/** @file Windows, input and events. The first surface starts the backend; use the
 * creating thread (main on Cocoa) for every call except yasl_wake. Coordinates are
 * logical units unless named pixel. */
#ifndef YASL_H
#define YASL_H
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "yasl/keycodes.h"
#if defined(__GNUC__)
#define YASL_API __attribute__((visibility("default")))
#else
#define YASL_API
#endif
#ifdef __cplusplus
extern "C" {
#endif
typedef struct yasl_surface yasl_surface;
typedef struct yasl_event yasl_event;
enum yasl_backend { YASL_BACKEND_AUTO, YASL_BACKEND_WAYLAND, YASL_BACKEND_X11, YASL_BACKEND_COCOA };
enum yasl_surface_flags { YASL_SURFACE_CPU=1u, YASL_SURFACE_HIDDEN=2u, YASL_SURFACE_UNDECORATED=4u, YASL_SURFACE_FIXED_SIZE=8u };
enum yasl_error { YASL_ERROR_NONE, YASL_ERROR_INVALID, YASL_ERROR_UNSUPPORTED, YASL_ERROR_NO_MEMORY,
    YASL_ERROR_NOT_INITIALIZED, YASL_ERROR_BUSY, YASL_ERROR_WRONG_THREAD, YASL_ERROR_CONTEXT_EXPIRED, YASL_ERROR_IO, YASL_ERROR_DISCONNECTED };
enum yasl_selection { YASL_CLIPBOARD, YASL_PRIMARY };
enum yasl_key_action { YASL_KEY_PRESS, YASL_KEY_RELEASE, YASL_KEY_REPEAT };
enum yasl_mod { YASL_MOD_SHIFT=1u, YASL_MOD_ALT=2u, YASL_MOD_CTRL=4u, YASL_MOD_SUPER=8u, YASL_MOD_CAPS=16u };
enum yasl_pointer_action { YASL_POINTER_MOVE, YASL_POINTER_DOWN, YASL_POINTER_UP, YASL_POINTER_LEAVE };
enum yasl_pointer_mode { YASL_POINTER_NORMAL, YASL_POINTER_RELATIVE };
enum yasl_button { YASL_BUTTON_PRIMARY, YASL_BUTTON_MIDDLE, YASL_BUTTON_SECONDARY, YASL_BUTTON_BACK, YASL_BUTTON_FORWARD };
#define YASL_BUTTON_BIT(button) (1u << (button))
enum yasl_pen_tool { YASL_PEN_UNKNOWN, YASL_PEN_PEN, YASL_PEN_ERASER, YASL_PEN_BRUSH, YASL_PEN_AIRBRUSH, YASL_PEN_PENCIL };
enum yasl_pen_action { YASL_PEN_ENTER, YASL_PEN_LEAVE, YASL_PEN_MOVE, YASL_PEN_DOWN, YASL_PEN_UP, YASL_PEN_BUTTON, YASL_PEN_CANCEL };
enum yasl_pen_axis { YASL_PEN_PRESSURE=1u, YASL_PEN_TILT=2u, YASL_PEN_ROTATION=4u, YASL_PEN_DISTANCE=8u, YASL_PEN_TANGENTIAL=16u, YASL_PEN_WHEEL=32u };
enum yasl_scroll_valid { YASL_SCROLL_LINES=1u, YASL_SCROLL_PIXELS=2u };
enum yasl_scroll_source { YASL_SCROLL_UNKNOWN, YASL_SCROLL_WHEEL, YASL_SCROLL_FINGER, YASL_SCROLL_CONTINUOUS };
enum yasl_scroll_phase { YASL_SCROLL_PHASE_UNKNOWN, YASL_SCROLL_BEGIN, YASL_SCROLL_UPDATE, YASL_SCROLL_END };
enum yasl_transfer_status { YASL_TRANSFER_OK, YASL_TRANSFER_UNAVAILABLE, YASL_TRANSFER_FAILED };
enum yasl_text_purpose { YASL_TEXT_NORMAL, YASL_TEXT_PASSWORD, YASL_TEXT_NUMBER, YASL_TEXT_TERMINAL };
enum yasl_cursor { YASL_CURSOR_ARROW, YASL_CURSOR_TEXT, YASL_CURSOR_LINK, YASL_CURSOR_CROSSHAIR, YASL_CURSOR_MOVE,
    YASL_CURSOR_RESIZE_NWSE, YASL_CURSOR_RESIZE_NESW, YASL_CURSOR_RESIZE_EW, YASL_CURSOR_RESIZE_NS, YASL_CURSOR_HIDDEN };
enum yasl_surface_state { YASL_STATE_FULLSCREEN=1u, YASL_STATE_MAXIMIZED=2u, YASL_STATE_ACTIVATED=4u,
    YASL_STATE_SUSPENDED=8u, YASL_STATE_CSD=16u, YASL_STATE_TILED=32u };
enum yasl_feature { YASL_CAP_POPUPS=1u, YASL_CAP_DRAG=2u, YASL_CAP_DRAG_CARRY=4u, YASL_CAP_PLACE_WINDOW=8u,
