#ifndef UI_LUA_H
#define UI_LUA_H

#include "ui.h"

// Registers the `ui`/`app` globals and input constants in the Lua state
void ui_lua_register(lua_State* L);

// Loads and runs a script file in its own sandboxed environment. Creation
// and script execution are decoupled: this makes no container. The script
// calls ui.create_overlay itself, from wherever it wants one — top level,
// a dispatch handler, or a bus subscription callback, any of which may run
// after this call returns, since app.subscribe can defer indefinitely.
VkResult ui_lua_run_script(
    lua_State* L,
    UIContext* ui,
    RenderContext* gpu,
    const char* path);

// The container an input dispatch is currently calling into; NULL outside
// dispatch (top-level script execution, bus subscription callbacks) — those
// contexts have no single "current" overlay, so ui.rect/ui.text require one
// to have been created first.
Container* ui_lua_current_container(lua_State* L);

// Resolves an overlay handle argument (as returned by ui.create_overlay) to
// its Container, raising a Lua error if the argument isn't an overlay
// handle or its container was already destroyed. For bindings outside
// ui_lua.c (e.g. editor_lua.c's camera:attach) that need to accept an
// overlay handle without reaching into its opaque internals.
Container* ui_lua_check_overlay(lua_State* L, int idx);

// Points the binding's registry context at a container (or NULL) before
// calling into a script from outside the normal dispatch path
void ui_lua_set_current(
    lua_State* L,
    Container* c,
    UIContext* ui,
    RenderContext* gpu);

// The script_env of whichever script is conceptually "running" right now —
// the script executing its top level, the script owning the container an
// input dispatch is calling into, or the script that registered the bus
// subscription currently being delivered. Used to attribute new overlays
// (ui.create_overlay) and new subscriptions (app.subscribe) to the right
// script. LUA_NOREF if nothing is running (shouldn't happen in practice).
int ui_lua_current_script(lua_State* L);

void ui_lua_set_current_script(lua_State* L, int script_env);

// Called by the engine input path. Each returns true if the container's script
// defined the handler and it returned a truthy value (event consumed). The
// handler receives the dispatching container's overlay handle as its first
// argument, before element: a script's script_env may back more than one
// container, so a shared on_button etc. needs to know which one fired.
bool ui_lua_dispatch_button(
    UIContext* ui,
    RenderContext* gpu,
    Container* c,
    uint32_t element,
    float x,
    float y,
    int button,
    int action,
    int mods);

bool ui_lua_dispatch_cursor(
    UIContext* ui,
    RenderContext* gpu,
    Container* c,
    uint32_t element,
    float x,
    float y);

bool ui_lua_dispatch_scroll(
    UIContext* ui,
    RenderContext* gpu,
    Container* c,
    uint32_t element,
    double x,
    double y);

bool ui_lua_dispatch_key(
    UIContext* ui,
    RenderContext* gpu,
    Container* c,
    uint32_t element,
    int key,
    int action,
    int mods);

bool ui_lua_dispatch_text(
    UIContext* ui,
    RenderContext* gpu,
    Container* c,
    uint32_t element,
    unsigned int codepoint);

bool ui_lua_dispatch_deselect(
    UIContext* ui,
    RenderContext* gpu,
    Container* c,
    uint32_t element);

#endif