package Torello.Browser;

import static Torello.Java.C.BCYAN;
import static Torello.Java.C.BGREEN_BKGND;
import static Torello.Java.C.RESET;

import Torello.Java.StorageWriter;
import Torello.Java.StrIndent;
import Torello.Java.StrPrint;

import Torello.Java.Additional.AppendableSafe;
import Torello.Browser.WebSocketSender;
import Torello.Java.EXCC;

import java.lang.reflect.Constructor;
import java.util.function.Consumer;
import javax.json.JsonObject;


// ************************************************************************************************
// ************************************************************************************************
// Chat-GPT wrote the summary below: July 20th, 2025 -  VERY ACCURATE!
// ************************************************************************************************
// ************************************************************************************************
// 
// Package-private class used internally by WebSocketSender to process incoming CDP event messages.
// These messages are not responses to sent commands, but spontaneous notifications sent by the
// browser (e.g., "Page.loadEventFired", "Runtime.consoleAPICalled").
//
// This class extracts the method name, prepares a simplified payload, and forwards the event to
// the active WSAdapter instance. It plays a critical role in dispatching asynchronous events that
// originate from the browser without being tied to a request ID.
//
// When a browser-generated event is received over the WebSocket connection, this class is
// responsible for handling and routing that event to the appropriate typed POJO that represents
// it. Every event generated by the Chrome DevTools Protocol (e.g., "Debugger.paused",
// "Network.requestWillBeSent") is associated with a dedicated Java class — typically implemented
// as a nested type within its corresponding domain class (like `Debugger.paused` inside `Debugger`).
//
// To perform this lookup, the incoming CDP event name is mapped to its associated partially-qualified
// class name (e.g., "Debugger.paused") using a static TreeMap located in class 'EVENT_DATA_FILE'.
// This map is loaded at runtime from a precompiled data file. The TreeMap provides a way to
// translate the simple event string received from Chrome into a class that can be dynamically
// loaded and instantiated via reflection.
//
// Note that the TreeMap’s value is only "partially-qualified": it includes the containing class
// name and nested type (e.g., `Debugger.paused`), but omits the `Torello.Browser.` prefix.
// This separation allows the Java class to be fully resolved at runtime using the known package
// path in combination with the lookup result.
// 
// 
// ************************************************************************************************
// ************************************************************************************************
// Chat-GPT Generated Explanation, Version 2 
// ************************************************************************************************
// ************************************************************************************************
// 
// 
// (This is a ** GREAT SUMMARY **, by the way - I REALLY GET WRITER'S BLOCK VERY VERY EASILY!)
// 
// When Chrome fires asynchronous browser events over the DevTools Protocol, they are delivered as
// JSON-formatted WebSocket messages received by the underlying Neovisionaries WebSocket API. These
// datagrams typically contain two key fields: an "event" property (representing the event name such
// as "paused" or "loadEventFired"), and a "params" object containing structured event-specific data.
// The raw event name received is not namespaced — Chrome does not include the domain or fully
// qualified class name, only the event's local identifier.
//
// To determine which Java class should be used to handle each incoming event, a
// TreeMap<String, String> is loaded at runtime. This map connects the unqualified Chrome event name
// (e.g., "paused") to a fully scoped class path segment like "Debugger$paused", where the domain and
// event are combined into a nested type using Java’s '$' separator. This allows the system to
// resolve the appropriate event-type class reflectively by constructing a fully-qualified name and
// invoking Class.forName("Torello.Browser." + className).
//
// Each event class is a POJO generated by a code generator, and every such class includes a
// constructor that accepts a single javax.json.JsonObject — this constructor is used to deserialize
// the incoming "params" payload into a strongly typed Java object. Once instantiated, the resulting
// object is cast to the BrowserEvent interface and dispatched to the Consumer<BrowserEvent> handler
// originally provided by the user when creating the WebSocketSender instance. This flow allows raw
// Chrome events to be automatically transformed into domain-typed Java objects and seamlessly
// delivered to user-defined callback logic.
// 
// 
// ************************************************************************************************
// ************************************************************************************************
// TEST CLASS:
// ************************************************************************************************
// ************************************************************************************************
// 
// 
// import Torello.Java.FileRW;
// import java.util.Map;
// import java.util.TreeMap;
// 
// class df 
// {
//     public static void main(String[] argv) throws Exception
//     {
//         final String dataFileName = "Torello/Browser/data-files/EventNames.tmdat";
// 
//         @SuppressWarnings("unchecked")
//         final TreeMap<String, String> tm = (TreeMap<String, String>)
//             FileRW.readObjectFromFile(dataFileName, TreeMap.class, true);
// 
//         for (final Map.Entry<String, String> e : tm.entrySet())
//             System.out.println(e.toString());
//     }
// }
// 
// 
// ************************************************************************************************
// ************************************************************************************************
// OUTPUTS:
// ************************************************************************************************
// ************************************************************************************************
// 
// 
// narrative@cloudshell:~$ java df
// accepted=Tethering$accepted
// addDatabase=Database$addDatabase
// addHeapSnapshotChunk=HeapProfiler$addHeapSnapshotChunk
// animationCanceled=Animation$animationCanceled
// animationCreated=Animation$animationCreated
// animationStarted=Animation$animationStarted
// attachedToTarget=Target$attachedToTarget
// attributeModified=DOM$attributeModified
// attributeRemoved=DOM$attributeRemoved
// ...
// windowOpen=Page$windowOpen
// workerErrorReported=ServiceWorker$workerErrorReported
// workerRegistrationUpdated=ServiceWorker$workerRegistrationUpdated
// workerVersionUpdated=ServiceWorker$workerVersionUpdated
// narrative@cloudshell:~$ 