    YASL_CAP_PRIMARY_SELECTION=16u, YASL_CAP_CSD=32u, YASL_CAP_NATIVE_GRAPHICS=64u, YASL_CAP_FRAME_PACING=128u,
    YASL_CAP_TABLET=256u, YASL_CAP_OPENGL=512u, YASL_CAP_VULKAN=1024u, YASL_CAP_TEXT_INPUT=2048u };
enum yasl_popup_edge { YASL_POPUP_CENTER, YASL_POPUP_TOP, YASL_POPUP_BOTTOM, YASL_POPUP_LEFT,
    YASL_POPUP_RIGHT, YASL_POPUP_TOP_LEFT, YASL_POPUP_BOTTOM_LEFT, YASL_POPUP_TOP_RIGHT, YASL_POPUP_BOTTOM_RIGHT };
enum yasl_popup_constraint { YASL_POPUP_SLIDE_X=1u, YASL_POPUP_SLIDE_Y=2u, YASL_POPUP_FLIP_X=4u,
    YASL_POPUP_FLIP_Y=8u, YASL_POPUP_RESIZE_X=16u, YASL_POPUP_RESIZE_Y=32u };
enum yasl_resize_edge { YASL_EDGE_TOP=1, YASL_EDGE_BOTTOM=2, YASL_EDGE_LEFT=4, YASL_EDGE_TOP_LEFT=5,
    YASL_EDGE_BOTTOM_LEFT=6, YASL_EDGE_RIGHT=8, YASL_EDGE_TOP_RIGHT=9, YASL_EDGE_BOTTOM_RIGHT=10 };
enum yasl_event_type { YASL_EVENT_NONE, YASL_EVENT_CLOSE, YASL_EVENT_QUIT, YASL_EVENT_REOPEN, YASL_EVENT_WINDOW,
    YASL_EVENT_REFRESH, YASL_EVENT_KEY, YASL_EVENT_TEXT, YASL_EVENT_POINTER, YASL_EVENT_SCROLL, YASL_EVENT_PEN,
    YASL_EVENT_INPUT_RESET, YASL_EVENT_COMPOSITION, YASL_EVENT_TEXT_EDIT, YASL_EVENT_CLIPBOARD, YASL_EVENT_DROP,
    YASL_EVENT_DRAG, YASL_EVENT_DISPLAY_LOST, YASL_EVENT_DISPLAY_RESTORED };
enum yasl_drop_action { YASL_DROP_OVER, YASL_DROP_LEAVE, YASL_DROP_DATA };
enum yasl_drag_action { YASL_DRAG_OVER, YASL_DRAG_LEAVE, YASL_DRAG_DROP };
struct yasl_window_payload { int width,height,pixel_width,pixel_height; double scale; unsigned state; };
struct yasl_key_payload { enum yasl_key key; enum yasl_key_action action; unsigned mods;
        uint32_t codepoint, shifted, native_code; };
struct yasl_text_payload { const char *data; size_t length; };
struct yasl_pointer_payload { double x,y,dx,dy; enum yasl_pointer_action action; unsigned button,buttons,mods; };
struct yasl_scroll_payload { double x,y,lines_x,lines_y,pixels_x,pixels_y; unsigned valid,source,phase,mods; bool momentum; };
struct yasl_pen_payload { uint64_t device_id,tool_id; double x,y,pressure,tilt_x,tilt_y,rotation,distance,tangential,wheel_degrees;
        unsigned axes_valid,axes_changed,buttons,changed_button,tool,action; bool in_contact; };
struct yasl_composition_payload { const char *data; size_t length; int begin,end; bool active; uint64_t revision,generation; };
struct yasl_text_edit_payload { const char *data; size_t length,begin,end; uint64_t revision,generation; };
struct yasl_clipboard_payload { const char *data; size_t length; uint64_t request_id; enum yasl_transfer_status status; };
struct yasl_drop_payload { enum yasl_drop_action action; double x,y; const char *data; size_t length; };
struct yasl_drag_payload { enum yasl_drag_action action; double x,y; };

/** Read the union member named by type. Strings stay valid until the next wait.
 * CLOSE: the user closed this window. QUIT: the system asked the app to quit.
 * WINDOW: size, scale or state changed. REFRESH: draw now; sent once the window
 * has a size, after every resize and when the system needs the contents again.
