package io.trygvis.queue;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collections;
import java.util.Date;
import java.util.List;

import static java.util.Arrays.asList;
import static org.springframework.transaction.annotation.Propagation.MANDATORY;

@Component
public class TaskDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Transactional(propagation = MANDATORY)
    public long insert(String queue, Date scheduled, String arguments) {
        jdbcTemplate.update("INSERT INTO task(id, run_count, queue, scheduled, arguments) " +
                "VALUES(nextval('task_seq'), 0, ?, ?, ?)", queue, scheduled, arguments);
        return jdbcTemplate.queryForObject("SELECT currval('task_seq')", Long.class);
    }

    @Transactional(propagation = MANDATORY)
    public Task findById(long id) {
        return jdbcTemplate.queryForObject("SELECT " + TaskRowMapper.fields + " FROM task WHERE id=?",
                new TaskRowMapper(), id);
    }

    @Transactional(propagation = MANDATORY)
    public List<Task> findByNameAndCompletedIsNull(String name) {
        return jdbcTemplate.query("SELECT " + TaskRowMapper.fields + " FROM task WHERE queue=? AND completed IS NULL",
                new TaskRowMapper(), name);
    }

    @Transactional(propagation = MANDATORY)
    public void update(Task task) {
        jdbcTemplate.update("UPDATE task SET scheduled=?, last_run=?, run_count=?, completed=? WHERE id=?",
                task.scheduled, task.lastRun, task.runCount, task.completed, task.id);
    }

    private class TaskRowMapper implements RowMapper<Task> {
        public static final String fields = "id, queue, scheduled, last_run, run_count, completed, arguments";

        public Task mapRow(ResultSet rs, int rowNum) throws SQLException {
            String arguments = rs.getString(7);
            return new Task(
                    rs.getLong(1),
                    rs.getString(2),
                    rs.getTimestamp(3),
                    rs.getTimestamp(4),
                    rs.getInt(5),
                    rs.getTimestamp(6),
                    arguments != null ? asList(arguments.split(" ")) : Collections.<String>emptyList());
        }
    }
}