import { createHash, randomUUID } from 'node:crypto';
import type { Pool, PoolClient } from 'pg';
import { z } from 'zod';
import type { MoneroDepositAddressRpc } from './monero-observer.ts';
import { validateXmrSubaddress } from './xmr.ts';
import { IS_PILOT, NETWORK } from '../../shared/network.ts';
import { CHAIN_ID } from '../testnet/consensus.ts';
import type { PilotCustodyIdentity } from './pilot-custody-identity.ts';
import { assertPilotReservationDatabaseEmpty, verifyPilotCustodyIdentity } from './pilot-custody-identity.ts';
import { validatePilotMoneroDepositRequest, type PilotDepositRequestContext } from './pilot-monero-deposit-request.ts';
import { CUSTODY_WRITE_LOCK, verifyCustodySchema } from './postgres-schema.ts';

const MAX_INDEX = 0xffff_ffff;
const uuidPattern = /^[a-f0-9]{8}(-[a-f0-9]{4}){3}-[a-f0-9]{12}$/i;
const hexPattern = /^[a-f0-9]{64}$/;

export type PilotDepositReservation = {
  allocationId: string;
  requestId: string;
  custodianId: string;
  marketNetwork: 'wikideck-randomx-pilot-1';
  marketChainId: string;
  moneroNetwork: 'mainnet';
  beneficiary: string;
  walletGenerationId: string;
  walletFingerprint: string;
  accountIndex: number;
  addressIndex: number;
  requestDigest: string;
  allocationDigest: string;
  reservedAt: number;
};

type ReservationRow = {
  allocation_id: string; request_id: string; custodian_id: string;
  market_network: 'wikideck-randomx-pilot-1'; market_chain_id: string; monero_network: 'mainnet';
  beneficiary: string; wallet_generation_id: string; wallet_fingerprint: string;
  account_index: string; address_index: string; request_digest: string; allocation_digest: string; reserved_at: string;
};

export type PilotDepositAllocationIntent = {
  requestId: string; custodianId: string; marketNetwork: 'wikideck-randomx-pilot-1'; marketChainId: string;
  moneroNetwork: 'mainnet'; beneficiary: string; walletGenerationId: string; walletFingerprint: string;
  accountIndex: number; requestDigest: string;
};

type ReservationAddressRow = ReservationRow & {
  status: 'reserved' | 'creating' | 'registered';
  create_started_at: string | null;
  monero_address: string | null;
  registered_at: string | null;
};

function toReservation(row: ReservationRow): PilotDepositReservation {
  return { allocationId: row.allocation_id, requestId: row.request_id, custodianId: row.custodian_id,
    marketNetwork: row.market_network, marketChainId: row.market_chain_id, moneroNetwork: row.monero_network,
    beneficiary: row.beneficiary, walletGenerationId: row.wallet_generation_id, walletFingerprint: row.wallet_fingerprint,
    accountIndex: Number(row.account_index), addressIndex: Number(row.address_index), requestDigest: row.request_digest,
    allocationDigest: row.allocation_digest, reservedAt: Number(row.reserved_at) };
}

function validateIdentity(identity: PilotCustodyIdentity, intent: PilotDepositAllocationIntent, reservedAt: number): void {
  if (!IS_PILOT || NETWORK !== 'wikideck-randomx-pilot-1' || identity.version !== 1 || identity.mode !== 'pilot-custody' ||
      identity.policy !== 'pilot-custody-v1' || identity.marketNetwork !== NETWORK || identity.marketChainId !== CHAIN_ID ||
      identity.moneroNetwork !== 'mainnet' || identity.activationStatus !== 'identity-only') {
    throw new Error('Pilot deposit reservation requires the configured identity-only pilot custody profile');
  }
  if (!Number.isSafeInteger(reservedAt) || reservedAt < 0 || !uuidPattern.test(intent.requestId) ||
      !uuidPattern.test(intent.custodianId) || !uuidPattern.test(intent.walletGenerationId) ||
      intent.custodianId.toLowerCase() !== identity.custodianId.toLowerCase() ||
      intent.marketNetwork !== identity.marketNetwork || intent.marketChainId !== identity.marketChainId ||
      intent.moneroNetwork !== identity.moneroNetwork || !hexPattern.test(intent.beneficiary) ||
      !hexPattern.test(intent.walletFingerprint) || !hexPattern.test(intent.requestDigest) ||
      !Number.isSafeInteger(intent.accountIndex) || intent.accountIndex < 0 || intent.accountIndex > MAX_INDEX) {
    throw new Error('Invalid pilot deposit allocation intent');
  }
}

