#include "Project.hpp"

#include <json/reader.h>
#include <json/value.h>
#include <json/writer.h>
#include <filesystem>
#include <fstream>
#include <stdexcept>
#include <utility>

namespace fs = std::filesystem;

template <class T>
void ReadItemList(ItemList<T>& list, const fs::path& filePath) {
	std::ifstream ifs(filePath);
	if (ifs) {
		Json::Value root;
		ifs >> root;

		list = ItemList<T>(root);
	}
}

Project Project::Load(const fs::path& projectFilePath) {
	// TODO better diagnostic
	const char* kInvalidFormatErr = "Failed to load project: invalid format.";

	std::ifstream ifs(projectFilePath);
	if (!ifs) {
		std::string message;
		message += "Failed to load project file at '";
		message += projectFilePath.string();
		message += "'.";
		throw std::runtime_error(message);
	}

	Project proj;
	proj.mRootPath = projectFilePath.parent_path();
	proj.mRootPathString = proj.mRootPath.string();

	{
		Json::Value root;
		ifs >> root;

		const auto& croot = root; // Use const reference so that accessors default to returning a null if not found, instead of silently creating new elements
		if (!croot.isObject()) {
			throw std::runtime_error(kInvalidFormatErr);
		}

		if (auto& name = croot["Name"]; name.isString()) {
			proj.mName = name.asString();
		} else {
			throw std::runtime_error(kInvalidFormatErr);
		}
	}

	auto itemsDir = proj.mRootPath / "items";
	ReadItemList(proj.Products, itemsDir / "products.json");
	ReadItemList(proj.Factories, itemsDir / "factories.json");
	ReadItemList(proj.Customers, itemsDir / "customers.json");

	return proj;
}

Project Project::LoadDir(const std::filesystem::path& projectPath) {
	return Load(projectPath / "cplt_project.json");
}

Project Project::Create(std::string name, const fs::path& path) {
	Project proj;
	proj.mRootPath = path;
	proj.mRootPathString = path.string();
	proj.mName = std::move(name);
	return proj;
}

const fs::path& Project::GetPath() const {
	return mRootPath;
}

const std::string& Project::GetPathString() const {
	return mRootPathString;
}

const std::string& Project::GetName() const {
	return mName;
}

void Project::SetName(std::string name) {
	mName = std::move(name);
}

Json::Value Project::Serialize() {
	Json::Value root(Json::objectValue);

	root["Name"] = mName;

	return root;
}

template <class T>
static void WriteItemList(ItemList<T>& list, const fs::path& filePath) {
	std::ofstream ofs(filePath);
	ofs << list.Serialize();
}

void Project::WriteToDisk() {
	std::ofstream ofs(mRootPath / "cplt_project.json");
	ofs << this->Serialize();

	auto itemsDir = mRootPath / "items";
	fs::create_directories(itemsDir);

	WriteItemList(Products, itemsDir / "products.json");
	WriteItemList(Factories, itemsDir / "factories.json");
	WriteItemList(Customers, itemsDir / "customers.json");
}