package config

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

func TestLoadOrEmpty_NoFile(t *testing.T) {
	cfg, err := LoadOrEmpty("/tmp/unitdore-nonexistent-test.yaml")
	if err != nil {
		t.Fatalf("expected no error for missing file, got: %v", err)
	}
	if len(cfg.Units) != 0 {
		t.Errorf("expected empty units, got %d", len(cfg.Units))
	}
}

func TestSaveAndLoad(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "units.yaml")

	cfg := &Config{
		Units: []Unit{
			{Name: "nginx", Runtime: "podman", Order: 1, Enabled: true},
			{Name: "myapp", Runtime: "docker", User: "hein", Order: 2, Enabled: true},
		},
	}

	if err := cfg.Save(path); err != nil {
		t.Fatalf("Save failed: %v", err)
	}

	loaded, err := Load(path)
	if err != nil {
		t.Fatalf("Load failed: %v", err)
	}

	if len(loaded.Units) != 2 {
		t.Errorf("expected 2 units, got %d", len(loaded.Units))
	}
	if loaded.Units[0].Name != "nginx" {
		t.Errorf("expected nginx, got %s", loaded.Units[0].Name)
	}
	if loaded.Units[1].User != "hein" {
		t.Errorf("expected user hein, got %s", loaded.Units[1].User)
	}
}

func TestFindUnit(t *testing.T) {
	cfg := &Config{
		Units: []Unit{
			{Name: "nginx", Runtime: "podman"},
			{Name: "myapp", Runtime: "docker"},
		},
	}

	u := cfg.FindUnit("nginx")
	if u == nil {
		t.Fatal("expected to find nginx, got nil")
	}
	if u.Runtime != "podman" {
		t.Errorf("expected podman, got %s", u.Runtime)
	}

	missing := cfg.FindUnit("nothere")
	if missing != nil {
		t.Errorf("expected nil for missing unit, got %+v", missing)
	}
}

func TestAddUnit(t *testing.T) {
	cfg := &Config{}

	added := cfg.AddUnit(Unit{Name: "nginx", Runtime: "podman", Enabled: true})
	if !added {
		t.Error("expected AddUnit to return true for new unit")
	}
	if len(cfg.Units) != 1 {
		t.Errorf("expected 1 unit, got %d", len(cfg.Units))
	}

	// Adding a duplicate should return false and not grow the list
	added = cfg.AddUnit(Unit{Name: "nginx", Runtime: "docker"})
	if added {
		t.Error("expected AddUnit to return false for duplicate")
	}
	if len(cfg.Units) != 1 {
		t.Errorf("expected still 1 unit, got %d", len(cfg.Units))
	}
}

func TestLoad_InvalidYAML(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "bad.yaml")
	// Use a tab character in a mapping key — this is genuinely invalid YAML
	os.WriteFile(path, []byte("units:\n  - name: ok\n\t  broken: tab-indent"), 0644)

	_, err := Load(path)
	if err == nil {
		t.Error("expected error for invalid YAML, got nil")
	}
}

func TestSave_CreatesParentDir(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "subdir", "nested", "units.yaml")

	cfg := &Config{Units: []Unit{{Name: "test", Runtime: "podman", Enabled: true}}}
	if err := cfg.Save(path); err != nil {
		t.Fatalf("Save failed to create parent dirs: %v", err)
	}

	if _, err := os.Stat(path); err != nil {
		t.Errorf("expected file to exist: %v", err)
	}
}

func TestDisabledReason_Roundtrip(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "units.yaml")

	cfg := &Config{
		Units: []Unit{
			{
				Name:           "ghost",
				Runtime:        "podman",
				Enabled:        false,
				DisabledReason: "container not found",
			},
		},
	}

	if err := cfg.Save(path); err != nil {
		t.Fatalf("Save failed: %v", err)
	}

	loaded, err := Load(path)
	if err != nil {
		t.Fatalf("Load failed: %v", err)
	}

	if loaded.Units[0].DisabledReason != "container not found" {
		t.Errorf("expected disabled_reason to survive roundtrip, got: %q", loaded.Units[0].DisabledReason)
	}
}