import express from "express";
import bodyParser from "body-parser";
import multer from "multer";
import userRoutes from "./routes/users.js";
import sshRoutes from "./routes/ssh.js";
import alertRoutes from "./routes/alerts.js";
import credentialsRoutes from "./routes/credentials.js";
import cors from "cors";
import fetch from "node-fetch";
import fs from "fs";
import path from "path";
import "dotenv/config";
import { databaseLogger, apiLogger } from "../utils/logger.js";
import { DatabaseEncryption } from "../utils/database-encryption.js";
import { EncryptionMigration } from "../utils/encryption-migration.js";
import { DatabaseMigration } from "../utils/database-migration.js";
import { DatabaseSQLiteExport } from "../utils/database-sqlite-export.js";
import { DatabaseFileEncryption } from "../utils/database-file-encryption.js";

const app = express();
app.use(
  cors({
    origin: "*",
    methods: ["GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"],
    allowedHeaders: [
      "Content-Type",
      "Authorization",
      "User-Agent",
      "X-Electron-App",
    ],
  }),
);

// Configure multer for file uploads
const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, 'uploads/');
  },
  filename: (req, file, cb) => {
    // Preserve original filename with timestamp prefix to avoid conflicts
    const timestamp = Date.now();
    cb(null, `${timestamp}-${file.originalname}`);
  }
});

const upload = multer({
  storage: storage,
  limits: {
    fileSize: 100 * 1024 * 1024, // 100MB limit
  },
  fileFilter: (req, file, cb) => {
    // Allow SQLite files
    if (file.originalname.endsWith('.termix-export.sqlite') || file.originalname.endsWith('.sqlite')) {
      cb(null, true);
    } else {
      cb(new Error('Only .termix-export.sqlite files are allowed'));
    }
  }
});

interface CacheEntry {
  data: any;
  timestamp: number;
  expiresAt: number;
}

class GitHubCache {
  private cache: Map<string, CacheEntry> = new Map();
  private readonly CACHE_DURATION = 30 * 60 * 1000;

  set(key: string, data: any): void {
    const now = Date.now();
    this.cache.set(key, {
      data,
      timestamp: now,
      expiresAt: now + this.CACHE_DURATION,
    });
  }

  get(key: string): any | null {
    const entry = this.cache.get(key);
    if (!entry) {
      return null;
    }

    if (Date.now() > entry.expiresAt) {
      this.cache.delete(key);
      return null;
    }

    return entry.data;
  }
}

const githubCache = new GitHubCache();

const GITHUB_API_BASE = "https://api.github.com";
const REPO_OWNER = "LukeGus";
const REPO_NAME = "Termix";

interface GitHubRelease {
  id: number;
  tag_name: string;
  name: string;
  body: string;
  published_at: string;
  html_url: string;
  assets: Array<{
    id: number;
    name: string;
    size: number;
    download_count: number;
    browser_download_url: string;
  }>;
  prerelease: boolean;
  draft: boolean;
}

async function fetchGitHubAPI(
  endpoint: string,
  cacheKey: string,
): Promise<any> {
  const cachedData = githubCache.get(cacheKey);
  if (cachedData) {
    return {
      data: cachedData,
      cached: true,
      cache_age: Date.now() - cachedData.timestamp,
    };
  }

  try {
    const response = await fetch(`${GITHUB_API_BASE}${endpoint}`, {
      headers: {
        Accept: "application/vnd.github+json",
        "User-Agent": "TermixUpdateChecker/1.0",
        "X-GitHub-Api-Version": "2022-11-28",
      },
    });

    if (!response.ok) {
      throw new Error(
        `GitHub API error: ${response.status} ${response.statusText}`,
      );
    }

    const data = await response.json();
    githubCache.set(cacheKey, data);

    return {
      data: data,
      cached: false,
    };
  } catch (error) {
    databaseLogger.error(`Failed to fetch from GitHub API`, error, {
      operation: "github_api",
      endpoint,
    });
    throw error;
  }
}

