From 8158edf88c66af9d798f300da7c045c57921c1aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Denis=20Nu=C8=9Biu?= <denis.nutiu@gmail.com>
Date: Wed, 8 Nov 2017 22:18:23 +0200
Subject: [PATCH] Refactoring to use Client and Stack

---
 server/server/commands.go   | 27 ++++++++++++++++++---------
 server/server/connection.go |  2 +-
 server/server/errors.go     |  1 +
 server/server/parser.go     |  8 ++++----
 4 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/server/server/commands.go b/server/server/commands.go
index 003cc15..74a10d0 100644
--- a/server/server/commands.go
+++ b/server/server/commands.go
@@ -4,17 +4,21 @@ import (
 	"bytes"
 	"io/ioutil"
 	"log"
-	"net"
 	"os"
 	"strconv"
 	"strings"
 )
 
 // GetFile sends the file to the client and returns true if it succeeds and false otherwise.
-func GetFile(c net.Conn, path string) (int, error) {
+func GetFile(c Client, path string) (int, error) {
 	fileName := sanitizeFilePath(path)
 
-	file, err := os.Open(BasePath + fileName)
+	stack, ok := c.Stack().(*StringStack)
+	if !ok {
+		return 0, ErrStackCast
+	}
+
+	file, err := os.Open(MakePathFromStringStack(stack) + fileName)
 	if err != nil {
 		log.Println(err)
 		return 0, err
@@ -26,7 +30,7 @@ func GetFile(c net.Conn, path string) (int, error) {
 		return 0, err
 	}
 
-	n, err := c.Write(data)
+	n, err := c.Connection().Write(data)
 	if err != nil {
 		log.Println(err)
 		return 0, err
@@ -61,8 +65,13 @@ func sanitizeFilePath(path string) string {
 }
 
 // ListFiles list the files from path and sends them to the connection
-func ListFiles(c net.Conn) error {
-	files, err := ioutil.ReadDir(BasePath)
+func ListFiles(c Client) error {
+	stack, ok := c.Stack().(*StringStack)
+	if !ok {
+		return ErrStackCast
+	}
+
+	files, err := ioutil.ReadDir(MakePathFromStringStack(stack))
 	if err != nil {
 		return err
 	}
@@ -73,7 +82,7 @@ func ListFiles(c net.Conn) error {
 			strconv.FormatInt(f.Size(), 10) + " " + f.ModTime().String() + " " + string(f.Name()) + " " + "\n")
 	}
 
-	_, err = c.Write(buffer.Bytes())
+	_, err = c.Connection().Write(buffer.Bytes())
 	if err != nil {
 		return err
 	}
@@ -81,7 +90,7 @@ func ListFiles(c net.Conn) error {
 	return nil
 }
 
-func ShowHelp(c net.Conn) error {
+func ShowHelp(c Client) error {
 	var helpText = `
 The available commands are:
 get <filename> - Download the requested filename.
@@ -89,7 +98,7 @@ ls - List the files in the current directory.
 clear - Clear the screen.
 exit - Close the connection with the server.
 `
-	_, err := c.Write([]byte(helpText))
+	_, err := c.Connection().Write([]byte(helpText))
 
 	return err
 }
diff --git a/server/server/connection.go b/server/server/connection.go
index f43f84c..1c36664 100644
--- a/server/server/connection.go
+++ b/server/server/connection.go
@@ -13,7 +13,7 @@ type Client interface {
 	Connection() net.Conn        // Connection returns the connection stream.
 	SetConnection(conn net.Conn) // SetConnection sets the connection for the client.
 	Disconnect()                 // Disconnect closes the Client's connections and clears up resources.
-	Stack() Stack                // Returns the underlying Stack.
+	Stack() Stack                // Returns the underlying String Stack.
 }
 
 // FTPClient represents a FTPClient connection, it holds a root cage and the underlying connection.
diff --git a/server/server/errors.go b/server/server/errors.go
index dd8443b..74b7473 100644
--- a/server/server/errors.go
+++ b/server/server/errors.go
@@ -36,6 +36,7 @@ var (
 	StackInvalidTypeError = StackError{"InvalidTypeError", errors.New("invalid item type for the Stack")}
 	StackOverflowError    = StackError{"StackOverflowError", errors.New("stack capacity exceeded")}
 	StackUnderflowError   = StackError{"StackUnderflowError", errors.New("stack is empty")}
+	ErrStackCast          = StackError{"StackCastError", errors.New("stack can't be casted to selected type")}
 )
 
 // PathErrors
diff --git a/server/server/parser.go b/server/server/parser.go
index 6cee415..8420eec 100644
--- a/server/server/parser.go
+++ b/server/server/parser.go
@@ -32,7 +32,7 @@ func ProcessInput(c Client, text string) error {
 		}
 
 		// Get the file
-		_, err = GetFile(c.Connection(), commands[1])
+		_, err = GetFile(c, commands[1])
 		if err != nil {
 			return &InputError{thisCommand, err}
 		}
@@ -42,7 +42,7 @@ func ProcessInput(c Client, text string) error {
 			return &InputError{thisCommand, err}
 		}
 
-		err = ListFiles(c.Connection())
+		err = ListFiles(c)
 		if err != nil {
 			return &InputError{thisCommand, err}
 		}
@@ -64,7 +64,7 @@ func ProcessInput(c Client, text string) error {
 			return &InputError{thisCommand, err}
 		}
 
-		err = ShowHelp(c.Connection())
+		err = ShowHelp(c)
 		if err != nil {
 			return &InputError{thisCommand, err}
 		}
@@ -74,7 +74,7 @@ func ProcessInput(c Client, text string) error {
 			return &InputError{thisCommand, err}
 		}
 
-		c.Connection().Close()
+		c.Disconnect()
 	default:
 		return &InputError{thisCommand, InputInvalidCommand}
 	}