#include "ark_wayland_client.h"
#include <wayland-client.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>

static struct wl_display *display = NULL;
static struct wl_registry *registry = NULL;
static struct wl_compositor *compositor = NULL;
static struct wl_shm *shm = NULL;

static struct wl_surface *surface = NULL;
static struct wl_buffer *buffer = NULL;
static uint8_t *shm_data = NULL;
static int shm_size = 0;

static void registry_handler(void *data, struct wl_registry *registry, uint32_t id, const char *interface, uint32_t version) {
    if (strcmp(interface, "wl_compositor") == 0) {
        compositor = wl_registry_bind(registry, id, &wl_compositor_interface, 1);
    } else if (strcmp(interface, "wl_shm") == 0) {
        shm = wl_registry_bind(registry, id, &wl_shm_interface, 1);
    }
}

static void registry_remover(void *data, struct wl_registry *registry, uint32_t id) {
    // Handling removals not strictly needed for this simple client
}

static const struct wl_registry_listener registry_listener = {
    registry_handler,
    registry_remover
};

bool ark_wayland_client_init(void) {
    display = wl_display_connect(NULL);
    if (!display) {
        fprintf(stderr, "ArkGraphics (Client): Failed to connect to Wayland display\n");
        return false;
    }
    
    registry = wl_display_get_registry(display);
    wl_registry_add_listener(registry, &registry_listener, NULL);
    
    // Wait for globals
    wl_display_roundtrip(display);
    
    if (!compositor || !shm) {
        fprintf(stderr, "ArkGraphics (Client): Compositor or SHM interface not found on Wayland server\n");
        return false;
    }
    
    printf("ArkGraphics (Client): Connected to Wayland Server\n");
    return true;
}

void ark_wayland_client_shutdown(void) {
    if (buffer) wl_buffer_destroy(buffer);
    if (surface) wl_surface_destroy(surface);
    if (shm_data) munmap(shm_data, shm_size);
    
    if (shm) wl_shm_destroy(shm);
    if (compositor) wl_compositor_destroy(compositor);
    if (registry) wl_registry_destroy(registry);
    if (display) wl_display_disconnect(display);
}

// OS helper for memfd create (if syscall not wrapped by libc, we can just use memfd_create)
#include <sys/syscall.h>
#include <linux/memfd.h>
static int os_create_anonymous_file(off_t size) {
    int fd = syscall(SYS_memfd_create, "ark_wayland_shm", MFD_CLOEXEC);
    if (fd < 0) return -1;
    if (ftruncate(fd, size) < 0) {
        close(fd);
        return -1;
    }
    return fd;
}

uint8_t* ark_wayland_client_create_surface(int width, int height) {
    if (!compositor || !shm) return NULL;
    
    surface = wl_compositor_create_surface(compositor);
    if (!surface) return NULL;
    
    int stride = width * 4; // 4 bytes per pixel (ARGB8888)
    shm_size = stride * height;
    
    int fd = os_create_anonymous_file(shm_size);
    if (fd < 0) {
        fprintf(stderr, "ArkGraphics (Client): Failed to create SHM file\n");
        return NULL;
    }
    
    shm_data = mmap(NULL, shm_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (shm_data == MAP_FAILED) {
        close(fd);
        return NULL;
    }
    
    struct wl_shm_pool *pool = wl_shm_create_pool(shm, fd, shm_size);
    buffer = wl_shm_pool_create_buffer(pool, 0, width, height, stride, WL_SHM_FORMAT_ARGB8888);
    wl_shm_pool_destroy(pool); // Pool object can be destroyed once buffer is created
    
    close(fd); // Wayland server keeps the fd open internally
    
    return shm_data;
}

void ark_wayland_client_commit(void) {
    if (!surface || !buffer) return;
    
    // Attach the buffer to the surface
    wl_surface_attach(surface, buffer, 0, 0);
    // Mark the entire surface as damaged so the compositor redraws it
    wl_surface_damage(surface, 0, 0, INT32_MAX, INT32_MAX);
    // Commit the surface state
    wl_surface_commit(surface);
    
    // Flush the display to ensure messages are sent
    wl_display_flush(display);
}