import { exec } from "child_process";
import { promisify } from "util";
import * as fs from "fs-extra";
import { readdir, stat as fsStat } from "fs/promises";
import * as path from "path";
import { logger } from "../server.js";
import { FolderPaths } from "./serverInit.js";
import axios from "axios";
import { UUID } from "crypto";
import fsPromises from "fs/promises";
import crypto from "crypto";
import { createReadStream } from "fs";

const execAsync = promisify(exec);

interface S3SyncConfig {
  bucketName: string;
  region: string;
  accessKeyId: string;
  secretAccessKey: string;
  keyPrefix?: string;
}

export interface JobFolderStats {
  bodyshopid: UUID;
  jobid: UUID | string | null;
  //relativePath: string;
  document_count: number;
  unique_document_count: number;
  duplicate_count: number;
  total_size_bytes: number;
  total_size_mb: number;
  file_type_stats: { [extension: string]: number };
}

export interface JobsDirectoryAnalysis {
  bodyshopid: UUID;
  total_jobs: number;
  total_documents: number;
  unique_documents: number;
  duplicate_documents: number;
  total_size_bytes: number;
  total_size_mb: number;
  file_type_stats: { [extension: string]: number };
  media_analytics_details: {
    data: JobFolderStats[];
  };
}

export class S3Sync {
  private config: S3SyncConfig;

  constructor(config: S3SyncConfig) {
    this.config = config;
  }

  /**
   * Sync the Jobs directory to S3 bucket using AWS CLI
   */
  async syncJobsToS3(): Promise<void> {
    try {
      logger.info("Starting S3 sync for Jobs directory using AWS CLI...");

      const jobsPath = FolderPaths.Jobs;
      const keyPrefix = this.config.keyPrefix || "jobs/";
      const s3Path = `s3://${this.config.bucketName}/${keyPrefix}`;

      // Check if Jobs directory exists
      if (!(await fs.pathExists(jobsPath))) {
        logger.error(`Jobs directory does not exist: ${jobsPath}`);
        return;
      }

      // Check if AWS CLI is available
      await this.checkAwsCli();

      // Set AWS credentials as environment variables for the command
      const env = {
        ...process.env,
        AWS_ACCESS_KEY_ID: this.config.accessKeyId,
        AWS_SECRET_ACCESS_KEY: this.config.secretAccessKey,
        AWS_DEFAULT_REGION: this.config.region
      };

      // Run AWS S3 sync command
      const syncCommand = `aws s3 sync "${jobsPath}" "${s3Path}"`;

      logger.info(`Executing AWS S3 sync command`);

      const { stdout, stderr } = await execAsync(syncCommand, {
        env,
        maxBuffer: 1024 * 1024 * 10 // 10MB buffer for large sync outputs
      });

      if (stdout) {
        logger.info("S3 sync output:", stdout);
      }

      if (stderr) {
        logger.warning("S3 sync warnings:", stderr);
      }

      logger.info("S3 sync completed successfully using AWS CLI");
    } catch (error) {
      logger.error("S3 sync failed:", error);
      throw error;
    }
  }

  /**
   * Check if AWS CLI is available
   */
  private async checkAwsCli(): Promise<void> {
    try {
      await execAsync("aws --version");
    } catch (error) {
      throw new Error(
        "AWS CLI not found. Please install AWS CLI: https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html"
      );
    }
  }

  /**
   * Test S3 connection using AWS CLI
   */
  async testConnection(): Promise<boolean> {
    try {
      // Check if AWS CLI is available first
      await this.checkAwsCli();

      // Set AWS credentials as environment variables
      const env = {
        ...process.env,
        AWS_ACCESS_KEY_ID: this.config.accessKeyId,
        AWS_SECRET_ACCESS_KEY: this.config.secretAccessKey,
        AWS_DEFAULT_REGION: this.config.region
      };

