package config

import (
	"path/filepath"
	"testing"
)

func TestDefault(t *testing.T) {
	cfg := Default()
	if cfg.Display.Speed != 1.0 {
		t.Errorf("default speed = %v, want 1.0", cfg.Display.Speed)
	}
	if cfg.USB.VendorID != DefaultVendorID || cfg.USB.ProductID != DefaultProductID {
		t.Errorf("default usb ids = %x:%x, want %x:%x",
			cfg.USB.VendorID, cfg.USB.ProductID, DefaultVendorID, DefaultProductID)
	}
	if cfg.Stream.CachePath == "" {
		t.Error("default cache_path must not be empty")
	}
}

func TestLoadMissingFileReturnsDefaults(t *testing.T) {
	cfg, err := Load(filepath.Join(t.TempDir(), "nope.toml"))
	if err != nil {
		t.Fatalf("Load(missing) error = %v", err)
	}
	if cfg.Display.Input != "" {
		t.Errorf("input = %q, want empty", cfg.Display.Input)
	}
}

func TestSaveAndLoadRoundTrip(t *testing.T) {
	path := filepath.Join(t.TempDir(), "sub", "galahad2lcd.toml")
	orig := Default()
	orig.Display.Input = "/tmp/demo.gif"
	orig.Display.Rotate = 180
	orig.Display.Speed = 1.5
	orig.USB.VendorID = 0x1234
	orig.Stream.FPS = 15

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

	got, err := Load(path)
	if err != nil {
		t.Fatalf("Load error = %v", err)
	}
	if got.Display != orig.Display {
		t.Errorf("display = %+v, want %+v", got.Display, orig.Display)
	}
	if got.USB != orig.USB {
		t.Errorf("usb = %+v, want %+v", got.USB, orig.USB)
	}
	if got.Stream != orig.Stream {
		t.Errorf("stream = %+v, want %+v", got.Stream, orig.Stream)
	}
}

func TestValidate(t *testing.T) {
	tests := []struct {
		name    string
		mutate  func(*Config)
		wantErr bool
	}{
		{"valid", func(c *Config) { c.Display.Input = "/tmp/x.gif" }, false},
		{"empty input", func(c *Config) {}, true},
		{"bad rotate", func(c *Config) { c.Display.Input = "/tmp/x.gif"; c.Display.Rotate = 45 }, true},
		{"negative speed", func(c *Config) { c.Display.Input = "/tmp/x.gif"; c.Display.Speed = -1 }, true},
		{"negative fps", func(c *Config) { c.Display.Input = "/tmp/x.gif"; c.Stream.FPS = -2 }, true},
		{"empty cache", func(c *Config) { c.Display.Input = "/tmp/x.gif"; c.Stream.CachePath = "" }, true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			cfg := Default()
			tt.mutate(&cfg)
			err := cfg.Validate()
			if (err != nil) != tt.wantErr {
				t.Errorf("Validate() error = %v, wantErr = %v", err, tt.wantErr)
			}
		})
	}
}