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

#include "PrefabGen.hpp"

using namespace Dawn;

void PrefabGen::generate(
  std::vector<std::string> *out,
  struct Prefab *info,
  std::string tabs
) {
  struct ClassGenInfo classInfo;
  classInfo.clazz = info->name;
  classInfo.extend = "SceneItemPrefab<" + info->name + ">";
  classInfo.constructorArgs = "Scene *scene, sceneitemid_t id";
  classInfo.extendArgs = "scene, id";

  struct MethodGenInfo methodAssets;
  methodAssets.name = "prefabAssets";
  methodAssets.isStatic = true;
  methodAssets.type = "std::vector<Asset*>";
  methodAssets.args = "AssetManager *man";
  line(&methodAssets.body, "std::vector<Asset*> assets;", "");

  struct MethodGenInfo methodInit;
  methodInit.name = "prefabInit";
  methodInit.isOverride = true;
  methodInit.args = "AssetManager *man";

  classInfo.includes.push_back("prefab/SceneItemPrefab.hpp");

  // Process assets
  int32_t assetNumber = 0;
  std::map<std::string, std::string> assetMap;
  auto processAsset = [&](struct PrefabAsset a) {
    std::string assetType = "";
    a.usageName = "asset" + std::to_string(assetNumber++);
    switch(a.type) {
      case PREFAB_ASSET_TYPE_TEXTURE:
        assetType = "TextureAsset";
        assetMap[a.fileName] = "&" + a.usageName + "->texture";
        break;

      case PREFAB_ASSET_TYPE_TRUETYPE_FONT:
        assetType = "TrueTypeAsset";
        assetMap[a.fileName] = "&" + a.usageName + "->font";
        break;

      default:
        assertUnreachable();
    }
    line(&methodInit.body, "auto " + a.usageName + " = man->get<" + assetType + ">(\"" + a.fileName + "\");", "");
    line(&methodAssets.body, "assets.push_back(man->get<" + assetType + ">(\"" + a.fileName + "\"));", "");
  };

  // Load self assets
  auto itAssets = info->root.assets.begin();
  while(itAssets != info->root.assets.end()) {
    processAsset(*itAssets);
    ++itAssets;
  }
  // TODO: Load child assets?
  line(&methodInit.body, "", "");

  // Process root and all of its children
  int32_t childNumber = 0;
  int32_t componentNumber = 0;

  auto processComponent = [&](struct PrefabComponent c, std::string item) {
    auto componentName = "cmp" + std::to_string(componentNumber++);
    bool_t componentInit = true;
    if(c.ref.size() > 0) {
      componentInit = false;
      componentName = c.ref;
      line(&classInfo.publicProperties, c.type + " *" + c.ref + " = nullptr;", "");
    }

    // Initialize
    line(&methodInit.body, (componentInit ? "auto " : "") + componentName + " = " + item + "->addComponent<" + c.type + ">();", "");

    // Now set each property
    auto itValues = c.values.begin();
    while(itValues != c.values.end()) {
      auto value = itValues->second;
      if(assetMap.find(value) != assetMap.end()) {
        value = assetMap[value];
      }
      line(&methodInit.body, componentName + "->" + itValues->first + " = " + value + ";", "");
      ++itValues;
    }

    classInfo.includes.push_back(c.include);
  };

  std::function<void(struct PrefabChild &, std::string)> processChild;
  processChild = [&](struct PrefabChild &child, std::string parent) {
    auto name = "itm" + std::to_string(childNumber++);
    bool_t init = true;
    if(child.ref.size() > 0) {
      init = false;
      name = child.ref;
      line(&classInfo.publicProperties, "SceneItemComponent *" + name + " = nullptr;", "");
    }
    line(&methodInit.body, (init ? "auto " : "") + name + " = scene->createSceneItem();", "");

    // Process extra properties
    if(child.position.size() > 0) {
      line(&methodInit.body, name + "->transform.setLocalPosition(" + child.position + ");", "");
    }

    if(child.scale.size() > 0) {
      line(&methodInit.body, name + "->transform.setLocalScale(" + child.scale + ");", "");
    }

    // Add components for children
    auto itComponents = child.components.begin();
    while(itComponents != child.components.end()) {
      auto c = *itComponents;
      processComponent(c, name);
      ++itComponents;
    }

    // Process sub children
    auto itChildren = child.children.begin();
    while(itChildren != child.children.end()) {
      processChild(*itChildren, name);
      ++itChildren;
    }

    // Set parent
    line(&methodInit.body, name + "->transform.setParent(&"+parent+"->transform);", "");
  };
  
  // Process each child
  auto itChildren = info->root.children.begin();
  while(itChildren != info->root.children.end()) {
    processChild(*itChildren, "this");
    line(&methodInit.body, "", "");
    ++itChildren;
  }

  // Process self components
  auto itComponents = info->root.components.begin();
  while(itComponents != info->root.components.end()) {
    auto c = *itComponents;
    processComponent(c, "this");
    ++itComponents;
  }
  
  // Seal methods
  line(&methodAssets.body, "return assets;", "");

  // Add in methods
  CodeGen::methodGen(&classInfo.publicCode, methodAssets);
  line(&classInfo.publicCode, "", "");
  CodeGen::methodGen(&classInfo.publicCode, methodInit);

  CodeGen::classGen(out, classInfo);
}