users dont store their own history

main.go

@@ -14,7 +14,7 @@ import (
 
 type (
 	DB interface {
-		HistoryOf(IDU) map[IDQ][]History
+		HistoryOf(IDU) map[IDQ][]Answer
 		Next(IDU, IDQ) time.Time
 		Question(IDQ) Question
 		LastAnswer(IDU, IDQ) (IDA, Answer)
@@ -32,11 +32,7 @@ type (
 		A      Renderable
 		TS     int64
 		Author IDU
-	}
-	History struct {
-		A    IDA
-		TS   int64
-		Pass bool
+		Pass   bool
 	}
 	IDA        string
 	IDQ        string

yamldb.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"os"
+	"sort"
 	"time"
 
 	"github.com/google/uuid"
@@ -19,8 +20,7 @@ type (
 		Answers   map[IDA]Answer
 	}
 	user struct {
-		Tags    tags
-		History map[IDQ][]History
+		Tags tags
 	}
 	tags struct {
 		Assignments []IDT
@@ -60,23 +60,31 @@ func (db yamlDB) Close() {
 	}
 }
 
-func (db yamlDB) HistoryOf(user IDU) map[IDQ][]History {
-	result := map[IDQ][]History{}
-	for k, v := range db.Users[user].History {
-		result[k] = append([]History{}, v...)
+func (db yamlDB) HistoryOf(user IDU) map[IDQ][]Answer {
+	result := map[IDQ][]Answer{}
+	for _, v := range db.Knowledge.Answers {
+		if v.Author == user {
+			result[v.Q] = append(result[v.Q], v)
+		}
 	}
 	for _, tag := range db.Users[user].Tags.Assignments {
 		for qid, q := range db.Knowledge.Questions {
 			if _, ok := result[qid]; !ok && q.Tagged(tag) {
-				result[qid] = []History{}
+				result[qid] = []Answer{}
 			}
 		}
 	}
+	for _, v := range result {
+		sort.Slice(v, func(i, j int) bool {
+			return v[i].TS < v[j].TS
+		})
+	}
 	return result
 }
 
 func (db yamlDB) Next(user IDU, q IDQ) time.Time {
-	history := db.Users[user].History[q]
+	allHistory := db.HistoryOf(user)
+	history := allHistory[q]
 	last := db.lastTS(user, q)
 	log := make([]int, 0, len(history))
 	for i := range history {
@@ -118,21 +126,16 @@ func (db yamlDB) PushAnswer(user IDU, q IDQ, a Renderable, pass bool) error {
 		A:      a,
 		TS:     time.Now().UnixNano(),
 		Author: user,
+		Pass:   pass,
 	}
-	db.Users[user].History[q] = append(db.Users[user].History[q], History{
-		A:    uuid,
-		Pass: pass,
-		TS:   db.Knowledge.Answers[uuid].TS,
-	})
 	return nil
 }
 
 func (db yamlDB) lastTS(user IDU, q IDQ) time.Time {
-	max := int64(0)
-	for _, v := range db.Users[user].History[q] {
-		if v.TS > max {
-			max = v.TS
-		}
+	allHistory := db.HistoryOf(user)
+	history := allHistory[q]
+	if len(history) == 0 {
+		return time.Unix(0, 0)
 	}
-	return time.Unix(0, max)
+	return time.Unix(0, history[len(history)-1].TS)
 }