/**
 * @ai-summary Controller for OCR API endpoints
 */
import { FastifyReply, FastifyRequest } from 'fastify';
import { logger } from '../../../core/logging/logger';
import { ocrService } from '../domain/ocr.service';
import type { ExtractQuery, JobIdParams, JobSubmitBody } from './ocr.validation';

/** Supported MIME types for OCR */
const SUPPORTED_TYPES = new Set([
  'image/jpeg',
  'image/png',
  'image/heic',
  'image/heif',
  'application/pdf',
]);

/** Image-only MIME types for receipt extraction (no PDF) */
const SUPPORTED_IMAGE_TYPES = new Set([
  'image/jpeg',
  'image/png',
  'image/heic',
  'image/heif',
]);

export class OcrController {
  /**
   * POST /api/ocr/extract
   * Extract text from an uploaded image using synchronous OCR.
   */
  async extract(
    request: FastifyRequest<{ Querystring: ExtractQuery }>,
    reply: FastifyReply
  ) {
    const userId = (request as any).user?.sub as string;
    const preprocess = request.query.preprocess !== false;

    logger.info('OCR extract requested', {
      operation: 'ocr.controller.extract',
      userId,
      preprocess,
    });

    // Get uploaded file
    const file = await (request as any).file({ limits: { files: 1 } });
    if (!file) {
      logger.warn('No file provided for OCR', {
        operation: 'ocr.controller.extract.no_file',
        userId,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'No file provided',
      });
    }

    // Validate content type
    const contentType = file.mimetype as string;
    if (!SUPPORTED_TYPES.has(contentType)) {
      logger.warn('Unsupported file type for OCR', {
        operation: 'ocr.controller.extract.unsupported_type',
        userId,
        contentType,
        fileName: file.filename,
      });
      return reply.code(415).send({
        error: 'Unsupported Media Type',
        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC, PDF`,
      });
    }

    // Read file content
    const chunks: Buffer[] = [];
    for await (const chunk of file.file) {
      chunks.push(chunk);
    }
    const fileBuffer = Buffer.concat(chunks);

    if (fileBuffer.length === 0) {
      logger.warn('Empty file provided for OCR', {
        operation: 'ocr.controller.extract.empty_file',
        userId,
        fileName: file.filename,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'Empty file provided',
      });
    }

    try {
      const result = await ocrService.extract(userId, {
        fileBuffer,
        contentType,
        preprocess,
      });

      logger.info('OCR extract completed', {
        operation: 'ocr.controller.extract.success',
        userId,
        success: result.success,
        documentType: result.documentType,
        processingTimeMs: result.processingTimeMs,
      });

      return reply.code(200).send(result);
    } catch (error: any) {
      if (error.statusCode === 413) {
        return reply.code(413).send({
          error: 'Payload Too Large',
          message: error.message,
        });
      }
      if (error.statusCode === 415) {
        return reply.code(415).send({
          error: 'Unsupported Media Type',
          message: error.message,
        });
      }

      logger.error('OCR extract failed', {
        operation: 'ocr.controller.extract.error',
        userId,
        error: error.message,
      });

      return reply.code(500).send({
        error: 'Internal Server Error',
        message: 'OCR processing failed',
      });
    }
  }

  /**
   * POST /api/ocr/extract/vin
   * Extract VIN from an uploaded image using VIN-specific OCR.
   */
  async extractVin(
    request: FastifyRequest,
    reply: FastifyReply
  ) {
    const userId = (request as any).user?.sub as string;

    logger.info('VIN extract requested', {
      operation: 'ocr.controller.extractVin',
      userId,
    });

    const file = await (request as any).file({ limits: { files: 1 } });
    if (!file) {
      logger.warn('No file provided for VIN extraction', {
        operation: 'ocr.controller.extractVin.no_file',
        userId,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'No file provided',
      });
    }

    const contentType = file.mimetype as string;
    if (!SUPPORTED_TYPES.has(contentType)) {
      logger.warn('Unsupported file type for VIN extraction', {
        operation: 'ocr.controller.extractVin.unsupported_type',
        userId,
        contentType,
        fileName: file.filename,
      });
      return reply.code(415).send({
        error: 'Unsupported Media Type',
        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC, PDF`,
      });
    }

    const chunks: Buffer[] = [];
    for await (const chunk of file.file) {
      chunks.push(chunk);
    }
    const fileBuffer = Buffer.concat(chunks);

    if (fileBuffer.length === 0) {
      logger.warn('Empty file provided for VIN extraction', {
        operation: 'ocr.controller.extractVin.empty_file',
        userId,
        fileName: file.filename,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'Empty file provided',
      });
    }

    try {
      const result = await ocrService.extractVin(userId, {
        fileBuffer,
        contentType,
      });

      logger.info('VIN extract completed', {
        operation: 'ocr.controller.extractVin.success',
        userId,
        success: result.success,
        processingTimeMs: result.processingTimeMs,
      });

      return reply.code(200).send(result);
    } catch (error: any) {
      if (error.statusCode === 413) {
        return reply.code(413).send({
          error: 'Payload Too Large',
          message: error.message,
        });
      }
      if (error.statusCode === 415) {
        return reply.code(415).send({
          error: 'Unsupported Media Type',
          message: error.message,
        });
      }

      logger.error('VIN extract failed', {
        operation: 'ocr.controller.extractVin.error',
        userId,
        error: error.message,
      });

      return reply.code(500).send({
        error: 'Internal Server Error',
        message: 'VIN extraction failed',
      });
    }
  }

