1//
  2// Copyright (c) 2019 Ted Unangst <tedu@tedunangst.com>
  3//
  4// Permission to use, copy, modify, and distribute this software for any
  5// purpose with or without fee is hereby granted, provided that the above
  6// copyright notice and this permission notice appear in all copies.
  7//
  8// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15
 16package main
 17
 18import (
 19	"fmt"
 20	notrand "math/rand"
 21	"time"
 22
 23	"humungus.tedunangst.com/r/webs/gate"
 24)
 25
 26type Doover struct {
 27	ID   int64
 28	When time.Time
 29}
 30
 31func sayitagain(goarounds int64, userid int64, rcpt string, msg []byte) {
 32	var drift time.Duration
 33	switch goarounds {
 34	case 1:
 35		drift = 5 * time.Minute
 36	case 2:
 37		drift = 1 * time.Hour
 38	case 3:
 39		drift = 4 * time.Hour
 40	case 4:
 41		drift = 12 * time.Hour
 42	case 5:
 43		drift = 24 * time.Hour
 44	default:
 45		ilog.Printf("he's dead jim: %s", rcpt)
 46		clearoutbound(rcpt)
 47		return
 48	}
 49	drift += time.Duration(notrand.Int63n(int64(drift / 10)))
 50	when := time.Now().UTC().Add(drift)
 51	_, err := stmtAddDoover.Exec(when.Format(dbtimeformat), goarounds, userid, rcpt, msg)
 52	if err != nil {
 53		elog.Printf("error saving doover: %s", err)
 54	}
 55	select {
 56	case pokechan <- 0:
 57	default:
 58	}
 59}
 60
 61func clearoutbound(rcpt string) {
 62	hostname := originate(rcpt)
 63	if hostname == "" {
 64		return
 65	}
 66	xid := fmt.Sprintf("%%https://%s/%%", hostname)
 67	ilog.Printf("clearing outbound for %s", xid)
 68	db := opendatabase()
 69	db.Exec("delete from doovers where rcpt like ?", xid)
 70}
 71
 72var garage = gate.NewLimiter(40)
 73
 74func deliverate(goarounds int64, userid int64, rcpt string, msg []byte, prio bool) {
 75	garage.Start()
 76	defer garage.Finish()
 77
 78	var ki *KeyInfo
 79	ok := ziggies.Get(userid, &ki)
 80	if !ok {
 81		elog.Printf("lost key for delivery")
 82		return
 83	}
 84	var inbox string
 85	// already did the box indirection
 86	if rcpt[0] == '%' {
 87		inbox = rcpt[1:]
 88	} else {
 89		var box *Box
 90		ok := boxofboxes.Get(rcpt, &box)
 91		if !ok {
 92			ilog.Printf("failed getting inbox for %s", rcpt)
 93			sayitagain(goarounds+1, userid, rcpt, msg)
 94			return
 95		}
 96		inbox = box.In
 97	}
 98	err := PostMsg(ki.keyname, ki.seckey, inbox, msg)
 99	if err != nil {
100		ilog.Printf("failed to post json to %s: %s", inbox, err)
101		if prio {
102			sayitagain(goarounds+1, userid, rcpt, msg)
103		}
104		return
105	}
106}
107
108var pokechan = make(chan int, 1)
109
110func getdoovers() []Doover {
111	rows, err := stmtGetDoovers.Query()
112	if err != nil {
113		elog.Printf("wat?")
114		time.Sleep(1 * time.Minute)
115		return nil
116	}
117	defer rows.Close()
118	var doovers []Doover
119	for rows.Next() {
120		var d Doover
121		var dt string
122		err := rows.Scan(&d.ID, &dt)
123		if err != nil {
124			elog.Printf("error scanning dooverid: %s", err)
125			continue
126		}
127		d.When, _ = time.Parse(dbtimeformat, dt)
128		doovers = append(doovers, d)
129	}
130	return doovers
131}
132
133func redeliverator() {
134	sleeper := time.NewTimer(0)
135	for {
136		select {
137		case <-pokechan:
138			if !sleeper.Stop() {
139				<-sleeper.C
140			}
141			time.Sleep(5 * time.Second)
142		case <-sleeper.C:
143		}
144
145		doovers := getdoovers()
146
147		now := time.Now().UTC()
148		nexttime := now.Add(24 * time.Hour)
149		for _, d := range doovers {
150			if d.When.Before(now) {
151				var goarounds, userid int64
152				var rcpt string
153				var msg []byte
154				row := stmtLoadDoover.QueryRow(d.ID)
155				err := row.Scan(&goarounds, &userid, &rcpt, &msg)
156				if err != nil {
157					elog.Printf("error scanning doover: %s", err)
158					continue
159				}
160				_, err = stmtZapDoover.Exec(d.ID)
161				if err != nil {
162					elog.Printf("error deleting doover: %s", err)
163					continue
164				}
165				ilog.Printf("redeliverating %s try %d", rcpt, goarounds)
166				deliverate(goarounds, userid, rcpt, msg, true)
167			} else if d.When.Before(nexttime) {
168				nexttime = d.When
169			}
170		}
171		dur := nexttime.Sub(now).Round(time.Second) + 5*time.Second
172		sleeper.Reset(dur)
173	}
174}