package remind

import (
	"b612.me/sdk/candy/when"
	"b612.me/stardb"
	"b612.me/startimer"
	"errors"
	"sync"
	"time"
)

type Remind struct {
	db       *stardb.StarDB
	tasks    map[int]RemindTask
	mu       sync.RWMutex
	callback func(remind RemindTask)
}

type RemindTask struct {
	ID      int    `db:"id"`
	Origin  string `db:"text"`
	timer   *startimer.StarTimer
	TmrInfo string `db:"code"`
	Key     string `db:"key"`
	Msg     []byte `db:"msg"`
}

func getCreateSql() []string {
	return []string{
		"CREATE TABLE IF NOT EXISTS remind(id INTEGER PRIMARY KEY AUTOINCREMENT,key VARCHAR(64),code TEXT,text TEXT,msg BLOB)",
		"CREATE INDEX IF NOT EXISTS key_idx ON remind (key)",
	}
}

func NewRemind(db *stardb.StarDB, callback func(task RemindTask)) (*Remind, error) {
	if db == nil || db.Db == nil {
		return nil, errors.New("Invalid hanlder of database")
	}
	if err := db.Ping(); err != nil {
		return nil, err
	}
	for _, sql := range getCreateSql() {
		_, err := db.Exec(sql)
		if err != nil {
			return nil, err
		}
	}
	return innerLoadDB(db, callback)
}

func innerLoadDB(db *stardb.StarDB, callback func(task RemindTask)) (*Remind, error) {
	var rem = Remind{
		db:       db,
		mu:       sync.RWMutex{},
		callback: callback,
	}
	var res []RemindTask
	data, err := db.Query("select * from remind")
	if err != nil {
		return nil, err
	}
	err = data.Orm(&res)
	if err != nil {
		return nil, err
	}
	if len(res) != 0 {
		rem.tasks = make(map[int]RemindTask, len(res))
		for _, task := range res {
			tmr := startimer.NewTimer(time.Now())
			err = tmr.ImportRepeats(task.TmrInfo)
			if err != nil {
				return nil, err
			}
			task.timer = &tmr
			task.timer.AddTask(func() {
				rem.callbackFn(task)
			})
			err = task.timer.Run()
			if err != nil {
				return nil, err
			}
			rem.tasks[task.ID] = task
		}
	}
	return &rem, nil
}

func (t RemindTask) GetTimer() startimer.StarTimer {
	return *t.timer
}
func (r *Remind) callbackFn(task RemindTask) {
	r.callback(task)
}

func (r *Remind) AddTask(taskStr, key string, msg []byte) (RemindTask, error) {
	tmr, err := when.WhenWithPeriod(taskStr)
	if err != nil {
		return RemindTask{}, err
	}
	exp, err := tmr.ExportRepeats()
	if err != nil {
		return RemindTask{}, err
	}
	var rmt = RemindTask{
		Origin:  taskStr,
		TmrInfo: exp,
		Key:     key,
		Msg:     msg,
		timer:   &tmr,
	}
	rmt.timer.AddTask(func() {
		r.callbackFn(rmt)
	})
	res, err := r.db.Insert(rmt, "remind", "id")
	if err != nil {
		return RemindTask{}, err
	}
	id, err := res.LastInsertId()
	if err != nil {
		return RemindTask{}, err
	}
	rmt.ID = int(id)
	r.mu.Lock()
	r.tasks[rmt.ID] = rmt
	r.mu.Unlock()
	rmt.timer.Run()
	return rmt, nil
}

func (r *Remind) DeleteTask(id int) error {
	r.mu.RLock()
	data, ok := r.tasks[id]
	r.mu.RUnlock()
	if !ok {
		return errors.New("no such id")
	}
	r.mu.Lock()
	defer r.mu.Unlock()
	err := data.timer.Stop()
	if err != nil {
		return err
	}
	_, err = r.db.Exec("delete from remind where id=?", id)
	if err != nil {
		return err
	}
	delete(r.tasks, id)
	return nil
}