package be.jeffcheasey88.peeratcode.repository;

import be.jeffcheasey88.peeratcode.model.Chapter;
import be.jeffcheasey88.peeratcode.model.Puzzle;
import com.password4j.Hash;
import com.password4j.Password;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class DatabaseRepo {
	private static final String SPECIFIC_PUZZLE_QUERY = "SELECT * FROM puzzle WHERE id_puzzle = ?";
	private static final String SPECIFIC_CHAPTER_QUERY = "SELECT * FROM chapter WHERE id_chapter = ?";
	private static final String PUZZLES_IN_CHAPTER_QUERY = "SELECT * FROM puzzle WHERE fk_chapter = ?";
	private static final String ALL_CHAPTERS_QUERY = "SELECT * FROM chapter";
	private static final String CHECK_PSEUDO_AVAILABLE_QUERY = "SELECT * FROM user WHERE pseudo = ?";
	private static final String CHECK_EMAIL_AVAILABLE_QUERY = "SELECT * FROM user WHERE email = ?";
	private static final String REGISTER_QUERY = "INSERT INTO user (pseudo, email, passwd, firstname, lastname, description, `group`, avatar) VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
	private static final String PASSWORD_FOR_EMAIL_QUERY = "SELECT passwd FROM user WHERE pseudo = ?";
	private final Connection con;

	public DatabaseRepo(Connection con) {
		this.con = con;
	}

	private Puzzle makePuzzle(ResultSet puzzleResult) throws SQLException {
		return new Puzzle(puzzleResult.getInt("id_puzzle"), puzzleResult.getString("name"), puzzleResult.getString("content"));
	}

	private Chapter makeChapter(ResultSet chapterResult) throws SQLException {
		return new Chapter(chapterResult.getInt("id_chapter"), chapterResult.getString("name"));
	}

	private List<Puzzle> getPuzzlesInChapter(int id) throws SQLException {
		List<Puzzle> puzzles = new ArrayList<>();
		PreparedStatement puzzleStmt = con.prepareStatement(PUZZLES_IN_CHAPTER_QUERY);
		puzzleStmt.setInt(1, id);
		ResultSet puzzleResult = puzzleStmt.executeQuery();
		while (puzzleResult.next()) {
			puzzles.add(makePuzzle(puzzleResult));
		}
		return puzzles;
	}

	/**
	 * Get a specific puzzle
	 *
	 * @param id The id of the puzzle
	 * @return The puzzle or null if an error occurred
	 */
	public Puzzle getPuzzle(int id) {
		try {
			PreparedStatement puzzleStmt = con.prepareStatement(SPECIFIC_PUZZLE_QUERY);
			puzzleStmt.setInt(1, id);
			ResultSet puzzleResult = puzzleStmt.executeQuery();
			if (puzzleResult.next()) {
				return makePuzzle(puzzleResult);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * Get a specific chapter
	 *
	 * @param id The id of the chapter
	 * @return The chapter or null if an error occurred
	 */
	public Chapter getChapter(int id) {
		try {
			PreparedStatement chapterStmt = con.prepareStatement(SPECIFIC_CHAPTER_QUERY);
			chapterStmt.setInt(1, id);
			ResultSet chapterResult = chapterStmt.executeQuery();
			if (chapterResult.next()) {
				Chapter chapter = makeChapter(chapterResult);
				List<Puzzle> puzzles = getPuzzlesInChapter(id);
				chapter.setPuzzles(puzzles);
				return chapter;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * Get all chapters in the database
	 *
	 * @return List of all chapters or null if an error occurred
	 */
	public List<Chapter> getAllChapters() {
		try {
			List<Chapter> chapterList = new ArrayList<>();
			PreparedStatement chapterStmt = con.prepareStatement(ALL_CHAPTERS_QUERY);
			ResultSet chapterResult = chapterStmt.executeQuery();
			while (chapterResult.next()) {
				Chapter chapter = makeChapter(chapterResult);
				chapter.setPuzzles(getPuzzlesInChapter(chapter.getId()));
				chapterList.add(chapter);
			}
			return chapterList;
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * Check if a pseudo is available
	 *
	 * @param pseudo The pseudo to check
	 * @return True if the pseudo is available, false if it's already taken
	 */
	public boolean checkPseudoAvailability(String pseudo) {
		return checkAvailability(pseudo, CHECK_PSEUDO_AVAILABLE_QUERY);
	}

	/**
	 * Check if an email is available
	 *
	 * @param email The email to check
	 * @return True if the email is available, false if it's already taken
	 */
	public boolean checkEmailAvailability(String email) {
		return checkAvailability(email, CHECK_EMAIL_AVAILABLE_QUERY);
	}

	private boolean checkAvailability(String queriedString, String correspondingQuery) {
		try {
			PreparedStatement statement = con.prepareStatement(correspondingQuery);
			statement.setString(1, queriedString);
			ResultSet result = statement.executeQuery();
			return !result.next();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return false;
	}

	/**
	 * Register a new user
	 *
	 * @param pseudo      The pseudo of the user
	 * @param email       The email of the user
	 * @param password    The password of the user
	 * @param firstname   The firstname of the user
	 * @param lastname    The lastname of the user
	 * @param description The description of the user
	 * @param group       The group of the user
	 * @param avatar      The avatar of the user
	 * @return True if the user was registered, false if an error occurred
	 */
	public boolean register(String pseudo, String email, String password, String firstname, String lastname, String description, String group, String avatar) {
		Hash hash = Password.hash(password).withArgon2();
		try {
			PreparedStatement statement = con.prepareStatement(REGISTER_QUERY);
			statement.setString(1, pseudo);
			statement.setString(2, email);
			statement.setString(3, hash.toString());
			statement.setString(4, firstname);
			statement.setString(5, lastname);
			statement.setString(6, description);
			statement.setString(7, group);
			statement.setString(8, avatar);
			return statement.executeUpdate() == 1;
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return false;
	}

	/**
	 * Login a user
	 *
	 * @param email    The email of the user
	 * @param password The password of the user
	 * @return True if the user's information are correct, false otherwise (or if an error occurred)
	 */
	public boolean login(String email, String password) {
		try {
			PreparedStatement statement = con.prepareStatement(PASSWORD_FOR_EMAIL_QUERY);
			statement.setString(1, email);
			statement.setString(2, password);
			ResultSet result = statement.executeQuery();
			if (result.next()) {
				String hashedPassword = result.getString("passwd");
				return Password.check(password, hashedPassword).withArgon2();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return false;
	}
}