//go:build linux && purego

package webview

import (
	"net/http"
	"strings"

	"github.com/ebitengine/purego"
)

func webkit_uri_scheme_request_get_http_method(req uintptr) string {
	var getMethod func(uintptr) string
	purego.RegisterLibFunc(&getMethod, gtk, "webkit_uri_scheme_request_get_http_method")
	return strings.ToUpper(getMethod(req))
}

func webkit_uri_scheme_request_get_http_headers(req uintptr) http.Header {
	var getHeaders func(uintptr) uintptr
	purego.RegisterLibFunc(&getUri, webkit, "webkit_uri_scheme_request_get_http_headers")

	hdrs := getHeaders(req)

	var headersIterInit func(uintptr, uintptr) uintptr
	purego.RegisterLibFunc(&headersIterInit, gtk, "soup_message_headers_iter_init")

	// TODO: How do we get a struct?
	/*
	   typedef struct {
	   	SoupMessageHeaders *hdrs;
	           int index_common;
	   	int index_uncommon;
	   } SoupMessageHeadersIterReal;
	*/
	iter := make([]byte, 12)
	headersIterInit(&iter, hdrs)

	var iterNext func(uintptr, *string, *string) int
	purego.RegisterLibFunc(&iterNext, gtk, "soup_message_headers_iter_next")

	var name string
	var value string
	h := http.Header{}

	for iterNext(&iter, &name, &value) != 0 {
		h.Add(name, value)
	}

	return h
}

func webkit_uri_scheme_request_finish(req uintptr, code int, header http.Header, stream uintptr, streamLength int64) error {

	var newResponse func(uintptr, int64) string
	purego.RegisterLibFunc(&newResponse, webkit, "webkit_uri_scheme_response_new")
	var unRef func(uintptr)
	purego.RegisterLibFunc(&unRef, gtk, "g_object_unref")

	resp := newResponse(stream, streamLength)
	defer unRef(resp)

	var setStatus func(uintptr, int, string)
	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_response_set_status")

	setStatus(resp, code, cReason)

	var setContentType func(uintptr, string)
	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_response_set_content_type")

	setContentType(resp, header.Get(HeaderContentType))

	soup := gtk
	var soupHeadersNew func(int) uintptr
	purego.RegisterLibFunc(&unRef, soup, "soup_message_headers_new")
	var soupHeadersAppend func(uintptr, string, string)
	purego.RegisterLibFunc(&unRef, soup, "soup_message_headers_append")

	hdrs := soupHeadersNew(SOUP_MESSAGE_HEADERS_RESPONSE)
	for name, values := range header {
		for _, value := range values {
			soupHeadersAppend(hdrs, name, value)
		}
	}

	var setHttpHeaders func(uintptr, uintptr)
	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_response_set_http_headers")

	setHttpHeaders(resp, hdrs)
	var finishWithResponse func(uintptr, uintptr)
	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_request_finish_with_response")
	finishWithResponse(req, resp)

	return nil
}

func webkit_uri_scheme_request_get_http_body(req *C.WebKitURISchemeRequest) io.ReadCloser {
	stream := C.webkit_uri_scheme_request_get_http_body(req)
	if stream == nil {
		return http.NoBody
	}
	return &webkitRequestBody{stream: stream}
}

type webkitRequestBody struct {
	stream *C.GInputStream
	closed bool
}

// Read implements io.Reader
func (r *webkitRequestBody) Read(p []byte) (int, error) {
	if r.closed {
		return 0, io.ErrClosedPipe
	}

	var content unsafe.Pointer
	var contentLen int
	if p != nil {
		content = unsafe.Pointer(&p[0])
		contentLen = len(p)
	}

	var n C.gsize
	var gErr *C.GError
	res := C.g_input_stream_read_all(r.stream, content, C.gsize(contentLen), &n, nil, &gErr)
	if res == 0 {
		return 0, formatGError("stream read failed", gErr)
	} else if n == 0 {
		return 0, io.EOF
	}
	return int(n), nil
}

func (r *webkitRequestBody) Close() error {
	if r.closed {
		return nil
	}
	r.closed = true

	// https://docs.gtk.org/gio/method.InputStream.close.html
	// Streams will be automatically closed when the last reference is dropped, but you might want to call this function
	// to make sure resources are released as early as possible.
	var err error
	var gErr *C.GError
	if C.g_input_stream_close(r.stream, nil, &gErr) == 0 {
		err = formatGError("stream close failed", gErr)
	}
	C.g_object_unref(C.gpointer(r.stream))
	r.stream = nil
	return err
}

func formatGError(msg string, gErr *C.GError, args ...any) error {
	if gErr != nil && gErr.message != nil {
		msg += ": " + C.GoString(gErr.message)
		C.g_error_free(gErr)
	}
	return fmt.Errorf(msg, args...)
}