5 files changed, 207 insertions, 4 deletions
diff --git a/go-src/directMessageChat.go b/go-src/directMessageChat.go
new file mode 100644
index 0000000..de287ed
--- /dev/null
+++ b/go-src/directMessageChat.go
@@ -0,0 +1,65 @@
+package ctfc
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gitlab.com/Syndamia/ctfc/go-src/folderPaths"
+	"gitlab.com/Syndamia/ctfc/go-src/utils"
+)
+
+type DirectMessageChat struct {
+	Author1  User
+	Author2  User
+	Messages []string
+}
+
+func (dmc DirectMessageChat) genFileName() string {
+	if dmc.Author1.Username > dmc.Author2.Username {
+		return dmc.Author1.Username + " " + dmc.Author2.Username
+	}
+	return dmc.Author2.Username + " " + dmc.Author1.Username
+}
+
+func (dmc DirectMessageChat) addMessage(value string, username string) {
+	if dmc.Author1.Username != username && dmc.Author2.Username != username {
+		return
+	}
+
+	value = username + " : " + value
+	dmc.Messages = append(dmc.Messages, value)
+
+	fileName := folderPaths.FileAtDirectMessagesFolder(dmc.genFileName())
+
+	if !utils.PathExists(fileName) {
+		utils.CreateFile(fileName)
+	}
+	utils.AppendToFile(fileName, value+"\n")
+}
+
+func getDirectMessageChat(otherAuthorUsername string) (dmc DirectMessageChat) {
+	dmc = DirectMessageChat{loggedInUser, getUser(otherAuthorUsername), []string{}}
+
+	if utils.PathExists(folderPaths.FileAtDirectMessagesFolder(dmc.genFileName())) {
+		f, _ := os.ReadFile(folderPaths.FileAtDirectMessagesFolder(dmc.genFileName()))
+		values := bytes.Split(f, []byte("\n"))
+		dmc.Messages = utils.TwoDByteArrayToStringArray(values[:len(values)-1])
+	}
+
+	return
+}
+
+func getAllDirectMessageChats() (chats []string) {
+	filepath.Walk(folderPaths.FileAtDirectMessagesFolder(""), func(path string, info os.FileInfo, err error) error {
+		if strings.Contains(path, loggedInUser.Username) {
+			authors := utils.StrMSplit(path, "/", ".", " ")
+			authors = authors[len(authors)-3 : len(authors)-1]
+			otherAuthor := getUser(utils.If(authors[0] == loggedInUser.Username).String(authors[1], authors[0]))
+			chats = append(chats, otherAuthor.Name+" ("+otherAuthor.Username+")")
+		}
+		return nil
+	})
+	return
+}
diff --git a/go-src/utils/utils.go b/go-src/utils/utils.go
index d6fc47c..271dd3e 100644
--- a/go-src/utils/utils.go
+++ b/go-src/utils/utils.go
@@ -3,6 +3,7 @@ package utils
 import (
 	"math"
 	"os"
+	"strings"
 )
 
 // Repeats a rune given amount of times and returns the result as a string
@@ -53,6 +54,21 @@ func StrShortenRight(s *string, amount int) {
 	*s = (*s)[:len(*s)-amount]
 }
 
+func StrMSplit(s string, seps ...string) (sret []string) {
+	for _, sep := range seps {
+		if len(sret) == 0 {
+			sret = strings.Split(s, sep)
+		} else {
+			var tmp []string
+			for _, sepStr := range sret {
+				tmp = append(tmp, strings.Split(sepStr, sep)...)
+			}
+			sret = tmp
+		}
+	}
+	return
+}
+
 func MaxInt(x int, y int) int {
 	if x > y {
 		return x
diff --git a/go-src/windowMessages.go b/go-src/windowMessages.go
index 786a3e5..12bbace 100644
--- a/go-src/windowMessages.go
+++ b/go-src/windowMessages.go
@@ -13,9 +13,11 @@ const (
 	editNameNavTitle       = "Editing Name"
 
 	// Help messages
-	chatsWindowHelpMsg   = "Chats page options: [(D)irect messages/(A)ccount/(L)ogout/(<) for previous page/(>) for next page/(C) for create chat/(name) for go to chat room by name/(number) for go to chat room by number/(H)elp]"
-	chatWindowHelpMsg    = "Chat options : [(C)hats/(D)irect messages/(A)ccount/(L)ogout/(<) for previous page/(>) for next page/(H)elp]"
-	accountWindowHelpMsg = "Account options : [(C)hats/(D)irect Messages/(L)ogout/(number) for edit option by number/(H)elp]"
+	chatsWindowHelpMsg          = "Chats page options: [(D)irect messages/(A)ccount/(L)ogout/(<) for previous page/(>) for next page/(C) for create chat/(name) for go to chat room by name/(number) for go to chat room by number/(H)elp]"
+	chatWindowHelpMsg           = "Chat options : [(C)hats/(D)irect messages/(A)ccount/(L)ogout/(<) for previous page/(>) for next page/(H)elp]"
+	directMessagesWindowHelpMsg = "Direct Messages page options: [(C)hats/(A)ccount/(L)ogout/(<) for previous page/(>) for next page/(name) for start chatting with username/(number) for go to direct messages by number/(H)elp]"
+	directMessageWindowHelpMsg  = "Direct Message options : [(C)hats/(D)irect messages/(A)ccount/(L)ogout/(<) for previous page/(>) for next page/(H)elp]"
+	accountWindowHelpMsg        = "Account options : [(C)hats/(D)irect Messages/(L)ogout/(number) for edit option by number/(H)elp]"
 