app.use(bodyParser.json());

app.get("/health", (req, res) => {
  res.json({ status: "ok" });
});

app.get("/version", async (req, res) => {
  let localVersion = process.env.VERSION;

  if (!localVersion) {
    try {
      const packagePath = path.resolve(process.cwd(), "package.json");
      const packageJson = JSON.parse(fs.readFileSync(packagePath, "utf8"));
      localVersion = packageJson.version;
    } catch (error) {
      databaseLogger.error("Failed to read version from package.json", error, {
        operation: "version_check",
      });
    }
  }

  if (!localVersion) {
    databaseLogger.error("No version information available", undefined, {
      operation: "version_check",
    });
    return res.status(404).send("Local Version Not Set");
  }

  try {
    const cacheKey = "latest_release";
    const releaseData = await fetchGitHubAPI(
      `/repos/${REPO_OWNER}/${REPO_NAME}/releases/latest`,
      cacheKey,
    );

    const rawTag = releaseData.data.tag_name || releaseData.data.name || "";
    const remoteVersionMatch = rawTag.match(/(\d+\.\d+(\.\d+)?)/);
    const remoteVersion = remoteVersionMatch ? remoteVersionMatch[1] : null;

    if (!remoteVersion) {
      databaseLogger.warn("Remote version not found in GitHub response", {
        operation: "version_check",
        rawTag,
      });
      return res.status(401).send("Remote Version Not Found");
    }

    const isUpToDate = localVersion === remoteVersion;

    const response = {
      status: isUpToDate ? "up_to_date" : "requires_update",
      localVersion: localVersion,
      version: remoteVersion,
      latest_release: {
        tag_name: releaseData.data.tag_name,
        name: releaseData.data.name,
        published_at: releaseData.data.published_at,
        html_url: releaseData.data.html_url,
      },
      cached: releaseData.cached,
      cache_age: releaseData.cache_age,
    };

    res.json(response);
  } catch (err) {
    databaseLogger.error("Version check failed", err, {
      operation: "version_check",
    });
    res.status(500).send("Fetch Error");
  }
});

app.get("/releases/rss", async (req, res) => {
  try {
    const page = parseInt(req.query.page as string) || 1;
    const per_page = Math.min(
      parseInt(req.query.per_page as string) || 20,
      100,
    );
    const cacheKey = `releases_rss_${page}_${per_page}`;

    const releasesData = await fetchGitHubAPI(
      `/repos/${REPO_OWNER}/${REPO_NAME}/releases?page=${page}&per_page=${per_page}`,
      cacheKey,
    );

    const rssItems = releasesData.data.map((release: GitHubRelease) => ({
      id: release.id,
      title: release.name || release.tag_name,
      description: release.body,
      link: release.html_url,
      pubDate: release.published_at,
      version: release.tag_name,
      isPrerelease: release.prerelease,
      isDraft: release.draft,
      assets: release.assets.map((asset) => ({
        name: asset.name,
        size: asset.size,
        download_count: asset.download_count,
        download_url: asset.browser_download_url,
      })),
    }));

    const response = {
      feed: {
        title: `${REPO_NAME} Releases`,
        description: `Latest releases from ${REPO_NAME} repository`,
        link: `https://github.com/${REPO_OWNER}/${REPO_NAME}/releases`,
        updated: new Date().toISOString(),
      },
      items: rssItems,
      total_count: rssItems.length,
      cached: releasesData.cached,
      cache_age: releasesData.cache_age,
    };

    res.json(response);
  } catch (error) {
    databaseLogger.error("Failed to generate RSS format", error, {
      operation: "rss_releases",
    });
    res.status(500).json({
      error: "Failed to generate RSS format",
      details: error instanceof Error ? error.message : "Unknown error",
    });
  }
});

