#pragma once

#if !(defined(STELA_API_NULL) || defined(STELA_API_OPENGL) || \
    defined(STELA_API_VULKAN) || defined(STELA_API_DX11))
#error "No graphics API defined."
#endif

#if defined(STELA_API_NULL) + defined(STELA_API_OPENGL) + \
    defined(STELA_API_VULKAN) + defined(STELA_API_DX11) != 1
#error "Conflicting graphics APIs."
#endif

#if !(defined(STELA_POLL_FD) || defined(STELA_POLL_INLINE))
#error "No poll method defined."
#endif

#include <al/types.h>
#include <al/lib.h>
#include <al/str.h>
#ifdef STELA_EVENT_BUFFER
#include <al/ring_buffer.h>
#endif

#if defined STELA_API_VULKAN
#if defined STELA_WINDOW_WIN32
#define VK_USE_PLATFORM_WIN32_KHR
#elif defined STELA_WINDOW_WAYLAND
#define VK_USE_PLATFORM_WAYLAND_KHR
#elif defined STELA_WINDOW_X11
#define VK_USE_PLATFORM_XLIB_KHR
#endif
#include <vulkan/vulkan.h>
#elif defined STELA_API_DX11
#include <nnwt/windows.h>
#elif defined STELA_API_OPENGL && defined STELA_USE_EGL
#include "egl_common.h"
#endif

#ifndef STELA_MIN_WIDTH
#define STELA_MIN_WIDTH 16u
#endif

#ifndef STELA_MIN_HEIGHT
#define STELA_MIN_HEIGHT 16u
#endif

#ifdef STELA_WINDOW_WAYLAND
#define STELA_ICON_AT_RUNTIME
#endif

// Drag window by clicking anywhere with MOUSE2.
#define STELA_MOUSE2_DRAG

enum {
    STELA_WINDOW_VSYNC = 1,
    STELA_WINDOW_WALLPAPER = 1 << 1
};

enum {
    STELA_CURSOR_NORMAL = 0,
    STELA_CURSOR_MOVE,
    STELA_CURSOR_CROSSHAIR,
    STELA_CURSOR_HIDDEN
};

#define STELA_MAX_MONITOR_NAME 255u

struct stl_monitor {
    u32 width;
    u32 height;
    u32 scale;
    bool vertical;
    char name[STELA_MAX_MONITOR_NAME];
};

#define STELA_EVENT_SIZE 24u
#ifndef STELA_EVENTS_SIZE
#define STELA_EVENTS_SIZE (STELA_EVENT_SIZE * 64u)
#endif

struct stl_window {
    u32 width;
    u32 height;
    u32 scale;
    bool fullscreen;
    u32 flags;
    // Methods.
    bool (*create_window)(struct stl_window *, u32, u32, u32, const char *, const char *, const char *);
    void (*resize_internal)(struct stl_window *, u32, u32);
    void (*resize)(struct stl_window *, u32, u32);
    void (*toggle_fullscreen)(struct stl_window *);
    void (*set_cursor)(struct stl_window *window, u8);
    void (*set_decorations)(struct stl_window *, bool);
#ifdef STELA_POLL_INLINE
    bool (*poll)(struct stl_window *, bool);
#ifdef STELA_PAUSE
    void (*wake)(struct stl_window *);
#endif
#endif
    void (*process_events)(struct stl_window *);
#ifdef STELA_PAUSE
    bool (*should_refresh)(struct stl_window *);
#endif
    void (*close)(struct stl_window *window);
    void (*free)(struct stl_window **);
    // Context specific.
#if defined STELA_API_VULKAN
    VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL (*get_vk_proc_address)(VkInstance, const char *);
    VkResult (*vk_create_surface)(void *, VkInstance, VkSurfaceKHR *);
    VkResult (*vk_destroy_surface)(VkInstance, VkSurfaceKHR);
    const char *const *(*vk_get_extensions)(u32 *);
#elif defined STELA_API_DX11
    HWND win32_window;
#elif defined STELA_API_OPENGL
#ifdef STELA_USE_EGL
    EGLDisplay egl_display;
    EGLContext egl_context;
#endif
    void (*(*get_gl_proc_address)(const char *))(void);
    bool (*gl_loader_load)(void *);
    bool (*gl_make_current)(void *);
    void (*gl_release_current)(void *);
    void (*gl_swap_buffers)(void *);
#endif
    // Callbacks.
    void (*output_discovered_callback)(void *, struct stl_monitor *);
    void (*render_callback)(void *);
    void (*resize_callback)(void *, u32, u32);
    bool (*pointer_pos_callback)(void *, f64, f64);
    bool (*touch_callback)(void *, s32, u8, f64, f64);
    bool (*scroll_callback)(void *, f64);
    bool (*mouse_button_callback)(void *, u8, u8);
    bool (*key_callback)(void *, u8, u16);
    // Immediate:
    // - Always runs on the thread that received the event.
    // - Return value decides if the event should "pass through" or not.
    //   True = Consume, False = Passthrough.
    bool (*key_immediate_callback)(void *, u8, u16);
    void (*should_close_callback)(void *);
    void *userdata;
    bool closed;
    u32 held_mouse_buttons;
    u32 held_modifiers;
#ifdef STELA_PAUSE
    bool pending_refresh;
#endif
#ifdef STELA_EVENT_BUFFER
    bool pending_resize;
    // Render thread events.
    struct al_ring_buffer events;
    u8 data[STELA_EVENTS_SIZE];
#endif
};