 	// Input names
 	usernameInName        = "Username"
diff --git a/go-src/windows.go b/go-src/windows.go
index 50bc5d5..c8e7234 100644
--- a/go-src/windows.go
+++ b/go-src/windows.go
@@ -221,6 +221,126 @@ func chatWindow(values ...string) {
 	lastLine = -2 // Practically stops execution of the paginated subwindow routine
 }
 
+func directMessagesWindow(values ...string) {
+	csi.ClearScreen()
+
+	initPaginatedValues(0, &values)
+
+	ui.NormalBox(true, chatNavTitle, accountNavTitle, logoutNavTitle)
+
+	allDirectMessageChats := getAllDirectMessageChats()
+	ui.EmptyLines(pageSize + 3) // empty line + message lines + page number line + empty line
+
+	customLinesBelow := utils.If(values[1] == showHelp).Int(3, 2)
+
+	lastLine := -1
+	go routinePaginatedSubwindow(&allDirectMessageChats,
+		func(s *[]string) { *s = (getAllDirectMessageChats()) },
+		&lastLine,
+		len(values[0]),
+		customLinesBelow,
+		true,
+	)
+
+	if values[1] == showHelp {
+		ui.TextField(directMessagesWindowHelpMsg)
+	}
+
+	input := ui.InputField(chatsSpec)
+
+	nextWindow := handleInputActions(input, true,
+		inputAction{"H", directMessagesWindow, []string{values[0], showHelp}},
+	)
+
+	if nextWindow == nil {
+		// If user input is number, navigate to chat of given number, else show error
+		if chatI, err := strconv.Atoi(input); chatI >= 0 && chatI <= len(allDirectMessageChats) && err == nil {
+			defer directMessageWindow(strings.Trim(strings.Split(allDirectMessageChats[utils.MaxInt(len(allDirectMessageChats)-pageSize*len(values[0]), 0)+chatI-1], " (")[1], ")"))
+		} else if input == ">" {
+			// If possible, increment to the next page (adds a dot to the end of the string)
+			if len(values[0]) < totalPages(len(allDirectMessageChats)) {
+				values[0] += "."
+			}
+			defer directMessagesWindow(values...)
+		} else if input == "<" {
+			// If possible, decrement to the previous page (removes a dot from the string)
+			if len(values[0]) > 1 {
+				utils.StrShortenRight(&values[0], 1)
+			}
+			defer directMessagesWindow(values...)
+		} else if usernameExists(input) {
+			defer directMessageWindow(input)
+		} else {
+			defer showError(invalidCommand, chatsWindow)
+		}
+	} else {
+		defer nextWindow()
+	}
+	lastLine = -2
+
+}
+
+func directMessageWindow(values ...string) {
+	csi.ClearScreen()
+
+	// We determine page number by length of a string
+	// This method should be faster than having to cast to int all the time
+	initPaginatedValues(1, &values)
+
+	currDirectMessagesChat := getDirectMessageChat(values[0])
+
+	ui.NormalBox(true, chatNavTitle, directMessagesNavTitle, accountNavTitle, logoutNavTitle)
+	ui.TextField(currDirectMessagesChat.Author2.Name + " (" + currDirectMessagesChat.Author2.Username + ")")
+
+	ui.EmptyLines(pageSize + 3) // empty line + messages lines + page number line + empty line
+
+	customLinesBelow := utils.If(values[2] == showHelp).Int(3, 2)
+
+	lastLine := -1
+	go routinePaginatedSubwindow(&currDirectMessagesChat.Messages,
+		func(s *[]string) { *s = getDirectMessageChat(values[0]).Messages },
+		&lastLine,
+		len(values[1]),
+		customLinesBelow,
+		false,
+	)
+
+	if values[2] == showHelp {
+		ui.TextField(directMessageWindowHelpMsg)
+		values[2] = ""
+	}
+
+	input := ui.InputField(chatWindowSpec)
+
+	nextWindow := handleInputActions(input, true,
+		inputAction{"H", directMessageWindow, []string{values[0], values[1], showHelp}},
+	)
+
+	if nextWindow == nil {
+		switch input {
+		case ">":
+			// If possible, increment to the next page (adds a dot to the end of the string)
+			if len(values[1]) < totalPages(len(currDirectMessagesChat.Messages)) {
+				values[1] += "."
+			}
+		case "<":
+			// If possible, decrement to the previous page (removes a dot from the string)
+			if len(values[1]) > 1 {
+				utils.StrShortenRight(&values[1], 1)
+			}
+		default: // Send a message
+			values[1] = "." // Make sure to be at the first page, when sending a message
+			// Since "C" is a command, to just enter the letter C you'll need to input "\C"
+			currDirectMessagesChat.addMessage(strings.TrimPrefix(input, "\\"), loggedInUser.Username)
+		}
+
+		defer directMessageWindow(values...)
+	} else {
+		defer nextWindow()
+	}
+	lastLine = -2 // Practically stops execution of the paginated subwindow routine
+}
+
 func accountWindow(values ...string) {
 	csi.ClearScreen()
 
diff --git a/go-src/windowsHelpers.go b/go-src/windowsHelpers.go
index f3b7ff0..9b1d2d9 100644
--- a/go-src/windowsHelpers.go
+++ b/go-src/windowsHelpers.go
@@ -76,7 +76,7 @@ func handleInputActions(input string, handleNav bool, ia ...inputAction) func()
 	if handleNav {
 		ia = append(ia,
 			inputAction{"C", chatsWindow, nil},
-			inputAction{"D", chatsWindow, nil},
+			inputAction{"D", directMessagesWindow, nil},
 			inputAction{"A", accountWindow, nil},
 			inputAction{"L", logoutWindow, nil},
 		)