// SEB TypeScript Contract Template
// Generated from: SEB_SOVEREIGN_EVENT_BUS_MASTER_SPECIFICATION.xml
// Version: 1.0.0
// Target: TypeScript Client Library

import { z } from 'zod';
import { ulid } from 'ulid';
import { createHash } from 'crypto';

// Branded types for type safety
export type EventId = string & { readonly __brand: 'EventId' };
export type PrincipalId = string & { readonly __brand: 'PrincipalId' };
export type Hash = string & { readonly __brand: 'Hash' };
export type Signature = string & { readonly __brand: 'Signature' };

// Zod schemas for runtime validation
export const NetworkPolicySchema = z.enum(['allow', 'deny', 'restricted']);
export type NetworkPolicy = z.infer<typeof NetworkPolicySchema>;

export const FilesystemPolicySchema = z.enum(['readonly', 'readwrite', 'deny']);
export type FilesystemPolicy = z.infer<typeof FilesystemPolicySchema>;

export const ConstraintsSchema = z.object({
  network: NetworkPolicySchema,
  max_runtime_ms: z.number().positive(),
  max_memory_bytes: z.number().positive(),
  filesystem: FilesystemPolicySchema,
});
export type Constraints = z.infer<typeof ConstraintsSchema>;

export const IntentSchema = z.object({
  action: z.string().min(1),
  subject: z.string().min(1),
  parameters: z.record(z.unknown()),
});
export type Intent = z.infer<typeof IntentSchema>;

export const ContextSchema = z.object({
  environment: z.string().min(1),
  constraints: ConstraintsSchema,
  metadata: z.record(z.unknown()),
});
export type Context = z.infer<typeof ContextSchema>;

export const CredentialsSchema = z.object({
  credential_type: z.string().min(1),
  value: z.string().min(1),
  signature: z.string().optional(),
});
export type Credentials = z.infer<typeof CredentialsSchema>;

export const AuthoritySchema = z.object({
  principal: z.string().min(1),
  credentials: CredentialsSchema,
  scope: z.array(z.string()),
});
export type Authority = z.infer<typeof AuthoritySchema>;

export const ContinuationSchema = z.object({
  step: z.number().int().positive(),
  total_steps: z.number().int().positive(),
  state: z.record(z.unknown()),
});
export type Continuation = z.infer<typeof ContinuationSchema>;

export const EvidenceSchema = z.object({
  evidence_type: z.string().min(1),
  hash: z.string().min(1),
  signature: z.string().min(1),
  timestamp: z.string().datetime(),
});
export type Evidence = z.infer<typeof EvidenceSchema>;

export const SealSchema = z.object({
  hash: z.string().min(1),
  signature: z.string().min(1),
  public_key: z.string().min(1),
  timestamp: z.string().datetime(),
  algorithm: z.string().min(1),
});
export type Seal = z.infer<typeof SealSchema>;

export const EventEnvelopeSchema = z.object({
  type: z.string().min(1),
  version: z.string().min(1),
  id: z.string().min(1),
  timestamp: z.string().datetime(),
  intent: IntentSchema,
  context: ContextSchema,
  authority: AuthoritySchema,
  continuation: ContinuationSchema.optional(),
  evidence: z.array(EvidenceSchema).default([]),
  seal: SealSchema.optional(),
});
export type EventEnvelope = z.infer<typeof EventEnvelopeSchema>;

/**
 * Result type for operations that can fail
 */
export type Result<T, E = Error> = 
  | { ok: true; value: T }
  | { ok: false; error: E };

/**
 * Create a successful Result
 */
export function Ok<T>(value: T): Result<T, never> {
  return { ok: true, value };
}

/**
 * Create a failed Result
 */
export function Err<E>(error: E): Result<never, E> {
  return { ok: false, error };
}

/**
 * Event envelope builder with fluent API
 */
export class EventEnvelopeBuilder {
  private envelope: Partial<EventEnvelope>;

  constructor(eventType: string) {
    this.envelope = {
      type: eventType,
      version: '1.0.0',
      id: ulid() as EventId,
      timestamp: new Date().toISOString(),
      evidence: [],
    };
  }

  withIntent(intent: Intent): this {
    this.envelope.intent = intent;
    return this;
  }

  withContext(context: Context): this {
    this.envelope.context = context;
    return this;
  }

  withAuthority(authority: Authority): this {
    this.envelope.authority = authority;
    return this;
  }

  withContinuation(continuation: Continuation): this {
    this.envelope.continuation = continuation;
    return this;
  }

  addEvidence(evidence: Evidence): this {
    this.envelope.evidence = [...(this.envelope.evidence || []), evidence];
    return this;
  }

  build(): Result<EventEnvelope, z.ZodError> {
    try {
      const validated = EventEnvelopeSchema.parse(this.envelope);
      return Ok(validated);
    } catch (error) {
      if (error instanceof z.ZodError) {
        return Err(error);
      }
      throw error;
    }
  }
}

