Kotlin System Framework

/**
 * Isolated System Architecture Framework
 *
 * A comprehensive framework for building isolated, testable systems with
 * configuration-driven behavior and clear boundaries.
 */

// ================================
// CONFIGURATION LAYER (Foundation)
// ================================

/**
 * Configuration represents the "beliefs" of the system - what it knows
 * about its environment, capabilities, and constraints.
 */
interface SystemConfiguration {
    fun <T> getProperty(key: ConfigurationKey<T>): T
    fun isFeatureEnabled(feature: FeatureFlag): Boolean
    fun getEnvironment(): Environment
}

data class ConfigurationKey<T>(
    val name: String,
    val defaultValue: T,
    val validator: (T) -> Boolean = { true }
)

enum class Environment { DEV, STAGING, PROD }

enum class FeatureFlag {
    COMPOSE_ENABLED,
    OFFLINE_MODE,
    ANALYTICS_ENABLED,
    DEBUG_LOGGING,
    EXPERIMENTAL_UI
}

class DefaultSystemConfiguration(
    private val properties: Map<String, Any> = emptyMap(),
    private val features: Set<FeatureFlag> = emptySet(),
    private val environment: Environment = Environment.PROD
) : SystemConfiguration {

    @Suppress("UNCHECKED_CAST")
    override fun <T> getProperty(key: ConfigurationKey<T>): T {
        val value = properties[key.name] as? T ?: key.defaultValue
        return if (key.validator(value)) value else key.defaultValue
    }

    override fun isFeatureEnabled(feature: FeatureFlag): Boolean =
        features.contains(feature)

    override fun getEnvironment(): Environment = environment
}

// ================================
// SYSTEM BOUNDARIES
// ================================

/**
 * Input - What enters the system from external sources
 */
interface SystemInput<T> {
    suspend fun receive(data: T): ProcessingResult<T>
    fun validate(data: T): ValidationResult
}

/**
 * Output - What the system produces and delivers
 */
interface SystemOutput<T> {
    suspend fun emit(data: T): EmissionResult
    fun canEmit(data: T): Boolean
}

/**
 * Process - How inputs are transformed internally
 */
interface SystemProcessor<I, O> {
    suspend fun process(
        input: I,
        configuration: SystemConfiguration
    ): ProcessingResult<O>
}

/**
 * Control - Rules and mechanisms that govern operation
 */
interface SystemController {
    suspend fun enforce(
        operation: SystemOperation,
        configuration: SystemConfiguration
    ): ControlResult

    fun getConstraints(): Set<SystemConstraint>
}

// ================================
// SYSTEM COMMUNICATION
// ================================

/**
 * Interface - How components connect and communicate
 */
interface SystemInterface<T> {
    suspend fun send(message: T, target: SystemComponent): InterfaceResult
    suspend fun receive(message: T, source: SystemComponent): InterfaceResult
    fun getProtocol(): CommunicationProtocol
}

/**
 * Feedback - Information that flows back to adjust behavior
 */
interface SystemFeedback<T> {
    suspend fun provideFeedback(
        operation: SystemOperation,
        result: T,
        configuration: SystemConfiguration
    ): FeedbackResult

    fun shouldAdjustBehavior(feedback: T): Boolean
}

// ================================
// SYSTEM STATE MANAGEMENT
// ================================

/**
 * State - Current condition or status of the system
 */
interface SystemState<T> {
    val currentState: StateFlow<T>
    suspend fun transition(newState: T, configuration: SystemConfiguration): TransitionResult
    fun canTransition(from: T, to: T): Boolean
}

/**
 * Environment - External context the system operates within
 */
interface SystemEnvironment {
    fun getResources(): Map<String, Any>
    fun getConstraints(): Set<EnvironmentalConstraint>
    fun isResourceAvailable(resource: String): Boolean
}

// ================================
// CORE SYSTEM COMPONENT
// ================================

/**
 * A complete isolated system component that combines all framework elements
 */
abstract class IsolatedSystemComponent<I, O, S>(
    protected val configuration: SystemConfiguration,
    protected val input: SystemInput<I>,
    protected val output: SystemOutput<O>,
    protected val processor: SystemProcessor<I, O>,
    protected val controller: SystemController,
    protected val state: SystemState<S>,
    protected val environment: SystemEnvironment,
    protected val feedback: SystemFeedback<O>? = null
) {

    /**
     * Main execution pipeline for the system component
     */
    suspend fun execute(inputData: I): SystemExecutionResult<O> {
        return try {
            // 1. Validate input
            val validationResult = input.validate(inputData)
            if (!validationResult.isValid) {
                return SystemExecutionResult.ValidationFailure(validationResult.errors)
            }

            // 2. Check system constraints
            val controlResult = controller.enforce(
                SystemOperation.PROCESS(inputData),
                configuration
            )
            if (!controlResult.allowed) {
                return SystemExecutionResult.ConstraintViolation(controlResult.violations)
            }