class HandleEvent 
{
    // A Browser Generated Event has fired.  Report this even.
    static void handle(
            final   JsonObject      jo,
                    String          eventName,
            final   WebSocketSender THIS
        )
    {
        final Consumer<RDPError>        rdpErrorHandler = THIS.rdpErrorHandler;
        final Consumer<BrowserEvent>    eventHandler    = THIS.eventHandler;

        final String eventClassName = eventName.replace(".", "$");

        // Convert the class-name from a string to a fully-qualified class name
        final String className = EVENT_DATA_FILE.getEventClassName(eventClassName);


        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // ERROR-CASE: "Method" Json-Property doesn't map to a type listed in the Data-File
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        if (className == null)
        {
            final String errMsg = "Un-Typed Browser Event Received";
            PrintUtil.ERR(THIS, errMsg, jo);
            rdpErrorHandler.accept(new RDPError(errMsg, jo));
            return;
        }
            

        final Class<?> c;

        try 
            { c = Class.forName("Torello.Browser." + className); }


        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // ERROR-CASE: The Class Loader thew an exception while attempting to load the Class
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        catch (Exception e)
        {
            final String errMsg = 
                "Event Class-Loader Attempt has Thrown Exception:\n" +
                "Guessed Event-Class Name [" + className + ']';

            PrintUtil.ERR(THIS, errMsg, jo, e);
            rdpErrorHandler.accept(new RDPError(errMsg, jo, e));
            return;
        }


        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // ERROR-CASE: The Class Loader seems to have returned 'null' from the Class.forName call
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        if (c == null)
        {
            final String errMsg = 
                "BrowserEvent Class-Loader Attempt has Returned a Null Class<?>:\n" +
                "Guessed Event-Class Name [" + className + ']';

            PrintUtil.ERR(THIS, errMsg, jo);
            rdpErrorHandler.accept(new RDPError(errMsg, jo));
            return;
        }


        final Object event;

        try 
        {
            final Constructor<?>    ctr     = c.getConstructor(JsonObject.class);
            final JsonObject        params  = jo.getJsonObject("params");
            event = ctr.newInstance(params);
        }


        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // ERROR-CASE: Retrieving the Class Constructor, or invoking it has caused an exception
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        catch (Exception e)
        {
            final String errMsg =
                "Failed to build BrowserEvent Class using Constructor: " + 
                '[' + BCYAN + "Torello.Browser." + className + RESET;

            PrintUtil.ERR(THIS, errMsg, jo, e);
            rdpErrorHandler.accept(new RDPError(errMsg, jo, e));
            return;
        }


        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // ERROR-CASE: (Likely Impossible) Constructor Invocation seems to have returned null
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        if (event == null)
        {
            final String errMsg =
                "Failed to build event-class using constructor: " + 
                '[' + BCYAN + className + RESET + ']';

            PrintUtil.ERR(THIS, errMsg, jo);
            rdpErrorHandler.accept(new RDPError(errMsg, jo));
            return;
        }

        final BrowserEvent browserEvent;


        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // ERROR-CASE: (Likely Impossible) Constructed Object is not an instance of BrowserEvent
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        if (! (event instanceof BrowserEvent))
        {
            final String errMsg =
                "Event Class not an Instance of BrowserEvent: " + 
                '[' + BCYAN + className + RESET + ']';

            PrintUtil.ERR(THIS, errMsg, jo);
            rdpErrorHandler.accept(new RDPError(errMsg, jo));
            return;
        }


        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // SUCCESS
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        else browserEvent = (BrowserEvent) event;

        THIS.app()
            .append(BGREEN_BKGND + " Browser Event Received: " + RESET + '\n')
            .append("Event-Class: " + event.getClass().getCanonicalName() + '\n')
            .append(StrIndent.indent(event.toString(), 8))
            .append('\n');

        eventHandler.accept(browserEvent);
    }
}