import { exec } from "child_process";
import { promisify } from "util";
import * as fs from "fs-extra";
import * as path from "path";
import { logger } from "../server.js";
import { FolderPaths } from "./serverInit.js";

const execAsync = promisify(exec);

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

export interface JobFolderStats {
  jobId: string;
  relativePath: string;
  documentCount: number;
  totalSizeBytes: number;
  totalSizeMB: number;
}

export interface JobsDirectoryAnalysis {
  totalJobs: number;
  totalDocuments: number;
  totalSizeBytes: number;
  totalSizeMB: number;
  jobs: 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.warn(`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.warn("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 = await this.testConnection();
    return {
      bucketName: this.config.bucketName,
      region: this.config.region,
      keyPrefix: this.config.keyPrefix || "jobs/",
      available
    };
  }

  /**
   * Analyze all job folders in the Jobs directory
   * Returns detailed statistics for each job folder
   */
  async analyzeJobsDirectory(): Promise<JobsDirectoryAnalysis> {
    try {
      logger.info("Starting Jobs directory analysis...");

      const jobsPath = FolderPaths.Jobs;

      // Check if Jobs directory exists
      if (!(await fs.pathExists(jobsPath))) {
        logger.warn(`Jobs directory does not exist: ${jobsPath}`);
        return {
          totalJobs: 0,
          totalDocuments: 0,
          totalSizeBytes: 0,
          totalSizeMB: 0,
          jobs: []
        };
      }

      const jobFolders = await fs.readdir(jobsPath);
      const jobStats: JobFolderStats[] = [];
      let totalDocuments = 0;
      let totalSizeBytes = 0;

      for (const jobFolder of jobFolders) {
        const jobFolderPath = path.join(jobsPath, jobFolder);
        const stat = await fs.stat(jobFolderPath);

        // Only process directories
        if (stat.isDirectory()) {
          const folderStats = await this.analyzeJobFolder(jobsPath, jobFolder);
          jobStats.push(folderStats);
          totalDocuments += folderStats.documentCount;
          totalSizeBytes += folderStats.totalSizeBytes;
        }
      }

      const analysis: JobsDirectoryAnalysis = {
        totalJobs: jobStats.length,
        totalDocuments,
        totalSizeBytes,
        totalSizeMB: Math.round((totalSizeBytes / (1024 * 1024)) * 100) / 100,
        jobs: jobStats.sort((a, b) => a.jobId.localeCompare(b.jobId))
      };

      logger.info(
        `Jobs directory analysis complete: ${analysis.totalJobs} jobs, ${analysis.totalDocuments} documents, ${analysis.totalSizeMB} MB`
      );
      return analysis;
    } catch (error) {
      logger.error("Failed to analyze Jobs directory:", error);
      throw error;
    }
  }

  /**
   * Analyze a single job folder
   */
  private async analyzeJobFolder(jobsPath: string, jobId: string): Promise<JobFolderStats> {
    const jobFolderPath = path.join(jobsPath, jobId);
    const relativePath = path.relative(FolderPaths.Root, jobFolderPath);

    const { documentCount, totalSizeBytes } = await this.getDirectoryStats(jobFolderPath);

    return {
      jobId,
      relativePath,
      documentCount,
      totalSizeBytes,
      totalSizeMB: Math.round((totalSizeBytes / (1024 * 1024)) * 100) / 100
    };
  }

  /**
   * Recursively get document count and total size for a directory
   */
  private async getDirectoryStats(dirPath: string): Promise<{ documentCount: number; totalSizeBytes: number }> {
    let documentCount = 0;
    let totalSizeBytes = 0;

    try {
      const items = await fs.readdir(dirPath);

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

        if (stat.isDirectory()) {
          // Recursively analyze subdirectories
          const subStats = await this.getDirectoryStats(itemPath);
          documentCount += subStats.documentCount;
          totalSizeBytes += subStats.totalSizeBytes;
        } else {
          // Count files as documents
          documentCount++;
          totalSizeBytes += stat.size;
        }
      }
    } catch (error) {
      logger.error(`Error analyzing directory ${dirPath}:`, error);
    }

    return { documentCount, totalSizeBytes };
  }
}

/**
 * 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.warn(
      "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
 */
export async function analyzeJobsDirectory(): Promise<JobsDirectoryAnalysis> {
  try {
    logger.info("Starting Jobs directory analysis...");

    const jobsPath = FolderPaths.Jobs;

    // Check if Jobs directory exists
    if (!(await fs.pathExists(jobsPath))) {
      logger.warn(`Jobs directory does not exist: ${jobsPath}`);
      return {
        totalJobs: 0,
        totalDocuments: 0,
        totalSizeBytes: 0,
        totalSizeMB: 0,
        jobs: []
      };
    }

    const jobFolders = await fs.readdir(jobsPath);
    const jobStats: JobFolderStats[] = [];
    let totalDocuments = 0;
    let totalSizeBytes = 0;

    for (const jobFolder of jobFolders) {
      const jobFolderPath = path.join(jobsPath, jobFolder);
      const stat = await fs.stat(jobFolderPath);

      // Only process directories
      if (stat.isDirectory()) {
        const folderStats = await analyzeJobFolder(jobsPath, jobFolder);
        jobStats.push(folderStats);
        totalDocuments += folderStats.documentCount;
        totalSizeBytes += folderStats.totalSizeBytes;
      }
    }

    const analysis: JobsDirectoryAnalysis = {
      totalJobs: jobStats.length,
      totalDocuments,
      totalSizeBytes,
      totalSizeMB: Math.round((totalSizeBytes / (1024 * 1024)) * 100) / 100,
      jobs: jobStats.sort((a, b) => a.jobId.localeCompare(b.jobId))
    };

    logger.info(
      `Jobs directory analysis complete: ${analysis.totalJobs} jobs, ${analysis.totalDocuments} documents, ${analysis.totalSizeMB} MB`
    );
    return analysis;
  } catch (error) {
    logger.error("Failed to analyze Jobs directory:", error);
    throw error;
  }
}

/**
 * Analyze a single job folder (standalone helper function)
 */
async function analyzeJobFolder(jobsPath: string, jobId: string): Promise<JobFolderStats> {
  const jobFolderPath = path.join(jobsPath, jobId);
  const relativePath = path.relative(FolderPaths.Root, jobFolderPath);

  const { documentCount, totalSizeBytes } = await getDirectoryStats(jobFolderPath);

  return {
    jobId,
    relativePath,
    documentCount,
    totalSizeBytes,
    totalSizeMB: Math.round((totalSizeBytes / (1024 * 1024)) * 100) / 100
  };
}

/**
 * Recursively get document count and total size for a directory (standalone helper function)
 */
async function getDirectoryStats(dirPath: string): Promise<{ documentCount: number; totalSizeBytes: number }> {
  let documentCount = 0;
  let totalSizeBytes = 0;

  try {
    const items = await fs.readdir(dirPath);

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

      if (stat.isDirectory()) {
        // Recursively analyze subdirectories
        const subStats = await getDirectoryStats(itemPath);
        documentCount += subStats.documentCount;
        totalSizeBytes += subStats.totalSizeBytes;
      } else {
        // Count files as documents
        documentCount++;
        totalSizeBytes += stat.size;
      }
    }
  } catch (error) {
    logger.error(`Error analyzing directory ${dirPath}:`, error);
  }

  return { documentCount, totalSizeBytes };
}