1 files changed, 350 insertions, 0 deletions
diff --git a/Sources/gopherHandler.swift b/Sources/gopherHandler.swift
new file mode 100644
index 0000000..2d369bf
--- /dev/null
+++ b/Sources/gopherHandler.swift
@@ -0,0 +1,350 @@
+import ArgumentParser
+import Foundation
+import Logging
+import NIO
+
+final class GopherHandler: ChannelInboundHandler {
+  typealias InboundIn = ByteBuffer
+  typealias OutboundOut = ByteBuffer
+
+  let gopherdata_dir: String
+  let gopherdata_host: String
+  let gopherdata_port: Int
+  let logger: Logger
+  let enableSearch: Bool
+  let disableGophermap: Bool
+
+  init(
+    logger: Logger,
+    gopherdata_dir: String = "./example-gopherdata", gopherdata_host: String = "localhost",
+    gopherdata_port: Int = 70, enableSearch: Bool = false,
+    disableGophermap: Bool = false
+  ) {
+    self.gopherdata_dir = gopherdata_dir
+    self.gopherdata_host = gopherdata_host
+    self.gopherdata_port = gopherdata_port
+    self.logger = logger
+    self.enableSearch = enableSearch
+    self.disableGophermap = disableGophermap
+  }
+
+  func channelRead(context: ChannelHandlerContext, data: NIOAny) {
+    let input = self.unwrapInboundIn(data)
+
+    guard let requestString = input.getString(at: 0, length: input.readableBytes) else {
+      return
+    }
+
+    if let remoteAddress = context.remoteAddress {
+        logger.info("Received request from \(remoteAddress) for '\(requestString.replacingOccurrences(of: "\r\n", with: "<GopherSequence>").replacingOccurrences(of: "\n", with: "<Linebreak>"))'")
+    } else {
+        logger.warning("Unable to retrieve remote address")
+    }
+
+    let response = processGopherRequest(requestString)
+
+    var buffer: ByteBuffer
+
+    switch response {
+    case .string(let string):
+      buffer = context.channel.allocator.buffer(string: string)
+    case .data(let data):
+      buffer = context.channel.allocator.buffer(bytes: data)
+    }
+
+    context.writeAndFlush(self.wrapOutboundOut(buffer)).whenComplete { _ in
+      context.close(mode: .all, promise: nil)
+    }
+  }
+
+  func requestHandler(path: URL) -> ResponseType {
+    logger.info("Handling request for '\(path.path)'")
+
+    // Check if path is a directory or a file
+    let fm = FileManager.default
+    var isDir: ObjCBool = false
+
+    if fm.fileExists(atPath: path.path, isDirectory: &isDir) {
+      if isDir.boolValue {
+        return .string(prepareGopherMenu(path: path))
+      } else {
+        // Check if file is plain text or binary
+        let fileExtension = path.pathExtension
+        let fileType = getFileType(fileExtension: fileExtension)
+
+        if fileType == .text || fileType == .html {
+          do {
+            let fileContents = try String(contentsOfFile: path.path, encoding: .utf8)
+
+            return .string(fileContents)
+          } catch {
+            logger.error("Error reading file: \(path.path)")
+            return .string("3Error reading file...\r\n")
+          }
+        } else {
+          // Handle binary file
+          do {
+            let fileContents = try Data(contentsOf: path)
+            return .data(fileContents)
+          } catch {
+            logger.error("Error reading file: \(path.path)")
+            return .string("3Error reading file...\r\n")
+          }
+        }
+
+      }
+    } else {
+      logger.error("Error reading file: \(path.path)")
+      return .string("3Error reading file...\r\n")
+    }
+
+  }
+
+  func preparePath(path: String = "/") -> URL {
+    var sanitizedPath = sanitizeSelectorPath(path: path)
+    let base_dir = URL(fileURLWithPath: gopherdata_dir)
+    if base_dir.path.hasSuffix("/") && sanitizedPath.hasPrefix("/") {
+      sanitizedPath = String(sanitizedPath.dropFirst())
+    }
+
+    // Now check if there is still a prefix
+    if sanitizedPath.hasPrefix("/") {
+        sanitizedPath = String(sanitizedPath.dropFirst())
+    }
+
+    let full_path = base_dir.appendingPathComponent(sanitizedPath)
+    return full_path
+  }
+
+  func generateGopherItem(
+    item_name: String, item_path: URL, item_host: String? = nil, item_port: String? = nil
+  ) -> String {
+    let myItemHost = item_host ?? gopherdata_host
