package config

import (
	"os"
	"path/filepath"
	"testing"
)

func TestDefault_EmptyHome_ReturnsError(t *testing.T) {
	t.Setenv("HOME", "")
	_, err := Default()
	if err == nil {
		t.Fatal("expected error when HOME is empty, got nil")
	}
}

func TestDefault_ValidHome_ReturnsConfig(t *testing.T) {
	t.Setenv("HOME", "/tmp/testhome")
	cfg, err := Default()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if cfg.DataDir != "/tmp/testhome/.claudomator" {
		t.Errorf("DataDir = %q, want /tmp/testhome/.claudomator", cfg.DataDir)
	}
}

func TestLoadFile_OverridesDefaults(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.toml")
	if err := os.WriteFile(path, []byte("server_addr = \":9191\"\n"), 0600); err != nil {
		t.Fatal(err)
	}
	t.Setenv("HOME", dir)

	cfg, err := LoadFile(path)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if cfg.ServerAddr != ":9191" {
		t.Errorf("ServerAddr = %q, want :9191", cfg.ServerAddr)
	}
	// Unset fields retain defaults.
	if cfg.MaxConcurrent != 3 {
		t.Errorf("MaxConcurrent = %d, want 3", cfg.MaxConcurrent)
	}
}

func TestLoadFile_MissingFile_ReturnsError(t *testing.T) {
	t.Setenv("HOME", t.TempDir())
	_, err := LoadFile("/nonexistent/config.toml")
	if err == nil {
		t.Fatal("expected error for missing file, got nil")
	}
}