package main

import (
	"log/slog"
	"time"

	"go-mod.ewintr.nl/planner/item"
)

type Recur struct {
	repo   Recurrer
	logger *slog.Logger
}

func NewRecur(repo Recurrer, interval time.Duration, logger *slog.Logger) *Recur {
	r := &Recur{
		repo:   repo,
		logger: logger,
	}
	go r.run(interval)

	return r
}

func (r *Recur) run(interval time.Duration) {
	ticker := time.NewTicker(interval)

	for range ticker.C {
		if err := r.recur(); err != nil {
			r.logger.Error("could not recur", "error", err)
		}
	}
}

func (r *Recur) recur() error {
	items, err := r.repo.RecursBefore(time.Now())
	if err != nil {
		return err
	}
	for _, i := range items {
		if err := r.repo.RecursNext(i.ID, NewNext(i.Recurrer, i.RecurNext)); err != nil {
			return err
		}
	}

	return nil
}

func NewNext(r *item.Recur, old time.Time) time.Time {
	day, _ := time.ParseDuration("1d")
	test := old.Add(day)
	for {
		if r.On(test) || test.After(time.Date(2500, 1, 1, 0, 0, 0, 0, time.UTC)) {
			return test
		}
		test.Add(day)
	}
}