/**
 * @file banking-bridge.ts
 * @notice Bridge between blockchain and traditional banking systems (SWIFT/TARGET2)
 */

import { ethers } from 'ethers';
import { SettlementFile } from '../../orchestration/tokenization/settlement-generator';

export interface BankingBridgeConfig {
    swiftApiUrl?: string;
    target2ApiUrl?: string;
    fireflyApiUrl: string;
}

export interface BankingSettlementRequest {
    settlementFile: SettlementFile;
    bankingSystem: 'SWIFT' | 'TARGET2' | 'BOTH';
    regulatoryFlags?: Record<string, any>;
}

export class BankingBridge {
    private config: BankingBridgeConfig;

    constructor(config: BankingBridgeConfig) {
        this.config = config;
    }

    /**
     * Submit settlement to traditional banking systems
     */
    async submitSettlement(request: BankingSettlementRequest): Promise<{
        swiftReference?: string;
        target2Reference?: string;
        status: string;
    }> {
        const results: {
            swiftReference?: string;
            target2Reference?: string;
            status: string;
        } = {
            status: 'pending'
        };

        // Submit to SWIFT if requested
        if (request.bankingSystem === 'SWIFT' || request.bankingSystem === 'BOTH') {
            if (this.config.swiftApiUrl) {
                results.swiftReference = await this.submitToSWIFT(request.settlementFile);
            } else {
                // Generate SWIFT reference without actual submission
                results.swiftReference = request.settlementFile.traditional.swiftReference;
            }
        }

        // Submit to TARGET2 if requested
        if (request.bankingSystem === 'TARGET2' || request.bankingSystem === 'BOTH') {
            if (this.config.target2ApiUrl) {
                results.target2Reference = await this.submitToTARGET2(request.settlementFile);
            } else {
                // Generate TARGET2 reference without actual submission
                results.target2Reference = request.settlementFile.traditional.target2Code;
            }
        }

        // Store dual records in FireFly
        await this.storeDualRecords(request.settlementFile, results);

        results.status = 'completed';
        return results;
    }

    /**
     * Submit to SWIFT
     */
    private async submitToSWIFT(settlementFile: SettlementFile): Promise<string> {
        if (!this.config.swiftApiUrl) {
            return settlementFile.traditional.swiftReference || this.generateSwiftReference();
        }

        try {
            // Generate SWIFT FIN message (MT103)
            const swiftMessage = this.generateSWIFTMessage(settlementFile);

            const response = await fetch(`${this.config.swiftApiUrl}/api/v1/swift/send`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    message: swiftMessage,
                    messageType: 'MT103',
                    priority: 'N'
                })
            });

            if (!response.ok) {
                throw new Error('SWIFT submission failed');
            }

            const result = await response.json();
            return result.reference || settlementFile.traditional.swiftReference || '';
        } catch (error) {
            console.error('SWIFT submission error:', error);
            // Return generated reference even if submission fails
            return settlementFile.traditional.swiftReference || this.generateSwiftReference();
        }
    }

    /**
     * Submit to TARGET2
     */
    private async submitToTARGET2(settlementFile: SettlementFile): Promise<string> {
        if (!this.config.target2ApiUrl) {
            return settlementFile.traditional.target2Code || this.generateTarget2Code();
        }

        try {
            // Generate TARGET2 message
            const target2Message = this.generateTARGET2Message(settlementFile);

            const response = await fetch(`${this.config.target2ApiUrl}/api/v1/target2/send`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    message: target2Message
                })
            });

            if (!response.ok) {
                throw new Error('TARGET2 submission failed');
            }

            const result = await response.json();
            return result.reference || settlementFile.traditional.target2Code || '';
        } catch (error) {
            console.error('TARGET2 submission error:', error);
            // Return generated code even if submission fails
            return settlementFile.traditional.target2Code || this.generateTarget2Code();
        }
    }

    /**
     * Store dual records in FireFly
     */
    private async storeDualRecords(
        settlementFile: SettlementFile,
        bankingResults: { swiftReference?: string; target2Reference?: string }
    ): Promise<void> {
        try {
            const dualRecord = {
                blockchain: settlementFile.blockchain,
                traditional: {
                    ...settlementFile.traditional,
                    swiftReference: bankingResults.swiftReference || settlementFile.traditional.swiftReference,
                    target2Code: bankingResults.target2Reference || settlementFile.traditional.target2Code
                },
                timestamp: new Date().toISOString(),
                status: 'settled'
            };

            await fetch(`${this.config.fireflyApiUrl}/api/v1/data`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    namespace: 'default',
                    data: dualRecord
                })
            });
        } catch (error) {
            console.error('FireFly dual record storage error:', error);
            // Non-critical error, continue
        }
    }

    /**
     * Generate SWIFT message
     */
    private generateSWIFTMessage(settlementFile: SettlementFile): string {
        // Simplified SWIFT message format
        return JSON.stringify({
            '20': settlementFile.traditional.swiftReference,
            '23B': 'CRED',
            '32A': `${new Date().toISOString().split('T')[0].replace(/-/g, '')}EUR${settlementFile.blockchain.value}`,
            '50K': settlementFile.blockchain.from,
            '59': settlementFile.blockchain.to,
            '71A': 'OUR',
            '72': `/TOKEN/${settlementFile.blockchain.hash}`
        });
    }

    /**
     * Generate TARGET2 message
     */
    private generateTARGET2Message(settlementFile: SettlementFile): string {
        return JSON.stringify({
            messageType: 'pacs.008',
            transactionId: settlementFile.blockchain.hash,
            amount: settlementFile.blockchain.value,
            currency: 'EUR',
            debtor: settlementFile.blockchain.from,
            creditor: settlementFile.blockchain.to,
            target2Code: settlementFile.traditional.target2Code
        });
    }

    /**
     * Generate SWIFT reference
     */
    private generateSwiftReference(): string {
        return `SWIFT-${Date.now()}-${Math.random().toString(36).substr(2, 9).toUpperCase()}`;
    }

    /**
     * Generate TARGET2 code
     */
    private generateTarget2Code(): string {
        return `T2-${Date.now()}`;
    }

    /**
     * Reconcile blockchain and banking records
     */
    async reconcileRecords(
        blockchainHash: string,
        swiftReference?: string,
        target2Code?: string
    ): Promise<{ reconciled: boolean; differences?: any }> {
        // Get blockchain record
        // Get banking records
        // Compare and report differences

        // Placeholder implementation
        return { reconciled: true };
    }
}
