// CIM Contracts Service
// DBIS Contract Templates (DBIS-CT) management
// Unified rule validation
// Time-locked cross-border contracts
// Condition-based execution

import prisma from '@/shared/database/prisma';
import { v4 as uuidv4 } from 'uuid';


export interface CimContractTemplateRequest {
  templateCode: string;
  templateName: string;
  templateType: string;
  contractLogic: Record<string, unknown>;
  validationRules: Record<string, unknown>;
}

export interface CimContractExecutionRequest {
  templateCode: string;
  parameters: Record<string, unknown>;
  signatories: string[];
  executionTime?: Date;
  conditions?: Record<string, unknown>;
}

export class CimContractsService {
  /**
   * Create DBIS Contract Template (DBIS-CT)
   */
  async createContractTemplate(
    request: CimContractTemplateRequest
  ): Promise<string> {
    const templateId = `CIM-TEMPLATE-${uuidv4()}`;

    const template = await prisma.cim_contract_templates.create({
      data: {
        id: uuidv4(),
        templateId,
        templateCode: request.templateCode,
        templateName: request.templateName,
        templateType: request.templateType,
        contractLogic: request.contractLogic as any,
        validationRules: request.validationRules as any,
        status: 'active',
        version: 1,
        effectiveDate: new Date(),
        createdAt: new Date(),
        updatedAt: new Date(),
      },
    });

    return template.templateId;
  }

  /**
   * Get contract template by code
   */
  async getContractTemplate(templateCode: string) {
    return await prisma.cim_contract_templates.findFirst({
      where: {
        templateCode,
        status: 'active',
      },
      orderBy: { version: 'desc' },
    });
  }

  /**
   * List all active contract templates
   */
  async listContractTemplates(templateType?: string) {
    return await prisma.cim_contract_templates.findMany({
      where: {
        ...(templateType && { templateType }),
        status: 'active',
      },
      orderBy: { templateCode: 'asc' },
    });
  }

  /**
   * Validate contract against unified rules
   */
  async validateContract(
    templateCode: string,
    parameters: Record<string, unknown>
  ): Promise<{ valid: boolean; errors: string[] }> {
    const template = await this.getContractTemplate(templateCode);

    if (!template) {
      return {
        valid: false,
        errors: ['Contract template not found'],
      };
    }

    const validationRules = template.validationRules as Record<string, unknown>;
    const errors: string[] = [];

    // Apply unified rule validation
    for (const [ruleKey, ruleValue] of Object.entries(validationRules)) {
      const paramValue = parameters[ruleKey];

      if (ruleValue === 'required' && !paramValue) {
        errors.push(`Required parameter ${ruleKey} is missing`);
      }

      if (typeof ruleValue === 'object' && ruleValue !== null) {
        const rule = ruleValue as Record<string, unknown>;

        // Type validation
        if (rule.type && typeof paramValue !== rule.type) {
          errors.push(`Parameter ${ruleKey} must be of type ${rule.type}`);
        }

        // Range validation
        if (rule.min !== undefined && (paramValue as number) < (rule.min as number)) {
          errors.push(`Parameter ${ruleKey} must be at least ${rule.min}`);
        }

        if (rule.max !== undefined && (paramValue as number) > (rule.max as number)) {
          errors.push(`Parameter ${ruleKey} must be at most ${rule.max}`);
        }
      }
    }

    return {
      valid: errors.length === 0,
      errors,
    };
  }

  /**
   * Create time-locked cross-border contract
   */
  async createTimeLockedContract(
    request: CimContractExecutionRequest
  ): Promise<string> {
    const template = await this.getContractTemplate(request.templateCode);

    if (!template) {
      throw new Error('Contract template not found');
    }

    // Validate contract
    const validation = await this.validateContract(
      request.templateCode,
      request.parameters
    );

    if (!validation.valid) {
      throw new Error(`Contract validation failed: ${validation.errors.join(', ')}`);
    }

    // Create smart contract with time-lock
    const contractId = `CIM-CONTRACT-${uuidv4()}`;

