// Copyright (c) 2026 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#include "scene.h"
#include "assert/assert.h"
#include "util/memory.h"
#include "debug/debug.h"
#include "time/time.h"

#include "display/camera/camera.h"
#include "display/screen.h"

scene_t SCENE;

errorret_t sceneInit(void) {
  memoryZero(&SCENE, sizeof(scene_t));

  errorChain(scriptContextInit(&SCENE.scriptContext));
  errorOk();
}

errorret_t sceneUpdate(void) {
  #if TIME_FIXED ==  0
  if(!TIME.dynamicUpdate) {
    errorOk();
  }
  #endif

  lua_getglobal(SCENE.scriptContext.luaState, "sceneUpdate");
  if(!lua_isfunction(SCENE.scriptContext.luaState, -1)) {
    lua_pop(SCENE.scriptContext.luaState, 1);
    errorOk();
  }

  if(lua_pcall(SCENE.scriptContext.luaState, 0, 0, 0) != LUA_OK) {
    const char_t *strErr = lua_tostring(SCENE.scriptContext.luaState, -1);
    lua_pop(SCENE.scriptContext.luaState, 1);
    errorThrow("Failed to call function '%s': %s", "sceneUpdate", strErr);
  }
  
  errorOk();
}

errorret_t sceneRender(void) {
  lua_getglobal(SCENE.scriptContext.luaState, "sceneRender");
  if(!lua_isfunction(SCENE.scriptContext.luaState, -1)) {
    lua_pop(SCENE.scriptContext.luaState, 1);
    errorOk();
  }

  if(lua_pcall(SCENE.scriptContext.luaState, 0, 0, 0) != LUA_OK) {
    const char_t *strErr = lua_tostring(SCENE.scriptContext.luaState, -1);
    lua_pop(SCENE.scriptContext.luaState, 1);
    errorThrow("Failed to call function '%s': %s", "sceneRender", strErr);
  }
  
  errorOk();
}

errorret_t sceneSet(const char_t *script) {
  // Cleanup old script context.
  lua_getglobal(SCENE.scriptContext.luaState, "sceneDispose");
  if(lua_isfunction(SCENE.scriptContext.luaState, -1)) {
    if(lua_pcall(SCENE.scriptContext.luaState, 0, 0, 0) != LUA_OK) {
      const char_t *strErr = lua_tostring(SCENE.scriptContext.luaState, -1);
      lua_pop(SCENE.scriptContext.luaState, 1);
      errorThrow("Failed to call function '%s': %s", "sceneDispose", strErr);
    }
  } else {
    lua_pop(SCENE.scriptContext.luaState, 1);
  }
  scriptContextDispose(&SCENE.scriptContext);

  // Create a new script context.
  errorChain(scriptContextInit(&SCENE.scriptContext));
  errorChain(scriptContextExecFile(&SCENE.scriptContext, script));
  errorOk();
}

void sceneDispose(void) {
  lua_getglobal(SCENE.scriptContext.luaState, "sceneDispose");
  if(lua_isfunction(SCENE.scriptContext.luaState, -1)) {
    if(lua_pcall(SCENE.scriptContext.luaState, 0, 0, 0) != LUA_OK) {
      const char_t *strErr = lua_tostring(SCENE.scriptContext.luaState, -1);
      lua_pop(SCENE.scriptContext.luaState, 1);
      debugPrint("Failed to call function '%s': %s\n", "sceneDispose", strErr);
      debugFlush();
    }
  } else {
    lua_pop(SCENE.scriptContext.luaState, 1);
  }
  
  scriptContextDispose(&SCENE.scriptContext);
}