// GRU Supranational Settlement Service
// Volume II: Supranational Reserve Framework
// Implements SupraGRU_settlement algorithm with Ω-Layer integration

import prisma from '@/shared/database/prisma';
import { Decimal } from '@prisma/client/runtime/library';
import { v4 as uuidv4 } from 'uuid';
import { logger } from '@/infrastructure/monitoring/logger';
import { gruIndexService } from './gru-index.service';


export interface SupraGruSettlementRequest {
  poolId: string;
  sourceBankId: string;
  destinationBankId: string;
  amount: string;
  currencyCode: string;
  atomicSettlementId?: string;
}

export interface SupraGruSettlementResult {
  settlementId: string;
  status: string;
  mergedAt?: Date;
  confirmedAt?: Date;
  omegaLayerState?: Record<string, unknown>;
}

export interface OmegaLayerState {
  truthState: Record<string, unknown>;
  gasConfirmation?: string;
  gqlTruthSample?: string;
  timestamp: Date;
}

export class GruSupranationalSettlementService {
  /**
   * SupraGRU_settlement algorithm:
   * MERGE(GRU_index_state, XAU_state, regional_fx_basket, Ω_truth_state)
   */
  async executeSupraGruSettlement(
    request: SupraGruSettlementRequest
  ): Promise<SupraGruSettlementResult> {
    logger.info('GRU Supranational Settlement: Executing settlement', {
      request,
    });

    // Verify pool exists
    const pool = await prisma.gru_reserve_pools.findUnique({
      where: { poolId: request.poolId },
    });

    if (!pool) {
      throw new Error(`Reserve pool not found: ${request.poolId}`);
    }

    const settlementId = `SUPRA-SETTLE-${uuidv4()}`;
    const amount = new Decimal(request.amount);

    // Step 1: Capture GRU index state
    const gruIndexState = await this.captureGruIndexState();

    // Step 2: Capture XAU state
    const xauState = await this.captureXauState();

    // Step 3: Capture regional FX basket state
    const regionalFxBasket = await this.captureRegionalFxBasket(
      request.currencyCode
    );

    // Step 4: Get Ω-Layer truth state (if available)
    const omegaLayerState = await this.getOmegaLayerState();

    // Step 5: Create settlement record
    const settlement = await prisma.gru_supranational_settlements.create({
      data: {
        settlementId,
        poolId: request.poolId,
        atomicSettlementId: request.atomicSettlementId || null,
        gruIndexState: gruIndexState as any,
        xauState: xauState as any,
        regionalFxBasket: regionalFxBasket as any,
        omegaLayerState: omegaLayerState?.truthState || null,
        gasConfirmation: omegaLayerState?.gasConfirmation || null,
        gqlTruthSample: omegaLayerState?.gqlTruthSample || null,
        settlementAmount: amount,
        currencyCode: request.currencyCode,
        status: 'pending',
      },
    });

    // Step 6: Merge states
    const mergedState = await this.mergeStates(
      gruIndexState,
      xauState,
      regionalFxBasket,
      omegaLayerState
    );

    // Step 7: Update settlement with merged state
    await prisma.gru_supranational_settlements.update({
      where: { settlementId },
      data: {
        status: 'merged',
        mergedAt: new Date(),
        omegaLayerState: mergedState as any,
      },
    });

    // Step 8: Confirm settlement (Ω-Layer finality)
    await this.confirmSettlement(settlementId);

    logger.info('GRU Supranational Settlement: Settlement completed', {
      settlementId,
      amount: amount.toString(),
    });

    const confirmed = await prisma.gru_supranational_settlements.findUnique({
      where: { settlementId },
    });

    return {
      settlementId,
      status: confirmed!.status,
      mergedAt: confirmed!.mergedAt || undefined,
      confirmedAt: confirmed!.confirmedAt || undefined,
      omegaLayerState: mergedState,
    };
  }

  /**
   * Capture GRU index state
   */
  private async captureGruIndexState(): Promise<Record<string, unknown>> {
    const indexes = await gruIndexService.getAllIndexes();

    const state: Record<string, unknown> = {
      timestamp: new Date().toISOString(),
      indexes: {},
    };

    for (const index of indexes) {
      (state.indexes as Record<string, unknown>)[index.indexCode] = {
        currentValue: index.currentValue.toString(),
        changePercent: index.changePercent?.toString(),
        lastUpdated: index.lastUpdated.toISOString(),
      };
    }

    return state;
  }

  /**
   * Capture XAU state
   */
  private async captureXauState(): Promise<Record<string, unknown>> {
    const xauIndex = await gruIndexService.getIndex('LiXAU');

    if (!xauIndex) {
      throw new Error('LiXAU index not found');
    }

    return {
      timestamp: new Date().toISOString(),
      xauValue: xauIndex.currentValue.toString(),
      indexId: xauIndex.indexId,
      lastUpdated: xauIndex.lastUpdated.toISOString(),
    };
  }

  /**
   * Capture regional FX basket state
   */
  private async captureRegionalFxBasket(
    baseCurrency: string
  ): Promise<Record<string, unknown>> {
    // In production, would fetch real-time FX rates
    // For now, return placeholder structure
    return {
      timestamp: new Date().toISOString(),
      baseCurrency,
      basket: {
        USD: { rate: 1.0, weight: 0.35 },
        EUR: { rate: 0.92, weight: 0.30 },
        CNY: { rate: 7.2, weight: 0.20 },
        GBP: { rate: 0.79, weight: 0.10 },
        JPY: { rate: 150.0, weight: 0.05 },
      },
    };
  }

