ERP-node/backend-node/src/services/flowExecutionService.ts

/**
 * 플로우 실행 서비스
 * 단계별 데이터 카운트 및 리스트 조회
 */

import db from "../database/db";
import { FlowStepDataCount, FlowStepDataList } from "../types/flow";
import { FlowDefinitionService } from "./flowDefinitionService";
import { FlowStepService } from "./flowStepService";
import { FlowConditionParser } from "./flowConditionParser";
import { executeExternalQuery } from "./externalDbHelper";
import { getPlaceholder, buildPaginationClause } from "./dbQueryBuilder";

export class FlowExecutionService {
  private flowDefinitionService: FlowDefinitionService;
  private flowStepService: FlowStepService;

  constructor() {
    this.flowDefinitionService = new FlowDefinitionService();
    this.flowStepService = new FlowStepService();
  }

  /**
   * 특정 플로우 단계에 해당하는 데이터 카운트
   */
  async getStepDataCount(flowId: number, stepId: number): Promise<number> {
    // 1. 플로우 정의 조회
    const flowDef = await this.flowDefinitionService.findById(flowId);
    if (!flowDef) {
      throw new Error(`Flow definition not found: ${flowId}`);
    }

    console.log("🔍 [getStepDataCount] Flow Definition:", {
      flowId,
      dbSourceType: flowDef.dbSourceType,
      dbConnectionId: flowDef.dbConnectionId,
      tableName: flowDef.tableName,
    });

    // 2. 플로우 단계 조회
    const step = await this.flowStepService.findById(stepId);
    if (!step) {
      throw new Error(`Flow step not found: ${stepId}`);
    }

    if (step.flowDefinitionId !== flowId) {
      throw new Error(`Step ${stepId} does not belong to flow ${flowId}`);
    }

    // 3. 테이블명 결정: 단계에 지정된 테이블이 있으면 사용, 없으면 플로우의 기본 테이블 사용
    const tableName = step.tableName || flowDef.tableName;

    // 4. 조건 JSON을 SQL WHERE절로 변환
    const { where, params } = FlowConditionParser.toSqlWhere(
      step.conditionJson
    );

    // 5. 카운트 쿼리 실행 (내부 또는 외부 DB)
    const query = `SELECT COUNT(*) as count FROM ${tableName} WHERE ${where}`;

    console.log("🔍 [getStepDataCount] Query Info:", {
      tableName,
      query,
      params,
      isExternal: flowDef.dbSourceType === "external",
      connectionId: flowDef.dbConnectionId,
    });

    let result: any;
    if (flowDef.dbSourceType === "external" && flowDef.dbConnectionId) {
      // 외부 DB 조회
      console.log(
        "✅ [getStepDataCount] Using EXTERNAL DB:",
        flowDef.dbConnectionId
      );
      const externalResult = await executeExternalQuery(
        flowDef.dbConnectionId,
        query,
        params
      );
      console.log("📦 [getStepDataCount] External result:", externalResult);
      result = externalResult.rows;
    } else {
      // 내부 DB 조회
      console.log("✅ [getStepDataCount] Using INTERNAL DB");
      result = await db.query(query, params);
    }

    const count = parseInt(result[0].count || result[0].COUNT);
    console.log("✅ [getStepDataCount] Final count:", count);
    return count;
  }

  /**
   * 특정 플로우 단계에 해당하는 데이터 리스트
   */
  async getStepDataList(
    flowId: number,
    stepId: number,
    page: number = 1,
    pageSize: number = 20
  ): Promise<FlowStepDataList> {
    // 1. 플로우 정의 조회
    const flowDef = await this.flowDefinitionService.findById(flowId);
    if (!flowDef) {
      throw new Error(`Flow definition not found: ${flowId}`);
    }

    // 2. 플로우 단계 조회
    const step = await this.flowStepService.findById(stepId);
    if (!step) {
      throw new Error(`Flow step not found: ${stepId}`);
    }

    if (step.flowDefinitionId !== flowId) {
      throw new Error(`Step ${stepId} does not belong to flow ${flowId}`);
    }

