package cz.muni.fi.books;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;
import org.springframework.jdbc.core.simple.SimpleJdbcInsert;
import org.springframework.transaction.annotation.Transactional;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.sql.DataSource;
import java.util.List;

/**
 * cz.muni.fi.books.Book manager class
 *
 * @author Martin Kacenga
 */
public class BookManagerImpl implements BookManager {
    private JdbcTemplate jdbc;

    final static Logger log = LoggerFactory.getLogger(BookManagerImpl.class);
    public BookManagerImpl(DataSource dataSource) {
        this.jdbc = new JdbcTemplate(dataSource);
    }

    @Override
    public void createBook(Book book) {
        if (book == null) {
            log.error("Null cannot he passed as argument.");
            throw new NullPointerException();
        }

        if (book.getName().equals("") || book.getAuthorName().equals("")) {
            log.error("Essential arguments from book are missing.");
            throw new IllegalArgumentException();
        }

        SimpleJdbcInsert insertBook = new SimpleJdbcInsert(jdbc)
                .withTableName("books").usingGeneratedKeyColumns("id");

        SqlParameterSource parameters = new MapSqlParameterSource()
                .addValue("name", book.getName())
                .addValue("author", book.getAuthorName())
                .addValue("publisher", book.getPublisher());
        log.debug("Creating book {}", book.getName());
        Number id = insertBook.executeAndReturnKey(parameters);
        book.setId(id.longValue());
    }

    @Override
    public Book getBookById(Long id) {
        if (id == null) {
            log.error("Book has no ID.");
            throw new NullPointerException();
        }
        log.debug("Getting book with {} ID", id);
        return jdbc.queryForObject("SELECT * FROM books WHERE id=?", bookMapper, id);
    }


    private RowMapper<Book> bookMapper = (rs, rowNum) ->
            new Book(rs.getLong("id"), rs.getString("name"), rs.getString("author"), rs.getString("publisher"));

    @Transactional
    @Override
    public List<Book> getAllBooks()  {
        log.debug("getting all books");
        return jdbc.query("SELECT * FROM books", bookMapper);
    }

    @Override
    public void updateBook(Book book) {
        throwPossibleExceptions(book);
        log.debug("Updating {0} book with {1}ID.", book.getName(), book.getId());
        jdbc.update("UPDATE books set name=?,author=? where id=?",
                book.getName(),
                book.getAuthorName(),
                book.getId());
    }

    @Override
    public void deleteBook(Book book) {
        throwPossibleExceptions(book);
        log.debug("Deleting {0} book with {1}ID.", book.getName(), book.getId());
        jdbc.update("DELETE FROM books WHERE id=?", book.getId());
    }

    private void throwPossibleExceptions(Book book) {
        if (book == null){
            log.error("Cannot do this operation with null argument.");
            throw new NullPointerException();
        }
        if (book.getId() == null) {
            log.error("ID cannot be set to NULL.");
            throw new IllegalArgumentException();
        }
    }
}