package switchcounter

import (
	"encoding/csv"
	"io"
	"log"
	"strconv"
	"time"

	"github.com/celrenheit/sandflake"
)

type Switch struct {
	ID        string        `json:"id"`
	Who       string        `json:"who"`
	StartedAt time.Time     `json:"started_at"`
	EndedAt   *time.Time    `json:"ended_at"`
	Duration  time.Duration `json:"duration"`
}

//                  2020-01-04 13:42:13 UTC
const timeFormat = `2006-01-02 15:04:05 MST`

func (s *Switches) ImportCSV(r io.Reader) ([]Switch, error) {
	var result []Switch
	rd := csv.NewReader(r)
	rows, err := rd.ReadAll()
	if err != nil {
		return nil, err
	}

	for _, row := range rows[1:] {
		log.Printf("%v", row)
		startedAtVal := row[1]
		endedAtVal := row[2]

		startedAt, err := time.Parse(timeFormat, startedAtVal)
		if err != nil {
			return nil, err
		}

		endedAt, err := time.Parse(timeFormat, endedAtVal)
		if err != nil {
			return nil, err
		}

		lenSeconds, err := strconv.ParseInt(row[3], 10, 64)
		if err != nil {
			return nil, err
		}

		g := sandflake.NewFixedTimeGenerator(startedAt)
		id := g.Next()
		sw := Switch{
			ID:        id.String(),
			Who:       row[0],
			StartedAt: startedAt,
			EndedAt:   &endedAt,
			Duration:  time.Duration(lenSeconds) * time.Second,
		}

		result = append(result, sw)
	}

	return result, nil
}