            // 3. Receive and process input
            val receivedResult = input.receive(inputData)
            if (!receivedResult.successful) {
                return SystemExecutionResult.InputFailure(receivedResult.error)
            }

            // 4. Process the data
            val processResult = processor.process(inputData, configuration)
            if (!processResult.successful) {
                return SystemExecutionResult.ProcessingFailure(processResult.error)
            }

            // 5. Validate output can be emitted
            val outputData = processResult.result
            if (!output.canEmit(outputData)) {
                return SystemExecutionResult.OutputConstraint("Cannot emit result")
            }

            // 6. Emit output
            val emissionResult = output.emit(outputData)
            if (!emissionResult.successful) {
                return SystemExecutionResult.EmissionFailure(emissionResult.error)
            }

            // 7. Provide feedback if configured
            feedback?.provideFeedback(
                SystemOperation.PROCESS(inputData),
                outputData,
                configuration
            )

            SystemExecutionResult.Success(outputData)

        } catch (exception: Exception) {
            SystemExecutionResult.SystemFailure(exception)
        }
    }

    /**
     * Health check for the system component
     */
    suspend fun healthCheck(): SystemHealth {
        val checks = mutableMapOf<String, Boolean>()

        // Check environment resources
        checks["environment"] = environment.isResourceAvailable("health_check")

        // Check configuration validity
        checks["configuration"] = try {
            configuration.getEnvironment() != null
        } catch (e: Exception) { false }

        // Check state consistency
        checks["state"] = try {
            state.currentState.value != null
        } catch (e: Exception) { false }

        return SystemHealth(
            isHealthy = checks.values.all { it },
            componentChecks = checks.toMap(),
            timestamp = System.currentTimeMillis()
        )
    }
}

// ================================
// RESULT TYPES
// ================================

sealed class SystemExecutionResult<out T> {
    data class Success<T>(val result: T) : SystemExecutionResult<T>()
    data class ValidationFailure(val errors: List<String>) : SystemExecutionResult<Nothing>()
    data class ConstraintViolation(val violations: List<String>) : SystemExecutionResult<Nothing>()
    data class InputFailure(val error: String) : SystemExecutionResult<Nothing>()
    data class ProcessingFailure(val error: String) : SystemExecutionResult<Nothing>()
    data class OutputConstraint(val reason: String) : SystemExecutionResult<Nothing>()
    data class EmissionFailure(val error: String) : SystemExecutionResult<Nothing>()
    data class SystemFailure(val exception: Exception) : SystemExecutionResult<Nothing>()
}

data class ProcessingResult<T>(
    val successful: Boolean,
    val result: T,
    val error: String? = null,
    val metadata: Map<String, Any> = emptyMap()
)

data class ValidationResult(
    val isValid: Boolean,
    val errors: List<String> = emptyList()
)

data class EmissionResult(
    val successful: Boolean,
    val error: String? = null
)

data class ControlResult(
    val allowed: Boolean,
    val violations: List<String> = emptyList()
)

data class InterfaceResult(
    val successful: Boolean,
    val error: String? = null
)

data class FeedbackResult(
    val processed: Boolean,
    val adjustmentRecommended: Boolean = false
)

data class TransitionResult(
    val successful: Boolean,
    val error: String? = null
)

data class SystemHealth(
    val isHealthy: Boolean,
    val componentChecks: Map<String, Boolean>,
    val timestamp: Long
)

// ================================
// SUPPORTING TYPES
// ================================

sealed class SystemOperation {
    data class PROCESS<T>(val data: T) : SystemOperation()
    object STARTUP : SystemOperation()
    object SHUTDOWN : SystemOperation()
}

data class SystemConstraint(
    val name: String,
    val description: String,
    val validator: (SystemOperation, SystemConfiguration) -> Boolean
)

data class EnvironmentalConstraint(
    val name: String,
    val description: String,
    val isActive: Boolean = true
)

enum class CommunicationProtocol {
    SYNCHRONOUS,
    ASYNCHRONOUS,
    EVENT_DRIVEN,
    REQUEST_RESPONSE
}

interface SystemComponent {
    val identifier: String
    val type: String
}

// ================================
// EXAMPLE USAGE - Android-Specific Implementation
// ================================

/**
 * Example: User Authentication System
 */
class AuthenticationSystemComponent(
    config: SystemConfiguration
) : IsolatedSystemComponent<
    AuthRequest,
    AuthResponse,
    AuthState
>(
    configuration = config,
    input = AuthInputValidator(),
    output = AuthOutputEmitter(),
    processor = AuthProcessor(),
    controller = AuthController(),
    state = AuthStateManager(),
    environment = AndroidEnvironment(),
    feedback = AuthFeedbackProvider()
)

data class AuthRequest(val username: String, val password: String)
data class AuthResponse(val token: String, val user: User)
data class AuthState(val isAuthenticated: Boolean, val currentUser: User?)
data class User(val id: String, val username: String)

// Implementation classes would follow the interface contracts...