import { createHash, generateKeyPairSync, randomUUID, sign, verify } from 'node:crypto';

import { canonicalize } from 'json-canonicalize';

import { z } from 'zod';

export const PROTOCOL_VERSION = '0.1' as const;

export const DEFAULT_EXTENSION_URI = 'https://openclasp.example/extensions/trust/v0.1';

export const ProvenanceSchema = z.enum([

  'self_declared',

  'operator_attested',

  'cryptographically_verified',

  'domain_verified',

  'third_party_verified',

  'observed',

  'disputed',

]);

export const VisibilitySchema = z.enum([

  'local_only',

  'private_requester',

  'private_responder',

  'shared_participants',

  'network_aggregate',

]);

export const DataSharingModeSchema = z.enum([

  'local_only',

  'structured_only',

  'permitted_evidence',

]);

export const SignatureSchema = z.object({

  algorithm: z.literal('Ed25519'),

  keyId: z.string().min(1),

  value: z.string().min(1),

});

export const ExpectationManifestSchema = z.object({

  requiredInputs: z.array(z.string()).default([]),

  supportedTaskCategories: z.array(z.string()).min(1),

  responseTimeMs: z.number().int().positive().optional(),

  dataRequirements: z.array(z.string()).default([]),

  prohibitedData: z.array(z.string()).default([]),

  humanApprovalThresholds: z.array(z.string()).default([]),

  delegationPolicy: z.string().default('explicit'),

  evidenceRequirements: z.array(z.string()).default([]),

  factCheckingPreference: z

    .enum(['none', 'important_claims', 'all_objective_claims'])

    .default('important_claims'),

  mediationPreference: z.enum(['never', 'mutual_consent']).default('mutual_consent'),

  retentionDays: z.number().int().nonnegative().default(30),

  communicationFormats: z.array(z.string()).default(['text/plain']),

  cancellationPolicy: z.string().default('either_party'),

  provenance: ProvenanceSchema,

});

export const AgentIdentitySchema = z.object({

  protocolVersion: z.literal(PROTOCOL_VERSION),

  agentId: z.string().min(1),

  publicKey: z.string().min(1),

  keyId: z.string().min(1),

  operatorRef: z.string().min(1),

  assurance: z.enum(['pseudonymous', 'domain_associated', 'organization_associated']),

  agentVersion: z.string().min(1),

  capabilities: z.array(z.string()),

  supportedProtocols: z.array(z.string()),

  parentAgentId: z.string().optional(),

  rootControllerId: z.string().min(1),

  revoked: z.boolean().default(false),

  provenance: ProvenanceSchema,

  createdAt: z.string().datetime(),

  signature: SignatureSchema.optional(),

});

export const DelegationCredentialSchema = z.object({

  protocolVersion: z.literal(PROTOCOL_VERSION),

  delegationId: z.string().uuid(),

  parentAgentId: z.string(),

  childAgentId: z.string(),

  rootControllerId: z.string(),

  capabilities: z.array(z.string()).min(1),

  issuedAt: z.string().datetime(),

  expiresAt: z.string().datetime(),

  revoked: z.boolean().default(false),

  signature: SignatureSchema.optional(),

});

export const InteractionContractSchema = z.object({

  protocolVersion: z.literal(PROTOCOL_VERSION),

  interactionId: z.string().uuid(),

  purpose: z.string(),

  parties: z.array(z.string()).min(1),

  taskCategory: z.string(),

  requestedOutcome: z.string(),

  successCriteria: z.array(z.string()),

  allowedActions: z.array(z.string()),

  prohibitedActions: z.array(z.string()),

  allowedData: z.array(z.string()),

  prohibitedData: z.array(z.string()),

  deadline: z.string().datetime().optional(),

  evidenceRequirements: z.array(z.string()),

  delegationRules: z.array(z.string()),

  humanApprovalRequirements: z.array(z.string()),

  factCheckingPolicy: z.string(),

  mediationPolicy: z.enum(['none', 'mutual_consent']),

  retentionDays: z.number().int().nonnegative(),

  completionConditions: z.array(z.string()),

  cancellationConditions: z.array(z.string()),

  signatures: z.record(z.string(), SignatureSchema).default({}),

});