    // Calculate execution time if not provided
    const executionTime = request.executionTime || new Date();

    const contract = await prisma.smart_contracts.create({
      data: {
        id: uuidv4(),
        contractId,
        sovereignBankId: '', // Will be set during execution
        templateType: `DBIS-CT:${request.templateCode}`,
        contractState: 'draft',
        parameters: {
          ...request.parameters,
          executionTime: executionTime.toISOString(),
          conditions: request.conditions,
        } as any,
        signatories: request.signatories as any,
        createdAt: new Date(),
        updatedAt: new Date(),
      },
    });

    return contract.contractId;
  }

  /**
   * Execute condition-based contract
   */
  async executeConditionBasedContract(
    contractId: string
  ): Promise<boolean> {
    const contract = await prisma.smart_contracts.findUnique({
      where: { contractId },
    });

    if (!contract) {
      return false;
    }

    const parameters = contract.parameters as Record<string, unknown>;
    const conditions = parameters.conditions as Record<string, unknown> | undefined;

    if (!conditions) {
      return false;
    }

    // Evaluate conditions
    const conditionsMet = await this.evaluateConditions(conditions);

    if (!conditionsMet) {
      return false;
    }

    // Check if execution time has been reached
    const executionTime = parameters.executionTime as string | undefined;
    if (executionTime) {
      const execTime = new Date(executionTime);
      if (new Date() < execTime) {
        return false; // Not yet time to execute
      }
    }

    // Execute contract
    const contractLogic = await this.getContractLogic(contract.templateType);
    const executionResult = await this.executeContractLogic(
      contractLogic,
      parameters
    );

    // Update contract
    await prisma.smart_contracts.update({
      where: { contractId },
      data: {
        contractState: 'executed',
        executionResult: executionResult as any,
        executedAt: new Date(),
      },
    });

    return true;
  }

  /**
   * Evaluate contract conditions
   */
  private async evaluateConditions(
    conditions: Record<string, unknown>
  ): Promise<boolean> {
    // In production, this would evaluate complex conditions
    // For now, simple evaluation
    for (const [key, value] of Object.entries(conditions)) {
      // Example: Check if account balance meets condition
      if (key === 'minBalance') {
        // Would check actual balance here
        // For now, assume condition is met
      }
    }

    return true;
  }

  /**
   * Get contract logic from template
   */
  private async getContractLogic(
    templateType: string
  ): Promise<Record<string, unknown> | null> {
    const templateCode = templateType.replace('DBIS-CT:', '');
    const template = await this.getContractTemplate(templateCode);

    return template?.contractLogic as Record<string, unknown> | null;
  }

  /**
   * Execute contract logic
   */
  private async executeContractLogic(
    contractLogic: Record<string, unknown> | null,
    parameters: Record<string, unknown>
  ): Promise<Record<string, unknown>> {
    if (!contractLogic) {
      return { status: 'no_logic' };
    }

    // In production, this would execute the contract logic
    // For now, return success
    return {
      status: 'executed',
      executedAt: new Date().toISOString(),
      parameters,
    };
  }

  /**
   * Update contract template
   */
  async updateContractTemplate(
    templateCode: string,
    updates: Partial<CimContractTemplateRequest>
  ): Promise<string> {
    const existingTemplate = await this.getContractTemplate(templateCode);

    if (!existingTemplate) {
      throw new Error('Contract template not found');
    }

    // Create new version
    const templateId = `CIM-TEMPLATE-${uuidv4()}`;

    const template = await prisma.cim_contract_templates.create({
      data: {
        id: uuidv4(),
        templateId,
        templateCode,
        templateName: updates.templateName || existingTemplate.templateName,
        templateType: updates.templateType || existingTemplate.templateType,
        contractLogic: (updates.contractLogic || existingTemplate.contractLogic) as any,
        validationRules: (updates.validationRules || existingTemplate.validationRules) as any,
        status: 'active',
        version: existingTemplate.version + 1,
        effectiveDate: new Date(),
        createdAt: new Date(),
        updatedAt: new Date(),
      },
    });

    // Archive old version
    await prisma.cim_contract_templates.update({
      where: { templateId: existingTemplate.templateId },
      data: {
        status: 'superseded',
        expiryDate: new Date(),
      },
    });

    return template.templateId;
  }
}

export const cimContractsService = new CimContractsService();