/**
 * Compute Blake3 hash of envelope (excluding seal)
 */
export function computeEnvelopeHash(envelope: EventEnvelope): Hash {
  const envelopeCopy = { ...envelope };
  delete envelopeCopy.seal;
  const json = JSON.stringify(envelopeCopy);
  // Note: In production, use actual Blake3 implementation
  // This is a placeholder using SHA-256
  const hash = createHash('sha256').update(json).digest('hex');
  return hash as Hash;
}

/**
 * Policy decision types
 */
export type PolicyDecision =
  | { type: 'allow' }
  | { type: 'deny'; reason: string }
  | { type: 'require_evidence'; required: string[] };

/**
 * Policy gate interface
 */
export interface PolicyGate {
  evaluate(envelope: EventEnvelope): Promise<Result<PolicyDecision, PolicyError>>;
}

export class PolicyError extends Error {
  constructor(
    message: string,
    public readonly code: string,
  ) {
    super(message);
    this.name = 'PolicyError';
  }
}

/**
 * Route destination types
 */
export type RouteDestination =
  | { type: 'adapter'; adapterId: string }
  | { type: 'queue'; queueName: string }
  | { type: 'reject'; reason: string };

/**
 * Routing engine interface
 */
export interface RoutingEngine {
  route(envelope: EventEnvelope): Promise<Result<RouteDestination, RoutingError>>;
}

export class RoutingError extends Error {
  constructor(
    message: string,
    public readonly code: string,
  ) {
    super(message);
    this.name = 'RoutingError';
  }
}

/**
 * Execution status types
 */
export type ExecutionStatus = 'success' | 'failure' | 'timeout' | 'denied';

/**
 * Execution metrics
 */
export interface ExecutionMetrics {
  duration_ms: number;
  memory_used_bytes: number;
  network_calls: number;
  filesystem_operations: number;
}

/**
 * Execution result
 */
export interface ExecutionResult {
  status: ExecutionStatus;
  output: unknown;
  evidence: Evidence[];
  metrics: ExecutionMetrics;
}

/**
 * Execution adapter interface
 */
export interface ExecutionAdapter {
  execute(envelope: EventEnvelope): Promise<Result<ExecutionResult, ExecutionError>>;
  capabilities(): string[];
  constraints(): Constraints;
}

export class ExecutionError extends Error {
  constructor(
    message: string,
    public readonly code: string,
    public readonly recoverable: boolean,
  ) {
    super(message);
    this.name = 'ExecutionError';
  }
}

/**
 * SEB Client for interacting with the Sovereign Event Bus
 */
export class SEBClient {
  constructor(
    private readonly endpoint: string,
    private readonly apiKey: string,
  ) {}

  /**
   * Submit an event envelope to the bus
   */
  async submit(envelope: EventEnvelope): Promise<Result<string, Error>> {
    try {
      const response = await fetch(`${this.endpoint}/events`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${this.apiKey}`,
        },
        body: JSON.stringify(envelope),
      });

      if (!response.ok) {
        const error = await response.text();
        return Err(new Error(`Failed to submit event: ${error}`));
      }

      const result = await response.json();
      return Ok(result.id);
    } catch (error) {
      return Err(error instanceof Error ? error : new Error(String(error)));
    }
  }

  /**
   * Query event status
   */
  async getStatus(eventId: EventId): Promise<Result<ExecutionResult, Error>> {
    try {
      const response = await fetch(`${this.endpoint}/events/${eventId}`, {
        headers: {
          'Authorization': `Bearer ${this.apiKey}`,
        },
      });

      if (!response.ok) {
        const error = await response.text();
        return Err(new Error(`Failed to get status: ${error}`));
      }

      const result = await response.json();
      return Ok(result);
    } catch (error) {
      return Err(error instanceof Error ? error : new Error(String(error)));
    }
  }
}

/**
 * Example usage
 */
export function createExampleEnvelope(): Result<EventEnvelope, z.ZodError> {
  return new EventEnvelopeBuilder('snapkitty.intent.verify_proof')
    .withIntent({
      action: 'verify_proof',
      subject: 'bundle:01J...',
      parameters: {},
    })
    .withContext({
      environment: 'production',
      constraints: {
        network: 'deny',
        max_runtime_ms: 5000,
        max_memory_bytes: 1024 * 1024,
        filesystem: 'readonly',
      },
      metadata: {},
    })
    .withAuthority({
      principal: 'user:alice',
      credentials: {
        credential_type: 'api_key',
        value: 'sk_...',
      },
      scope: ['read', 'verify'],
    })
    .build();
}