// Copyright (c) 2023 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#include "VNTextboxScroller.hpp"
#include "game/DawnGame.hpp"

using namespace Dawn;

VNTextboxScroller::VNTextboxScroller(SceneItem *item) :
  SceneItemComponent(item),
  label(nullptr),
  visibleLines(4)
{
}

void VNTextboxScroller::onStart() {
  assertNotNull(label);

  std::function<void()> x = [&]{
    this->lineCurrent = 0;
    this->timeCharacter = 0;
    this->label->quadStart = 0;
    this->label->quadCount = 0;
    this->readyToClose = false;
  };
  x();

  useEvent(x, this->label->eventTextChanged);
  // useEffect(x, visibleLines);

  useEvent([&](float_t delta){
    auto game = this->getGame();

    this->timeCharacter += delta;
    if(this->hasRevealedAllCurrentCharacters()) {
      if(this->hasRevealedAllCharacters()) {
        if(!this->label->lines.empty()) {
          this->label->quadStart = this->label->lines[this->lineCurrent].quadStart;
        }
        this->label->quadCount = this->getTotalQuadsToBeRevealed();

        if(!this->readyToClose) {
          this->readyToClose = true;
          this->eventReadyToClose.invoke();
        }
      } else {
        if(game->inputManager.isPressed(INPUT_BIND_ACCEPT)) {
          this->lineCurrent += this->visibleLines;
          if(!this->label->lines.empty()) {
            this->label->quadStart = this->label->lines[this->lineCurrent].quadStart;
          }
          this->label->quadCount = 0;
          this->timeCharacter = 0.0f;

          this->label->textOffset = (
            -this->label->lines[this->lineCurrent].position
          );
        }
      }
      return;
    }

    auto lastTimeCharacter = mathFloor<int32_t>(this->timeCharacter);
    if(game->inputManager.isDown(INPUT_BIND_ACCEPT)) {
      this->timeCharacter += game->timeManager.delta * VN_TEXTBOX_SPEED_FASTER;
    } else {
      this->timeCharacter += game->timeManager.delta * VN_TEXTBOX_SPEED;
    }

    auto newCount = mathFloor<int32_t>(this->timeCharacter);
    if(newCount == this->label->quadCount) return;
    this->label->quadCount = mathFloor<int32_t>(this->timeCharacter);
    this->eventCharacterRevealed.invoke();
  }, getScene()->eventSceneUpdate);
}

int32_t VNTextboxScroller::getTotalQuadsToBeRevealed() {
  int32_t quadsTotal = 0;
  for(
    size_t i = this->lineCurrent;
    i < mathMin<size_t>(
      this->label->lines.size(),
      this->lineCurrent + this->visibleLines
    );
    i++
  ) {
    quadsTotal += this->label->lines[i].quadCount;
  }
  return quadsTotal;
}

bool_t VNTextboxScroller::hasRevealedAllCurrentCharacters() {
  return mathFloor<int32_t>(this->timeCharacter) >= this->getTotalQuadsToBeRevealed();
}

bool_t VNTextboxScroller::hasRevealedAllCharacters() {
  return (
    this->lineCurrent + this->visibleLines >=
    this->label->lines.size()
  );
  assertUnreachable();
}