enum {
    STELA_EVENT_RESIZE = 0,
    STELA_EVENT_POINTER_POS,
    STELA_EVENT_TOUCH,
    STELA_EVENT_SCROLL,
    STELA_EVENT_MOUSE_BUTTON,
    STELA_EVENT_KEY,
    STELA_EVENT_SHOULD_CLOSE,
    STELA_EVENT_NONE = 255
};

enum {
    STELA_BUTTON_PRESSED = 0,
    STELA_BUTTON_RELEASED
};

enum {
    STELA_MOUSE1 = 1,
    STELA_MOUSE2 = 1 << 1,
    STELA_MOUSE3 = 1 << 2
};

AL_IGNORE_WARNING("-Wunused-variable")

static u8 stl_all_mouse_buttons[] = {
    STELA_MOUSE1,
    STELA_MOUSE2,
    STELA_MOUSE3
};

AL_IGNORE_WARNING_END

enum {
    STELA_TOUCH_HOVER = 0,
    STELA_TOUCH_BEGAN,
    STELA_TOUCH_MOVED,
    STELA_TOUCH_ENDED,
    STELA_TOUCH_CANCELLED
};

extern s32 stl_platform_main(u32 argc, str *argv);

f64 stl_scale_scroll(f64 v, f64 factor);
void stl_set_output_discovered_callback(void (*output_discovered)(void *, struct stl_monitor *), void *userdata);
#ifdef STELA_ICON_AT_RUNTIME
void stl_set_icon_data(u8 *data, u32 size);
#endif

bool stl_global_init(bool skip_graphics);
s32 stl_global_get_poll_fd(void);
void stl_global_process_events(void);
s32 stl_swallow_main(u32 argc, str *argv, s32 (*main)(u32, str *, void *), void *extra);
void stl_global_close(void);

struct stl_window *stl_window_create(void);
void stl_window_send_render_event(struct stl_window *window);
void stl_window_send_resize_event(struct stl_window *window, u32 width, u32 height);
void stl_window_send_pointer_pos_event(struct stl_window *window, f64 x, f64 y);
void stl_window_send_touch_event(struct stl_window *window, s32 index, u8 phase, f64 x, f64 y);
void stl_window_send_scroll_event(struct stl_window *window, f64 y);
void stl_window_send_mouse_button_event(struct stl_window *window, u8 state, u8 button);
void stl_window_drop_mouse_buttons(struct stl_window *window);
void stl_window_send_key_event(struct stl_window *window, u8 state, u16 button);
bool stl_window_send_key_immediate_event(struct stl_window *window, u8 state, u16 button);
void stl_window_drop_modifiers(struct stl_window *window);
void stl_window_send_should_close_event(struct stl_window *window);
#ifdef STELA_EVENT_BUFFER
bool stl_window_read_events(struct stl_window *window);
#endif