import { PrismaClient } from '@prisma/client';
import { ExcelReaderService } from './excel-reader';
import { BulkInserter } from './bulk-inserter';
import { ImportProgressServer } from './websocket-server';
import { ImportProgress, ImportResult, ProcessedSection } from './types';

export class ImportProcessor {
  private prisma: PrismaClient;
  private reader: ExcelReaderService;
  private inserter: BulkInserter;
  private progressServer: ImportProgressServer;

  constructor() {
    this.prisma = new PrismaClient();
    this.reader = new ExcelReaderService();
    this.inserter = new BulkInserter();
    this.progressServer = ImportProgressServer.getInstance();
  }

  async processImport(importId: number): Promise<ImportResult> {
    try {
      // Get import record with layout configuration
      const importRecord = await this.prisma.import.findUnique({
        where: { id: importId },
        include: {
          layout: {
            include: {
              sections: {
                include: { fields: true }
              }
            }
          },
          file: true
        }
      });

      if (!importRecord || !importRecord.file) {
        throw new Error('Import not found or no file attached');
      }

      // Initialize progress tracking
      const progress: ImportProgress = {
        importId,
        status: 'processing',
        currentSection: '',
        currentRow: 0,
        totalRows: 0,
        errors: [],
        processedSections: 0,
        totalSections: importRecord.layout?.sections?.length || 0
      };

      // Read Excel file
      const sections = await this.reader.readExcelFile(
        Buffer.from(importRecord.file.data),
        importRecord.layout,
        (sectionProgress) => {
          this.progressServer.broadcastProgress(importId, sectionProgress);
        }
      );

      // Process each section
      const processedSections: ProcessedSection[] = [];
      let totalInserted = 0;

      for (let i = 0; i < sections.length; i++) {
        const section = sections[i];

        progress.currentSection = section.name;
        progress.processedSections = i + 1;
        this.progressServer.broadcastProgress(importId, progress);

        try {
          const insertedRows = await this.inserter.insertSectionData(
            section,
            importId,
            (rows) => {
              progress.currentRow = rows;
              this.progressServer.broadcastProgress(importId, progress);
            }
          );

          processedSections.push({
            sectionData: section,
            insertedRows
          });

          totalInserted += insertedRows;

        } catch (error) {
          const errorMessage = `Error processing section ${section.name}: ${error instanceof Error ? error.message : 'Unknown error'}`;
          progress.errors.push(errorMessage);
          this.progressServer.broadcastProgress(importId, progress);
        }
      }

      // Import processing completed - no status field to update

      progress.status = 'completed';
      this.progressServer.broadcastProgress(importId, progress);

      return {
        success: true,
        totalInserted,
        sections: processedSections
      };

    } catch (error) {
      // Import processing failed - no status field to update

      const progress: ImportProgress = {
        importId,
        status: 'failed',
        currentSection: '',
        currentRow: 0,
        totalRows: 0,
        errors: [error instanceof Error ? error.message : 'Unknown error'],
        processedSections: 0,
        totalSections: 0
      };

      this.progressServer.broadcastProgress(importId, progress);

      return {
        success: false,
        totalInserted: 0,
        sections: [],
        errors: [error instanceof Error ? error.message : 'Unknown error']
      };
    }
  }

  async validateImport(importId: number): Promise<{ valid: boolean; errors: string[] }> {
    const errors: string[] = [];

    try {
      const importRecord = await this.prisma.import.findUnique({
        where: { id: importId },
        include: { file: true, layout: true }
      });

      if (!importRecord) {
        errors.push('Import record not found');
        return { valid: false, errors };
      }

      if (!importRecord.file) {
        errors.push('No file attached to import');
      }

      if (!importRecord.layout) {
        errors.push('No layout configuration found');
      }

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

    } catch (error) {
      errors.push(`Validation error: ${error instanceof Error ? error.message : 'Unknown error'}`);
      return { valid: false, errors };
    }
  }
}