chookchat/server/src/main/kotlin/Main.kt

package xyz.maxwellj.chookpen

import com.sun.net.httpserver.HttpExchange
import com.sun.net.httpserver.HttpHandler
import com.sun.net.httpserver.HttpServer
import java.net.InetSocketAddress

import java.io.File
import java.io.BufferedReader

fun main(args: Array<String>) {
    // Crete a server and start listening for arguments
    val server = HttpServer.create(InetSocketAddress(8000), 0)
    server.createContext("/test", ServerTester())
    server.createContext("/api", ApiHandler())
    server.createContext("/api/createAccount", CreateAccount())
    server.executor = null
    server.start()
    println("Server has started on port 8000")
}

class ServerTester : HttpHandler {
    override fun handle(t: HttpExchange) {
        val response = "Testing, testing, 1, 2, 3... Somehow this is going to make it to production one day"
        t.sendResponseHeaders(200, response.length.toLong())
        val os = t.responseBody
        os.write(response.toByteArray())
	println("Test request recieved!")
        os.close()
    }
}

class ApiHandler : HttpHandler {
    override fun handle(t: HttpExchange) {
        println("Request recieved...")
        // Get the data
        val path = t.requestURI.path
        val inputData = path.substringAfter("/api/")
        println("API request recieved: $inputData")
       
        // Parse data sent to the server by client
        var username = ""
        var token = ""
        var message = ""
        var dataType = ""
        var isParsingData = 0
        for (char in inputData) {
            val character = char
            if (character == ':') {
                isParsingData = 1
            } else if (isParsingData == 1) {
                if (character == '}') {
                    isParsingData = 0
                    dataType = ""
                } else if (character != '{') {
                    if (dataType == "username") {
                        username += character
                    } else if (dataType == "token") {
                        token += character
                    } else if (dataType == "message") {
                        message += character
                    }
                }
            } else {
                dataType += character
            }
        }
        val userDatabaseParser = BufferedReader(File("userDatabase").reader())
        var lineNumber = 1
        var userLine = ""
    
        // Search the user database to find required information about the user
        userDatabaseParser.forEachLine { line ->
            if (line.contains(username)) {
                userLine = line
            }
            lineNumber++
        }
        userDatabaseParser.close()

        if (userLine == "") {
            val response = "That account does not exist on this server."
            t.sendResponseHeaders(403, response.length.toLong())
            val os = t.responseBody
            os.write(response.toByteArray())
            os.close()
            return
        }
 
        var usernameInDatabase = ""
        var tokenInDatabase = ""
        var currentStage = 0
        for (char in userLine) {
            if (char == ':') {
                currentStage ++
            }
            if (currentStage == 0) {
                usernameInDatabase += char
            } else if (currentStage == 1) {
                tokenInDatabase += char
            }
        }
        tokenInDatabase = tokenInDatabase.replace(":", "")
        if (token != tokenInDatabase)  {
            val response = "Invalid token! Please try putting in your password right"
            t.sendResponseHeaders(403, response.length.toLong())
            val os = t.responseBody
            os.write(response.toByteArray())
            os.close()
            return
        }
        // Make the message to respond to the client
        val chatHistoryView = File("chatHistory")
        var fullMessage = ""
        if (message != "") {
            fullMessage = "${chatHistoryView.readText()}$username: $message"
            // Add the client's message to the chat history
            val chatHistory = File("chatHistory")
            chatHistory.appendText("$username: $message ${System.lineSeparator()}")
            message = ""
        } else {
            fullMessage = "${chatHistoryView.readText()}"
        }
        val response = if (inputData.isNotEmpty()) {
            fullMessage            
        } else {
            "No data provided"
        }

        // Send the message to the client
        t.sendResponseHeaders(200, response.length.toLong())
        val os = t.responseBody
        os.write(response.toByteArray())
        println("API request handled: $inputData")
        os.close()

    }
}
class CreateAccount : HttpHandler {
    override fun handle(t: HttpExchange) {
        val path = t.requestURI.path
        val inputData = path.substringAfter("/api/createAccount/")
        println("Account creation request recieved: $inputData")
       
        // Parse data sent to the server by client
        var username = ""
        var token = ""
        var message = ""
        var dataType = ""
        var isParsingData = 0
        for (char in inputData) {
            val character = char
            if (character == ':') {
                isParsingData = 1
            } else if (isParsingData == 1) {
                if (character == '}') {
                    isParsingData = 0
                    dataType = ""
                } else if (character != '{') {
                    if (dataType == "username") {
                        username += character
                    } else if (dataType == "token") {
                        token += character
                    } else if (dataType == "message") {
                        message += character
                    }
                }
            } else {
                dataType += character
            }
        }
        val userDatabaseParser = BufferedReader(File("userDatabase").reader())
        var lineNumber = 1
        var userExists = 0
    
        // Search the user database to find required information about the user
        userDatabaseParser.forEachLine { line ->
            if (line.contains(username)) {
                val response = "That username already exists on the server! Please choose a different username"
                t.sendResponseHeaders(422, response.length.toLong())
                val os = t.responseBody
                os.write(response.toByteArray())
                os.close()
                userExists = 1
            }
            lineNumber++
        }
        userDatabaseParser.close()
        if (userExists == 1) {return}
        println("$username:$token")

        if (username == "") {
            val response = "Please input a username"
            t.sendResponseHeaders(422, response.length.toLong())
            val os = t.responseBody
            os.write(response.toByteArray())
            os.close()
            return
        }

        if (token == "") {
            val response = "Please input a password"
            t.sendResponseHeaders(422, response.length.toLong())
            val os = t.responseBody
            os.write(response.toByteArray())
            os.close()
            return
        }

        val userDatabaseFile = File("userDatabase")
        userDatabaseFile.appendText("${System.lineSeparator()}$username:$token")
        val response = "Creating account was successful!"
        t.sendResponseHeaders(200, response.length.toLong())
        val os = t.responseBody
        os.write(response.toByteArray())
	    println("")
        os.close()
    }
}