package common

import (
	"fmt"
	"log"
	"strconv"
	"strings"
	"sync/atomic"
	"time"

	qgen "github.com/Azareal/Gosora/query_gen"
	"github.com/Azareal/Gosora/uutils"
	"github.com/pkg/errors"
)

var CTickLoop *TickLoop

type TickLoop struct {
	HalfSec    *time.Ticker
	Sec        *time.Ticker
	FifteenMin *time.Ticker
	Hour       *time.Ticker
	Day        *time.Ticker

	HalfSecf    func() error
	Secf        func() error
	FifteenMinf func() error
	Hourf       func() error
	Dayf        func() error
}

func NewTickLoop() *TickLoop {
	return &TickLoop{
		// TODO: Write tests for these
		// Run this goroutine once every half second
		HalfSec:    time.NewTicker(time.Second / 2),
		Sec:        time.NewTicker(time.Second),
		FifteenMin: time.NewTicker(15 * time.Minute),
		Hour:       time.NewTicker(time.Hour),
		Day:        time.NewTicker(time.Hour * 24),
	}
}

func (l *TickLoop) Loop() {
	r := func(e error) {
		if e != nil {
			LogError(e)
		}
	}
	defer EatPanics()
	for {
		select {
		case <-l.HalfSec.C:
			r(l.HalfSecf())
		case <-l.Sec.C:
			r(l.Secf())
		case <-l.FifteenMin.C:
			r(l.FifteenMinf())
		case <-l.Hour.C:
			r(l.Hourf())
		// TODO: Handle the instance going down a lot better
		case <-l.Day.C:
			r(l.Dayf())
		}
	}
}

var ErrDBDown = errors.New("The database is down")

func DBTimeout() time.Duration {
	if Dev.HourDBTimeout {
		return time.Hour
	}
	//db.SetConnMaxLifetime(time.Second * 60 * 5) // Make this infinite as the temporary lifetime change will purge the stale connections?
	return -1
}

var pint int64

func StartTick() (abort bool) {
	opint := pint
	db := qgen.Builder.GetConn()
	isDBDown := atomic.LoadInt32(&IsDBDown)
	if e := db.Ping(); e != nil {
		// TODO: There's a bit of a race here, but it doesn't matter if this error appears multiple times in the logs as it's capped at three times, we just want to cut it down 99% of the time
		if isDBDown == 0 {
			db.SetConnMaxLifetime(time.Second / 4) // Drop all the connections and start over
			LogWarning(e, ErrDBDown.Error())
		}
		atomic.StoreInt32(&IsDBDown, 1)
		return true
	}
	if isDBDown == 1 {
		log.Print("The database is back")
	}
	db.SetConnMaxLifetime(DBTimeout())
	atomic.StoreInt32(&IsDBDown, 0)
	return opint != pint
}

// TODO: Move these into DailyTick() methods?
func asmMatches() error {
	// TODO: Find a more efficient way of doing this
	return qgen.NewAcc().Select("activity_stream").Cols("asid").EachInt(func(asid int) error {
		if ActivityMatches.CountAsid(asid) > 0 {
			return nil
		}
		return Activity.Delete(asid)
	})
}

// TODO: Name the tasks so we can figure out which one it was when something goes wrong? Or maybe toss it up WithStack down there?
func RunTasks(tasks []func() error) error {
	for _, task := range tasks {
		if e := task(); e != nil {
			return e
		}
	}
	return nil
}

/*func init() {
	DbInits.Add(func(acc *qgen.Accumulator) error {
		replyStmts = ReplyStmts{
			isLiked:                acc.Select("likes").Columns("targetItem").Where("sentBy=? and targetItem=? and targetType='replies'").Prepare(),
		}
		return acc.FirstError()
	})
}*/

func StartupTasks() (e error) {
	r := func(ee error) {
		if e == nil {
			e = ee
		}
	}
	if Config.DisableRegLog {
		r(RegLogs.Purge())
	}
	if Config.DisableLoginLog {
		r(LoginLogs.Purge())
	}
	if Config.DisablePostIP {
		// TODO: Clear the caches?
		r(Topics.ClearIPs())
		r(Rstore.ClearIPs())
		r(Prstore.ClearIPs())
	}
	if Config.DisablePollIP {
		r(Polls.ClearIPs())
	}
	if Config.DisableLastIP {
		r(Users.ClearLastIPs())
	}
	return e
}

func Dailies() (e error) {
	if e = asmMatches(); e != nil {
		return e
	}
	newAcc := func() *qgen.Accumulator {
		return qgen.NewAcc()
	}
	exec := func(ac qgen.AccExec) {
		if e != nil {
			return
		}
		_, ee := ac.Exec()
		e = ee
	}
	r := func(ee error) {
		if e == nil {
			e = ee
		}
	}

	if Config.LogPruneCutoff > -1 {
		// TODO: Clear the caches?
		if !Config.DisableLoginLog {
			r(LoginLogs.DeleteOlderThanDays(Config.LogPruneCutoff))
		}
		if !Config.DisableRegLog {
			r(RegLogs.DeleteOlderThanDays(Config.LogPruneCutoff))
		}
	}

	if !Config.DisablePostIP && Config.PostIPCutoff > -1 {
		// TODO: Use unixtime to remove this MySQLesque logic?
		f := func(tbl string) {
			exec(newAcc().Update(tbl).Set("ip=''").DateOlderThan("createdAt", Config.PostIPCutoff, "day").Where("ip!=''"))
		}
		f("topics")
		f("replies")
		f("users_replies")
	}

	if !Config.DisablePollIP && Config.PollIPCutoff > -1 {
		// TODO: Use unixtime to remove this MySQLesque logic?
		exec(newAcc().Update("polls_votes").Set("ip=''").DateOlderThan("castAt", Config.PollIPCutoff, "day").Where("ip!=''"))

