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+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
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+
+                            Preamble
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+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

Makefile

@@ -0,0 +1,17 @@
+BIN_DIR:=bin
+SRC_DIR:=src
+EXE_NAME:=gochat
+PAGES_DIR:=pages
+STATIC_DIR:=static
+SCRIPTS_DIR:=scripts
+
+
+all: clean
+	mkdir $(BIN_DIR)
+	cd $(SRC_DIR) && go build && mv $(EXE_NAME) ../$(BIN_DIR)
+	cp -r $(PAGES_DIR) $(BIN_DIR)
+	cp -r $(STATIC_DIR) $(BIN_DIR)
+	cp -r $(SCRIPTS_DIR) $(BIN_DIR)
+
+clean:
+	rm -rf $(BIN_DIR)

README.md

@@ -0,0 +1,21 @@
+## gochat
+### A dead simple real time webchat with authorization using websockets
+
+### Building
+`make` or `cd src/ && go build && mv gochat ..`
+
+### Project structure
+As you are probably here for reconnaissance reasons for your own project here's a
+quick overview of the structure:
+
+- `pages` -> html pages
+- `scripts` -> js files where chat.js is the "heavy-lifter" which actually implements the websocket chat logic 
+- `static` -> icon, stylesheet for pages
+- `src/api` -> the fundament of backend logic, authorization, database and websocket handling,all necessary structs, constants
+- `src/log` -> a custom logger
+- `src/page` -> a shorcut function for handling html templates
+- `src/server` -> the main server struct that glues everything together. For a high-level inspection - refer there
+- `src/main.go` -> parse command line flags, set up logging and leave the rest for the server
+
+### License
+GPLv3

pages/base.html

@@ -0,0 +1,50 @@
+{{ define "base" }}
+
+<!-- gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>. -->
+
+<!DOCTYPE html>
+<html lang="en" dir="ltr">
+<head>
+    <meta charset="utf-8">
+    <title>gochat</title>
+    <link rel="shortcut icon" href="/static/images/favicon.png">
+    <link rel="stylesheet" href="/static/style.css">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <script src="/scripts/constants.js"></script>
+</head>
+
+<body>
+
+<div id="wrapper">
+    <nav>
+        <a href="/">main</a>
+        |
+        <a href="/register">register</a>
+        |
+        <a href="/login">log in</a>
+    </nav>
+    
+    <div id="content">
+        {{ template "content" .}}
+    </div>
+    
+    <footer id="error_output"></footer>
+</div>
+
+</body>
+   
+</html>
+
+{{ end }}

pages/index.html

@@ -0,0 +1,21 @@
+{{ template "base" . }}
+
+{{ define "content" }}
+
+<p>
+    logged in as <b id="logged_username" onload=""></b>
+</p>
+
+<pre id="chatbox"></pre>
+
+<div>
+    <input type="text" id="text_input">
+    <input type="button" value="Send" id="send_button">
+    <input type="button" value="Disconnect" id="disconnect_button">
+</div>
+
+
+<script src="/scripts/user.js"></script>
+<script src="/scripts/chat.js"></script>
+
+{{ end }}

pages/login.html

@@ -0,0 +1,26 @@
+{{ template "base" . }}
+
+{{ define "content" }}
+
+<h3>Log in</h3>
+
+<form name="auth_form" onsubmit="return false;">
+    <p>
+        <label for="username">Username</label> <br>
+        <input type="text" name="username">
+    </p>
+
+    <p>
+        <label for="password">Password</label> <br>
+        <input type="password" name="password">
+    </p>
+
+    <p>
+        <input type="submit" value="Log in" onmouseup="login()">
+    </p>
+</form>
+
+<script src="/scripts/sha256.js"></script>
+<script src="/scripts/user.js"></script>
+
+{{ end }}

pages/register.html

@@ -0,0 +1,26 @@
+{{ template "base" . }}
+
+{{ define "content" }}
+
+<h3>Register</h3>
+
+<form name="auth_form" onsubmit="return false;">
+    <p>
+        <label for="username">Username</label> <br>
+        <input type="text" name="username" required minlength="3">
+    </p>
+
+    <p>
+        <label for="password">Password</label> <br>
+        <input type="password" name="password" required minlength="3">
+    </p>
+
+    <p>
+        <input type="submit" value="Register" onmouseup="register()">
+    </p>
+</form>
+
+<script src="/scripts/sha256.js"></script>
+<script src="/scripts/user.js"></script>
+
+{{ end }}