app.get("/encryption/status", async (req, res) => {
  try {
    const detailedStatus = await DatabaseEncryption.getDetailedStatus();
    const migrationStatus = await EncryptionMigration.checkMigrationStatus();

    res.json({
      encryption: detailedStatus,
      migration: migrationStatus
    });
  } catch (error) {
    apiLogger.error("Failed to get encryption status", error, {
      operation: "encryption_status"
    });
    res.status(500).json({ error: "Failed to get encryption status" });
  }
});

app.post("/encryption/initialize", async (req, res) => {
  try {
    const { EncryptionKeyManager } = await import("../utils/encryption-key-manager.js");
    const keyManager = EncryptionKeyManager.getInstance();

    const newKey = await keyManager.generateNewKey();
    await DatabaseEncryption.initialize({ masterPassword: newKey });

    apiLogger.info("Encryption initialized via API", {
      operation: "encryption_init_api"
    });

    res.json({
      success: true,
      message: "Encryption initialized successfully",
      keyPreview: newKey.substring(0, 8) + "..."
    });
  } catch (error) {
    apiLogger.error("Failed to initialize encryption", error, {
      operation: "encryption_init_api_failed"
    });
    res.status(500).json({ error: "Failed to initialize encryption" });
  }
});

app.post("/encryption/migrate", async (req, res) => {
  try {
    const { dryRun = false } = req.body;

    const migration = new EncryptionMigration({
      dryRun,
      backupEnabled: true
    });

    if (dryRun) {
      apiLogger.info("Starting encryption migration (dry run)", {
        operation: "encryption_migrate_dry_run"
      });

      res.json({
        success: true,
        message: "Dry run mode - no changes made",
        dryRun: true
      });
    } else {
      apiLogger.info("Starting encryption migration", {
        operation: "encryption_migrate"
      });

      await migration.runMigration();

      res.json({
        success: true,
        message: "Migration completed successfully"
      });
    }
  } catch (error) {
    apiLogger.error("Migration failed", error, {
      operation: "encryption_migrate_failed"
    });
    res.status(500).json({
      error: "Migration failed",
      details: error instanceof Error ? error.message : "Unknown error"
    });
  }
});

app.post("/encryption/regenerate", async (req, res) => {
  try {
    await DatabaseEncryption.reinitializeWithNewKey();

    apiLogger.warn("Encryption key regenerated via API", {
      operation: "encryption_regenerate_api"
    });

    res.json({
      success: true,
      message: "New encryption key generated",
      warning: "All encrypted data must be re-encrypted"
    });
  } catch (error) {
    apiLogger.error("Failed to regenerate encryption key", error, {
      operation: "encryption_regenerate_failed"
    });
    res.status(500).json({ error: "Failed to regenerate encryption key" });
  }
});

// Database migration and backup endpoints
app.post("/database/export", async (req, res) => {
  try {
    const { customPath } = req.body;

    apiLogger.info("Starting SQLite database export via API", {
      operation: "database_sqlite_export_api",
      customPath: !!customPath
    });

    const exportPath = await DatabaseSQLiteExport.exportDatabase(customPath);

    res.json({
      success: true,
      message: "Database exported successfully as SQLite",
      exportPath,
      size: fs.statSync(exportPath).size,
      format: "sqlite"
    });
  } catch (error) {
    apiLogger.error("SQLite database export failed", error, {
      operation: "database_sqlite_export_api_failed"
    });
    res.status(500).json({
      error: "SQLite database export failed",
      details: error instanceof Error ? error.message : "Unknown error"
    });
  }
});

app.post("/database/import", upload.single('file'), async (req, res) => {
  try {
    if (!req.file) {
      return res.status(400).json({ error: "No file uploaded" });
    }

    const { backupCurrent = "true" } = req.body;
    const backupCurrentBool = backupCurrent === "true";
    const importPath = req.file.path;

    apiLogger.info("Starting SQLite database import via API (additive mode)", {
      operation: "database_sqlite_import_api",
      importPath,
      originalName: req.file.originalname,
      fileSize: req.file.size,
      mode: "additive",
      backupCurrent: backupCurrentBool
    });

