package services

import "time"

type SensorValuesService struct {
	ctx *Context
}

type sensorValue struct {
	Timestamp int64   `json:"timestamp"`
	Value     float64 `json:"value"`
}

func (s *SensorValuesService) Push(sensor string, value float64) (int64, error) {
	res, err := s.ctx.DB.Exec("INSERT INTO sensor_values (timestamp, sensor, value) VALUES (?, ?, ?)", time.Now().Unix(), sensor, value)

	if err != nil {
		return 0, err
	}

	return res.LastInsertId()
}

func (s *SensorValuesService) GetList(sensor string, from int64, to int64) ([]sensorValue, error) {
	var value float64
	var timestamp int64
	values := make([]sensorValue, 0)

	rows, err := s.ctx.DB.Query("SELECT timestamp, value FROM sensor_values WHERE sensor = ? AND timestamp > ? AND timestamp < ? ORDER BY timestamp ASC", sensor, from, to)

	if err != nil {
		return nil, err
	}

	defer rows.Close()

	for rows.Next() {
		err := rows.Scan(&timestamp, &value)
		if err != nil {
			return nil, err
		}

		values = append(values, sensorValue{Timestamp: timestamp, Value: value})
	}

	err = rows.Err()
	if err != nil {
		return nil, err
	}

	return values, nil
}

func (s *SensorValuesService) GetLatest(sensor string, to int64) (*sensorValue, error) {
	var value = sensorValue{}

	row := s.ctx.DB.QueryRow("SELECT timestamp, value FROM sensor_values WHERE sensor = ? timestamp < ? ORDER BY timestamp DESC LIMIT 1", sensor, to)

	err := row.Scan(&value.Timestamp, &value.Value)
	if err != nil {
		return nil, err
	}

	return &value, nil
}