From 49d975996b356f2ede5d96c6f1976fd4888af6ba Mon Sep 17 00:00:00 2001
From: Stephen Horvath <s.horvath@outlook.com.au>
Date: Sun, 22 Jun 2025 14:58:33 +1000
Subject: [PATCH] Add `MOZHI_DEFAULT_ENGINE` env var

---
 README.md      |  1 +
 pages/index.go | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 3be64d5..5b26ee8 100644
--- a/README.md
+++ b/README.md
@@ -59,6 +59,7 @@ Features of Mozhi can be customized and toggled on/off using Environment Variabl
 - `MOZHI_DEFAULT_SOURCE_LANG`: Language to default to if no source language is set by user. Defaults to Auto-Detect (or first available language in engines which dont support it)
 - `MOZHI_DEFAULT_PREFER_AUTODETECT`: Prefer autodetect if available instead of specified/default source language. Defaults to false
 - `MOZHI_DEFAULT_TARGET_LANG`: Language to default to if no target language is set by user. Defaults to English
+- `MOZHI_DEFAULT_ENGINE`: Engine to default to if no engine is set by user. Defaults to `google`
 
 These envvars turn off/on engines. By default all of them are enabled.
 - `MOZHI_GOOGLE_ENABLED`
diff --git a/pages/index.go b/pages/index.go
index 31824a2..9a819cb 100644
--- a/pages/index.go
+++ b/pages/index.go
@@ -33,6 +33,14 @@ func HandleIndex(c *fiber.Ctx) error {
 	for engine := range engines {
 		enginesAsArray = append(enginesAsArray, engine)
 	}
+	defaultEngine := os.Getenv("MOZHI_DEFAULT_ENGINE")
+	if defaultEngine == "" || !slices.Contains(enginesAsArray, defaultEngine) {
+		if slices.Contains(enginesAsArray, "google") {
+			defaultEngine = "google"
+		} else if len(enginesAsArray) > 0 {
+			defaultEngine = enginesAsArray[0]
+		}
+	}
 	engineCookie := c.Cookies("engine")
 	fromCookie := c.Cookies("from")
 	toCookie := c.Cookies("to")
@@ -41,7 +49,7 @@ func HandleIndex(c *fiber.Ctx) error {
 		if engineCookie != "" {
 			engine = engineCookie
 		} else {
-			engine = "google"
+			engine = defaultEngine
 		}
 	}