function allocationDigest(intent: PilotDepositAllocationIntent): string {
  return createHash('sha256').update(JSON.stringify([
    'wikideck-pilot-monero-deposit-allocation-v1', intent.custodianId, intent.marketNetwork,
    intent.marketChainId, intent.moneroNetwork, intent.beneficiary, intent.walletGenerationId,
    intent.walletFingerprint, intent.accountIndex,
  ])).digest('hex');
}

async function assertIdentityRecord(client: PoolClient, identity: PilotCustodyIdentity): Promise<void> {
  const result = await client.query(`SELECT version,mode,policy,market_network,market_chain_id,monero_network,
    custodian_id,activation_status FROM wk_custody.pilot_custody_identity WHERE singleton=1`);
  if (!result.rowCount) throw new Error('Pilot custody identity is not initialized');
  const row = result.rows[0];
  if (Number(row.version) !== identity.version || row.mode !== identity.mode || row.policy !== identity.policy ||
      row.market_network !== identity.marketNetwork || row.market_chain_id !== identity.marketChainId ||
      row.monero_network !== identity.moneroNetwork || row.custodian_id !== identity.custodianId ||
      row.activation_status !== identity.activationStatus) {
    throw new Error('Pilot custody identity changed or does not match the database binding');
  }
}

/**
 * Persist a never-reused Monero address index for a signed, validated pilot request.
 * This does not call Wallet-RPC, create/register an address, or permit crediting funds.
 */
export async function reservePilotMoneroDepositIndex(pool: Pool, identity: PilotCustodyIdentity,
  intentInput: PilotDepositAllocationIntent, reservedAt = Date.now()): Promise<{ reservation: PilotDepositReservation; replayed: boolean }> {
  const intent = { ...intentInput, custodianId: intentInput.custodianId.toLowerCase() };
  validateIdentity(identity, intent, reservedAt);
  const allocationHash = allocationDigest(intent);
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    await client.query("SET LOCAL statement_timeout='10s'; SET LOCAL lock_timeout='3s'; SET LOCAL idle_in_transaction_session_timeout='10s'; SET LOCAL synchronous_commit=on");
    await client.query('SELECT pg_advisory_xact_lock($1::bigint)', [CUSTODY_WRITE_LOCK]);
    await verifyCustodySchema(client);
    await assertPilotReservationDatabaseEmpty(client);
    await assertIdentityRecord(client, identity);
    // Serialize index allocation across app processes using the same watch-only wallet/account.
    await client.query('SELECT pg_advisory_xact_lock(hashtextextended($1,0))', [
      `wikideck-pilot-monero-reservation-v1:${intent.walletGenerationId}:${intent.accountIndex}`,
    ]);

    const byRequest = await client.query<ReservationRow>(`SELECT * FROM wk_custody.pilot_monero_deposit_reservations
      WHERE request_id=$1`, [intent.requestId]);
    if (byRequest.rowCount) {
      const row = byRequest.rows[0];
      if (row.request_digest !== intent.requestDigest || row.allocation_digest !== allocationHash) {
        throw new Error('Pilot deposit request ID was reused with different signed terms');
      }
      await client.query('COMMIT');
      return { reservation: toReservation(row), replayed: true };
    }

    const byBeneficiary = await client.query<ReservationRow>(`SELECT * FROM wk_custody.pilot_monero_deposit_reservations
      WHERE custodian_id=$1 AND market_network=$2 AND market_chain_id=$3 AND beneficiary=$4
        AND wallet_generation_id=$5`, [intent.custodianId, intent.marketNetwork, intent.marketChainId,
      intent.beneficiary, intent.walletGenerationId]);
    if (byBeneficiary.rowCount) {
      const row = byBeneficiary.rows[0];
      if (row.allocation_digest !== allocationHash) {
        throw new Error('Beneficiary already has a different pilot reservation for this wallet generation');
      }
      await client.query('COMMIT');
      return { reservation: toReservation(row), replayed: true };
    }

