#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "wayland.h"

static void wl_buffer_release(void *data, struct wl_buffer *wl_buffer) {
    /* Sent by the compositor when it's no longer using this buffer */
    wl_buffer_destroy(wl_buffer);
}

static const struct wl_buffer_listener wl_buffer_listener = {
    .release = wl_buffer_release,
};

static void xdg_surface_configure(void *data, struct xdg_surface *xdg_surface, uint32_t serial) {
    struct client_state *state = data;
    xdg_surface_ack_configure(xdg_surface, serial);
}

static const struct xdg_surface_listener xdg_surface_listener = {
    .configure = xdg_surface_configure,
};

static void xdg_wm_base_ping(void *data, struct xdg_wm_base *xdg_wm_base, uint32_t serial) {
    xdg_wm_base_pong(xdg_wm_base, serial);
} 

static const struct xdg_wm_base_listener xdg_wm_base_listener = {
    .ping = xdg_wm_base_ping,
};

static void xdg_toplevel_configure (
        void *data,
        struct xdg_toplevel *xdg_toplevel,
        int32_t width,
        int32_t height,
        struct wl_array *states
    ) {
    
    struct client_state *state = data;
    state->width = width;
    state->height = height;
    // resize egl window
    wl_egl_window_resize(state->egl_window, width, height, 0, 0);
}

static void xdg_toplevel_close(void *data, struct xdg_toplevel *xdg_toplevel) {
    struct client_state *state = data;
    state->running = 0;
}

void xdg_toplevel_configure_bounds(void *data, struct xdg_toplevel *xdg_toplevel, int32_t w, int32_t h) {
}

void xdg_toplevel_wm_capabilities(void *data, struct xdg_toplevel *xdg_toplevel, struct wl_array *capabilities) {
}

static const struct xdg_toplevel_listener xdg_toplevel_listener = {
    .configure = xdg_toplevel_configure,
    .close = xdg_toplevel_close,
    .configure_bounds = xdg_toplevel_configure_bounds,
    .wm_capabilities = xdg_toplevel_wm_capabilities,
};

static void zwlr_layer_surface_v1_configure(void *data, struct zwlr_layer_surface_v1 *zwlr_layer_surface_v1, uint32_t serial, uint32_t width, uint32_t height) {
    struct client_state *state = data;
    state->width = width;
    state->height = height;
    wl_egl_window_resize(state->egl_window, width, height, 0, 0);
    zwlr_layer_surface_v1_ack_configure(zwlr_layer_surface_v1, serial);
}

static void zwlr_layer_surface_v1_closed(void *data, struct zwlr_layer_surface_v1 * zwlr_layer_surface_v1) {
    struct client_state *state = data;
    state->running = 0;
}

static const struct zwlr_layer_surface_v1_listener zwlr_layer_surface_v1_listener = {
    .configure = zwlr_layer_surface_v1_configure,
    .closed = zwlr_layer_surface_v1_closed,
};

static void registry_handle_global(
        void *data,
        struct wl_registry *registry,
        uint32_t name,
        const char *interface,
        uint32_t version
    ) {
    printf("interface: '%s', version: %d, name: %d\n",
            interface, version, name);

    struct client_state *state = data;

    if (strcmp(interface, wl_compositor_interface.name) == 0) {
        state->wl_compositor = wl_registry_bind(
                registry, name, &wl_compositor_interface, 4);
        // Set up wl_surface
        state->wl_surface = wl_compositor_create_surface(state->wl_compositor);
    }
    if ((strcmp(interface, xdg_wm_base_interface.name) == 0) && (state->output_type == OUTPUT_WINDOW)) {
        state->xdg_wm_base = wl_registry_bind(
                registry, name, &xdg_wm_base_interface, 1);
        xdg_wm_base_add_listener(state->xdg_wm_base,
                &xdg_wm_base_listener, state);

        state->xdg_surface = xdg_wm_base_get_xdg_surface(
                state->xdg_wm_base, state->wl_surface);
        xdg_surface_add_listener(state->xdg_surface, &xdg_surface_listener, state);
        state->xdg_toplevel = xdg_surface_get_toplevel(state->xdg_surface);
        xdg_toplevel_set_title(state->xdg_toplevel, "GLONKERS! 🕴️");
        xdg_toplevel_add_listener(state->xdg_toplevel, &xdg_toplevel_listener, state);
    }
    if ((strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) && (state->output_type == OUTPUT_LAYER)) {
        state->zwlr_layer_shell_v1 = wl_registry_bind(registry, name, &zwlr_layer_shell_v1_interface, 4);
    }
    if (strcmp(interface, wl_output_interface.name) == 0) {
        state->wl_output = wl_registry_bind(
                registry, name, &wl_output_interface, 4);
    }
}