 * INPUT_RESET: forget held keys, buttons and strokes. DROP: external data over
 * the window, delivered as DATA. DRAG: another YASL surface dragged over.
 * DISPLAY_LOST: the display server went away. Destroy Vulkan surfaces and GL
 * objects now; windows stay valid. Wayland reconnects, then sends DISPLAY_RESTORED:
 * recreate them (GL contexts are new and must be bound again). Elsewhere loss is
 * final and later waits fail. */
struct yasl_event {
    enum yasl_event_type type;
    yasl_surface *surface;
    uint64_t time_ns;
    union {
        struct yasl_window_payload window;
        struct yasl_key_payload key;
        struct yasl_text_payload text;
        struct yasl_pointer_payload pointer;
        struct yasl_scroll_payload scroll;
        struct yasl_pen_payload pen;
        struct yasl_composition_payload composition;
        struct yasl_text_edit_payload text_edit;
        struct yasl_clipboard_payload clipboard;
        /** DATA carries a text/uri-list for yasl_drop_next_path; x/y are set for OVER. */
        struct yasl_drop_payload drop;
        struct yasl_drag_payload drag;
    };
};
/** Last error on this thread; success does not clear it. */
YASL_API enum yasl_error yasl_get_error(const char **description);
YASL_API int yasl_get_native_error(void);
/** Only before the first surface is created. */
YASL_API bool yasl_set_app_id(const char *app_id);
YASL_API bool yasl_set_backend(enum yasl_backend backend);
/** Flags zero creates a surface for your own Vulkan or Metal renderer. */
YASL_API yasl_surface *yasl_surface_create(const char *title, int width, int height, unsigned flags);
/** Also destroys its popups. */
YASL_API void yasl_surface_destroy(yasl_surface *surface);
/** Destroys all surfaces. Release your GPU objects first. */
YASL_API void yasl_shutdown(void);
/** 1 event, 0 none (timeout or wake), -1 failure. timeout_ms zero polls, negative
 * waits forever. Without an event, out->type is NONE. */
YASL_API int yasl_wait_event(yasl_event *out, int timeout_ms);
/** Makes a waiting yasl_wait_event return. Thread-safe. */
YASL_API void yasl_wake(void);
YASL_API uint64_t yasl_time_ns(void);
YASL_API enum yasl_backend yasl_surface_backend(const yasl_surface *surface);
YASL_API unsigned yasl_surface_features(const yasl_surface *surface);
YASL_API void yasl_surface_get_size(const yasl_surface *surface, int *width, int *height);
YASL_API void yasl_surface_get_framebuffer_size(const yasl_surface *surface, int *width, int *height);
YASL_API double yasl_surface_get_scale(const yasl_surface *surface);
YASL_API unsigned yasl_surface_state(const yasl_surface *surface);
YASL_API void *yasl_surface_userdata(const yasl_surface *surface);
YASL_API void yasl_surface_set_userdata(yasl_surface *surface, void *userdata);
YASL_API bool yasl_surface_set_title(yasl_surface *surface, const char *title);
/** Requests; the result arrives as a WINDOW event. */
YASL_API bool yasl_surface_request_size(yasl_surface *surface, int width, int height);
