Fix preset alliance teams being randomised by draft-order shuffle

app/Draft/Commands/GenerateDraft.php

@@ -65,6 +65,17 @@ public function generatePlayerData(): array
 
         $playerNames = [...$this->settings->playerNames];
 
+        // Preset teams are defined by the order players are entered in the form
+        // (adjacent pairs form a team). Capture that mapping from the original
+        // order *before* the draft-order shuffle below can scramble it.
+        $presetTeams = [];
+        if ($this->settings->allianceMode && $this->settings->allianceTeamMode == AllianceTeamMode::PRESET) {
+            $teamNames = $this->generateTeamNames();
+            foreach (array_values($playerNames) as $i => $name) {
+                $presetTeams[$name] = $teamNames[(int) floor($i / 2)];
+            }
+        }
+
         if (! $this->settings->presetDraftOrder) {
             shuffle($playerNames);
         }
@@ -75,16 +86,24 @@ public function generatePlayerData(): array
         }
 
         if ($this->settings->allianceMode) {
-            $teamNames = $this->generateTeamNames();
             $teamPlayers = [];
 
-            if ($this->settings->allianceTeamMode == AllianceTeamMode::RANDOM) {
-                shuffle($players);
-            }
-
-            foreach(array_values($players) as $i => $player) {
-                $teamName = $teamNames[(int) floor($i / 2)];
-                $teamPlayers[$player->id->value] = $player->putInTeam($teamName);
+            if ($this->settings->allianceTeamMode == AllianceTeamMode::PRESET) {
+                // Teams are fixed: keep each player's preset team regardless of
+                // the (possibly randomised) draft order.
+                foreach ($players as $id => $player) {
+                    $teamPlayers[$id] = $player->putInTeam($presetTeams[$player->name]);
+                }
+            } else {
+                // Random teams: pair players up by a fresh shuffle.
+                $teamNames = $this->generateTeamNames();
+                $shuffled = array_values($players);
+                shuffle($shuffled);
+
+                foreach ($shuffled as $i => $player) {
+                    $teamName = $teamNames[(int) floor($i / 2)];
+                    $teamPlayers[$player->id->value] = $player->putInTeam($teamName);
+                }
             }
 
             $players = $teamPlayers;

app/Draft/Commands/GenerateDraftTest.php

@@ -112,4 +112,36 @@ public function itCanGeneratePlayerDataForAlliances(): void
         $this->assertSame('Frank', $players[5]->name);
         $this->assertSame('C', $players[5]->team);
     }
+
+    #[Test]
+    public function itKeepsPresetTeamsWhenDraftOrderIsRandomised(): void
+    {
+        // Preset teams must stay fixed to the pairs entered in the form, even
+        // when the draft order is randomised (presetDraftOrder = false).
+        $originalPlayerNames = ['Alice', 'Bob', 'Christine', 'David', 'Elliot', 'Frank'];
+        $settings = DraftSettingsFactory::make([
+            'playerNames' => $originalPlayerNames,
+            'allianceMode' => true,
+            'allianceTeamMode' => AllianceTeamMode::PRESET,
+            'presetDraftOrder' => false,
+        ]);
+
+        // Run a few times because the draft order is shuffled; the team a player
+        // belongs to must never change.
+        for ($run = 0; $run < 20; $run++) {
+            $draft = (new GenerateDraft($settings))->handle();
+
+            $teamByName = [];
+            foreach ($draft->players as $player) {
+                $teamByName[$player->name] = $player->team;
+            }
+
+            $this->assertSame('A', $teamByName['Alice']);
+            $this->assertSame('A', $teamByName['Bob']);
+            $this->assertSame('B', $teamByName['Christine']);
+            $this->assertSame('B', $teamByName['David']);
+            $this->assertSame('C', $teamByName['Elliot']);
+            $this->assertSame('C', $teamByName['Frank']);
+        }
+    }
 }