package config

import "testing"

// TestLoadDefaults verifies that Load applies defaults when the environment is
// empty.
func TestLoadDefaults(t *testing.T) {
	t.Setenv("BACKEND_HTTP_ADDR", "")
	t.Setenv("BACKEND_LOG_LEVEL", "")

	c, err := Load()
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if c.HTTPAddr != defaultHTTPAddr {
		t.Errorf("HTTPAddr = %q, want %q", c.HTTPAddr, defaultHTTPAddr)
	}
	if c.LogLevel != defaultLogLevel {
		t.Errorf("LogLevel = %q, want %q", c.LogLevel, defaultLogLevel)
	}
}

// TestLoadOverrides verifies that environment variables override the defaults.
func TestLoadOverrides(t *testing.T) {
	t.Setenv("BACKEND_HTTP_ADDR", "127.0.0.1:9090")
	t.Setenv("BACKEND_LOG_LEVEL", "debug")

	c, err := Load()
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if c.HTTPAddr != "127.0.0.1:9090" {
		t.Errorf("HTTPAddr = %q, want %q", c.HTTPAddr, "127.0.0.1:9090")
	}
	if c.LogLevel != "debug" {
		t.Errorf("LogLevel = %q, want %q", c.LogLevel, "debug")
	}
}

// TestLoadRejectsInvalidLevel verifies that an unknown log level is rejected.
func TestLoadRejectsInvalidLevel(t *testing.T) {
	t.Setenv("BACKEND_LOG_LEVEL", "verbose")
	if _, err := Load(); err == nil {
		t.Fatal("Load: expected an error for an invalid log level, got nil")
	}
}