    // Validate export file first
    // Check file extension using original filename
    if (!req.file.originalname.endsWith('.termix-export.sqlite')) {
      // Clean up uploaded file
      fs.unlinkSync(importPath);
      return res.status(400).json({
        error: "Invalid SQLite export file",
        details: ["File must have .termix-export.sqlite extension"]
      });
    }

    const validation = DatabaseSQLiteExport.validateExportFile(importPath);
    if (!validation.valid) {
      // Clean up uploaded file
      fs.unlinkSync(importPath);
      return res.status(400).json({
        error: "Invalid SQLite export file",
        details: validation.errors
      });
    }

    const result = await DatabaseSQLiteExport.importDatabase(importPath, {
      replaceExisting: false, // Always use additive mode
      backupCurrent: backupCurrentBool
    });

    // Clean up uploaded file
    fs.unlinkSync(importPath);

    res.json({
      success: result.success,
      message: result.success ? "SQLite database imported successfully" : "SQLite database import completed with errors",
      imported: result.imported,
      errors: result.errors,
      warnings: result.warnings,
      format: "sqlite"
    });
  } catch (error) {
    // Clean up uploaded file if it exists
    if (req.file?.path) {
      try {
        fs.unlinkSync(req.file.path);
      } catch (cleanupError) {
        apiLogger.warn("Failed to clean up uploaded file", {
          operation: "file_cleanup_failed",
          filePath: req.file.path,
          error: cleanupError instanceof Error ? cleanupError.message : 'Unknown error'
        });
      }
    }

    apiLogger.error("SQLite database import failed", error, {
      operation: "database_sqlite_import_api_failed"
    });
    res.status(500).json({
      error: "SQLite database import failed",
      details: error instanceof Error ? error.message : "Unknown error"
    });
  }
});

app.get("/database/export/:exportPath/info", async (req, res) => {
  try {
    const { exportPath } = req.params;
    const decodedPath = decodeURIComponent(exportPath);

    const validation = DatabaseSQLiteExport.validateExportFile(decodedPath);
    if (!validation.valid) {
      return res.status(400).json({
        error: "Invalid SQLite export file",
        details: validation.errors
      });
    }

    res.json({
      valid: true,
      metadata: validation.metadata,
      format: "sqlite"
    });
  } catch (error) {
    apiLogger.error("Failed to get SQLite export info", error, {
      operation: "sqlite_export_info_failed"
    });
    res.status(500).json({ error: "Failed to get SQLite export information" });
  }
});

app.post("/database/backup", async (req, res) => {
  try {
    const { customPath } = req.body;

    apiLogger.info("Creating encrypted database backup via API", {
      operation: "database_backup_api"
    });

    // Import required modules
    const { databasePaths, getMemoryDatabaseBuffer } = await import("./db/index.js");

    // Get current in-memory database as buffer
    const dbBuffer = getMemoryDatabaseBuffer();

    // Create backup directory
    const backupDir = customPath || path.join(databasePaths.directory, 'backups');
    if (!fs.existsSync(backupDir)) {
      fs.mkdirSync(backupDir, { recursive: true });
    }

    // Generate backup filename with timestamp
    const timestamp = new Date().toISOString().replace(/[:.]/g, '-');
    const backupFileName = `database-backup-${timestamp}.sqlite.encrypted`;
    const backupPath = path.join(backupDir, backupFileName);

