export type JsonPrimitive = string | number | boolean | null;
export type JsonValue = JsonPrimitive | JsonValue[] | { [key: string]: JsonValue };
export type Awaitable<T> = T | Promise<T>;
export type JobData = Record<string, JsonValue>;
export type JobStatus =
  | 'pending'
  | 'active'
  | 'completed'
  | 'failed'
  | 'cancelled'
  | 'stale';
export type JobPhaseStatus = 'pending' | 'active' | 'completed' | 'failed' | 'cancelled';
export type RetryBackoffStrategy = 'fixed' | 'linear' | 'exponential';
export type ErrorDisposition = 'recoverable' | 'fatal';

export interface JobPhaseState {
  name: string;
  status: JobPhaseStatus;
  progress: number;
  message: string | null;
  startedAt: string | null;
  completedAt: string | null;
  error: string | null;
}

export interface JobFailure {
  message: string;
  phase: string | null;
  recoverable: boolean;
  timestamp: string;
  attempt: number;
}

export interface JobRetryEvent {
  jobId: string;
  phase: string | null;
  attempt: number;
  delayMs: number;
  nextRunAt: string;
  timestamp: string;
}

export interface JobProgressEvent {
  jobId: string;
  phase: string;
  phaseProgress: number;
  overallProgress: number;
  message: string | null;
  timestamp: string;
  details?: JsonValue;
}

export interface JobRecord<TData extends JobData = JobData> {
  id: string;
  status: JobStatus;
  data: TData;
  currentPhase: string | null;
  phases: JobPhaseState[];
  phaseResults: Record<string, JsonValue | undefined>;
  progress: number;
  progressMessage: string | null;
  error: JobFailure | null;
  retryCount: number;
  maxAttempts: number;
  webhookUrl: string | null;
  webhookSent: boolean;
  createdAt: string;
  startedAt: string | null;
  completedAt: string | null;
  updatedAt: string;
  scheduledAt: string | null;
  cancelledAt: string | null;
}

export interface EnqueueOptions {
  id?: string;
  scheduledAt?: string | Date;
  maxAttempts?: number;
  webhookUrl?: string;
}

export interface RetryOptions {
  fromStart?: boolean;
  scheduledAt?: string | Date;
}

export interface ListJobsOptions {
  statuses?: JobStatus[];
  limit?: number;
  offset?: number;
}

export interface StreamOptions {
  jobId?: string;
  includeSnapshot?: boolean;
  keepAliveMs?: number;
}

export interface RetryConfig<TData extends JobData = JobData> {
  maxAttempts?: number;
  strategy?: RetryBackoffStrategy;
  baseDelayMs?: number;
  maxDelayMs?: number;
  classifyError?: (
    error: unknown,
    job: JobRecord<TData>,
  ) => Awaitable<ErrorDisposition>;
}

export interface RetentionConfig<TData extends JobData = JobData> {
  staleAfterMs: number;
  deleteAfterMs: number;
  intervalMs?: number;
  onStale?: (job: JobRecord<TData>) => Awaitable<void>;
  onDelete?: (job: JobRecord<TData>) => Awaitable<void>;
}

export type WebhookEventName =
  | 'job:completed'
  | 'job:failed'
  | 'job:retrying'
  | 'job:cancelled'
  | 'job:stale';

export interface WebhookConfig {
  url?: string;
  events?: WebhookEventName[];
  secret?: string;
  timeoutMs?: number;
  headers?: Record<string, string>;
  maxAttempts?: number;
  baseDelayMs?: number;
  maxDelayMs?: number;
}

export interface QueueConfig<TData extends JobData = JobData> {
  dbPath: string;
  phases: readonly string[];
  concurrency?: number;
  retry?: RetryConfig<TData>;
  retention?: RetentionConfig<TData>;
  webhook?: WebhookConfig;
  shutdownTimeoutMs?: number;
}

export interface PhaseContext<TData extends JobData = JobData> {
  readonly job: JobRecord<TData>;
  readonly phase: string;
  readonly signal: AbortSignal;
  progress: (percent: number, message?: string, details?: JsonValue) => Promise<JobRecord<TData>>;
  phaseResult: <TResult extends JsonValue = JsonValue>(phaseName: string) => TResult | undefined;
  phaseResults: () => Record<string, JsonValue | undefined>;
  isCancelled: () => boolean;
  throwIfCancelled: () => Promise<void>;
}

export type PhaseHandler<TData extends JobData = JobData> = (
  job: JobRecord<TData>,
  context: PhaseContext<TData>,
) => Awaitable<JsonValue | undefined>;

export interface WebhookDispatchResult {
  event: WebhookEventName;
  jobId: string;
  status: number;
  deliveredAt: string;
}

export interface WebhookDispatchError {
  event: WebhookEventName;
  jobId: string;
  message: string;
  finalAttempt: number;
}

export interface QueueStreamEvent<TData extends JobData = JobData> {
  type:
    | 'snapshot'
    | 'job:enqueued'
    | 'job:started'
    | 'job:progress'
    | 'job:phase:completed'
    | 'job:completed'
    | 'job:failed'
    | 'job:retrying'
    | 'job:cancelled'
    | 'job:stale'
    | 'job:deleted'
    | 'job:webhook:delivered'
    | 'job:webhook:failed'
    | 'ping';
  jobId?: string;
  job?: JobRecord<TData>;
  progress?: JobProgressEvent;
  phase?: JobPhaseState;
  failure?: JobFailure;
  retry?: JobRetryEvent;
  webhook?: WebhookDispatchResult | WebhookDispatchError;
  deletedJobId?: string;
  timestamp: string;
}

export interface JobQueueEvents<TData extends JobData = JobData> {
  'job:enqueued': [job: JobRecord<TData>];
  'job:started': [job: JobRecord<TData>];
  'job:progress': [job: JobRecord<TData>, progress: JobProgressEvent];
  'job:phase:completed': [job: JobRecord<TData>, phase: JobPhaseState];
  'job:completed': [job: JobRecord<TData>];
  'job:failed': [job: JobRecord<TData>, failure: JobFailure];
  'job:retrying': [job: JobRecord<TData>, retry: JobRetryEvent];
  'job:cancelled': [job: JobRecord<TData>];
  'job:stale': [job: JobRecord<TData>];
  'job:deleted': [jobId: string];
  'job:webhook:delivered': [job: JobRecord<TData>, result: WebhookDispatchResult];
  'job:webhook:failed': [job: JobRecord<TData>, error: WebhookDispatchError];
}