  /**
   * Get Ω-Layer truth state
   * In production, would integrate with actual Ω-Layer/GQL system
   */
  private async getOmegaLayerState(): Promise<OmegaLayerState | null> {
    // Placeholder for Ω-Layer integration
    // In production, would:
    // 1. Query GQL (Global Quantum Ledger) for truth sample
    // 2. Get GAS atomic confirmation
    // 3. Merge multi-reality states

    const truthState: Record<string, unknown> = {
      timestamp: new Date().toISOString(),
      layer: 'omega',
      reconciled: true,
      multiRealityConsensus: true,
    };

    return {
      truthState,
      gasConfirmation: `GAS-${uuidv4()}`,
      gqlTruthSample: `GQL-SAMPLE-${uuidv4()}`,
      timestamp: new Date(),
    };
  }

  /**
   * Merge states: MERGE(GRU_index_state, XAU_state, regional_fx_basket, Ω_truth_state)
   */
  private async mergeStates(
    gruIndexState: Record<string, unknown>,
    xauState: Record<string, unknown>,
    regionalFxBasket: Record<string, unknown>,
    omegaLayerState: OmegaLayerState | null
  ): Promise<Record<string, unknown>> {
    const merged: Record<string, unknown> = {
      mergedAt: new Date().toISOString(),
      gruIndexState,
      xauState,
      regionalFxBasket,
    };

    if (omegaLayerState) {
      merged.omegaLayerState = omegaLayerState.truthState;
      merged.gasConfirmation = omegaLayerState.gasConfirmation;
      merged.gqlTruthSample = omegaLayerState.gqlTruthSample;
    }

    // Add reconciliation hash
    merged.reconciliationHash = this.generateReconciliationHash(merged);

    return merged;
  }

  /**
   * Confirm settlement (Ω-Layer finality)
   */
  private async confirmSettlement(settlementId: string): Promise<void> {
    const settlement = await prisma.gru_supranational_settlements.findUnique({
      where: { settlementId },
    });

    if (!settlement) {
      throw new Error(`Settlement not found: ${settlementId}`);
    }

    if (settlement.status !== 'merged') {
      throw new Error(`Settlement not merged: ${settlementId}`);
    }

    // In production, would:
    // 1. Verify Ω-Layer finality
    // 2. Confirm GAS atomic confirmation
    // 3. Validate GQL truth sample
    // 4. Cross-chain reconciliation

    // For now, mark as confirmed
    await prisma.gru_supranational_settlements.update({
      where: { settlementId },
      data: {
        status: 'confirmed',
        confirmedAt: new Date(),
      },
    });

    logger.info('GRU Supranational Settlement: Settlement confirmed', {
      settlementId,
    });
  }

  /**
   * Generate reconciliation hash
   */
  private generateReconciliationHash(
    state: Record<string, unknown>
  ): string {
    // In production, would use cryptographic hash (SHA-256, etc.)
    const crypto = require('crypto');
    const hash = crypto
      .createHash('sha256')
      .update(JSON.stringify(state))
      .digest('hex');
    return hash;
  }

  /**
   * Get settlement by ID
   */
  async getSettlement(settlementId: string) {
    return await prisma.gru_supranational_settlements.findUnique({
      where: { settlementId },
      include: {
        pool: true,
      },
    });
  }

  /**
   * Get settlements for a pool
   */
  async getSettlementsForPool(
    poolId: string,
    status?: string,
    limit: number = 100
  ) {
    const where: any = { poolId };
    if (status) where.status = status;

    return await prisma.gru_supranational_settlements.findMany({
      where,
      include: {
        pool: true,
      },
      orderBy: { createdAt: 'desc' },
      take: limit,
    });
  }

  /**
   * Cross-chain reconciliation
   * Reconciles settlement across different chains (Ω-Layer merge, GAS atomic confirmation, GQL truth sampling)
   */
  async reconcileCrossChain(settlementId: string): Promise<void> {
    logger.info('GRU Supranational Settlement: Cross-chain reconciliation', {
      settlementId,
    });

    const settlement = await prisma.gru_supranational_settlements.findUnique({
      where: { settlementId },
    });

    if (!settlement) {
      throw new Error(`Settlement not found: ${settlementId}`);
    }

    // Ω-Layer merge
    const omegaState = await this.getOmegaLayerState();
    if (omegaState) {
      await prisma.gru_supranational_settlements.update({
        where: { settlementId },
        data: {
          omegaLayerState: omegaState.truthState as any,
          gasConfirmation: omegaState.gasConfirmation,
          gqlTruthSample: omegaState.gqlTruthSample,
        },
      });
    }

    // GAS atomic confirmation
    // In production, would verify actual GAS confirmation

    // GQL truth sampling
    // In production, would query GQL for truth sample

    logger.info('GRU Supranational Settlement: Cross-chain reconciliation completed', {
      settlementId,
    });
  }
}

export const gruSupranationalSettlementService =
  new GruSupranationalSettlementService();

