#pragma once


#include <iostream>
#include <utility>
#include <vector>
#include <map>

enum class IndexedDataType {
	integer,
	string
};


template <typename K>
class Index {
public:
	Index(std::string index_name, std::string col_name, IndexedDataType type) :
			m_index_name(std::move(index_name)), m_column_name(std::move(col_name)),
			m_data_type(type), m_uniq(false) {}

	void insert(K key, int rowid) {
		// std::cout << "inserting key: " << key << " val: " << rowid << std::endl;
		
		// TODO handle uniqueness
		auto search = m_index.find(key);
		if (search != m_index.end()) {
			search->second.push_back(rowid);
		} else {
			std::vector<int> rowids{rowid};
			m_index[key] = rowids;
  		}
	}

	void update(K old_key, K new_key, int rowid) {
		// std::cout << "updating key: " << old_key << " to: " << new_key << " val: " <<  rowid << std::endl;

		// TODO handle uniqueness
	}

	void remove(K key, int rowid) {
		// std::cout << "removing key: " << key << " val: " <<  rowid << std::endl;

		auto search = m_index.find(key);
		if (search != m_index.end()) {
			search->second.erase(find(search->second.begin(), search->second.end(), rowid));
  		}
	}

	std::vector<int> search(K key) {
		// std::cout << "returning rowids for key: " << key << std::endl;

		auto search = m_index.find(key);
		if (search != m_index.end()) {
			return search->second;
		} else {
			return std::vector<int>{};
  		}
	}

	void truncate() {
		// std::cout << "truncating" << std::endl;
		m_index.clear();
	}

	void dump() {
		std::for_each(m_index.begin(), m_index.end(),
			      [](std::pair<K, std::vector<int>> element){
			K key = element.first;
			std::vector<int> rowids = element.second;
			std::cout << "key: " << key << ",  rowids count:" << rowids.size() << std::endl;
		});
	}

	[[nodiscard]] const std::string &get_column_name() const {
	    return m_column_name;
	}

	[[nodiscard]] const std::string &get_index_name() const {
		return m_index_name;
	}

	[[nodiscard]] IndexedDataType get_data_type() const {
		return m_data_type;
	}
	
private:
	bool m_uniq;
	std::string m_index_name;
	std::string m_column_name;
	IndexedDataType m_data_type;

// DEBUG for debug it is public
public:
	std::map<K, std::vector<int> >	m_index;
};