Refactored, added comprehensive testing.

config/env.go

@@ -0,0 +1,34 @@
+package config
+
+import "os"
+import "strings"
+
+func loadEnvironment() envValues {
+	ev := envValues{}
+
+	if val := os.Getenv("AICLI_PROTOCOL"); val != "" {
+		ev.protocol = val
+	}
+	if val := os.Getenv("AICLI_URL"); val != "" {
+		ev.url = val
+	}
+	if val := os.Getenv("AICLI_API_KEY"); val != "" {
+		ev.key = val
+	} else if val := os.Getenv("AICLI_API_KEY_FILE"); val != "" {
+		content, err := os.ReadFile(val)
+		if err == nil {
+			ev.key = strings.TrimSpace(string(content))
+		}
+	}
+	if val := os.Getenv("AICLI_MODEL"); val != "" {
+		ev.model = val
+	}
+	if val := os.Getenv("AICLI_FALLBACK"); val != "" {
+		ev.fallback = val
+	}
+	if val := os.Getenv("AICLI_SYSTEM"); val != "" {
+		ev.system = val
+	}
+
+	return ev
+}