// Package persistence provides repository implementations for the infrastructure layer.
package persistence

import (
	"context"
	"os"
	"path/filepath"
	"sync"

	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/domain/errors"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/domain/ports"
)

// ConfigRepository implements the ports.ConfigRepository interface
// using file system storage.
type ConfigRepository struct {
	configPath string
	mu         sync.RWMutex
}

// NewConfigRepository creates a new ConfigRepository
func NewConfigRepository(configPath string) *ConfigRepository {
	return &ConfigRepository{
		configPath: configPath,
	}
}

// Load retrieves the current configuration from file
func (r *ConfigRepository) Load(ctx context.Context) (*config.Config, error) {
	r.mu.RLock()
	defer r.mu.RUnlock()

	if r.configPath == "" {
		return nil, errors.ErrConfigNotFound
	}

	cfg, err := config.LoadConfig(r.configPath)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, errors.Wrap(errors.NotFound, "configuration file not found", err)
		}
		return nil, errors.Wrap(errors.InternalError, "failed to load configuration", err)
	}

	return cfg, nil
}

// Save persists the configuration to file
func (r *ConfigRepository) Save(ctx context.Context, cfg *config.Config) error {
	return r.SaveWithPath(ctx, r.configPath, cfg)
}

// SaveWithPath persists the configuration to a specific path
func (r *ConfigRepository) SaveWithPath(ctx context.Context, path string, cfg *config.Config) error {
	r.mu.Lock()
	defer r.mu.Unlock()

	if path == "" {
		return errors.New(errors.InvalidInput, "config path is empty")
	}

	if cfg == nil {
		return errors.New(errors.InvalidInput, "config is nil")
	}

	// Validate before saving
	if err := r.Validate(ctx, cfg); err != nil {
		return err
	}

	// Ensure directory exists
	dir := filepath.Dir(path)
	if err := os.MkdirAll(dir, 0755); err != nil {
		return errors.Wrap(errors.InternalError, "failed to create config directory", err)
	}

	// Save with comment preservation
	if err := config.SaveConfigPreserveComments(path, cfg); err != nil {
		return errors.Wrap(errors.InternalError, "failed to save configuration", err)
	}

	return nil
}

// Validate validates the configuration without saving
func (r *ConfigRepository) Validate(ctx context.Context, cfg *config.Config) error {
	if cfg == nil {
		return errors.ErrInvalidConfig.WithDetail("reason", "configuration is nil")
	}

	// Create temporary file for validation
	tmpDir := filepath.Dir(r.configPath)
	if tmpDir == "" {
		tmpDir = os.TempDir()
	}

	tmpFile, err := os.CreateTemp(tmpDir, "config-validate-*.yaml")
	if err != nil {
		return errors.Wrap(errors.InternalError, "failed to create temp file for validation", err)
	}
	tmpPath := tmpFile.Name()

	// Cleanup
	_ = tmpFile.Close()
	defer os.Remove(tmpPath)

	// Validate by loading
	_, err = config.LoadConfigOptional(tmpPath, false)
	if err != nil {
		return errors.Wrap(errors.ValidationFailed, "configuration validation failed", err)
	}

	return nil
}

// GetConfigPath returns the current configuration file path
func (r *ConfigRepository) GetConfigPath() string {
	r.mu.RLock()
	defer r.mu.RUnlock()
	return r.configPath
}

// SetConfigPath updates the configuration file path
func (r *ConfigRepository) SetConfigPath(path string) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.configPath = path
}

// Ensure ConfigRepository implements the interface
var _ ports.ConfigRepository = (*ConfigRepository)(nil)