export const TrustEnvelopeSchema = z.object({

  protocolVersion: z.literal(PROTOCOL_VERSION),

  interactionId: z.string().uuid(),

  requestingAgentId: z.string(),

  respondingAgentId: z.string(),

  rootControllerId: z.string(),

  parentAgentId: z.string().optional(),

  agentVersion: z.string(),

  delegationId: z.string().uuid().optional(),

  requestedCapability: z.string(),

  taskCategory: z.string(),

  contractHash: z.string(),

  dataSharingMode: DataSharingModeSchema,

  evidenceRequirements: z.array(z.string()),

  timestamp: z.string().datetime(),

  expiresAt: z.string().datetime(),

  nonce: z.string().min(12),

  signature: SignatureSchema.optional(),

});

export const EventTypeSchema = z.enum([

  'claim',

  'evidence',

  'constraint',

  'commitment',

  'proposal',

  'objection',

  'policy_warning',

  'policy_violation',

  'private_suggestion',

  'shared_intervention',

  'delegation',

  'task_result',

  'resolution',

  'receipt',

  'feedback',

  'dispute',

]);

export const InteractionEventSchema = z.object({

  protocolVersion: z.literal(PROTOCOL_VERSION),

  eventId: z.string().uuid(),

  interactionId: z.string().uuid(),

  eventType: EventTypeSchema,

  agentId: z.string(),

  agentVersion: z.string(),

  timestamp: z.string().datetime(),

  visibility: VisibilitySchema,

  provenance: ProvenanceSchema,

  payloadHash: z.string(),

  payload: z.record(z.string(), z.unknown()),

  evidenceRefs: z.array(z.string()).optional(),

  signature: SignatureSchema.optional(),

});

export const FeedbackSchema = z.object({

  feedbackId: z.string().uuid(),

  interactionId: z.string().uuid(),

  receiptId: z.string().uuid(),

  reviewerAgentId: z.string(),

  subjectAgentId: z.string(),

  taskCompleted: z.boolean(),

  outputAccepted: z.boolean(),

  specificationMatched: z.boolean(),

  deadlineMet: z.boolean(),

  communicationQuality: z.number().min(0).max(1),

  evidenceProvided: z.boolean(),

  scopeRespected: z.boolean(),

  disputeRaised: z.boolean(),

  comment: z.string().max(1000).optional(),

  submittedAt: z.string().datetime(),

  signature: SignatureSchema.optional(),

});

export const ReceiptSchema = z.object({

  receiptId: z.string().uuid(),

  interactionId: z.string().uuid(),

  participants: z.array(z.string()),

  agentVersions: z.record(z.string(), z.string()),

  contractHash: z.string(),

  startedAt: z.string().datetime(),

  completedAt: z.string().datetime(),

  outcome: z.enum(['success', 'partial', 'failure', 'cancelled']),

  commitmentsFulfilled: z.array(z.string()),

  commitmentsMissed: z.array(z.string()),

  evidenceHashes: z.array(z.string()),

  policyWarnings: z.array(z.string()),

  policyViolations: z.array(z.string()),

  disputeStatus: z.enum(['none', 'open', 'resolved']),

  delegationChainHash: z.string(),

  unilateral: z.boolean(),

  signatures: z.record(z.string(), SignatureSchema).default({}),

});

export const RiskDecisionSchema = z.object({

  decision: z.enum(['ALLOW', 'CHALLENGE', 'DENY']),

  confidence: z.number().min(0).max(1),

  taskCategory: z.string(),

  sampleSize: z.number().int().nonnegative(),

  dimensions: z.record(z.string(), z.number()),

  reasons: z.array(z.string()),

  warnings: z.array(z.string()),

  dataFreshness: z.record(z.string(), z.string()),

  requiredChallenges: z.array(z.string()),

});

export const FactCheckResultSchema = z.object({

  claim: z.string(),

  claimType: z.enum(['objective', 'subjective', 'prediction']),

  status: z.enum([

    'verified',

    'supported',

    'contradicted',

    'unverified',

    'not_fact_checkable',

    'insufficient_permission',

  ]),

  confidence: z.number().min(0).max(1),

  evidenceReferences: z.array(z.string()),

  sourceAuthority: z.string(),

  sourceFreshness: z.string(),

  contradictingEvidence: z.array(z.string()),

  suggestedNextAction: z.string(),

});