		// TODO: Find some way of purging the ip data in polls_votes without breaking any anti-cheat measures which might be running... maybe hash it instead?
	}

	// TODO: lastActiveAt isn't currently set, so we can't rely on this to purge last_ips of users who haven't been on in a while
	if !Config.DisableLastIP && Config.LastIPCutoff > 0 {
		//exec(newAcc().Update("users").Set("last_ip='0'").DateOlderThan("lastActiveAt",c.Config.PostIPCutoff,"day").Where("last_ip!='0'"))
		mon := time.Now().Month()
		exec(newAcc().Update("users").Set("last_ip=''").Where("last_ip!='' AND last_ip NOT LIKE '" + strconv.Itoa(int(mon)) + "-%'"))
	}

	if e != nil {
		return e
	}
	if e = Tasks.Day.Run(); e != nil {
		return e
	}
	if e = ForumActionStore.DailyTick(); e != nil {
		return e
	}

	{
		e := Meta.SetInt64("lastDaily", time.Now().Unix())
		if e != nil {
			return e
		}
	}

	return nil
}

type TickWatch struct {
	Name      string
	Start     int64
	DBCheck   int64
	StartHook int64
	Tasks     int64
	EndHook   int64

	Ticker     *time.Ticker
	Deadline   *time.Ticker
	EndChan    chan bool
	OutEndChan chan bool
}

func NewTickWatch() *TickWatch {
	return &TickWatch{
		Ticker:   time.NewTicker(time.Second * 5),
		Deadline: time.NewTicker(time.Hour),
	}
}

func (w *TickWatch) DumpElapsed() {
	var sb strings.Builder
	f := func(str string) {
		sb.WriteString(str)
	}
	ff := func(str string, args ...interface{}) {
		f(fmt.Sprintf(str, args...))
	}
	elapse := func(name string, bef, v int64) {
		if bef == 0 || v == 0 {
			ff("%s: %d\n", v)
			return
		}
		dur := time.Duration(v - bef)
		milli := dur.Milliseconds()
		if milli < 1000 {
			ff("%s: %d - %d ms\n", name, v, milli)
		} else if milli > 60000 {
			secs := milli / 1000
			mins := secs / 60
			ff("%s: %d - m%d s%.2f\n", name, v, mins, float64(milli-(mins*60*1000))/1000)
		} else {
			ff("%s: %d - %.2f secs\n", name, v, dur.Seconds())
		}
	}

	f("Name: " + w.Name + "\n")
	ff("Start: %d\n", w.Start)
	elapse("DBCheck", w.Start, w.DBCheck)
	if w.DBCheck == 0 {
		Log(sb.String())
		return
	}
	elapse("StartHook", w.DBCheck, w.StartHook)
	if w.StartHook == 0 {
		Log(sb.String())
		return
	}
	elapse("Tasks", w.StartHook, w.Tasks)
	if w.Tasks == 0 {
		Log(sb.String())
		return
	}
	elapse("EndHook", w.Tasks, w.EndHook)

	Log(sb.String())
}

func (w *TickWatch) Run() {
	w.EndChan = make(chan bool)
	// Use a goroutine to circumvent ticks which never end
	// TODO: Reuse goroutines across multiple *TickWatch?
	go func() {
		defer w.Ticker.Stop()
		defer close(w.EndChan)
		defer EatPanics()
		var n int
		var downOnce bool
		for {
			select {
			case <-w.Ticker.C:
				// Less noisy logs
				if n > 20 && n%5 == 0 {
					Logf("%d seconds elapsed since tick %s started", 5*n, w.Name)
				} else if n > 2 && n%2 != 0 {
					Logf("%d seconds elapsed since tick %s started", 5*n, w.Name)
				}
				if !downOnce && w.DBCheck == 0 {
					qgen.Builder.GetConn().SetConnMaxLifetime(time.Second / 4) // Drop all the connections and start over
					LogWarning(ErrDBDown)
					atomic.StoreInt32(&IsDBDown, 1)
					downOnce = true
				}
				n++
			case <-w.Deadline.C:
				Log("Hit TickWatch deadline")
				dur := time.Duration(uutils.Nanotime() - w.Start)
				if dur.Seconds() > 5 {
					Log("tick " + w.Name + " has run for " + dur.String())
					w.DumpElapsed()
				}
				return
			case <-w.EndChan:
				dur := time.Duration(uutils.Nanotime() - w.Start)
				if dur.Seconds() > 5 {
					Log("tick " + w.Name + " completed in " + dur.String())
					w.DumpElapsed()
				}
				if w.OutEndChan != nil {
					w.OutEndChan <- true
					close(w.OutEndChan)
				}
				return
			}
		}
	}()
}

func (w *TickWatch) Stop() {
	w.EndChan <- true
}

func (w *TickWatch) Set(a *int64, v int64) {
	atomic.StoreInt64(a, v)
}

func (w *TickWatch) Clear() {
	w.Start = 0
	w.DBCheck = 0
	w.StartHook = 0
	w.Tasks = 0
	w.EndHook = 0
}