From ac88a74bd7413bf91daabf5fda557ee03f70a96d Mon Sep 17 00:00:00 2001
From: Thomas von Dein <tom@vondein.org>
Date: Tue, 27 Feb 2024 16:52:20 +0100
Subject: [PATCH] turn player into primary if only one left

---
 assets/levels/04-mayhem.lvl |  2 +-
 observers/game_observer.go  |  3 +++
 systems/player_system.go    | 26 ++++++++++++++++++--------
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/assets/levels/04-mayhem.lvl b/assets/levels/04-mayhem.lvl
index 52353b9..ebd53b6 100644
--- a/assets/levels/04-mayhem.lvl
+++ b/assets/levels/04-mayhem.lvl
@@ -5,7 +5,7 @@ Background: background-lila
                     
                     
      ########W#     
-    #     v    #    
+    #         v#    
     #          #    
     #S        s#    
     ############    
diff --git a/observers/game_observer.go b/observers/game_observer.go
index 4a28853..1e0568a 100644
--- a/observers/game_observer.go
+++ b/observers/game_observer.go
@@ -3,6 +3,8 @@ package observers
 import (
 	"openquell/components"
 
+	"log/slog"
+
 	"github.com/mlange-42/arche/ecs"
 	"github.com/mlange-42/arche/ecs/event"
 	"github.com/mlange-42/arche/generic"
@@ -27,6 +29,7 @@ func (observer *GameObserver) GetListenerCallback(comp ecs.ID) listener.Callback
 	return listener.NewCallback(
 		func(world *ecs.World, event ecs.EntityEvent) {
 			observer.RemoveEntity(event.Entity, comp)
+			slog.Debug("player removed")
 		},
 		event.EntityRemoved,
 		comp,
diff --git a/systems/player_system.go b/systems/player_system.go
index 078d7b1..979aa6b 100644
--- a/systems/player_system.go
+++ b/systems/player_system.go
@@ -32,6 +32,8 @@ func (system PlayerSystem) Update() error {
 	// first check if we need to switch player
 	switchable := false
 	query := system.Selector.Query(system.World)
+	count := query.Count()
+
 	for query.Next() {
 		_, _, player, _ := query.Get()
 		if !player.IsPrimary {
@@ -43,14 +45,22 @@ func (system PlayerSystem) Update() error {
 		query := system.Selector.Query(system.World)
 		for query.Next() {
 			_, _, player, render := query.Get()
-			if inpututil.IsKeyJustPressed(ebiten.KeyTab) {
-				slog.Debug("switch players")
-				if player.IsPrimary {
-					player.IsPrimary = false
-					render.Image = player.SwitchSprite()
-				} else {
-					player.IsPrimary = true
-					render.Image = player.SwitchSprite()
+
+			if count == 1 && !player.IsPrimary {
+				// there's only one player left, make it the primary one
+				player.IsPrimary = true
+				render.Image = player.SwitchSprite()
+			} else {
+				// many players, switch when requested
+				if inpututil.IsKeyJustPressed(ebiten.KeyTab) {
+					slog.Debug("switch players")
+					if player.IsPrimary {
+						player.IsPrimary = false
+						render.Image = player.SwitchSprite()
+					} else {
+						player.IsPrimary = true
+						render.Image = player.SwitchSprite()
+					}
 				}
 			}
 		}