export type AgentIdentity = z.infer<typeof AgentIdentitySchema>;

export type DelegationCredential = z.infer<typeof DelegationCredentialSchema>;

export type InteractionContract = z.infer<typeof InteractionContractSchema>;

export type TrustEnvelope = z.infer<typeof TrustEnvelopeSchema>;

export type InteractionEvent = z.infer<typeof InteractionEventSchema>;

export type Feedback = z.infer<typeof FeedbackSchema>;

export type Receipt = z.infer<typeof ReceiptSchema>;

export type RiskDecision = z.infer<typeof RiskDecisionSchema>;

export type FactCheckResult = z.infer<typeof FactCheckResultSchema>;

export type ExpectationManifest = z.infer<typeof ExpectationManifestSchema>;

export interface KeyPair {

  keyId: string;

  publicKey: string;

  privateKey: string;

}

export function createKeyPair(keyId: string = randomUUID()): KeyPair {

  const pair = generateKeyPairSync('ed25519');

  return {

    keyId,

    publicKey: pair.publicKey.export({ type: 'spki', format: 'der' }).toString('base64url'),

    privateKey: pair.privateKey.export({ type: 'pkcs8', format: 'der' }).toString('base64url'),

  };

}

export function canonicalHash(value: unknown): string {

  return createHash('sha256').update(canonicalize(value)).digest('base64url');

}

function unsigned(value: Record<string, unknown>): Record<string, unknown> {

  const copy = structuredClone(value);

  delete copy.signature;

  delete copy.signatures;

  return copy;

}

export function signObject<T extends Record<string, unknown>>(

  value: T,

  key: KeyPair,

): T & { signature: z.infer<typeof SignatureSchema> } {

  const payload = Buffer.from(canonicalize(unsigned(value)));

  const privateKey = {

    key: Buffer.from(key.privateKey, 'base64url'),

    type: 'pkcs8' as const,

    format: 'der' as const,

  };

  return {

    ...value,

    signature: {

      algorithm: 'Ed25519',

      keyId: key.keyId,

      value: sign(null, payload, privateKey).toString('base64url'),

    },

  };

}

export function verifyObject(value: Record<string, unknown>, publicKey: string): boolean {

  const parsed = SignatureSchema.safeParse(value.signature);

  if (!parsed.success) return false;

  const key = {

    key: Buffer.from(publicKey, 'base64url'),

    type: 'spki' as const,

    format: 'der' as const,

  };

  return verify(

    null,

    Buffer.from(canonicalize(unsigned(value))),

    key,

    Buffer.from(parsed.data.value, 'base64url'),

  );

}

export function signNamed<T extends Record<string, unknown>>(

  value: T,

  signerId: string,

  key: KeyPair,

): T & { signatures: Record<string, z.infer<typeof SignatureSchema>> } {

  const payload = Buffer.from(canonicalize(unsigned(value)));

  const privateKey = {

    key: Buffer.from(key.privateKey, 'base64url'),

    type: 'pkcs8' as const,

    format: 'der' as const,

  };

  const signature = {

    algorithm: 'Ed25519' as const,

    keyId: key.keyId,

    value: sign(null, payload, privateKey).toString('base64url'),

  };

  return {

    ...value,

    signatures: { ...((value.signatures as object) ?? {}), [signerId]: signature },

  };

}

export function verifyNamed(

  value: Record<string, unknown>,

  signerId: string,

  publicKey: string,

): boolean {

  const signatures = value.signatures as Record<string, unknown> | undefined;

  const parsed = SignatureSchema.safeParse(signatures?.[signerId]);

  if (!parsed.success) return false;

  const key = {

    key: Buffer.from(publicKey, 'base64url'),

    type: 'spki' as const,

    format: 'der' as const,

  };

  return verify(

    null,

    Buffer.from(canonicalize(unsigned(value))),

    key,

    Buffer.from(parsed.data.value, 'base64url'),

  );

}