/**
 * Copyright (c) 2026 Niolla
 * All rights reserved.
 *
 * This source code is proprietary and confidential.
 * Unauthorized copying, modification, distribution, or use
 * of this file, via any medium, is strictly prohibited.
 */

// app/controllers/generateDocument.controller.js

const fs = require("fs");
const path = require("path");
const documentQueue = require("../queues/document.queue");
const { createDocumentData } = require("../utils/document.utill");
const {
  generateId,
  generateDocumentReferenceNo,
} = require("../utils/idGen.util");

const { GetObjectCommand, DeleteObjectCommand } = require("@aws-sdk/client-s3");

const {log} = require("../utils/consoleLog.utill");

const s3 = require("../config/s3.config");
const db = require("../models");
const Document = db.Document;
const DocumentType = db.DocumentType;

const normalizeDocumentData = (value) => {
  if (!value) {
    return {};
  }

  if (typeof value === "string") {
    try {
      return JSON.parse(value);
    } catch (error) {
      return {};
    }
  }

  return value;
};

/**
 * Get available document types
 */
exports.getAvailableDocumentTypes = async (req, res) => {
  try {

    const doc_types = await DocumentType.findAll({
      attributes: ["doc_type_name"],
    });

    const types = doc_types.map((t) => t.doc_type_name);

    return res.json({
      success: true,
      availableDocumentTypes: types,
      note: "Use these document type names in your requests (case-insensitive)",
    });

  } catch (error) {
    log("Error fetching document types:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
};

// Get Saved documents
exports.getSavedDocuments = async (req, res) => {
  try {
    const { documentType } = req.body;

    if (!documentType) {
      return res.status(400).json({
        success: false,
        message: "documentType query parameter is required",
      });
    }

    // Fetch saved documents based on documentType
    const savedDocuments = await Document.findAll({
      where: { doc_type: documentType.toUpperCase() },
      order: [["createdAt", "DESC"]],
      exclude: ["data"],
    });

    // extract only necessary fields to return
    const formattedDocuments = savedDocuments.map((doc) => ({
      doc_id: doc.doc_id,
      reference_no: doc.reference_no,
      doc_type: doc.doc_type,
      status: doc.status,
      createdAt: doc.createdAt,
      updatedAt: doc.updatedAt,
    }));

    return res.json({
      success: true,
      savedDocuments: formattedDocuments,
    });
  } catch (error) {
    log("Error fetching saved documents:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
};

// Get specific document data by doc_id
exports.getDocumentData = async (req, res) => {
  try {
    const { docId } = req.params;

    if (!docId) {
      return res.status(400).json({
        success: false,
        message: "docId parameter is required",
      });
    }

    const document = await Document.findOne({
      where: { doc_id: docId },
    });

    if (!document) {
      return res.status(404).json({
        success: false,
        message: "Document not found",
      });
    }

    return res.json({
      success: true,
      document: {
        doc_id: document.doc_id,
        reference_no: document.reference_no,
        doc_type: document.doc_type,
        data: document.data,
        status: document.status,
        createdAt: document.createdAt,
        updatedAt: document.updatedAt,
      },
    });

  } catch (error) {
    log("Error fetching document data:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
}

exports.generateReferenceNo = async (req, res) => {
  try {
    const { documentType } = req.params;

    if (!documentType) {
      return res.status(400).json({
        success: false,
        message: "documentType is required",
      });
    }

    // Generate reference number
    const reference_no = await generateDocumentReferenceNo(documentType);

    return res.json({
      success: true,
      reference_no,
    });
  } catch (error) {
    log("Error generating reference number:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
};

exports.generateDraftDocument = async (req, res) => {
  try {
    const { document } = req.body;
    const documentData = normalizeDocumentData(req.body.documentData || req.body.data || req.body);

    // Validation
    if (!document || !documentData) {
      return res.status(400).json({
        success: false,
        message: "document and documentData are required",
      });
    }

    let documentDetails;

    if (document !== "PRECOST") {
      // Save document details before generating
      documentDetails = await createDocumentData(
        document,
        documentData,
        "DRAFT",
      );
    } else {
      return res.status(400).json({
        success: false,
        message:
          "Invalid document type, This document type is not allowed to be generated as draft",
      });
    }

    return res.status(201).json({
      success: true,
      message: "Draft document created successfully",
      documentDetails,
    });
  } catch (error) {
    log("Error generating draft document:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
};