      // Test connection by listing bucket
      const testCommand = `aws s3 ls s3://${this.config.bucketName} --max-items 1`;
      await execAsync(testCommand, { env });

      logger.info(`S3 connection test successful for bucket: ${this.config.bucketName}`);
      return true;
    } catch (error) {
      logger.error("S3 connection test failed:", error);
      return false;
    }
  }

  /**
   * Get sync statistics using AWS CLI
   */
  async getSyncStats(): Promise<{ bucketName: string; region: string; keyPrefix: string; available: boolean }> {
    const available = false; //await this.testConnection();
    return {
      bucketName: this.config.bucketName,
      region: this.config.region,
      keyPrefix: this.config.keyPrefix || "jobs/",
      available
    };
  }
}

/**
 * Create S3Sync instance from environment variables
 */
export function createS3SyncFromEnv(): S3Sync | null {
  const bucketName = process.env.S3_BUCKET_NAME || "test";
  const region = process.env.S3_REGION || "ca-central-1";
  const accessKeyId = process.env.S3_ACCESS_KEY_ID || "key";
  const secretAccessKey = process.env.S3_SECRET_ACCESS_KEY || "secret";
  const keyPrefix = process.env.S3_KEY_PREFIX || "prefix";

  if (!bucketName || !accessKeyId || !secretAccessKey) {
    logger.warning(
      "S3 configuration incomplete. Required env vars: S3_BUCKET_NAME, S3_ACCESS_KEY_ID, S3_SECRET_ACCESS_KEY"
    );
    return null;
  }

  return new S3Sync({
    bucketName,
    region,
    accessKeyId,
    secretAccessKey,
    keyPrefix
  });
}

/**
 * Standalone function to analyze Jobs directory without S3 configuration
 * Uses streaming to a temporary file to avoid memory issues with large datasets
 */
export async function analyzeJobsDirectory(): Promise<JobsDirectoryAnalysis> {
  const tempFilePath = path.join(FolderPaths.Jobs, "..", "jobs_analysis_temp.jsonl");

  try {
    logger.info("Starting Jobs directory analysis...");
    //Read from the config.json  file in the root directory to get the bodyshopid
    const bodyshopid: UUID = await getBodyshopIdFromConfig();

    const jobsPath = FolderPaths.Jobs;

    // Check if Jobs directory exists
    if (!(await fs.pathExists(jobsPath))) {
      logger.warning(`Jobs directory does not exist: ${jobsPath}`);
      return {
        bodyshopid,
        total_jobs: 0,
        total_documents: 0,
        unique_documents: 0,
        duplicate_documents: 0,
        total_size_bytes: 0,
        total_size_mb: 0,
        file_type_stats: {},
        media_analytics_details: { data: [] }
      };
    }

    // Clear/create temporary file for streaming job stats
    await fsPromises.writeFile(tempFilePath, "", "utf-8");
    logger.info(`Created temporary file for streaming analysis: ${tempFilePath}`);

    const jobFolders = await readdir(jobsPath);
    let total_documents = 0;
    let total_unique_documents = 0;
    let total_duplicate_documents = 0;
    let total_size_bytes = 0;
    let total_jobs = 0;
    const aggregated_file_type_stats: { [extension: string]: number } = {};

    const uuidRegex = /^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$/;
    for (const jobFolder of jobFolders) {
      if (jobFolder !== "temporary" && !uuidRegex.test(jobFolder)) {
        logger.info(`Skipping invalid jobid directory: ${jobFolder}`);
        continue;
      }
      const jobFolderPath = path.join(jobsPath, jobFolder);
      const stat = await fsStat(jobFolderPath);
      // Only process directories
      if (stat.isDirectory()) {
        const folderStats = await analyzeJobFolder(jobsPath, jobFolder, bodyshopid);

        // Stream to file immediately (one JSON object per line)
        await fsPromises.appendFile(tempFilePath, JSON.stringify(folderStats) + "\n", "utf-8");

        total_jobs++;
        total_documents += folderStats.document_count;
        total_unique_documents += folderStats.unique_document_count;
        total_duplicate_documents += folderStats.duplicate_count;
        total_size_bytes += folderStats.total_size_bytes;