  /**
   * POST /api/ocr/extract/receipt
   * Extract data from a receipt image using receipt-specific OCR.
   */
  async extractReceipt(
    request: FastifyRequest,
    reply: FastifyReply
  ) {
    const userId = (request as any).user?.sub as string;

    logger.info('Receipt extract requested', {
      operation: 'ocr.controller.extractReceipt',
      userId,
    });

    const file = await (request as any).file({ limits: { files: 1 } });
    if (!file) {
      logger.warn('No file provided for receipt extraction', {
        operation: 'ocr.controller.extractReceipt.no_file',
        userId,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'No file provided',
      });
    }

    const contentType = file.mimetype as string;
    if (!SUPPORTED_IMAGE_TYPES.has(contentType)) {
      logger.warn('Unsupported file type for receipt extraction', {
        operation: 'ocr.controller.extractReceipt.unsupported_type',
        userId,
        contentType,
        fileName: file.filename,
      });
      return reply.code(415).send({
        error: 'Unsupported Media Type',
        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC`,
      });
    }

    const chunks: Buffer[] = [];
    for await (const chunk of file.file) {
      chunks.push(chunk);
    }
    const fileBuffer = Buffer.concat(chunks);

    if (fileBuffer.length === 0) {
      logger.warn('Empty file provided for receipt extraction', {
        operation: 'ocr.controller.extractReceipt.empty_file',
        userId,
        fileName: file.filename,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'Empty file provided',
      });
    }

    // Get optional receipt_type from form fields
    const receiptType = file.fields?.receipt_type?.value as string | undefined;

    try {
      const result = await ocrService.extractReceipt(userId, {
        fileBuffer,
        contentType,
        receiptType,
      });

      logger.info('Receipt extract completed', {
        operation: 'ocr.controller.extractReceipt.success',
        userId,
        success: result.success,
        receiptType: result.receiptType,
        processingTimeMs: result.processingTimeMs,
      });

      return reply.code(200).send(result);
    } catch (error: any) {
      if (error.statusCode === 413) {
        return reply.code(413).send({
          error: 'Payload Too Large',
          message: error.message,
        });
      }
      if (error.statusCode === 415) {
        return reply.code(415).send({
          error: 'Unsupported Media Type',
          message: error.message,
        });
      }
      if (error.statusCode === 422) {
        return reply.code(422).send({
          error: 'Unprocessable Entity',
          message: error.message,
        });
      }

      logger.error('Receipt extract failed', {
        operation: 'ocr.controller.extractReceipt.error',
        userId,
        error: error.message,
      });

      return reply.code(500).send({
        error: 'Internal Server Error',
        message: 'Receipt extraction failed',
      });
    }
  }

  /**
   * POST /api/ocr/extract/manual
   * Submit an async manual extraction job for PDF owner's manuals.
   * Requires Pro tier (document.scanMaintenanceSchedule).
   */
  async extractManual(
    request: FastifyRequest,
    reply: FastifyReply
  ) {
    const userId = (request as any).user?.sub as string;

    logger.info('Manual extract requested', {
      operation: 'ocr.controller.extractManual',
      userId,
    });

    const file = await (request as any).file({ limits: { files: 1 } });
    if (!file) {
      logger.warn('No file provided for manual extraction', {
        operation: 'ocr.controller.extractManual.no_file',
        userId,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'No file provided',
      });
    }

    const contentType = file.mimetype as string;
    const fileName = file.filename as string | undefined;
    const isPdfMime = contentType === 'application/pdf';
    const isPdfExtension = fileName?.toLowerCase().endsWith('.pdf') ?? false;

    if (!isPdfMime && !isPdfExtension) {
      logger.warn('Non-PDF file provided for manual extraction', {
        operation: 'ocr.controller.extractManual.not_pdf',
        userId,
        contentType,
        fileName,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: `Manual extraction requires PDF files. Received: ${contentType}`,
      });
    }

    const chunks: Buffer[] = [];
    for await (const chunk of file.file) {
      chunks.push(chunk);
    }
    const fileBuffer = Buffer.concat(chunks);

    if (fileBuffer.length === 0) {
      logger.warn('Empty file provided for manual extraction', {
        operation: 'ocr.controller.extractManual.empty_file',
        userId,
        fileName,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'Empty file provided',
      });
    }

