package main

import (
	"strings"
	"time"

	todo "github.com/1set/todotxt"
)

type Frequency = int

const (
	Day Frequency = iota
	Week
	Month
	Quarter
	Year
)

var frequencyMap = map[string]Frequency{
	"day":      Day,
	"daily":    Day,
	"week":     Week,
	"weekly":   Week,
	"month":    Month,
	"monthly":  Month,
	"quarter":  Quarter,
	"quartery": Quarter,
	"year":     Year,
	"yearly":   Year,
}

func handleRecurringTask(task todo.Task) *todo.Task {
	freqValue := task.AdditionalTags["freq"]

	if freqValue != "" {
		newTask, _ := todo.ParseTask(task.Original)
		dueDate := getDueDate(task)
		frequency := frequencyMap[strings.ToLower(freqValue)]
		newTask.DueDate = getNextDueDate(dueDate, frequency)
		return newTask
	}

	return &todo.Task{}
}

func getNextDueDate(dueDate time.Time, frequency Frequency) time.Time {

	if dueDate.Before(time.Now()) {
		dueDate = time.Now()
	}

	switch frequency {
	case Day:
		return dueDate.AddDate(0, 0, 1)
	case Week:
		return dueDate.AddDate(0, 0, 7)
	case Month:
		return dueDate.AddDate(0, 1, 0)
	case Quarter:
		return dueDate.AddDate(0, 3, 0)
	case Year:
		return dueDate.AddDate(1, 0, 0)
	default:
		return dueDate
	}
}

func getDueDate(task todo.Task) time.Time {
	if task.HasDueDate() {
		return task.DueDate
	} else {
		return time.Now()
	}
}