#include "Project.hpp"

#include "Model/Workflow/Workflow.hpp"
#include "Utils/Macros.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(const fs::path& rootPath)
	: mRootPath{ rootPath }
	, mRootPathString{ mRootPath.string() }
	, Database(*this)
{
	// TODO better diagnostic
	const char* kInvalidFormatErr = "Failed to load project: invalid format.";

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

	{
		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()) {
			mName = name.asString();
		} else {
			throw std::runtime_error(kInvalidFormatErr);
		}
	}

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

	auto workflowsDir = mRootPath / "workflows";
	fs::create_directories(workflowsDir);

	for (auto& entry : fs::directory_iterator(workflowsDir)) {
		if (!entry.is_regular_file()) continue;
		auto& path = entry.path();
		if (path.extension() != ".cplt-workflow") continue;

		auto name = path.stem().string();
		auto [it, DISCARD] = mWorkflows.insert(name, WorkflowInfo{});
		auto& info = it.value();

		info.Name = std::move(name);
		info.PathStringCache = path.string();
		info.Path = path;
	}
}

Project::Project(std::filesystem::path rootPath, std::string name)
	: mRootPath{ std::move(rootPath) }
	, mRootPathString{ mRootPath.string() }
	, mName{ std::move(name) }
	, Database(*this)
{
}

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);
}

const decltype(Project::mWorkflows)& Project::GetWorkflows() const
{
	return mWorkflows;
}

std::unique_ptr<Workflow> Project::LoadWorkflow(std::string_view name)
{
	auto iter = mWorkflows.find(name);
	if (iter == mWorkflows.end()) {
		return iter.value().LoadFromDisk();
	} else {
		return nullptr;
	}
}

std::unique_ptr<Workflow> Project::CreateWorkflow(std::string_view name)
{
	if (mWorkflows.find(name) != mWorkflows.end()) {
		// Workflow with name already exists
		return nullptr;
	}

	auto workflow = std::make_unique<Workflow>();
	auto [it, DISCARD] = mWorkflows.insert(name, WorkflowInfo{});
	auto& info = it.value();

	info.Name = name;
	info.Path = GetWorkflowPath(name);

	return workflow;
}

bool Project::RemoveWorkflow(std::string_view name)
{
	auto iter = mWorkflows.find(name);
	if (iter == mWorkflows.end()) {
		return false;
	}
	auto& info = iter.value();

	fs::remove(info.Path);
	mWorkflows.erase(iter);

	return true;
}

bool Project::RenameWorkflow(std::string_view name, std::string_view newName)
{
	auto iter = mWorkflows.find(name);
	if (iter == mWorkflows.end()) return false;

	auto info = std::move(iter.value());

	auto& oldPath = info.Path;
	auto newPath = GetWorkflowPath(newName);
	fs::rename(oldPath, newPath);
	info.Path = std::move(newPath);

	mWorkflows.insert(newName, std::move(info));
	mWorkflows.erase(iter);

	return true;
}

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");
}

std::filesystem::path Project::GetDatabasesDirectory() const
{
	return mRootPath / "databases";
}

std::filesystem::path Project::GetItemsDirectory() const
{
	return mRootPath / "items";
}

std::filesystem::path Project::GetWorkflowsDirectory() const
{
	return mRootPath / "workflows";
}

std::filesystem::path Project::GetWorkflowPath(std::string_view name) const
{
	return (mRootPath / "workflows" / name).concat(".cplt-workflow");
}