package main

import (
	"errors"
	"log"
	"regexp"
	"time"
)

type Entry struct {
	Id      int
	Date    Date
	From    *Time
	To      *Time
	Tasks   map[int]*time.Duration
	Comment string
}

type Task struct {
	Id    int
	Group *string
	Ident *string
	Text  string
}

type Date string

type Time string

type EntrySubDuration string

var (
	timeMatch = regexp.MustCompile("[0-9]{2}:[0-9]{2}")
	dateMatch = regexp.MustCompile("[0-9]{4}-[0-9]{2}-[0-9]{2}")
	subDurationMatch = regexp.MustCompile("[0-9]")
)

var (
	ErrInvalidTime = errors.New("Invalid time string")
	ErrInvalidDate = errors.New("Invalid date string")
)

func NewEntry(date Date) *Entry {
	return &Entry{
		Id:      -1,
		From:    nil,
		Date:    date,
		To:      nil,
		Tasks:   map[int]*time.Duration{},
		Comment: "",
	}

}

func NewTask() *Task {
	return &Task{
		Id:    -1,
		Group: nil,
		Ident: nil,
		Text:  "",
	}
}

func TimeFromStd(time time.Time) Time {
	return Time(time.Format("15:04"))
}

func TimeFromString(str string) (*Time, error) {
	if str == "" {
		return nil, nil
	}

	matched := timeMatch.MatchString(str)
	if !matched {
		return nil, ErrInvalidTime
	}
	time := Time(str)
	return &time, nil
}

func DateFromStd(time time.Time) Date {
	return Date(time.Format("2006-01-02"))
}

func DateFromString(str string) (*Date, error) {
	if str == "" {
		return nil, nil
	}

	matched := dateMatch.MatchString(str)
	if !matched {
		return nil, ErrInvalidTime
	}
	date := Date(str)
	return &date, nil
}

func (d Date) ToStd() time.Time {
	t, err := time.Parse("2006-01-02", string(d))
	if err != nil {
		log.Fatal(err)
	}
	return t
}