+    let myItemPort = item_port ?? String(gopherdata_port)
+    let base_path = URL(fileURLWithPath: gopherdata_dir)
+    var relative_path = item_path.path.replacingOccurrences(of: base_path.path, with: "")
+    if !relative_path.hasPrefix("/") {
+      relative_path = "/\(relative_path)"
+    }
+    return "\(item_name)\t\(relative_path)\t\(myItemHost)\t\(myItemPort)\r\n"
+  }
+
+  func generateGopherMap(path: URL) -> [String] {
+    var items: [String] = []
+
+    var basePath = URL(fileURLWithPath: gopherdata_dir).path
+    if basePath.hasSuffix("/") {
+        basePath = String(basePath.dropLast())
+    }
+
+    let fm = FileManager.default
+    do {
+        print("Reading directory: \(path.path)")
+        let itemsInDirectory = try fm.contentsOfDirectory(at: path, includingPropertiesForKeys: nil)
+        for item in itemsInDirectory {
+            let isDirectory = try item.resourceValues(forKeys: [.isDirectoryKey]).isDirectory ?? false
+            let name = item.lastPathComponent
+            if isDirectory {
+                items.append(generateGopherItem(item_name: "1\(name)", item_path: item))
+            } else {
+                let fileType = getFileType(fileExtension: item.pathExtension)
+                let gopherFileType = fileTypeToGopherItem(fileType: fileType)
+                items.append(generateGopherItem(item_name: "\(gopherFileType)\(name)", item_path: item))
+            }
+        }
+    } catch {
+        print("Error reading directory: \(path.path)")
+    }
+    return items
+  }
+
+  func prepareGopherMenu(path: URL = URL(string: "/")!) -> String {
+    var gopherResponse: [String] = []
+
+    let fm = FileManager.default
+
+    do {
+      let gophermap_path = path.appendingPathComponent("gophermap")
+      if fm.fileExists(atPath: gophermap_path.path) && !disableGophermap {
+        let gophermap_contents = try String(contentsOfFile: gophermap_path.path, encoding: .utf8)
+        let gophermap_lines = gophermap_contents.components(separatedBy: "\n")
+        for originalLine in gophermap_lines {
+          // Only keep first 80 characters
+          var line = String(originalLine)//.prefix(80)
+           if "0123456789+gIT:;<dhprsPXi".contains(line.prefix(1)) && line.count > 1 {
+            if line.hasSuffix("\n") {
+              line = String(line.dropLast())
+            }
+            if line.prefix(1) == "i" {
+              gopherResponse.append("\(line)\r\n")
+                continue
+            }
+
+            let regex = try! NSRegularExpression(pattern: "\\t+| {2,}")
+            let nsString = line as NSString
+            let range = NSRange(location: 0, length: nsString.length)
+            let matches = regex.matches(in: String(line), range: range)
+
+            var lastRangeEnd = 0
+            var components = [String]()
+
+            for match in matches {
+              let range = NSRange(
+                location: lastRangeEnd, length: match.range.location - lastRangeEnd)
+              components.append(nsString.substring(with: range))
+              lastRangeEnd = match.range.location + match.range.length
+            }
+
+            if lastRangeEnd < nsString.length {
+              components.append(nsString.substring(from: lastRangeEnd))
+            }
+
+            if components.count < 3 {
+                continue
+            }
+
+            let item_name = components[0]
+            let item_path = components[1]
+            let item_host = components[2]
+            let item_port = components.count > 3 ? components[3] : "70"
+
+            let item_line = "\(item_name)\t\(item_path)\t\(item_host)\t\(item_port)\r\n"
+            gopherResponse.append(item_line)
+          } else {
+            line = line.replacingOccurrences(of: "\n", with: "")
+            gopherResponse.append("i\(line)\r\n")
+          }
+        }
+      } else {
+        print("No gophermap found for \(path.path)")
+        gopherResponse = generateGopherMap(path: path)
+      }
+    } catch {
+      logger.error("Error reading directory: \(path.path)")
+      gopherResponse.append("3Error reading directory...\r\n")
+    }
+
+    // Append Search
+    if enableSearch {
