#include "ark_wayland_server.h"
#include <wayland-server.h>
#include <wayland-server-protocol.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

static struct wl_display *display = NULL;
static struct wl_event_loop *event_loop = NULL;

static uint8_t* g_render_buffer = NULL;
static int g_width = 1920;
static int g_height = 1080;
static int g_bpp = 4;

struct ark_surface {
    struct wl_resource *resource;
    struct wl_resource *pending_buffer;
};

// Surface interface implementations
static void surface_destroy(struct wl_client *client, struct wl_resource *resource) {
    wl_resource_destroy(resource);
}

static void surface_attach(struct wl_client *client, struct wl_resource *resource, struct wl_resource *buffer, int32_t x, int32_t y) {
    struct ark_surface *surface = wl_resource_get_user_data(resource);
    surface->pending_buffer = buffer;
}

static void surface_damage(struct wl_client *client, struct wl_resource *resource, int32_t x, int32_t y, int32_t width, int32_t height) {
    // Basic implementation ignores partial damage and redraws all
}

static void surface_frame(struct wl_client *client, struct wl_resource *resource, uint32_t callback) {
    // Send frame event immediately for now (60fps limit handled by client or main loop)
    struct wl_resource *cb_resource = wl_resource_create(client, &wl_callback_interface, 1, callback);
    wl_callback_send_done(cb_resource, 0);
    wl_resource_destroy(cb_resource);
}

static void surface_set_opaque_region(struct wl_client *client, struct wl_resource *resource, struct wl_resource *region) {}
static void surface_set_input_region(struct wl_client *client, struct wl_resource *resource, struct wl_resource *region) {}

static void surface_commit(struct wl_client *client, struct wl_resource *resource) {
    struct ark_surface *surface = wl_resource_get_user_data(resource);
    
    if (surface->pending_buffer && g_render_buffer) {
        struct wl_shm_buffer *shm_buffer = wl_shm_buffer_get(surface->pending_buffer);
        if (shm_buffer) {
            wl_shm_buffer_begin_access(shm_buffer);
            void *data = wl_shm_buffer_get_data(shm_buffer);
            int stride = wl_shm_buffer_get_stride(shm_buffer);
            int height = wl_shm_buffer_get_height(shm_buffer);
            int width = wl_shm_buffer_get_width(shm_buffer);
            
            // Copy buffer to global render buffer
            int max_y = (height < g_height) ? height : g_height;
            int max_bytes = (stride < g_width * g_bpp) ? stride : g_width * g_bpp;
            
            for (int y = 0; y < max_y; y++) {
                memcpy(g_render_buffer + (y * g_width * g_bpp), 
                       ((uint8_t*)data) + (y * stride), 
                       max_bytes);
            }
            
            wl_shm_buffer_end_access(shm_buffer);
            
            // Send release event to client
            wl_buffer_send_release(surface->pending_buffer);
            surface->pending_buffer = NULL;
        }
    }
}

static void surface_set_buffer_transform(struct wl_client *client, struct wl_resource *resource, int32_t transform) {}
static void surface_set_buffer_scale(struct wl_client *client, struct wl_resource *resource, int32_t scale) {}
static void surface_damage_buffer(struct wl_client *client, struct wl_resource *resource, int32_t x, int32_t y, int32_t width, int32_t height) {}

static const struct wl_surface_interface surface_implementation = {
    surface_destroy,
    surface_attach,
    surface_damage,
    surface_frame,
    surface_set_opaque_region,
    surface_set_input_region,
    surface_commit,
    surface_set_buffer_transform,
    surface_set_buffer_scale,
    surface_damage_buffer
};

static void destroy_surface(struct wl_resource *resource) {
    struct ark_surface *surface = wl_resource_get_user_data(resource);
    free(surface);
}

// Compositor interface implementations
static void compositor_create_surface(struct wl_client *client, struct wl_resource *resource, uint32_t id) {
    struct ark_surface *surface = calloc(1, sizeof(struct ark_surface));
    surface->resource = wl_resource_create(client, &wl_surface_interface, 4, id);
    wl_resource_set_implementation(surface->resource, &surface_implementation, surface, destroy_surface);
}

static void compositor_create_region(struct wl_client *client, struct wl_resource *resource, uint32_t id) {
    // Regions are not fully supported yet in minimal server
}

static const struct wl_compositor_interface compositor_implementation = {
    compositor_create_surface,
    compositor_create_region
};

static void bind_compositor(struct wl_client *client, void *data, uint32_t version, uint32_t id) {
    struct wl_resource *resource = wl_resource_create(client, &wl_compositor_interface, version, id);
    wl_resource_set_implementation(resource, &compositor_implementation, NULL, NULL);
}

void ark_compositor_set_render_buffer(uint8_t* buffer, int width, int height, int bpp) {
    g_render_buffer = buffer;
    g_width = width;
    g_height = height;
    g_bpp = bpp;
}

bool ark_compositor_init(void) {
    display = wl_display_create();
    if (!display) {
        fprintf(stderr, "ArkCompositor: Failed to create Wayland display\n");
        return false;
    }
    
    event_loop = wl_display_get_event_loop(display);
    
    // Initialize SHM (shared memory)
    wl_display_init_shm(display);
    
    // Initialize Compositor
    wl_global_create(display, &wl_compositor_interface, 4, display, bind_compositor);
    
    // Add socket (this will usually bind to wayland-0)
    const char *socket = wl_display_add_socket_auto(display);
    if (!socket) {
        fprintf(stderr, "ArkCompositor: Failed to add socket\n");
        wl_display_destroy(display);
        display = NULL;
        return false;
    }
    
    printf("ArkCompositor: Wayland server listening on socket '%s'\n", socket);
    return true;
}

void ark_compositor_dispatch(void) {
    if (display && event_loop) {
        wl_display_flush_clients(display);
        wl_event_loop_dispatch(event_loop, 0); // Non-blocking dispatch
    }
}

void ark_compositor_shutdown(void) {
    if (display) {
        wl_display_destroy(display);
        display = NULL;
        event_loop = NULL;
    }
}