        // Aggregate file type stats
        for (const [ext, count] of Object.entries(folderStats.file_type_stats)) {
          aggregated_file_type_stats[ext] = (aggregated_file_type_stats[ext] || 0) + count;
        }

        // Log progress every 100 jobs
        if (total_jobs % 100 === 0) {
          logger.info(`Progress: Analyzed ${total_jobs} jobs...`);
        }
      }
    }

    logger.info(`Reading back job stats from temporary file...`);

    // Read back the job stats from file
    const fileContent = await fsPromises.readFile(tempFilePath, "utf-8");
    const jobStats: JobFolderStats[] = fileContent
      .trim()
      .split("\n")
      .filter((line) => line.length > 0)
      .map((line) => JSON.parse(line));

    // Sort by jobid
    jobStats.sort((a, b) => a.jobid?.localeCompare(b.jobid!) || 0);

    const analysis: JobsDirectoryAnalysis = {
      bodyshopid, //read from the config.json  file in the root directory
      total_jobs,
      total_documents,
      unique_documents: total_unique_documents,
      duplicate_documents: total_duplicate_documents,
      total_size_bytes,
      total_size_mb: Math.round((total_size_bytes / (1024 * 1024)) * 100) / 100,
      file_type_stats: aggregated_file_type_stats,
      media_analytics_details: { data: jobStats }
    };

    logger.info(
      `Jobs directory analysis complete: ${analysis.total_jobs} jobs, ${analysis.total_documents} documents (${analysis.unique_documents} unique, ${analysis.duplicate_documents} duplicates), ${analysis.total_size_mb} MB`
    );
    
    //Add an upload to the IO database to categorize all of this.
    const apiURL = process.env.IS_TEST
      ? "https://api.test.imex.online/analytics/documents"
      : "https://api.imex.online/analytics/documents";
    const result = await axios.post(apiURL, { data: analysis });

    logger.info(`Uploaded analysis results, response status: ${result.status}`);
    // Clean up temporary file
    await fsPromises.unlink(tempFilePath);
    logger.info("Cleaned up temporary analysis file");

    return analysis;
  } catch (error) {
    logger.error("Failed to analyze Jobs directory:", (error as Error).message, (error as Error).stack);
    // Attempt to clean up temp file on error
    try {
      if (await fs.pathExists(tempFilePath)) {
        await fs.remove(tempFilePath);
        logger.info("Cleaned up temporary file after error");
      }
    } catch (cleanupError) {
      logger.warning("Failed to clean up temporary file:", cleanupError);
    }
    throw error;
  }
}

/**
 * Analyze a single job folder (helper function)
 */
async function analyzeJobFolder(jobsPath: string, jobid: string, bodyshopid: UUID): Promise<JobFolderStats> {
  const jobFolderPath = path.join(jobsPath, jobid);

  const { document_count, unique_document_count, duplicate_count, total_size_bytes, file_type_stats } =
    await getDirectoryStats(jobFolderPath);

  const uuidRegex = /^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$/;
  let validJobid: UUID | string | null = null;
  if (jobid === "temporary") {
    validJobid = null;
  } else if (uuidRegex.test(jobid)) {
    validJobid = jobid as UUID;
  } else {
    logger.warning(`Invalid jobid encountered in analyzeJobFolder: ${jobid}`);
    validJobid = null;
  }
  return {
    bodyshopid,
    jobid: validJobid,
    document_count,
    unique_document_count,
    duplicate_count,
    total_size_bytes,
    total_size_mb: Math.round((total_size_bytes / (1024 * 1024)) * 100) / 100,
    file_type_stats
  };
}

/**
 * Calculate SHA256 hash of a file's content
 */
async function calculateFileHash(filePath: string): Promise<string> {
  return new Promise((resolve, reject) => {
    const hash = crypto.createHash("sha256");
    const stream = createReadStream(filePath);

    stream.on("data", (data: string | Buffer) => hash.update(data));
    stream.on("end", () => resolve(hash.digest("hex")));
    stream.on("error", (error: Error) => {
      console.error("Hashing error:", error);
      reject(error);
    });
  });
}

