package log

import (
	"sync"
	"time"

	"github.com/globalsign/mgo/bson"
)

var scheduleCharacterUpdate = func() func() {
	var mutex sync.Mutex
	var scheduled bool

	return func() {
		mutex.Lock()
		if !scheduled {
			go func() {
				time.Sleep(time.Second * 60)

				// If another comes along in the next 2-3 seconds, it should schedule a new
				// round to avoid a character only appearing in half their logs.
				mutex.Lock()
				scheduled = false
				mutex.Unlock()

				UpdateAllCharacters()
			}()

			scheduled = true
		}
		mutex.Unlock()
	}
}()

// ScheduleCharacterUpdate schedules a full update within the minute.
// Subsequent calls within that time will not schedule anything. Even
// if the operation takes a few seconds at most, it need not be ran often.
func ScheduleCharacterUpdate() {
	scheduleCharacterUpdate()
}

// UpdateCharacters is a shorthand for getting a log and updaing its characters
func UpdateCharacters(logID string) error {
	log, err := FindID(logID)
	if err != nil {
		return err
	}

	return log.UpdateCharacters()
}

// UpdateAllCharacters updates character list on all logs. This should
// be done if one or more characters failed to be added.
func UpdateAllCharacters() (updated int, err error) {
	updated = 0

	err = clearUnknownNicks()
	if err != nil {
		return
	}

	iter := iterLogs(bson.M{}, 0)
	err = iter.Err()
	if err != nil {
		return
	}

	log := Log{}
	for iter.Next(&log) {
		err = log.UpdateCharacters()
		if err != nil {
			return
		}

		updated++
	}

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

	return
}