scripts/chat.js

@@ -0,0 +1,96 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+let username = localStorage.getItem(LOCALSTORAGE_NAME_KEY);
+let secret_hash = localStorage.getItem(LOCALSTORAGE_PASSWORD_HASH_KEY);
+
+// check whether credentials are right or not
+areCredentialsValid({username:username, secret_hash:secret_hash})
+.then(valid => {
+    if (valid === true) {
+        // they are valid, connect as a websocket
+        document.getElementById("logged_username").innerHTML = username;
+        let socket = new WebSocket(`ws://${BACKEND_URL}/${API_WEBSOCKET_ENDPOINT}`);
+    
+        // send auth data right away, as API tells us to do
+        socket.onopen = event => {
+            console.log("Connected to the server");
+            let auth_data = JSON.stringify({
+                username: username,
+                secret_hash: secret_hash,
+            });
+            socket.send(auth_data);
+        }
+    
+        socket.onclose = event => {
+            console.log("Closed connection: ", event);
+            socket.close();
+
+            let chatbox = document.getElementById("chatbox");
+            chatbox.innerHTML += "Connection closed";
+            chatbox.scrollTop = chatbox.scrollHeight;
+        };
+    
+        // display it
+        socket.onmessage = event => {
+            let message = JSON.parse(event.data); 
+            let from_user = message.from.username;
+
+            let constructed_message_to_display = `${from_user}: ${message.contents}` + "\n";
+
+            let chatbox = document.getElementById("chatbox");
+            chatbox.innerHTML += constructed_message_to_display;
+            chatbox.scrollTop = chatbox.scrollHeight;
+        }
+
+        // make buttons do intended
+        let send_button = document.getElementById("send_button");
+        send_button.addEventListener("click", (event) => {
+            let text_input = document.getElementById("text_input");
+
+            socket.send(
+                JSON.stringify({
+                    contents: String(text_input.value),
+                }));
+
+            text_input.value = "";
+            text_input.focus();
+        });
+
+        let disconnect_button = document.getElementById("disconnect_button");
+        disconnect_button.addEventListener("click", (event) => {
+            socket.close();
+            disconnect_button.value = "Reconnect";
+            disconnect_button.addEventListener("click", (event) => {
+               location.reload();
+            })
+        })
+
+        // make message to be sent via pressing 'Enter' key
+        document.addEventListener("keypress", (event) => {
+            if (event.key == "Enter") {
+                send_button.click();               
+            }
+        })
+
+        // and focus the text input so the user does not have to click it manually
+        document.getElementById("text_input").focus();
+
+    } else {
+        // credentials are not valid ! To the registration page you go
+        window.location.replace("/register");
+    }
+})

scripts/constants.js

@@ -0,0 +1,27 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+const API_BASE_ENDPOINT = "api";
+const API_USER_ENDPOINT = "api/user"
+const API_WEBSOCKET_ENDPOINT = "api/ws";
+
+const AUTH_HEADER_KEY = "AUTH_INFO";
+const AUTH_SEPARATOR = ":"
+
+const LOCALSTORAGE_NAME_KEY = "username";
+const LOCALSTORAGE_PASSWORD_HASH_KEY = "secret_hash";
+
+const BACKEND_URL = window.location.host;

scripts/sha256.js

@@ -0,0 +1,26 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+function sha256(string) {
+    const encoded_string = new TextEncoder().encode(string);
+    return crypto.subtle.digest('SHA-256', encoded_string).then((hash_sum) => {
+      const hashArray = Array.from(new Uint8Array(hash_sum));
+      const hashHex = hashArray
+        .map((bytes) => bytes.toString(16).padStart(2, '0'))
+        .join('');
+      return hashHex;
+    });
+  }

scripts/to_hex_string.js

@@ -0,0 +1,22 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+
+function to_hex_string(byteArr) {
+    return Array.from(byteArr, function(byte) {
+        return ('0' + (byte & 0xFF).toString(16).slice(-2));
+    }).join('')
+}