+        let search_line = "7Search Server\t/search\t\(gopherdata_host)\t\(gopherdata_port)\r\n"
+        gopherResponse.append(search_line)
+    }
+    
+
+    return gopherResponse.joined(separator: "")
+  }
+
+    // TODO: Refactor
+  func performSearch(query: String) -> String {
+    // Really basic search implementation
+
+    var search_results = [String: String]()
+
+    let fm = FileManager.default
+
+    let base_dir = URL(fileURLWithPath: gopherdata_dir)
+
+    let enumerator = fm.enumerator(at: base_dir, includingPropertiesForKeys: nil)
+
+    while let file = enumerator?.nextObject() as? URL {
+      let file_name = file.lastPathComponent
+      let file_path = file.path
+      let file_type =
+        try? file.resourceValues(forKeys: [.isDirectoryKey]).isDirectory ?? false ? "1" : "0"
+
+      if file_type == "0" {
+        // Check if file name or contents match the query
+        let file_contents = try? String(contentsOfFile: file_path, encoding: .utf8)
+        if file_name.lowercased().contains(query)
+          || (file_contents?.lowercased().contains(query) ?? false)
+        {
+          search_results[file_name] = file_path
+        }
+      } else {
+        // Check if directory name matches the query
+        if file_name.lowercased().contains(query) {
+          search_results[file_name] = file_path
+        }
+      }
+    }
+
+    // Prepare Gopher menu with search results
+    var gopherResponse: [String] = []
+
+    for (_, file_path) in search_results {
+      let item_type =
+        try? URL(fileURLWithPath: file_path).resourceValues(forKeys: [.isDirectoryKey]).isDirectory
+        ?? false ? "1" : "0"
+      let item_host = gopherdata_host
+      let item_port = gopherdata_port
+      let item_path = file_path.replacingOccurrences(of: base_dir.path, with: "")
+      let item_line =
+        "\(item_type ?? "0")\(item_path)\t\(item_path)\t\(item_host)\t\(item_port)\r\n"
+      gopherResponse.append(item_line)
+    }
+
+    if gopherResponse.count == 0 {
+      gopherResponse.append("iNo results found for the query \(query)\r\n")
+    }
+
+    return gopherResponse.joined(separator: "")
+
+  }
+
+  func sanitizeSelectorPath(path: String) -> String {
+    // Replace \r\n with empty string
+    var sanitizedRequest = path.replacingOccurrences(of: "\r\n", with: "")
+
+    // Basic escape against directory traversal
+    while sanitizedRequest.contains("..") {
+      sanitizedRequest = sanitizedRequest.replacingOccurrences(of: "..", with: "")
+    }
+
+    while sanitizedRequest.contains("//") {
+      sanitizedRequest = sanitizedRequest.replacingOccurrences(of: "//", with: "/")
+    }
+
+    return sanitizedRequest
+  }
+
+  func channelReadComplete(context: ChannelHandlerContext) {
+    context.flush()
+  }
+
+  func errorCaught(context: ChannelHandlerContext, error: Error) {
+    print("Error: \(error)")
+    logger.error("Error: \(error)")
+    context.close(promise: nil)
+  }
+
+  private func processGopherRequest(_ originalRequest: String) -> ResponseType {
+    var request = originalRequest
+
+    // Fix for "Gopher" (iOS) client sending an extra \n
+    if request.hasSuffix("\n\n") {
+        request = String(request.dropLast())
+    }
+
+    if request == "\r\n" { // Empty request
+      return .string(prepareGopherMenu(path: preparePath()))
+    }
+
+    // Again, fix for the iOS client. Might as well make my own client
+    if request.hasSuffix("\n") {
+        request = String(request.dropLast())
+    }
+
+    if request.contains("\t") {
+        if enableSearch {
+            var searchQuery = request.components(separatedBy: "\t")[1]
+            searchQuery = searchQuery.replacingOccurrences(of: "\r\n", with: "")
+            return .string(performSearch(query: searchQuery.lowercased()))
+        } else {
+            return .string("3Search is disabled on this server.\r\n")
+        }
+    }
+    
+    //TODO: Potential Bug in Gopher implementation? curl gopher://localhost:8080/new_folder/ does not work but curl gopher://localhost:8080//new_folder/ works (tested with gopher://gopher.meulie.net//EFFector/ as well)
+    return requestHandler(path: preparePath(path: request))
+  }
+}