package config

import (
	"os"
	"path/filepath"
	"runtime"
	"strings"
)

// EnvironmentProfile represents the deployment environment
type EnvironmentProfile int

const (
	ProfileLocal EnvironmentProfile = iota
	ProfileContainer
	ProfileCI
	ProfileProduction
)

// DetectEnvironment determines the current environment profile
func DetectEnvironment() EnvironmentProfile {
	// CI detection
	if os.Getenv("CI") != "" || os.Getenv("GITHUB_ACTIONS") != "" || os.Getenv("GITLAB_CI") != "" {
		return ProfileCI
	}

	// Container detection
	if _, err := os.Stat("/.dockerenv"); err == nil {
		return ProfileContainer
	}
	if os.Getenv("KUBERNETES_SERVICE_HOST") != "" {
		return ProfileContainer
	}
	if os.Getenv("CONTAINER") != "" {
		return ProfileContainer
	}

	// Production detection (customizable)
	if os.Getenv("FETCH_ML_ENV") == "production" || os.Getenv("ENV") == "production" {
		return ProfileProduction
	}

	// Default to local development
	return ProfileLocal
}

// SmartDefaults provides environment-aware default values
type SmartDefaults struct {
	Profile EnvironmentProfile
}

// GetSmartDefaults returns defaults for the current environment
func GetSmartDefaults() *SmartDefaults {
	return &SmartDefaults{
		Profile: DetectEnvironment(),
	}
}

// Host returns the appropriate default host
func (s *SmartDefaults) Host() string {
	switch s.Profile {
	case ProfileContainer, ProfileCI:
		return "host.docker.internal" // Docker Desktop/Colima
	case ProfileProduction:
		return "0.0.0.0"
	default: // ProfileLocal
		return "localhost"
	}
}

// BasePath returns the appropriate default base path
func (s *SmartDefaults) BasePath() string {
	switch s.Profile {
	case ProfileContainer, ProfileCI:
		return "/workspace/ml-experiments"
	case ProfileProduction:
		return "/var/lib/fetch_ml/experiments"
	default: // ProfileLocal
		if home, err := os.UserHomeDir(); err == nil {
			return filepath.Join(home, "ml-experiments")
		}
		return "./ml-experiments"
	}
}

// DataDir returns the appropriate default data directory
func (s *SmartDefaults) DataDir() string {
	switch s.Profile {
	case ProfileContainer, ProfileCI:
		return "/workspace/data"
	case ProfileProduction:
		return "/var/lib/fetch_ml/data"
	default: // ProfileLocal
		if home, err := os.UserHomeDir(); err == nil {
			return filepath.Join(home, "ml-data")
		}
		return "./data"
	}
}

// RedisAddr returns the appropriate default Redis address
func (s *SmartDefaults) RedisAddr() string {
	switch s.Profile {
	case ProfileContainer, ProfileCI:
		return "redis:6379" // Service name in containers
	case ProfileProduction:
		return "redis:6379"
	default: // ProfileLocal
		return "localhost:6379"
	}
}

// SSHKeyPath returns the appropriate default SSH key path
func (s *SmartDefaults) SSHKeyPath() string {
	switch s.Profile {
	case ProfileContainer, ProfileCI:
		return "/workspace/.ssh/id_rsa"
	case ProfileProduction:
		return "/etc/fetch_ml/ssh/id_rsa"
	default: // ProfileLocal
		if home, err := os.UserHomeDir(); err == nil {
			return filepath.Join(home, ".ssh", "id_rsa")
		}
		return "~/.ssh/id_rsa"
	}
}

// KnownHostsPath returns the appropriate default known_hosts path
func (s *SmartDefaults) KnownHostsPath() string {
	switch s.Profile {
	case ProfileContainer, ProfileCI:
		return "/workspace/.ssh/known_hosts"
	case ProfileProduction:
		return "/etc/fetch_ml/ssh/known_hosts"
	default: // ProfileLocal
		if home, err := os.UserHomeDir(); err == nil {
			return filepath.Join(home, ".ssh", "known_hosts")
		}
		return "~/.ssh/known_hosts"
	}
}

// LogLevel returns the appropriate default log level
func (s *SmartDefaults) LogLevel() string {
	switch s.Profile {
	case ProfileCI:
		return "debug" // More verbose for CI debugging
	case ProfileProduction:
		return "info"
	default: // ProfileLocal, ProfileContainer
		return "info"
	}
}

// MaxWorkers returns the appropriate default worker count
func (s *SmartDefaults) MaxWorkers() int {
	switch s.Profile {
	case ProfileCI:
		return 1 // Conservative for CI
	case ProfileProduction:
		return runtime.NumCPU() // Scale with CPU cores
	default: // ProfileLocal, ProfileContainer
		return 2 // Reasonable default for local dev
	}
}

// PollInterval returns the appropriate default poll interval in seconds
func (s *SmartDefaults) PollInterval() int {
	switch s.Profile {
	case ProfileCI:
		return 1 // Fast polling for quick tests
	case ProfileProduction:
		return 10 // Conservative for production
	default: // ProfileLocal, ProfileContainer
		return 5 // Balanced default
	}
}

// IsInContainer returns true if running in a container environment
func (s *SmartDefaults) IsInContainer() bool {
	return s.Profile == ProfileContainer || s.Profile == ProfileCI
}

// IsProduction returns true if this is a production environment
func (s *SmartDefaults) IsProduction() bool {
	return s.Profile == ProfileProduction
}

// IsCI returns true if this is a CI environment
func (s *SmartDefaults) IsCI() bool {
	return s.Profile == ProfileCI
}

// ExpandPath expands ~ and environment variables in paths
func (s *SmartDefaults) ExpandPath(path string) string {
	if strings.HasPrefix(path, "~/") {
		if home, err := os.UserHomeDir(); err == nil {
			path = filepath.Join(home, path[2:])
		}
	}

	// Expand environment variables
	path = os.ExpandEnv(path)

	return path
}

// GetEnvironmentDescription returns a human-readable description
func (s *SmartDefaults) GetEnvironmentDescription() string {
	switch s.Profile {
	case ProfileLocal:
		return "Local Development"
	case ProfileContainer:
		return "Container Environment"
	case ProfileCI:
		return "CI/CD Environment"
	case ProfileProduction:
		return "Production Environment"
	default:
		return "Unknown Environment"
	}
}