scripts/user.js

@@ -0,0 +1,112 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+
+async function register() {
+    let auth_form = document.forms["auth_form"];
+
+    let username = String(auth_form.elements["username"].value).trim();
+    if (username.length < 3) {
+        document.getElementById("error_output").innerHTML = "Username must be >= 3 characters long";
+        return;
+    }
+
+    let password = String(auth_form.elements["password"].value).trim();
+    if (password.length < 3) {
+        document.getElementById("error_output").innerHTML = "Password must be >= 3 characters long";
+        return;
+    }
+
+    sha256(password).then((password_sha256) => {
+        let post_data = {
+            username: username,
+            secret_hash: password_sha256,
+        };
+    
+        fetch(API_USER_ENDPOINT, {
+            method: "POST",
+            headers: {"Content-Type": "application/json"},
+            body: JSON.stringify(post_data),
+        })
+        .then(response => {
+            if (response.status == 200) {
+                localStorage.setItem(LOCALSTORAGE_NAME_KEY, username);
+                localStorage.setItem(LOCALSTORAGE_PASSWORD_HASH_KEY, password_sha256); 
+                window.location.replace("/")
+            }
+        })
+        .catch((error) => {
+            document.getElementById("error_output").innerHTML = error;
+        });
+    });
+};
+
+async function areCredentialsValid(user_credentials) {    
+    let valid = false;
+
+    await fetch(API_USER_ENDPOINT, {
+        method: "GET",
+        headers: {"AUTH_INFO": user_credentials.username+":"+user_credentials.secret_hash},
+    })
+    .then(response => {
+        return response.text();
+    })
+    .then(response_data => {
+        let response = JSON.parse(response_data)
+        console.log(response);
+        if (response.valid === true) {
+            valid = true;
+        } else {
+            valid = false;
+        }
+    });
+
+    return valid;
+}
+
+async function login() {
+    let auth_form = document.forms["auth_form"];
+
+    let username = String(auth_form.elements["username"].value).trim();
+    if (username.length < 3) {
+        document.getElementById("error_output").innerHTML = "Username must be >= 3 characters long";
+        return;
+    }
+
+    let password = String(auth_form.elements["password"].value).trim();
+    if (password.length < 3) {
+        document.getElementById("error_output").innerHTML = "Password must be >= 3 characters long";
+        return;
+    }
+
+    await sha256(password).then((password_sha256) => {
+        let user_credentials = {
+            "username": username,
+            "secret_hash": password_sha256,
+        };
+
+        areCredentialsValid(user_credentials)
+        .then(valid => {
+            if (valid === true) {
+                localStorage.setItem(LOCALSTORAGE_NAME_KEY, username);
+                localStorage.setItem(LOCALSTORAGE_PASSWORD_HASH_KEY, password_sha256); 
+                window.location.replace("/");
+            } else {
+                document.getElementById("error_output").innerHTML = "Invalid credentials";
+            }
+        })
+    });
+}

src/api/auth.go

@@ -0,0 +1,81 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package api
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+)
+
+const (
+	AuthHeaderKey string = "AUTH_INFO"
+	AuthSeparator string = ":"
+)
+
+var ErrNotAuthorized error = fmt.Errorf("not authorized")
+
+// Extract information about the sender from request headers.
+// If no data is given or just wrong - returns a default user struct
+func GetUserAuthHeaderData(req *http.Request) User {
+	authData := req.Header.Get(AuthHeaderKey)
+	dividedAuthData := strings.Split(authData, AuthSeparator)
+	if len(dividedAuthData) != 2 {
+		return User{}
+	}
+	username, passHash := dividedAuthData[0], dividedAuthData[1]
+
+	return User{
+		Name:       username,
+		SecretHash: passHash,
+	}
+}
+
+// Checks whether provided request indeed contains SOME authentication information.
+// Does not check it for being legitimate or not
+func WithAuth(req *http.Request) bool {
+	authenticationData := req.Header.Get(AuthHeaderKey)
+	if authenticationData == "" || len(authenticationData) < 3 {
+		return false
+	}
+
+	return true
+}
+
+// Checks whether request contains valid and real user authorization data that is in the database
+func (db *DB) IsValidAuth(req *http.Request) bool {
+	if !WithAuth(req) {
+		return false
+	}
+
+	headerUser := GetUserAuthHeaderData(req)
+
+	if !db.DoesUserExist(headerUser.Name) {
+		return false
+	}
+
+	userDB, err := db.GetUser(headerUser.Name)
+	if err != nil {
+		return false
+	}
+
+	if userDB.SecretHash != headerUser.SecretHash {
+		return false
+	}
+
+	return true
+}