    // Create encrypted backup directly from memory buffer
    DatabaseFileEncryption.encryptDatabaseFromBuffer(dbBuffer, backupPath);

    res.json({
      success: true,
      message: "Encrypted backup created successfully",
      backupPath,
      size: fs.statSync(backupPath).size
    });
  } catch (error) {
    apiLogger.error("Database backup failed", error, {
      operation: "database_backup_api_failed"
    });
    res.status(500).json({
      error: "Database backup failed",
      details: error instanceof Error ? error.message : "Unknown error"
    });
  }
});

app.post("/database/restore", async (req, res) => {
  try {
    const { backupPath, targetPath } = req.body;

    if (!backupPath) {
      return res.status(400).json({ error: "Backup path is required" });
    }

    apiLogger.info("Restoring database from backup via API", {
      operation: "database_restore_api",
      backupPath
    });

    // Validate backup file
    if (!DatabaseFileEncryption.isEncryptedDatabaseFile(backupPath)) {
      return res.status(400).json({ error: "Invalid encrypted backup file" });
    }

    // Check hardware compatibility
    if (!DatabaseFileEncryption.validateHardwareCompatibility(backupPath)) {
      return res.status(400).json({
        error: "Hardware fingerprint mismatch",
        message: "This backup was created on different hardware and cannot be restored"
      });
    }

    const restoredPath = DatabaseFileEncryption.restoreFromEncryptedBackup(backupPath, targetPath);

    res.json({
      success: true,
      message: "Database restored successfully",
      restoredPath
    });
  } catch (error) {
    apiLogger.error("Database restore failed", error, {
      operation: "database_restore_api_failed"
    });
    res.status(500).json({
      error: "Database restore failed",
      details: error instanceof Error ? error.message : "Unknown error"
    });
  }
});

app.use("/users", userRoutes);
app.use("/ssh", sshRoutes);
app.use("/alerts", alertRoutes);
app.use("/credentials", credentialsRoutes);

app.use(
  (
    err: unknown,
    req: express.Request,
    res: express.Response,
    next: express.NextFunction,
  ) => {
    apiLogger.error("Unhandled error in request", err, {
      operation: "error_handler",
      method: req.method,
      url: req.url,
      userAgent: req.get("User-Agent"),
    });
    res.status(500).json({ error: "Internal Server Error" });
  },
);

const PORT = 8081;

async function initializeEncryption() {
  try {
    databaseLogger.info("Initializing database encryption...", {
      operation: "encryption_init"
    });

    await DatabaseEncryption.initialize({
      encryptionEnabled: process.env.ENCRYPTION_ENABLED !== 'false',
      forceEncryption: process.env.FORCE_ENCRYPTION === 'true',
      migrateOnAccess: process.env.MIGRATE_ON_ACCESS !== 'false'
    });

    const status = await DatabaseEncryption.getDetailedStatus();
    if (status.configValid && status.key.keyValid) {
      databaseLogger.success("Database encryption initialized successfully", {
        operation: "encryption_init_complete",
        enabled: status.enabled,
        keyId: status.key.keyId,
        hasStoredKey: status.key.hasKey
      });
    } else {
      databaseLogger.error("Database encryption configuration invalid", undefined, {
        operation: "encryption_init_failed",
        status
      });
    }
  } catch (error) {
    databaseLogger.error("Failed to initialize database encryption", error, {
      operation: "encryption_init_error"
    });
  }
}

app.listen(PORT, async () => {
  // Ensure uploads directory exists
  const uploadsDir = path.join(process.cwd(), 'uploads');
  if (!fs.existsSync(uploadsDir)) {
    fs.mkdirSync(uploadsDir, { recursive: true });
  }

  await initializeEncryption();

  databaseLogger.success(`Database API server started on port ${PORT}`, {
    operation: "server_start",
    port: PORT,
    routes: [
      "/users",
      "/ssh",
      "/alerts",
      "/credentials",
      "/health",
      "/version",
      "/releases/rss",
      "/encryption/status",
      "/encryption/initialize",
      "/encryption/migrate",
      "/encryption/regenerate",
      "/database/export",
      "/database/import",
      "/database/export/:exportPath/info",
      "/database/backup",
      "/database/restore",
    ],
  });
});