/**
 * Generate document asynchronously
 * Returns jobId immediately
 */
exports.generateDocument = async (req, res) => {
  try {
    const { document, documentType } = req.body;
    const documentData = normalizeDocumentData(req.body.documentData || req.body.data || req.body);

    // Validation
    if (!document || !documentType || !documentData) {
      return res.status(400).json({
        success: false,
        message: "document, documentType, and documentData are required",
      });
    }

    console.log(
      `📨 generateDocument request: document="${document}", documentType="${documentType}"`,
    );

    if (document !== "PRECOST") {
      // Save document details before generating
      // If doc_id exists, finalize (update existing); otherwise create as DRAFT
      const status = documentData.doc_id ? "FINAL" : "DRAFT";
      await createDocumentData(document, documentData, status);
    }

    // Add job to queue
    const job = await documentQueue.add("generate-document", {
      document,
      documentType,
      data: documentData,
    });

    log(
      `📋 Document generation job queued: ${job.id} (document="${document}", type="${documentType}")`,
    );

    return res.status(202).json({
      success: true,
      message: "Document generation started",
      jobId: job.id,
    });
  } catch (error) {
    log("Error queuing document generation:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
};

/**
 * Get job status and result
 */
exports.getJobStatus = async (req, res) => {
  try {
    const { jobId } = req.params;

    if (!jobId) {
      return res.status(400).json({
        success: false,
        message: "jobId is required",
      });
    }

    // Get job from queue
    const job = await documentQueue.getJob(jobId);

    if (!job) {
      return res.status(404).json({
        success: false,
        message: "Job not found",
      });
    }

    // Get job state
    const state = await job.getState();
    const result = job.returnvalue;
    const failedReason = job.failedReason;

    return res.json({
      success: true,
      jobId: job.id,
      state, // "waiting" | "active" | "completed" | "failed" | "delayed"
      result: state === "completed" ? result : null,
      error: state === "failed" ? failedReason : null,
      attempts: job.attemptsMade,
      stacktrace: job.stacktrace,
    });
  } catch (error) {
    log("Error fetching job status:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
};

/**
 * Download generated document
 */
exports.downloadDocument = async (req, res) => {
  try {
    const { uuid } = req.params;

    const key = `uploads/${uuid}.pdf`;

    const command = new GetObjectCommand({
      Bucket: process.env.AWS_S3_BUCKET_NAME,
      Key: key,
    });

    const response = await s3.send(command);

    res.setHeader(
      "Content-Type",
      response.ContentType || "application/octet-stream",
    );

    res.setHeader("Content-Disposition", `attachment; filename="${uuid}.pdf"`);

    response.Body.pipe(res);

    res.on("finish", async () => {
      try {
        await s3.send(
          new DeleteObjectCommand({
            Bucket: process.env.AWS_S3_BUCKET_NAME,
            Key: key,
          }),
        );

        log(`Deleted from S3: ${key}`);
      } catch (err) {
        log(`Failed to delete ${key}:`, err.message);
      }
    });
  } catch (error) {
    log("Download error:", error.message);

    return res.status(404).json({
      success: false,
      message: "Document not found",
    });
  }
};

/**
 * Cancel/delete a job
 */
exports.cancelJob = async (req, res) => {
  try {
    const { jobId } = req.params;

    if (!jobId) {
      return res.status(400).json({
        success: false,
        message: "jobId is required",
      });
    }

    const job = await documentQueue.getJob(jobId);

    if (!job) {
      return res.status(404).json({
        success: false,
        message: "Job not found",
      });
    }

    await job.remove();

    return res.json({
      success: true,
      message: "Job cancelled successfully",
      jobId,
    });
  } catch (error) {
    log("Error cancelling job:", error.message);
    return res.status(500).json({
      success: false,
      message: error.message,
    });
  }
};