From e2b87a41f878d37d5e9063204ccd27fcabc5abc4 Mon Sep 17 00:00:00 2001
From: David Florness <david@florness.com>
Date: Tue, 19 Jan 2021 21:07:59 -0500
Subject: [PATCH] Properly sort elections by room in TUI

---
 election/map.go | 34 ++++++++++++++++++----------------
 ui/tui.go       | 19 ++++++++++++++-----
 2 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/election/map.go b/election/map.go
index ac4be84..8999934 100644
--- a/election/map.go
+++ b/election/map.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"sort"
 	"sync"
+	"time"
 
 	log "github.com/sirupsen/logrus"
 
@@ -16,8 +17,12 @@ import (
 
 type ElectionsMap struct {
 	sync.RWMutex
-	M     map[id.EventID]*Election
-	L     []*Election // sorted list of elections by CreationTimestamp (newest to oldest)
+	M map[id.EventID]*Election
+
+	// by room, sorted list of elections by CreationTimestamp (newest to oldest)
+	L     map[id.RoomID][]*Election
+	Ltime time.Time // last time list was update
+
 	Joins map[id.EventID]*Voter
 	Save  func()
 }
@@ -43,7 +48,8 @@ func GetElections() (elections *ElectionsMap, err error) {
 func NewElectionsMap() *ElectionsMap {
 	em := &ElectionsMap{
 		M:     make(map[id.EventID]*Election),
-		L:     make([]*Election, 0),
+		L:     make(map[id.RoomID][]*Election, 0),
+		Ltime: time.Now(),
 		Joins: make(map[id.EventID]*Voter),
 	}
 	em.Save = func() {
@@ -73,7 +79,7 @@ func (em *ElectionsMap) UnmarshalJSON(b []byte) error {
 	if err := json.Unmarshal(b, &em.M); err != nil {
 		return err
 	}
-	em.L = make([]*Election, 0)
+	em.L = make(map[id.RoomID][]*Election, 0)
 	for createEventId, el := range em.M {
 		em.insort(createEventId, el)
 	}
@@ -100,12 +106,6 @@ func (em *ElectionsMap) GetOk(createEventID id.EventID) (*Election, bool) {
 	return el, ok
 }
 
-func (em *ElectionsMap) GetI(i int) *Election {
-	em.RLock()
-	defer em.RUnlock()
-	return em.L[i]
-}
-
 func (em *ElectionsMap) SetIfNotExists(createEventID id.EventID, el *Election) {
 	em.Lock()
 	defer em.Save()
@@ -126,12 +126,14 @@ func (em *ElectionsMap) set(createEventID id.EventID, el *Election) {
 }
 
 func (em *ElectionsMap) insort(createEventID id.EventID, el *Election) {
-	i := sort.Search(len(em.L), func(i int) bool {
-		return em.L[i].CreationTimestamp < el.CreationTimestamp
+	list := em.L[el.RoomID]
+	i := sort.Search(len(list), func(i int) bool {
+		return list[i].CreationTimestamp < el.CreationTimestamp
 	})
-	newList := make([]*Election, len(em.L)+1)
-	copy(newList[:i], em.L[:i])
+	newList := make([]*Election, len(list)+1)
+	copy(newList[:i], list[:i])
 	newList[i] = el
-	copy(newList[i+1:], em.L[i:])
-	em.L = newList
+	copy(newList[i+1:], list[i:])
+	em.L[el.RoomID] = newList
+	em.Ltime = time.Now()
 }
diff --git a/ui/tui.go b/ui/tui.go
index e3e8027..b69bf10 100644
--- a/ui/tui.go
+++ b/ui/tui.go
@@ -70,15 +70,17 @@ func RoomTUI(client *mautrix.Client, roomID id.RoomID, elections *election.Elect
 	app := tview.NewApplication()
 	list := tview.NewList().
 		AddItem("Create Election", "start a new election in this room", '+', nil)
-	n := 0
+	var L     []*election.Election
+	var Ltime time.Time = elections.Ltime.Add(-1 * time.Millisecond)
 	update := func() {
 		elections.RLock()
 		defer elections.RUnlock()
-		if n == len(elections.L) {
+		if !Ltime.Before(elections.Ltime) {
 			return
 		}
-		n = len(elections.L)
-		for i, el := range elections.L {
+		L = elections.L[roomID]
+		Ltime = elections.Ltime
+		for i, el := range L {
 			title := el.Title
 			if title == "" {
 				title = "<no name>"
@@ -104,11 +106,18 @@ func RoomTUI(client *mautrix.Client, roomID id.RoomID, elections *election.Elect
 	list.SetSelectedFunc(func(i int, _ string, _ string, _ rune) {
 		alive = false
 		app.Stop()
+		elections.RLock()
+		// don't do anything if the election under the cursor has
+		// changed
+		if Ltime.Before(elections.Ltime) && L[i] != elections.L[roomID][i] {
+			return
+		}
+		elections.RUnlock()
 
 		if i > 0 {
 			// user wants to join election
 
-			el = elections.GetI(i - 1)
+			el = L[i - 1]
 			// don't need to lock because this goroutine controls LocalVoter
 			if el.LocalVoter != nil {
 				if el.LocalVoter.Ballot == nil {
-- 
2.38.4