    // 3. 테이블명 결정: 단계에 지정된 테이블이 있으면 사용, 없으면 플로우의 기본 테이블 사용
    const tableName = step.tableName || flowDef.tableName;

    // 4. 조건 JSON을 SQL WHERE절로 변환
    const { where, params } = FlowConditionParser.toSqlWhere(
      step.conditionJson
    );

    const offset = (page - 1) * pageSize;

    const isExternalDb =
      flowDef.dbSourceType === "external" && flowDef.dbConnectionId;

    // 5. 전체 카운트
    const countQuery = `SELECT COUNT(*) as count FROM ${tableName} WHERE ${where}`;
    let countResult: any;
    let total: number;

    if (isExternalDb) {
      const externalCountResult = await executeExternalQuery(
        flowDef.dbConnectionId!,
        countQuery,
        params
      );
      countResult = externalCountResult.rows;
      total = parseInt(countResult[0].count || countResult[0].COUNT);
    } else {
      countResult = await db.query(countQuery, params);
      total = parseInt(countResult[0].count);
    }

    // 6. 데이터 조회 (DB 타입별 페이징 처리)
    let dataQuery: string;
    let dataParams: any[];

    if (isExternalDb) {
      // 외부 DB는 id 컬럼으로 정렬 (가정)
      // DB 타입에 따른 페이징 절은 빌더에서 처리하지 않고 직접 작성
      // PostgreSQL, MySQL, MSSQL, Oracle 모두 지원하도록 단순화
      dataQuery = `
        SELECT * FROM ${tableName} 
        WHERE ${where} 
        ORDER BY id DESC
        LIMIT ${pageSize} OFFSET ${offset}
      `;
      dataParams = params;

      const externalDataResult = await executeExternalQuery(
        flowDef.dbConnectionId!,
        dataQuery,
        dataParams
      );

      return {
        records: externalDataResult.rows,
        total,
        page,
        pageSize,
      };
    } else {
      // 내부 DB (PostgreSQL)
      // Primary Key 컬럼 찾기
      let orderByColumn = "";
      try {
        const pkQuery = `
          SELECT a.attname
          FROM pg_index i
          JOIN pg_attribute a ON a.attrelid = i.indrelid AND a.attnum = ANY(i.indkey)
          WHERE i.indrelid = $1::regclass
          AND i.indisprimary
          LIMIT 1
        `;
        const pkResult = await db.query(pkQuery, [tableName]);
        if (pkResult.length > 0) {
          orderByColumn = pkResult[0].attname;
        }
      } catch (err) {
        console.warn(`Could not find primary key for table ${tableName}:`, err);
      }

      const orderByClause = orderByColumn
        ? `ORDER BY ${orderByColumn} DESC`
        : "";
      dataQuery = `
        SELECT * FROM ${tableName} 
        WHERE ${where} 
        ${orderByClause}
        LIMIT $${params.length + 1} OFFSET $${params.length + 2}
      `;
      const dataResult = await db.query(dataQuery, [
        ...params,
        pageSize,
        offset,
      ]);

      return {
        records: dataResult,
        total,
        page,
        pageSize,
      };
    }
  }

  /**
   * 플로우의 모든 단계별 데이터 카운트
   */
  async getAllStepCounts(flowId: number): Promise<FlowStepDataCount[]> {
    const steps = await this.flowStepService.findByFlowId(flowId);
    const counts: FlowStepDataCount[] = [];

    for (const step of steps) {
      const count = await this.getStepDataCount(flowId, step.id);
      counts.push({
        stepId: step.id,
        count,
      });
    }

    return counts;
  }

  /**
   * 특정 레코드의 현재 플로우 상태 조회
   */
  async getCurrentStatus(
    flowId: number,
    recordId: string
  ): Promise<{ currentStepId: number | null; tableName: string } | null> {
    const query = `
      SELECT current_step_id, table_name 
      FROM flow_data_status 
      WHERE flow_definition_id = $1 AND record_id = $2
    `;

    const result = await db.query(query, [flowId, recordId]);

    if (result.length === 0) {
      return null;
    }

    return {
      currentStepId: result[0].current_step_id,
      tableName: result[0].table_name,
    };
  }
}