package config

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

	"github.com/pelletier/go-toml/v2"
)

func TestDefaultConfigData(t *testing.T) {
	data := DefaultConfigData()
	if data.Misc.Version != CurrentConfigVersion {
		t.Fatalf("version = %q, want %q", data.Misc.Version, CurrentConfigVersion)
	}
	if data.Downloads.Folder == "" {
		t.Fatalf("downloads folder should not be empty")
	}
	if data.Database.DownloadsPath == "" || data.Database.FailedDownloadsPath == "" {
		t.Fatalf("database paths should not be empty")
	}
}

func TestLoadCreatesDefaultConfigWhenMissing(t *testing.T) {
	tmpDir := t.TempDir()
	path := filepath.Join(tmpDir, "config.toml")

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

	if cfg.Path != path {
		t.Fatalf("path = %q, want %q", cfg.Path, path)
	}
	if _, err = os.Stat(path); err != nil {
		t.Fatalf("expected created config file: %v", err)
	}
}

func TestLoadOutdatedConfig(t *testing.T) {
	tmpDir := t.TempDir()
	path := filepath.Join(tmpDir, "config.toml")

	data := DefaultConfigData()
	data.Misc.Version = "1.0.0"
	if err := saveConfigData(path, data); err != nil {
		t.Fatalf("saveConfigData() error = %v", err)
	}

	_, err := Load(path)
	if !errors.Is(err, ErrOutdatedConfig) {
		t.Fatalf("Load() error = %v, want ErrOutdatedConfig", err)
	}
}

func TestUpgradeOutdatedConfig(t *testing.T) {
	tmpDir := t.TempDir()
	path := filepath.Join(tmpDir, "config.toml")

	data := DefaultConfigData()
	data.Misc.Version = "1.0.0"
	data.Downloads.Folder = filepath.Join(tmpDir, "Music")
	if err := saveConfigData(path, data); err != nil {
		t.Fatalf("saveConfigData() error = %v", err)
	}

	resolved, err := UpgradeOutdated(path)
	if err != nil {
		t.Fatalf("UpgradeOutdated() error = %v", err)
	}
	if resolved != path {
		t.Fatalf("resolved path = %q, want %q", resolved, path)
	}

	cfg, err := Load(path)
	if err != nil {
		t.Fatalf("Load() after upgrade error = %v", err)
	}
	if cfg.File.Misc.Version != CurrentConfigVersion {
		t.Fatalf("version = %q, want %q", cfg.File.Misc.Version, CurrentConfigVersion)
	}
	if cfg.File.Downloads.Folder != data.Downloads.Folder {
		t.Fatalf("downloads folder changed unexpectedly")
	}
}

func TestSessionCloneDoesNotAliasSlices(t *testing.T) {
	tmpDir := t.TempDir()
	path := filepath.Join(tmpDir, "config.toml")

	data := DefaultConfigData()
	data.Metadata.Exclude = []string{"lyrics"}
	data.Qobuz.Secrets = []string{"s1"}
	if err := saveConfigData(path, data); err != nil {
		t.Fatalf("saveConfigData() error = %v", err)
	}

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

	cfg.Session.Metadata.Exclude[0] = "comment"
	cfg.Session.Qobuz.Secrets[0] = "s2"

	if cfg.File.Metadata.Exclude[0] != "lyrics" {
		t.Fatalf("file metadata exclude unexpectedly mutated")
	}
	if cfg.File.Qobuz.Secrets[0] != "s1" {
		t.Fatalf("file qobuz secrets unexpectedly mutated")
	}
}

func TestDefaultConfigPassesValidation(t *testing.T) {
	d := DefaultConfigData()
	applyRuntimeDefaults(&d)
	if err := Validate(&d); err != nil {
		t.Fatalf("shipped defaults fail validation: %v", err)
	}
}

// TestExampleConfigIsValid guards the file users are told to copy.
func TestExampleConfigIsValid(t *testing.T) {
	raw, err := os.ReadFile(filepath.Join("..", "..", "config.toml.example"))
	if err != nil {
		t.Skipf("example config not found: %v", err)
	}
	data := DefaultConfigData()
	if err := toml.Unmarshal(raw, &data); err != nil {
		t.Fatalf("config.toml.example does not parse: %v", err)
	}
	applyRuntimeDefaults(&data)
	if err := Validate(&data); err != nil {
		t.Fatalf("config.toml.example fails validation: %v", err)
	}
	if data.Misc.Version != CurrentConfigVersion {
		t.Errorf("config.toml.example version = %q, want %q", data.Misc.Version, CurrentConfigVersion)
	}
}