/**
 * Recursively get document count and total size for a directory (helper function)
 * Now with duplicate detection using content-based hashing
 */
async function getDirectoryStats(dirPath: string): Promise<{
  document_count: number;
  unique_document_count: number;
  duplicate_count: number;
  total_size_bytes: number;
  file_type_stats: { [extension: string]: number };
  contentHashes: Set<string>;
}> {
  let document_count = 0;
  let unique_document_count = 0;
  let duplicate_count = 0;
  let total_size_bytes = 0;
  const file_type_stats: { [extension: string]: number } = {};
  const contentHashes = new Set<string>();

  try {
    const items = await readdir(dirPath);

    for (const item of items) {
      const itemPath = path.join(dirPath, item);
      const stat = await fsStat(itemPath);

      if (stat.isDirectory()) {
        // Skip thumbs and ConvertedOriginals folders (case-insensitive)
        const itemLower = item.toLowerCase();
        if (itemLower === "thumbs" || itemLower === "convertedoriginal" || itemLower === "bills") {
          continue;
        }

        // Recursively analyze subdirectories
        const subStats = await getDirectoryStats(itemPath);
        document_count += subStats.document_count;
        unique_document_count += subStats.unique_document_count;
        duplicate_count += subStats.duplicate_count;
        total_size_bytes += subStats.total_size_bytes;

        // Merge file type stats
        for (const [ext, count] of Object.entries(subStats.file_type_stats)) {
          file_type_stats[ext] = (file_type_stats[ext] || 0) + count;
        }

        // Merge content hashes to detect duplicates across subdirectories
        for (const hash of subStats.contentHashes) {
          contentHashes.add(hash);
        }
      } else {
        // Count files as documents
        document_count++;
        total_size_bytes += stat.size;

        // Track file extension
        const ext = path.extname(item).toLowerCase() || "no-extension";

        // Calculate content hash for image files to detect duplicates
        const isImageFile = [
          ".jpg",
          ".jpeg",
          ".png",
          ".gif",
          ".bmp",
          ".webp",
          ".heic",
          ".heif",
          ".tiff",
          ".tif"
        ].includes(ext);

        if (isImageFile) {
          try {
            const fileHash = await calculateFileHash(itemPath);

            if (contentHashes.has(fileHash)) {
              // This is a duplicate - don't count in file_type_stats
              duplicate_count++;
            } else {
              // This is unique
              contentHashes.add(fileHash);
              unique_document_count++;
              // Only count unique files in file_type_stats
              file_type_stats[ext] = (file_type_stats[ext] || 0) + 1;
            }
          } catch (hashError) {
            logger.warning(`Failed to hash file ${itemPath}:`, hashError);
            // If hashing fails, count as unique to avoid losing data
            unique_document_count++;
            file_type_stats[ext] = (file_type_stats[ext] || 0) + 1;
          }
        } else {
          // Non-image files are counted as unique (not checking for duplicates)
          unique_document_count++;
          file_type_stats[ext] = (file_type_stats[ext] || 0) + 1;
        }
      }
    }
  } catch (error) {
    logger.error(`Error analyzing directory ${dirPath}:`, error);
  }

  return { document_count, unique_document_count, duplicate_count, total_size_bytes, file_type_stats, contentHashes };
}

let bodyshopid: UUID;
const getBodyshopIdFromConfig = async (): Promise<UUID> => {
  if (bodyshopid) return bodyshopid;
  try {
    const fs = await import("fs/promises"); //Required as fs-extra fails.
    const configData = await fs.readFile(FolderPaths.Config, "utf-8");
    const config = JSON.parse(configData);
    bodyshopid = config.bodyshopIds[0] as UUID;
    return bodyshopid;
  } catch (error) {
    logger.error("Failed to read bodyshopid from config.json:", error, (error as Error).stack);
    throw new Error("Could not read bodyshopid from config.json");
  }
};