import type { ITaskStep } from './taskbuffer.classes.taskstep.js';
import type { Task } from './taskbuffer.classes.task.js';

export interface IRateLimitConfig {
  maxPerWindow: number;  // max completions allowed within the sliding window
  windowMs: number;      // sliding window duration in ms
}

export type TResultSharingMode = 'none' | 'share-latest';

export interface ITaskConstraintGroupOptions<TData extends Record<string, unknown> = Record<string, unknown>> {
  name: string;
  constraintKeyForExecution: (task: Task<any, any, TData>, input?: any) => string | null | undefined;
  maxConcurrent?: number;  // default: Infinity
  cooldownMs?: number;     // default: 0
  shouldExecute?: (task: Task<any, any, TData>, input?: any) => boolean | Promise<boolean>;
  rateLimit?: IRateLimitConfig;
  resultSharingMode?: TResultSharingMode;  // default: 'none'
}

export interface ITaskExecution<TData extends Record<string, unknown> = Record<string, unknown>> {
  task: Task<any, any, TData>;
  input: any;
}

export interface IConstrainedTaskEntry {
  task: Task<any, any, any>;
  input: any;
  deferred: import('@push.rocks/smartpromise').Deferred<any>;
  constraintKeys: Map<string, string>;  // groupName -> key
}

export interface ITaskMetadata {
  name: string;
  version?: string;
  status: 'idle' | 'running' | 'completed' | 'failed';
  steps: ITaskStep[];
  currentStep?: string;
  currentProgress: number; // 0-100
  lastRun?: Date;
  nextRun?: Date; // For scheduled tasks
  runCount: number;
  averageDuration?: number;
  cronSchedule?: string;
  buffered?: boolean;
  bufferMax?: number;
  timeout?: number;
  lastError?: string;
  errorCount?: number;
  labels?: Record<string, string>;
}

export interface ITaskExecutionReport {
  taskName: string;
  startTime: number;
  endTime: number;
  duration: number;
  steps: ITaskStep[];
  stepsCompleted: string[];
  progress: number;
  result?: any;
  error?: Error;
}

export interface IScheduledTaskInfo {
  name: string;
  schedule: string;
  nextRun: Date;
  lastRun?: Date;
  steps?: ITaskStep[];
  metadata?: ITaskMetadata;
}

export type TTaskEventType = 'started' | 'step' | 'completed' | 'failed';

export interface ITaskEvent {
  type: TTaskEventType;
  task: ITaskMetadata;
  timestamp: number;
  stepName?: string;   // present when type === 'step'
  error?: string;      // present when type === 'failed'
}

// ── Service Lifecycle Types ──────────────────────────────────────

export type TServiceState =
  | 'stopped'
  | 'starting'
  | 'running'
  | 'degraded'
  | 'failed'
  | 'stopping';

export type TServiceCriticality = 'critical' | 'optional';

export type TServiceEventType =
  | 'started'
  | 'stopped'
  | 'failed'
  | 'degraded'
  | 'recovered'
  | 'retrying'
  | 'healthCheck';

export interface IServiceEvent {
  type: TServiceEventType;
  serviceName: string;
  state: TServiceState;
  timestamp: number;
  error?: string;
  attempt?: number;
}

export interface IServiceStatus {
  name: string;
  state: TServiceState;
  criticality: TServiceCriticality;
  startedAt?: number;
  stoppedAt?: number;
  lastHealthCheck?: number;
  healthCheckOk?: boolean;
  uptime?: number;
  errorCount: number;
  lastError?: string;
  retryCount: number;
  dependencies: string[];
}

export interface IRetryConfig {
  /** Maximum retry attempts. 0 = no retries. Default: 3 */
  maxRetries?: number;
  /** Base delay in ms. Default: 1000 */
  baseDelayMs?: number;
  /** Maximum delay cap in ms. Default: 30000 */
  maxDelayMs?: number;
  /** Multiplier per attempt. Default: 2 */
  backoffFactor?: number;
}

export interface IHealthCheckConfig {
  /** Interval in ms between health checks. Default: 30000 */
  intervalMs?: number;
  /** Timeout for a single health check call. Default: 5000 */
  timeoutMs?: number;
  /** Consecutive failures before marking degraded. Default: 3 */
  failuresBeforeDegraded?: number;
  /** Consecutive failures before marking failed. Default: 5 */
  failuresBeforeFailed?: number;
}

export interface IServiceOptions<T = any> {
  name: string;
  start: () => Promise<T>;
  stop: () => Promise<void>;
  healthCheck?: () => Promise<boolean>;
  criticality?: TServiceCriticality;
  dependencies?: string[];
  retry?: IRetryConfig;
  healthCheckConfig?: IHealthCheckConfig;
}

export interface IServiceManagerOptions {
  name?: string;
  defaultRetry?: IRetryConfig;
  defaultHealthCheck?: IHealthCheckConfig;
  /** Timeout in ms for the entire startup sequence. Default: 120000 */
  startupTimeoutMs?: number;
  /** Timeout in ms for the entire shutdown sequence. Default: 30000 */
  shutdownTimeoutMs?: number;
}

export type TOverallHealth = 'healthy' | 'degraded' | 'unhealthy';

export interface IServiceManagerHealth {
  overall: TOverallHealth;
  services: IServiceStatus[];
  startedAt?: number;
  uptime?: number;
}