from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: str | None = None
    traceparent: str | None = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(
    headers: Annotated[CommonHeaders, Header(convert_underscores=False)],
):

describing the request at a high-level: _“fetch me this URL with these headers.”_ For correctness and efficiency, OkHttp rewrites your request before transmitting it.

OkHttp may add headers that are absent from the original request, including `Content-Length`, `Transfer-Encoding`, `User-Agent`, `Host`, `Connection`, and `Content-Type`. It will add an `Accept-Encoding` header for transparent response compression unless the header is already present. If you’ve got cookies, OkHttp will add a `Cookie`...

    val headers = response.headers
    assertThat(headers.size).isEqualTo(1)
    assertThat(headers.name(0)).isEqualTo(":version")
    assertThat(headers.value(0)).isEqualTo("HTTP/1.1")
  }

  @Test fun http2HeadersListDropsForbiddenHeadersHttp2() {
    val request =
      Request
        .Builder()
        .url("http://square.com/")
        .header("Connection", "upgrade")

    assertThat(cacheControl.toString()).isEqualTo(header)
  }

  @Test
  @Throws(Exception::class)
  fun parseIgnoreCacheControlExtensions() {
    // Example from http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.6
    val header = "private, community=\"UCI\""
    val cacheControl =
      parse(
        Headers
          .Builder()
          .set("Cache-Control", header)
          .build(),
      )

	}
	if err != nil {
		return n, err
	}
	return n, err
}

// Write the headers into the given buffer
func (lrw *ResponseRecorder) writeHeaders(w io.Writer, statusCode int, headers http.Header) {
	n, _ := fmt.Fprintf(w, "%d %s\n", statusCode, http.StatusText(statusCode))
	lrw.headerBytesWritten += n
	for k, v := range headers {
		n, _ := fmt.Fprintf(w, "%s: %s\n", k, v[0])
		lrw.headerBytesWritten += n
	}
}

		if crypto.S3.IsEncrypted(info.UserDefined) && r.Header.Get(xhttp.AmzCopySource) == "" {
			if crypto.SSEC.IsRequested(headers) || crypto.SSECopy.IsRequested(headers) {
				return encrypted, errEncryptedObject
			}
		}

		if crypto.S3KMS.IsEncrypted(info.UserDefined) && r.Header.Get(xhttp.AmzCopySource) == "" {
			if crypto.SSEC.IsRequested(headers) || crypto.SSECopy.IsRequested(headers) {
				return encrypted, errEncryptedObject

    val body = "hello".toRequestBody()
    val headers = headersOf("User-Agent", "RequestTest")
    val method = "PUT"
    val request =
      Request(
        url = url,
        headers = headers,
        method = method,
        body = body,
      )
    assertThat(request.url).isEqualTo(url)
    assertThat(request.headers).isEqualTo(headers)
    assertThat(request.method).isEqualTo(method)

  data?.let {
    request.method(requestMethod, it.toRequestBody(mediaType()))
  }

  for (header in headers.orEmpty()) {
    val parts = header.split(':', limit = 2)
    if (!isSpecialHeader(parts[0])) {
      request.header(parts[0], parts[1])
    }
  }
  referer?.let {
    request.header("Referer", it)
  }
  request.header("User-Agent", userAgent)

  return request.build()
}

  }

  class Part private constructor(
    @get:JvmName("headers") val headers: Headers?,
    @get:JvmName("body") val body: RequestBody,
  ) {
    @JvmName("-deprecated_headers")
    @Deprecated(
      message = "moved to val",
      replaceWith = ReplaceWith(expression = "headers"),
      level = DeprecationLevel.ERROR,
    )
    fun headers(): Headers? = headers

    @JvmName("-deprecated_body")
    @Deprecated(

        if (headers != null) {
            headers.forEach(header -> callback.accept(header.getFirst(), header.getSecond()));
        }
    }