    const next = await client.query<{ next_index: string }>(`SELECT (COALESCE(MAX(address_index),-1)+1)::text AS next_index
      FROM wk_custody.pilot_monero_deposit_reservations WHERE wallet_generation_id=$1 AND account_index=$2`,
    [intent.walletGenerationId, intent.accountIndex]);
    const index = BigInt(next.rows[0].next_index);
    if (index > BigInt(MAX_INDEX)) throw new Error('Pilot Monero subaddress index space is exhausted for this account');
    const inserted = await client.query<ReservationRow>(`INSERT INTO wk_custody.pilot_monero_deposit_reservations(
      allocation_id,request_id,custodian_id,market_network,market_chain_id,monero_network,beneficiary,
      wallet_generation_id,wallet_fingerprint,account_index,address_index,request_digest,allocation_digest,reserved_at)
      VALUES($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14) RETURNING *`, [randomUUID(), intent.requestId,
      intent.custodianId, intent.marketNetwork, intent.marketChainId, intent.moneroNetwork, intent.beneficiary,
      intent.walletGenerationId, intent.walletFingerprint, intent.accountIndex, index.toString(), intent.requestDigest,
      allocationHash, reservedAt]);
    await client.query('COMMIT');
    return { reservation: toReservation(inserted.rows[0]), replayed: false };
  } catch (error) {
    await client.query('ROLLBACK').catch(() => {});
    if (typeof error === 'object' && error !== null && 'code' in error && error.code === '23505') {
      throw new Error('Pilot deposit reservation conflicts with an existing request, beneficiary, or wallet index');
    }
    throw error;
  } finally { client.release(); }
}

/** Full signed-request path: verify durable identity, cryptographically validate, then reserve an index. */
export async function reservePilotMoneroDepositRequest(pool: Pool,
  context: Omit<PilotDepositRequestContext, 'identity'>,
  rawRequest: unknown, reservedAt = Date.now()) {
  const custodianId = z.object({ custodianId: z.string().uuid() }).passthrough().parse(rawRequest).custodianId;
  const identity = await verifyPilotCustodyIdentity(pool, custodianId);
  const intent = validatePilotMoneroDepositRequest({ ...context, identity }, rawRequest);
  return reservePilotMoneroDepositIndex(pool, identity, intent, reservedAt);
}

async function registerPilotAddress(pool: Pool, reservation: PilotDepositReservation, moneroAddress: string,
  registeredAt: number): Promise<{ reservation: PilotDepositReservation; address: string; replayed: boolean }> {
  const checkedAddress = await validateXmrSubaddress(moneroAddress);
  if (!Number.isSafeInteger(registeredAt) || registeredAt < reservation.reservedAt) {
    throw new Error('Pilot address registration predates its durable index reservation');
  }
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    await client.query("SET LOCAL statement_timeout='10s'; SET LOCAL lock_timeout='3s'; SET LOCAL synchronous_commit=on");
    const result = await client.query<ReservationAddressRow>(`SELECT * FROM wk_custody.pilot_monero_deposit_reservations
      WHERE allocation_id=$1 AND wallet_generation_id=$2`, [reservation.allocationId, reservation.walletGenerationId]);
    if (!result.rowCount) throw new Error('Pilot deposit reservation was not found for this wallet generation');
    const row = result.rows[0];
    if (row.status === 'registered') {
      if (row.monero_address !== checkedAddress) throw new Error('Registered pilot deposit address cannot be replaced');
      await client.query('COMMIT');
      return { reservation: toReservation(row), address: checkedAddress, replayed: true };
    }
    if (row.status !== 'creating' || row.create_started_at === null || row.monero_address !== null ||
        row.registered_at !== null || registeredAt < Number(row.create_started_at)) {
      throw new Error('Pilot deposit reservation registration state is inconsistent');
    }
    const updated = await client.query<ReservationAddressRow>(`UPDATE wk_custody.pilot_monero_deposit_reservations
      SET status='registered',monero_address=$2,registered_at=$3
      WHERE allocation_id=$1 AND status='creating' AND monero_address IS NULL RETURNING *`, [reservation.allocationId, checkedAddress, registeredAt]);
    if (!updated.rowCount) {
      const already = await client.query<ReservationAddressRow>(`SELECT * FROM wk_custody.pilot_monero_deposit_reservations
        WHERE allocation_id=$1 AND status='registered'`, [reservation.allocationId]);
      if (!already.rowCount || already.rows[0].monero_address !== checkedAddress) {
        throw new Error('Pilot deposit reservation changed during address registration');
      }
      await client.query('COMMIT');
      return { reservation: toReservation(already.rows[0]), address: checkedAddress, replayed: true };
    }
    await client.query('COMMIT');
    return { reservation: toReservation(updated.rows[0]), address: checkedAddress, replayed: false };
  } catch (error) { await client.query('ROLLBACK').catch(() => {}); throw error; }
  finally { client.release(); }
}

