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 }
              }
            }
          }
        }
      });

      if (!importRecord) {
        throw new Error('Import not found');
      }

      if (!importRecord.fileId) {
        throw new Error('No file attached to import');
      }

      // Get the actual file
      const fileRecord = await this.prisma.file.findUnique({
        where: { id: importRecord.fileId }
      });

      if (!fileRecord) {
        throw new Error('File not found');
      }

      // 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(
        fileRecord.data,
        importRecord.layout,
        (sectionProgress: ImportProgress) => {
          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];

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

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

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

            totalInserted += insertedRows;

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

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

      return {
        success: true,
        totalInserted,
        sections: processedSections
      };
    } catch (error) {
      // Import processing failed
      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: {
          layout: true
        }
      });

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

      if (!importRecord.fileId) {
        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 };
    }
  }
}