/*
 * w3m Event System Implementation
 * 
 * Basic event system for JavaScript integration.
 * This provides minimal event functionality for Phase 1.
 */

#include "fm.h"

#ifdef USE_JAVASCRIPT

#include "w3m_events.h"
#include "w3m_javascript.h"
#include "w3m_dom.h"
#include <stdlib.h>
#include <string.h>

/* Event System Management */

W3MEventSystem *
w3m_events_create_system(void)
{
    W3MEventSystem *system = GC_MALLOC(sizeof(W3MEventSystem));
    if (!system) return NULL;
    
    /* Initialize listener arrays */
    for (int i = 0; i < W3M_EVENT_TYPE_COUNT; i++) {
        system->listeners[i] = NULL;
    }
    
    /* Initialize event queue */
    system->event_queue = NULL;
    system->queue_size = 0;
    system->queue_capacity = 0;
    system->processing_events = 0;
    
    return system;
}

void
w3m_events_destroy_system(W3MEventSystem *system)
{
    if (!system) return;
    
    /* Free event listeners */
    for (int i = 0; i < W3M_EVENT_TYPE_COUNT; i++) {
        W3MEventListener *listener = system->listeners[i];
        while (listener) {
            W3MEventListener *next = listener->next;
            if (!JS_IsNull(listener->callback)) {
                /* Note: We can't free the callback here as we don't have context */
            }
            GC_free(listener);
            listener = next;
        }
    }
    
    /* Free event queue */
    if (system->event_queue) {
        for (int i = 0; i < system->queue_size; i++) {
            w3m_events_destroy_event(system->event_queue[i]);
        }
        GC_free(system->event_queue);
    }
    
    GC_free(system);
}

/* Event Type Utilities */

W3MEventType
w3m_events_string_to_type(const char *type_string)
{
    if (!type_string) return W3M_EVENT_TYPE_COUNT;
    
    if (strcasecmp(type_string, "click") == 0) return W3M_EVENT_CLICK;
    if (strcasecmp(type_string, "submit") == 0) return W3M_EVENT_SUBMIT;
    if (strcasecmp(type_string, "load") == 0) return W3M_EVENT_LOAD;
    if (strcasecmp(type_string, "unload") == 0) return W3M_EVENT_UNLOAD;
    if (strcasecmp(type_string, "focus") == 0) return W3M_EVENT_FOCUS;
    if (strcasecmp(type_string, "blur") == 0) return W3M_EVENT_BLUR;
    if (strcasecmp(type_string, "change") == 0) return W3M_EVENT_CHANGE;
    if (strcasecmp(type_string, "keypress") == 0) return W3M_EVENT_KEYPRESS;
    if (strcasecmp(type_string, "keydown") == 0) return W3M_EVENT_KEYDOWN;
    if (strcasecmp(type_string, "keyup") == 0) return W3M_EVENT_KEYUP;
    if (strcasecmp(type_string, "mouseover") == 0) return W3M_EVENT_MOUSEOVER;
    if (strcasecmp(type_string, "mouseout") == 0) return W3M_EVENT_MOUSEOUT;
    
    return W3M_EVENT_TYPE_COUNT;
}

const char *
w3m_events_type_to_string(W3MEventType type)
{
    switch (type) {
        case W3M_EVENT_CLICK: return "click";
        case W3M_EVENT_SUBMIT: return "submit";
        case W3M_EVENT_LOAD: return "load";
        case W3M_EVENT_UNLOAD: return "unload";
        case W3M_EVENT_FOCUS: return "focus";
        case W3M_EVENT_BLUR: return "blur";
        case W3M_EVENT_CHANGE: return "change";
        case W3M_EVENT_KEYPRESS: return "keypress";
        case W3M_EVENT_KEYDOWN: return "keydown";
        case W3M_EVENT_KEYUP: return "keyup";
        case W3M_EVENT_MOUSEOVER: return "mouseover";
        case W3M_EVENT_MOUSEOUT: return "mouseout";
        default: return "unknown";
    }
}

/* Event Management */

W3MEvent *
w3m_events_create_event(W3MEventType type, W3MElement *target)
{
    W3MEvent *event = GC_MALLOC(sizeof(W3MEvent));
    if (!event) return NULL;
    
    event->type = type;
    event->type_string = w3m_events_type_to_string(type);
    event->target = target;
    event->currentTarget = target;
    
    event->bubbles = 1;
    event->cancelable = 1;
    event->defaultPrevented = 0;
    event->propagationStopped = 0;
    
    /* Initialize event data */
    memset(&event->data, 0, sizeof(event->data));
    
    event->js_event = JS_NULL;
    
    return event;
}

void
w3m_events_destroy_event(W3MEvent *event)
{
    if (!event) return;
    
    /* Free any generic data */
    if (event->data.generic.data) {
        GC_free(event->data.generic.data);
    }
    
    GC_free(event);
}

/* Event Listener Management */

void
w3m_events_add_listener(W3MEventSystem *system, W3MElement *target, 
                       const char *type, JSValue callback, int use_capture)
{
    if (!system || !target || !type) return;
    
    W3MEventType event_type = w3m_events_string_to_type(type);
    if (event_type >= W3M_EVENT_TYPE_COUNT) return;
    
    W3MEventListener *listener = GC_MALLOC(sizeof(W3MEventListener));
    if (!listener) return;
    
    listener->type = event_type;
    listener->callback = callback;
    listener->target = target;
    listener->use_capture = use_capture;
    
    /* Add to linked list */
    listener->next = system->listeners[event_type];
    system->listeners[event_type] = listener;
}

int
w3m_events_has_listener(W3MEventSystem *system, W3MElement *target, const char *type)
{
    if (!system || !target || !type) return 0;
    
    W3MEventType event_type = w3m_events_string_to_type(type);
    if (event_type >= W3M_EVENT_TYPE_COUNT) return 0;
    
    W3MEventListener *listener = system->listeners[event_type];
    while (listener) {
        if (listener->target == target) {
            return 1;
        }
        listener = listener->next;
    }
    
    return 0;
}

/* Integration with w3m Input System (Stubs for Phase 1) */

int
w3m_events_handle_click(Buffer *buf, Anchor *anchor)
{
    /* Phase 1: Always return 0 to continue normal processing */
    return 0;
}

int
w3m_events_handle_form_submit(Buffer *buf, FormList *form)
{
    /* Phase 1: Always return 0 to continue normal processing */
    return 0;
}

int
w3m_events_handle_key_press(Buffer *buf, int key)
{
    /* Phase 1: Always return 0 to continue normal processing */
    return 0;
}

void
w3m_events_handle_page_load(Buffer *buf)
{
    /* Phase 1: Execute pending scripts */
    if (buf && buf->js_state) {
        w3m_js_execute_pending_scripts((BufferJSState *)buf->js_state);
    }
}

void
w3m_events_handle_page_unload(Buffer *buf)
{
    /* Phase 1: No action needed */
}

/* JavaScript Event API Stubs */

void
w3m_events_bind_to_js(W3MJSContext *ctx, W3MEventSystem *system)
{
    /* Phase 1: Create empty addEventListener function */
    if (!ctx || !system) return;
    
    /* This will be implemented in later phases */
}

JSValue
js_addEventListener(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
{
    /* Phase 1: Do nothing */
    return JS_UNDEFINED;
}

JSValue
js_removeEventListener(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
{
    /* Phase 1: Do nothing */
    return JS_UNDEFINED;
}

#endif /* USE_JAVASCRIPT */