#include "crow.h"
#include "crow/middlewares/cors.h"

#include <driver.h>
#include <statement.h>
#include <prepared_statement.h>

using namespace sql;
using namespace std;

Driver *driver;
Connection *con;
Statement *stmt;
PreparedStatement *prep_stmt;

void exiting(){
	delete con;
	delete stmt;
}

void connect(){
	con = driver->connect(getenv("DBURL"),getenv("DBUSER"),getenv("DBPWD"));
	con->setSchema("practice");
	stmt = con->createStatement();
}

int main()
{
	crow::App<crow::CORSHandler> app;

	driver = get_driver_instance();

	CROW_ROUTE(app, "/sessions").methods(crow::HTTPMethod::POST)([](const crow::request& req){
		connect();
		crow::json::wvalue status;
		auto request_body = crow::json::load(req.body);
		int new_session_id;
		if(request_body.has("comments")){

			prep_stmt = con->prepareStatement("INSERT INTO practice_sessions (description, seconds, comments, practice_category_id) VALUES (?, ?, ?, ?) RETURNING id");

			string description = request_body["description"].s();
			int seconds = request_body["seconds"].i();
			string comments = request_body["comments"].s();
			int practice_category_id = request_body["practice_category_id"].i();

			prep_stmt->setString(1, description);
			prep_stmt->setInt(2, seconds);
			prep_stmt->setString(3, comments);
			prep_stmt->setInt(4, practice_category_id);
			ResultSet *res = prep_stmt->executeQuery();
			res->next();
			new_session_id = res->getInt("id");

		} else {

			prep_stmt = con->prepareStatement("INSERT INTO practice_sessions (description, seconds, practice_category_id) VALUES (?, ?, ?) RETURNING id");

			string description = request_body["description"].s();
			int seconds = request_body["seconds"].i();
			int practice_category_id = request_body["practice_category_id"].i();

			prep_stmt->setString(1, description);
			prep_stmt->setInt(2, seconds);
			prep_stmt->setInt(3, practice_category_id);
			ResultSet *res = prep_stmt->executeQuery();
			res->next();
			new_session_id = res->getInt("id");

		}

		if(request_body.has("songs")){
			for(const auto& song : request_body["songs"]){
				prep_stmt = con->prepareStatement("INSERT INTO songs_practiced (practice_session_id, song_id) VALUES (?, ?)");
				prep_stmt->setInt(1, new_session_id);
				prep_stmt->setInt(2, int(song["id"]));
				prep_stmt->execute();
			}
		}

		status = {{"status", "success"}};
		return status;
	});

	CROW_ROUTE(app, "/songs")([](){
		connect();
		crow::json::wvalue entries;

		ResultSet *res = stmt->executeQuery("SELECT * FROM songs WHERE learned=True ORDER BY title ASC;");

		int i = 0;
		while (res->next()) {
			int id = res->getInt("id");
			string title = res->getString("title");
			string notes = res->getString("notes");
			entries[i] = {{"id", id}, {"title", title}, {"notes", notes}};
			i++;
		}

		delete res;
		return entries;
	});

	CROW_ROUTE(app, "/instruments")([](){
		connect();
		crow::json::wvalue entries;

		ResultSet *res = stmt->executeQuery("SELECT * FROM instruments");

		int i = 0;
		while (res->next()) {
			int id = res->getInt("id");
			string instrument = res->getString("name");
			entries[i] = {{"id", id}, {"name", instrument}};
			i++;
		}

		delete res;
		return entries;
	});

	CROW_ROUTE(app, "/categories")([](){
		connect();
		crow::json::wvalue entries;

		ResultSet *res = stmt->executeQuery("SELECT practice_categories.id, practice_categories.name AS category, instruments.name AS instrument FROM practice_categories JOIN instruments ON practice_categories.instrument_id = instruments.id ORDER BY practice_categories.id ASC");

		int i = 0;
		while (res->next()) {
			int id = res->getInt("id");
			string category = res->getString("category");
			string instrument = res->getString("instrument");
			entries[i] = {{"id", id}, {"category", category}, {"instrument", instrument}};
			i++;
		}

		delete res;
		return entries;
	});

	CROW_ROUTE(app, "/summary")([](){
		connect();
		crow::json::wvalue entries;

		ResultSet *res = stmt->executeQuery("SELECT * FROM summary ORDER BY chunks_practiced ASC;");

		int i = 0;
		while (res->next()) {
			int category_id = res->getInt("category_id");
			string category = res->getString("category");
			string instrument = res->getString("instrument");
			double chunks_practiced = res->getDouble("chunks_practiced"); 
			int weight = res->getInt("weight");
			entries[i] = {{"category_id", category_id}, {"category", category}, {"instrument", instrument}, {"chunks_practiced", chunks_practiced}, {"weight", weight}};
			i++;
		}

		delete res;
		return entries;
	});

	CROW_ROUTE(app, "/status")([](){
		connect();
		crow::json::wvalue entries;

		ResultSet *res = stmt->executeQuery("SELECT * FROM practice_status;");
		res->next();
		int practiced = res->getInt("seconds_practiced_today"); 
		int left = res->getInt("seconds_left"); 
		int to_get_ahead = res->getInt("seconds_left_to_get_ahead"); 

		entries = {{"seconds_practiced", practiced}, {"seconds_left_to_practice_today", left}, {"seconds_left_to_get_ahead", to_get_ahead}};

		delete res;
		return entries;
	});

	CROW_ROUTE(app, "/show-category/<int>")([](int category_id){
		connect();
		crow::json::wvalue entries;

		prep_stmt = con->prepareStatement("SELECT practice_sessions.id, practice_sessions.description, seconds, songs.id AS song_id, songs.title, comments, created_at, practice_categories.name AS category, instruments.name AS instrument "
				"FROM practice_sessions JOIN practice_categories ON practice_category_id = practice_categories.id "
				"JOIN instruments ON instrument_id = instruments.id "
				"LEFT JOIN songs_practiced ON practice_sessions.id = songs_practiced.practice_session_id "
				"LEFT JOIN songs ON songs_practiced.song_id = songs.id WHERE practice_category_id = ? ORDER BY practice_sessions.id DESC;");
		prep_stmt->setInt(1, category_id);
		ResultSet *res = prep_stmt->executeQuery();

		int i = -1;
		int previous_session_id = 0;
		int current_song_index;
		while (res->next()) {

			int id = res->getInt("id");
			string description = res->getString("description");
			int seconds = res->getInt("seconds");
			string comments = res->getString("comments");
			string created_at = res->getString("created_at");
			string category = res->getString("category");
			string instrument = res->getString("instrument");
			int song_id = res->getInt("song_id");
			string song_title = res->getString("title");

			if(id != previous_session_id){
				i++;

				previous_session_id = id;
				current_song_index = 0;
				crow::json::wvalue songs = crow::json::wvalue::list();
				if(song_id != 0){
					songs[current_song_index] = {
						{"id", song_id},
						{"title", song_title}
					};
				}

				entries[i] = {
					{"id", id},
					{"description", description},
					{"seconds", seconds},
					{"comments", comments},
					{"created_at", created_at},
					{"category", category},
					{"instrument", instrument},
					{"songs", songs}
				};
				current_song_index++;
			} else {
				entries[i]["songs"][current_song_index] = {
						{"id", song_id},
						{"title", song_title}
				};
				current_song_index++;
			}

		}
		delete res;
		return entries;
	});

	app.port(18080).run();

	atexit(exiting);
}