///////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  File:   HttpRequestContract.sg
//  Note:   Contract definition for HTTP requests processed by web apps
//

using System;
using Microsoft.Singularity.Channels;

namespace Microsoft.Singularity.WebApps.Contracts
{
    public contract HttpRequestContract
    {
        // Information requests
        in message GetUriPath(); // e.g., "/foo/bar.html"
        in message GetQueryString();
        in message GetVerb(); // e.g., "GET"
        in message GetHeader(char[]! in ExHeap name);
        in message GetBody();
        in message GetRemoteAddress();

        // Response-data pushes
        in message SendStatus(int code, char[]! in ExHeap description);
        in message SendHeader(char[]! in ExHeap name, char[]! in ExHeap value); // Can call repeatedly
        in message SendBodyData(byte[]! in ExHeap data); // Can call repeatedly

        in message Done();

        // Responses
        out message UriPath(char[]! in ExHeap vPath);
        out message QueryString(char[] in ExHeap queryString);
        out message Verb(char[]! in ExHeap verb);
        out message HeaderValue(char[] in ExHeap val);
        out message BodyData(byte[] in ExHeap body);
        out message RemoteAddress(char[]! in ExHeap address);
        out message OK();

        state Start : one
        {
            GetUriPath? -> UriPath! -> Start;
            GetQueryString? -> QueryString! -> Start;
            GetVerb? -> Verb! -> Start;
            GetHeader? -> HeaderValue! -> Start;
            GetBody? -> BodyData! -> Start;
            GetRemoteAddress? -> RemoteAddress! -> Start;

            SendStatus? -> OK! -> Start;
            SendHeader? -> OK! -> Start;
            SendBodyData? -> OK! -> Start;

            Done? -> Completed;
        }

        state Completed : {} // Nothing is permissible here
    }
}