wails/v3/pkg/application/messageprocessor.go

package application

import (
	"fmt"
	"log/slog"
	"net/http"
	"strconv"
	"strings"

	jsoniter "github.com/json-iterator/go"
)

// TODO maybe we could use a new struct that has the targetWindow as an attribute so we could get rid of passing the targetWindow
// as parameter through every function call.

const (
	callRequest        int = 0
	clipboardRequest       = 1
	applicationRequest     = 2
	eventsRequest          = 3
	contextMenuRequest     = 4
	dialogRequest          = 5
	windowRequest          = 6
	screensRequest         = 7
	systemRequest          = 8
)

type MessageProcessor struct {
	pluginManager *PluginManager
	logger        *slog.Logger
}

func NewMessageProcessor(logger *slog.Logger) *MessageProcessor {
	return &MessageProcessor{
		logger: logger,
	}
}

func (m *MessageProcessor) httpError(rw http.ResponseWriter, message string, args ...any) {
	m.Error(message, args...)
	rw.WriteHeader(http.StatusBadRequest)
	rw.Write([]byte(fmt.Sprintf(message, args...)))
}

func (m *MessageProcessor) getTargetWindow(r *http.Request) *WebviewWindow {
	windowName := r.Header.Get(webViewRequestHeaderWindowName)
	if windowName != "" {
		return globalApplication.GetWindowByName(windowName)
	}
	windowID := r.Header.Get(webViewRequestHeaderWindowId)
	if windowID == "" {
		return nil
	}
	wID, err := strconv.ParseUint(windowID, 10, 64)
	if err != nil {
		m.Error("Window ID '%s' not parsable: %s", windowID, err)
		return nil
	}
	targetWindow := globalApplication.getWindowForID(uint(wID))
	if targetWindow == nil {
		m.Error("Window ID %d not found", wID)
		return nil
	}
	return targetWindow
}

func (m *MessageProcessor) HandleRuntimeCall(rw http.ResponseWriter, r *http.Request) {
	object := r.URL.Query().Get("object")
	if object != "" {
		m.HandleRuntimeCallWithIDs(rw, r)
		return
	}
	// Read "method" from query string
	method := r.URL.Query().Get("method")
	if method == "" {
		m.httpError(rw, "No method specified")
		return
	}
	splitMethod := strings.Split(method, ".")
	if len(splitMethod) != 2 {
		m.httpError(rw, "Invalid method format")
		return
	}
	// Get the object
	object = splitMethod[0]
	// Get the method
	method = splitMethod[1]

	params := QueryParams(r.URL.Query())

	targetWindow := m.getTargetWindow(r)
	if targetWindow == nil {
		m.httpError(rw, "No valid window found")
		return
	}

	switch object {
	//case "window":
	//	m.processWindowMethod(method, rw, r, targetWindow, params)
	//case "clipboard":
	//	m.processClipboardMethod(method, rw, r, targetWindow, params)
	//case "dialog":
	//	m.processDialogMethod(method, rw, r, targetWindow, params)
	//case "events":
	//	m.processEventsMethod(method, rw, r, targetWindow, params)
	//case "application":
	//	m.processApplicationMethod(method, rw, r, targetWindow, params)
	//case "contextmenu":
	//	m.processContextMenuMethod(method, rw, r, targetWindow, params)
	//case "screens":
	//	m.processScreensMethod(method, rw, r, targetWindow, params)
	case "call":
		m.processCallMethod(method, rw, r, targetWindow, params)
	//case "system":
	//	m.processSystemMethod(method, rw, r, targetWindow, params)
	default:
		m.httpError(rw, "Unknown runtime call: %s", object)
	}
}

func (m *MessageProcessor) HandleRuntimeCallWithIDs(rw http.ResponseWriter, r *http.Request) {
	object, err := strconv.Atoi(r.URL.Query().Get("object"))
	if err != nil {
		m.httpError(rw, "Error decoding object value: "+err.Error())
		return
	}
	method, err := strconv.Atoi(r.URL.Query().Get("method"))
	if err != nil {
		m.httpError(rw, "Error decoding method value: "+err.Error())
		return
	}
	params := QueryParams(r.URL.Query())

	targetWindow := m.getTargetWindow(r)
	if targetWindow == nil {
		m.httpError(rw, "No valid window found")
		return
	}

	switch object {
	case windowRequest:
		m.processWindowMethod(method, rw, r, targetWindow, params)
	case clipboardRequest:
		m.processClipboardMethod(method, rw, r, targetWindow, params)
	case dialogRequest:
		m.processDialogMethod(method, rw, r, targetWindow, params)
	case eventsRequest:
		m.processEventsMethod(method, rw, r, targetWindow, params)
	case applicationRequest:
		m.processApplicationMethod(method, rw, r, targetWindow, params)
	case contextMenuRequest:
		m.processContextMenuMethod(method, rw, r, targetWindow, params)
	case screensRequest:
		m.processScreensMethod(method, rw, r, targetWindow, params)
	//case callRequest:
	//	m.processCallMethod(method, rw, r, targetWindow, params)
	case systemRequest:
		m.processSystemMethod(method, rw, r, targetWindow, params)
	default:
		m.httpError(rw, "Unknown runtime call: %s", object)
	}
}

func (m *MessageProcessor) Error(message string, args ...any) {
	m.logger.Error(message, args...)
}

func (m *MessageProcessor) Info(message string, args ...any) {
	m.logger.Info(message, args...)
}

func (m *MessageProcessor) json(rw http.ResponseWriter, data any) {
	rw.Header().Set("Content-Type", "application/json")
	// convert data to json
	var jsonPayload = []byte("{}")
	var err error
	if data != nil {
		jsonPayload, err = jsoniter.Marshal(data)
		if err != nil {
			m.Error("Unable to convert data to JSON. Please report this to the Wails team! Error: %s", err)
			return
		}
	}
	_, err = rw.Write(jsonPayload)
	if err != nil {
		m.Error("Unable to write json payload. Please report this to the Wails team! Error: %s", err)
		return
	}
	m.ok(rw)
}

func (m *MessageProcessor) text(rw http.ResponseWriter, data string) {
	_, err := rw.Write([]byte(data))
	if err != nil {
		m.Error("Unable to write json payload. Please report this to the Wails team! Error: %s", err)
		return
	}
	rw.Header().Set("Content-Type", "text/plain")
	rw.WriteHeader(http.StatusOK)
}

func (m *MessageProcessor) ok(rw http.ResponseWriter) {
	rw.WriteHeader(http.StatusOK)
}