static void registry_handle_global_remove(
        void *data,
        struct wl_registry *registry,
        uint32_t name
    ) {
    // This space deliberately left blank
}

static const struct wl_registry_listener wl_registry_listener = {
    .global = registry_handle_global,
    .global_remove = registry_handle_global_remove,
};

static void egl_init(struct client_state *state) {
    EGLint config_attribs[] = {
        EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
        EGL_RED_SIZE, 8,
        EGL_GREEN_SIZE, 8,
        EGL_BLUE_SIZE, 8,
        EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
        EGL_NONE
    };

    static const EGLint context_attribs[] = {
        EGL_CONTEXT_CLIENT_VERSION, 2,
        EGL_NONE
    };
    
    state->egl_display = eglGetDisplay((EGLNativeDisplayType) state->wl_display);

    if (state->egl_display == EGL_NO_DISPLAY) {
        fprintf(stderr, "Can't create egl display\n");
        exit(1);
    } else {
        fprintf(stderr, "Created egl display\n");
    }

    EGLint major, minor;
    if (eglInitialize(state->egl_display, &major, &minor) != EGL_TRUE) {
        fprintf(stderr, "Can't initialise egl display\n");
        exit(1);
    }
    printf("EGL major: %d, minor %d\n", major, minor);

    EGLint count;
    eglGetConfigs(state->egl_display, NULL, 0, &count);
    printf("EGL has %d configs\n", count);


    EGLConfig *configs = calloc(count, sizeof *configs);
    
    EGLint n;
    eglChooseConfig(state->egl_display, config_attribs,
              configs, count, &n);
    
    for (int i = 0; i < n; i++) {
        EGLint size;
        eglGetConfigAttrib(state->egl_display,
            configs[i], EGL_BUFFER_SIZE, &size);
        printf("Buffer size for config %d is %d\n", i, size);
        eglGetConfigAttrib(state->egl_display,
               configs[i], EGL_RED_SIZE, &size);
        printf("Red size for config %d is %d\n", i, size);
        // just choose the first one
        state->egl_config = configs[i];
        break;
    }

    // Desktop GL?
    eglBindAPI(EGL_OPENGL_API);

    state->egl_context =
    eglCreateContext(state->egl_display,
             state->egl_config,
             EGL_NO_CONTEXT, context_attribs);

    // EGL window
    state->egl_window = wl_egl_window_create(state->wl_surface,
                              state->width, state->height);
    if (state->egl_window == EGL_NO_SURFACE) {
        fprintf(stderr, "Can't create egl window\n");
        exit(1);
    } else {
        fprintf(stderr, "Created egl window\n");
    }

    state->egl_surface =
        eglCreateWindowSurface(state->egl_display,
                               state->egl_config,
                               (unsigned long) state->egl_window, NULL);

    if (eglMakeCurrent(state->egl_display, state->egl_surface,
                       state->egl_surface, state->egl_context)) {
        fprintf(stderr, "Made current\n");
    } else {
        fprintf(stderr, "Made current failed\n");
    }
}

/// Initializes wayland and creates an opengl context
void wayland_init(struct client_state *state, int output_type) {
    int width = 700, height = 700;
    state->width = width;
    state->height = height;
    state->running = 1;
    state->output_type = output_type;
    state->wl_display = wl_display_connect(NULL);
    state->wl_registry = wl_display_get_registry(state->wl_display);
    state->wl_output = NULL;
    wl_registry_add_listener(state->wl_registry, &wl_registry_listener, state);
    wl_display_roundtrip(state->wl_display);

    if (output_type == OUTPUT_LAYER) {
        // wlr_layer_shell
        int layer = ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND;
        state->zwlr_layer_surface_v1 = zwlr_layer_shell_v1_get_layer_surface(state->zwlr_layer_shell_v1, state->wl_surface, state->wl_output, layer, "wallpaper");
	    zwlr_layer_surface_v1_set_anchor(state->zwlr_layer_surface_v1,
             ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP
             | ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT);
        zwlr_layer_surface_v1_set_size(state->zwlr_layer_surface_v1, 0, 0);
        zwlr_layer_surface_v1_add_listener(state->zwlr_layer_surface_v1, &zwlr_layer_surface_v1_listener, state);
    }

    wl_surface_commit(state->wl_surface);

    egl_init(state);
}

/// Swaps front/backbuffers and dispatches pending wayland commands.
void commit(struct client_state *state) {
    wl_display_dispatch(state->wl_display);
    eglSwapBuffers(state->egl_display, state->egl_surface);
}