sourceafBedSheet::HttpResponse.fan

using afIoc::Inject
using web::Cookie

** (Service) - An injectable 'const' version of [WebRes]`web::WebRes`.
** 
** This will always refers to the current web response.
const mixin HttpResponse {

    ** Get / set the HTTP status code for this response.
    ** Setter throws Err if response is already committed.
    ** 
    ** @see `web::WebRes.statusCode`
    abstract Int statusCode
    
    ** Map of HTTP response headers.  You must set all headers before you access out() for the 
    ** first time, which commits the response.  
    ** 
    ** @see 
    **  - `web::WebRes.headers`
    **  - `http://en.wikipedia.org/wiki/List_of_HTTP_header_fields#Responses`
    abstract HttpResponseHeaders headers()
    
    ** Return true if this response has been committed.  A committed response has written its 
    ** response headers, and can no longer modify its status code or headers.  A response is 
    ** committed the first time that `out` is called.
    ** 
    ** @see `web::WebRes.isCommitted`
    abstract Bool isCommitted()
    
    ** Returns the 'OutStream' for this response. 
    ** Should current settings allow, the 'OutStream' is automatically gzipped.
    ** 
    ** @see `web::WebRes.out`
    abstract OutStream out()
    
    ** Set to 'true' to disable gzip compression for this response.
    abstract Bool disableGzip
    
    ** Set to 'true' to disable buffering for this response.
    abstract Bool disableBuffering

    ** Directs the client to display a 'save as' dialog by setting the 'Content-Disposition' HTTP 
    ** response header. 
    ** 
    ** The 'Content-Type' HTTP response header is set to the MimeType derived from the fileName's 
    ** extension.
    ** 
    ** @see `HttpResponseHeaders.contentDisposition`
    abstract Void saveAsAttachment(Str fileName)
}

** Wraps a given `HttpResponse`, delegating all its methods. 
** You may find it handy to use when contributing to the 'HttpResponse' delegate chain.
@NoDoc
const class HttpResponseWrapper : HttpResponse {
    const    HttpResponse res
    new      make(HttpResponse res)              { this.res = res   } 
    override HttpResponseHeaders headers()       { res.headers      }
    override Bool isCommitted()                  { res.isCommitted  }
    override OutStream out()                     { res.out          }
    override Void saveAsAttachment(Str fileName) { res.saveAsAttachment(fileName) }
    override Bool disableGzip {
        get { res.disableGzip }
        set { res.disableGzip = it}
    }
    override Bool disableBuffering {
        get { res.disableBuffering }
        set { res.disableBuffering = it}
    }
    override Int statusCode {
        get { res.statusCode }
        set { res.statusCode = it }
    }
}


internal const class HttpResponseImpl : HttpResponse {
    
    @Inject  const |->RequestState|     reqState
    override const HttpResponseHeaders  headers

    new make(|This|in) { 
        in(this)
        this.headers = HttpResponseHeaders(|->Str:Str| {
            // cache the headers so we can access / read it after the response has been committed - handy for logging
            // note this only works while 'webRes.headers' returns the actual map used, and not a copy
            reqState().responseHeaders
        }, |->| {
            if (reqState().webRes.isCommitted)
                throw Err("HTTP Response has already been committed")
        })
    } 

    override Bool disableGzip {
        get { reqState().disableGzip ?: false }
        set { reqState().disableGzip = it}
    }
    override Bool disableBuffering {
        get { reqState().disableBuffering ?: false }
        set { reqState().disableBuffering = it}
    }
    override Int statusCode {
        get { reqState().webRes.statusCode }
        set { reqState().webRes.statusCode = it }
    }   
    override Bool isCommitted() {
        reqState().webRes.isCommitted
    }
    override OutStream out() {
        reqState().out
    }
    override Void saveAsAttachment(Str fileName) {
        headers.contentDisposition = "Attachment; filename=${fileName}"
        headers.contentType = fileName.toUri.mimeType
    }
}