    // Validate PDF magic bytes (%PDF)
    const PDF_MAGIC = Buffer.from('%PDF');
    if (fileBuffer.length < 4 || !fileBuffer.subarray(0, 4).equals(PDF_MAGIC)) {
      logger.warn('File lacks PDF magic bytes', {
        operation: 'ocr.controller.extractManual.invalid_magic',
        userId,
        fileName,
        firstBytes: fileBuffer.subarray(0, 4).toString('hex'),
      });
      return reply.code(415).send({
        error: 'Unsupported Media Type',
        message: 'File does not appear to be a valid PDF (missing %PDF header)',
      });
    }

    // Get optional vehicle_id from form fields
    const vehicleId = file.fields?.vehicle_id?.value as string | undefined;

    try {
      const result = await ocrService.submitManualJob(userId, {
        fileBuffer,
        contentType,
        vehicleId,
      });

      logger.info('Manual extract job submitted', {
        operation: 'ocr.controller.extractManual.success',
        userId,
        jobId: result.jobId,
        status: result.status,
        estimatedSeconds: result.estimatedSeconds,
      });

      return reply.code(202).send(result);
    } catch (error: any) {
      if (error.statusCode === 413) {
        return reply.code(413).send({
          error: 'Payload Too Large',
          message: error.message,
        });
      }
      if (error.statusCode === 400) {
        return reply.code(400).send({
          error: 'Bad Request',
          message: error.message,
        });
      }

      logger.error('Manual extract failed', {
        operation: 'ocr.controller.extractManual.error',
        userId,
        error: error.message,
      });

      return reply.code(500).send({
        error: 'Internal Server Error',
        message: 'Manual extraction submission failed',
      });
    }
  }

  /**
   * POST /api/ocr/jobs
   * Submit an async OCR job for large files.
   */
  async submitJob(
    request: FastifyRequest<{ Body: JobSubmitBody }>,
    reply: FastifyReply
  ) {
    const userId = (request as any).user?.sub as string;

    logger.info('OCR job submit requested', {
      operation: 'ocr.controller.submitJob',
      userId,
    });

    // Get uploaded file
    const file = await (request as any).file({ limits: { files: 1 } });
    if (!file) {
      logger.warn('No file provided for OCR job', {
        operation: 'ocr.controller.submitJob.no_file',
        userId,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'No file provided',
      });
    }

    // Validate content type
    const contentType = file.mimetype as string;
    if (!SUPPORTED_TYPES.has(contentType)) {
      logger.warn('Unsupported file type for OCR job', {
        operation: 'ocr.controller.submitJob.unsupported_type',
        userId,
        contentType,
        fileName: file.filename,
      });
      return reply.code(415).send({
        error: 'Unsupported Media Type',
        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC, PDF`,
      });
    }

    // Read file content
    const chunks: Buffer[] = [];
    for await (const chunk of file.file) {
      chunks.push(chunk);
    }
    const fileBuffer = Buffer.concat(chunks);

    if (fileBuffer.length === 0) {
      logger.warn('Empty file provided for OCR job', {
        operation: 'ocr.controller.submitJob.empty_file',
        userId,
        fileName: file.filename,
      });
      return reply.code(400).send({
        error: 'Bad Request',
        message: 'Empty file provided',
      });
    }

    // Get callback URL from form data (if present)
    const callbackUrl = file.fields?.callbackUrl?.value as string | undefined;

    try {
      const result = await ocrService.submitJob(userId, {
        fileBuffer,
        contentType,
        callbackUrl,
      });

      logger.info('OCR job submitted', {
        operation: 'ocr.controller.submitJob.success',
        userId,
        jobId: result.jobId,
        status: result.status,
      });

      return reply.code(202).send(result);
    } catch (error: any) {
      if (error.statusCode === 413) {
        return reply.code(413).send({
          error: 'Payload Too Large',
          message: error.message,
        });
      }
      if (error.statusCode === 415) {
        return reply.code(415).send({
          error: 'Unsupported Media Type',
          message: error.message,
        });
      }

      logger.error('OCR job submit failed', {
        operation: 'ocr.controller.submitJob.error',
        userId,
        error: error.message,
      });

      return reply.code(500).send({
        error: 'Internal Server Error',
        message: 'Job submission failed',
      });
    }
  }

  /**
   * GET /api/ocr/jobs/:jobId
   * Get the status of an async OCR job.
   */
  async getJobStatus(
    request: FastifyRequest<{ Params: JobIdParams }>,
    reply: FastifyReply
  ) {
    const userId = (request as any).user?.sub as string;
    const { jobId } = request.params;

    logger.debug('OCR job status requested', {
      operation: 'ocr.controller.getJobStatus',
      userId,
      jobId,
    });

    try {
      const result = await ocrService.getJobStatus(userId, jobId);

      return reply.code(200).send(result);
    } catch (error: any) {
      if (error.statusCode === 410) {
        return reply.code(410).send({
          error: 'Gone',
          message: error.message,
        });
      }

      logger.error('OCR job status failed', {
        operation: 'ocr.controller.getJobStatus.error',
        userId,
        jobId,
        error: error.message,
      });

      return reply.code(500).send({
        error: 'Internal Server Error',
        message: 'Failed to retrieve job status',
      });
    }
  }
}