        ParameterView parameters,
        TimeSpan? dataExpiration = default)
    {
        var expiration = dataExpiration ?? ServerComponentSerializationSettings.DataExpiration;
        var (sequence, serverComponent) = CreateSerializedServerComponent(invocationId, type, parameters, marker.Key, expiration);
        marker.WriteServerData(sequence, serverComponent);
    }
 
    private (int sequence, string payload) CreateSerializedServerComponent(
        ServerComponentInvocationSequence invocationId,
        Type rootComponent,
        ParameterView parameters,
        ComponentMarkerKey? key,
        TimeSpan dataExpiration)
    {
        var sequence = invocationId.Next();
 
        var (definitions, values) = ComponentParameter.FromParameterView(parameters);
 
        var serverComponent = new ServerComponent(
            sequence,
            key,
            rootComponent.Assembly.GetName().Name ?? throw new InvalidOperationException("Cannot prerender components from assemblies with a null name"),
            rootComponent.FullName ?? throw new InvalidOperationException("Cannot prerender component types with a null name"),
            definitions,
            values,
            invocationId.Value);
 
        var serializedServerComponentBytes = JsonSerializer.SerializeToUtf8Bytes(serverComponent, ServerComponentSerializationSettings.JsonSerializationOptions);
        var protectedBytes = _dataProtector.Protect(serializedServerComponentBytes, dataExpiration);
        return (serverComponent.Sequence, Convert.ToBase64String(protectedBytes));
    }
}