YASL_API bool yasl_surface_request_fullscreen(yasl_surface *surface, bool enabled);
YASL_API bool yasl_surface_request_maximized(yasl_surface *surface, bool enabled);
YASL_API bool yasl_surface_request_minimize(yasl_surface *surface);
YASL_API bool yasl_surface_set_cursor(yasl_surface *surface, enum yasl_cursor cursor);
YASL_API bool yasl_surface_set_pointer_mode(yasl_surface *surface, enum yasl_pointer_mode mode);
/** Draws during native modal loops such as a live resize. The callback may render
 * but must not wait, create or destroy surfaces, or shut down. */
YASL_API void yasl_surface_set_refresh_callback(yasl_surface *surface, void (*refresh)(yasl_surface *,void *), void *userdata);
YASL_API int yasl_double_click_ms(void);
YASL_API bool yasl_clipboard_set(enum yasl_selection selection, const char *text);
/** Returns a request ID; the text arrives as a CLIPBOARD event. Zero on failure. */
YASL_API uint64_t yasl_clipboard_request(yasl_surface *target, enum yasl_selection selection);
/** IME support for a text field. */
YASL_API bool yasl_surface_set_text_input(yasl_surface *surface, bool active, enum yasl_text_purpose purpose);
/** UTF-8; selection offsets are bytes. */
YASL_API bool yasl_surface_set_surrounding_text(yasl_surface *surface, const char *text, size_t length,
    size_t selection_begin, size_t selection_end, uint64_t revision);
YASL_API bool yasl_surface_set_ime_caret(yasl_surface *surface, double x, double y, double width, double height);
/** Anchor picks a point on the x/y/anchor rectangle of the parent; gravity is the
 * direction the popup grows. Functions taking a trigger need a recent press event. */
YASL_API yasl_surface *yasl_popup_create(yasl_surface *parent, int width, int height,
    double x, double y, double anchor_width, double anchor_height, enum yasl_popup_edge anchor,
    enum yasl_popup_edge gravity, unsigned constraints, const yasl_event *trigger);
YASL_API bool yasl_popup_reposition(yasl_surface *popup, int width, int height,
    double x, double y, double anchor_width, double anchor_height, enum yasl_popup_edge anchor,
    enum yasl_popup_edge gravity, unsigned constraints);
YASL_API bool yasl_surface_start_interactive_move(yasl_surface *surface, const yasl_event *trigger);
YASL_API bool yasl_surface_start_interactive_resize(yasl_surface *surface, enum yasl_resize_edge edge, const yasl_event *trigger);
YASL_API bool yasl_surface_show_window_menu(yasl_surface *surface, double x, double y, const yasl_event *trigger);
YASL_API bool yasl_drag_start(yasl_surface *origin, const yasl_event *trigger,
    const uint32_t *pixels, int width, int height, int hotspot_x, int hotspot_y);
YASL_API void yasl_drag_cancel(void);
YASL_API bool yasl_surface_drag_carry(yasl_surface *surface, double x, double y);
YASL_API bool yasl_surface_place_under_pointer(yasl_surface *surface, double x, double y);
YASL_API size_t yasl_drop_next_path(const char **cursor, char *out, size_t capacity);
#ifdef __cplusplus
}
#endif
#endif