/**
 * Operator/library-only address creation for a durable reservation. A lost create_address
 * response is recovered by the stable label at the exact reserved index on the next call.
 * No HTTP route invokes this function and the result is not a credit or payment authorization.
 */
export async function createOrRecoverPilotMoneroDepositAddress(pool: Pool, rpc: MoneroDepositAddressRpc,
  context: Omit<PilotDepositRequestContext, 'identity'>, rawRequest: unknown,
  now = Date.now()): Promise<{ reservation: PilotDepositReservation; address: string; replayed: boolean }> {
  const reserved = await reservePilotMoneroDepositRequest(pool, context, rawRequest, now);
  const initial = await pool.query<ReservationAddressRow>(`SELECT * FROM wk_custody.pilot_monero_deposit_reservations
    WHERE allocation_id=$1 AND wallet_generation_id=$2`, [reserved.reservation.allocationId, reserved.reservation.walletGenerationId]);
  if (!initial.rowCount) throw new Error('Pilot deposit reservation was not found for its wallet generation');
  if (initial.rows[0].status === 'registered') {
    const address = await validateXmrSubaddress(initial.rows[0].monero_address ?? '');
    return { reservation: toReservation(initial.rows[0]), address, replayed: true };
  }

  const row = initial.rows[0];
  const lockKey = `wikideck-pilot-deposit-address-v1:${row.wallet_generation_id}:${row.account_index}`;
  const lockClient = await pool.connect();
  let locked = false;
  try {
    await lockClient.query('SELECT pg_advisory_lock(hashtextextended($1,0))', [lockKey]);
    locked = true;
    // Another worker may have completed while this call waited for the per-wallet fence.
    const current = await pool.query<ReservationAddressRow>(`SELECT * FROM wk_custody.pilot_monero_deposit_reservations
      WHERE allocation_id=$1 AND wallet_generation_id=$2`, [row.allocation_id, row.wallet_generation_id]);
    if (!current.rowCount) throw new Error('Pilot deposit reservation disappeared');
    if (current.rows[0].status === 'registered') {
      const address = await validateXmrSubaddress(current.rows[0].monero_address ?? '');
      return { reservation: toReservation(current.rows[0]), address, replayed: true };
    }
    const allocation = current.rows[0];
    if (await rpc.verifyWallet() !== allocation.wallet_fingerprint) {
      throw new Error('Configured Monero wallet identity differs from the durable pilot reservation');
    }
    const expectedIndex = Number(allocation.address_index);
    const expectedLabel = `wikideck-pilot-deposit-v1:${allocation.allocation_id}`;
    const createWasAlreadyStarted = allocation.status === 'creating';
    let existing = await rpc.getSubaddress(Number(allocation.account_index), expectedIndex);
    if (!createWasAlreadyStarted) {
      // Persist the side-effect intent first. If the process or transport fails afterwards,
      // retry is reconciliation-only: it may recover an existing labeled index but never create twice.
      const createStartedAt = Math.max(now, Number(allocation.reserved_at));
      const started = await pool.query(`UPDATE wk_custody.pilot_monero_deposit_reservations
        SET status='creating',create_started_at=$2 WHERE allocation_id=$1 AND status='reserved'
        RETURNING allocation_id`, [allocation.allocation_id, createStartedAt]);
      if (started.rowCount !== 1) throw new Error('Pilot address create intent could not be committed before Wallet-RPC');
    }
    if (!existing) {
      if (createWasAlreadyStarted) {
        throw new Error('Pilot Wallet-RPC create outcome is uncertain; reconcile the reserved index and wallet before retrying');
      }
      const created = await rpc.createSubaddress(Number(allocation.account_index), expectedLabel);
      if (created.addressIndex !== expectedIndex) {
        throw new Error('Monero wallet created an unexpected pilot subaddress index; reservation requires operator reconciliation');
      }
      // Never trust the create response alone; query the exact reserved index and stable label.
      existing = await rpc.getSubaddress(Number(allocation.account_index), expectedIndex);
      if (!existing || existing.address !== created.address) {
        throw new Error('Monero wallet subaddress could not be recovered at the reserved pilot index');
      }
    }
    if (existing.label !== expectedLabel) {
      throw new Error('Reserved pilot Monero subaddress index is occupied by a different wallet label');
    }
    const address = await validateXmrSubaddress(existing.address);
    const reservation = toReservation(allocation);
    return await registerPilotAddress(pool, reservation, address, now);
  } finally {
    if (locked) await lockClient.query('SELECT pg_advisory_unlock(hashtextextended($1,0))', [lockKey]).catch(() => {});
    lockClient.release();
  }
}