src/api/db.go

@@ -0,0 +1,114 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package api
+
+import (
+	"database/sql"
+	"fmt"
+	"os"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+const (
+	UsersTablename string = "users"
+	// MessagesTablename string = "messages"
+)
+
+// SQL database wrapper
+type DB struct {
+	*sql.DB
+}
+
+// Closes database connection
+func (db *DB) ShutDown() {
+	db.Close()
+}
+
+func (db *DB) createUsersTable() error {
+	command := fmt.Sprintf(
+		`CREATE TABLE IF NOT EXISTS %s 
+		(username TEXT NOT NULL PRIMARY KEY, secret_hash TEXT NOT NULL)`, UsersTablename)
+	_, err := db.Exec(command)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// func (db *DB) createMessagesTable() error {
+// 	command := fmt.Sprintf(
+// 		`CREATE TABLE IF NOT EXISTS %s
+// 		(id INTEGER NOT NULL PRIMARY KEY, content TEXT NOT NULL,
+// 		from_name TEXT NOT NULL, FOREIGN KEY(from_name) REFERENCES %s(username))`,
+// 		MessagesTablename, UsersTablename,
+// 	)
+
+// 	_, err := db.Exec(command)
+// 	if err != nil {
+// 		return err
+// 	}
+
+// 	return nil
+// }
+
+func (db *DB) setUpTables() error {
+	err := db.createUsersTable()
+	if err != nil {
+		return fmt.Errorf("error creating users table: %s", err)
+	}
+
+	return nil
+}
+
+// Creates a database if does not exist
+func CreateDB(path string) error {
+	dbFile, err := os.OpenFile(path, os.O_CREATE|os.O_RDWR, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	dbFile.Close()
+
+	sqlDB, err := sql.Open("sqlite3", path)
+	if err != nil {
+		return err
+	}
+	db := DB{
+		sqlDB,
+	}
+
+	err = db.setUpTables()
+	if err != nil {
+		return fmt.Errorf("could not set up tables: %s", err)
+	}
+
+	return nil
+}
+
+// Opens a DB
+func OpenDB(path string) (*DB, error) {
+	sqlDB, err := sql.Open("sqlite3", path)
+	if err != nil {
+		return nil, err
+	}
+	db := DB{
+		sqlDB,
+	}
+
+	return &db, nil
+}

src/api/message.go

@@ -0,0 +1,58 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package api
+
+// A message struct that is converted back and forth to JSON in order to communicate with frontend
+type Message struct {
+	TimeStamp uint64 `json:"timestamp"`
+	From      User   `json:"from"`
+	Contents  string `json:"contents"`
+}
+
+/* PROBABLY come back later and implement a message-remembering feature */
+
+// func (db *DB) AddMessage(message Message) error {
+// 	command := fmt.Sprintf("INSERT INTO %s(from, contents) VALUES(%s, %s)", MessagesTablename, message.From.Name, message.Contents)
+// 	_, err := db.Exec(command)
+// 	if err != nil {
+// 		return err
+// 	}
+
+// 	return nil
+// }
+
+// func (db *DB) GetAllMessages() (*[]Message, error) {
+// 	command := fmt.Sprintf("SELECT * FROM %s", MessagesTablename)
+// 	rows, err := db.Query(command)
+// 	if err != nil {
+// 		return nil, err
+// 	}
+
+// 	var messages []Message
+
+// 	/*
+// 		(id INTEGER NOT NULL PRIMARY KEY, content TEXT NOT NULL,
+// 		 to_name TEXT NOT NULL, from_name TEXT NOT NULL, FOREIGN KEY(from_name, to_name) REFERENCES %s(username, username))`,
+// 	*/
+// 	for rows.Next() {
+// 		var message Message
+// 		rows.Scan(&message.ID, &message.Contents, message.From.Name)
+// 		messages = append(messages, message)
+// 	}
+
+// 	return &messages, nil
+// }

src/api/routes.go

@@ -0,0 +1,24 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package api
+
+const (
+	RouteBase       string = "/api"
+	RouteUsers      string = RouteBase + "/user"
+	RouteWebsockets string = RouteBase + "/ws"
+	RouteRooms      string = RouteBase + "/room"
+)

src/api/user.go

@@ -0,0 +1,102 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package api
+
+import (
+	"fmt"
+
+	"unbewohnte.xyz/gochat/log"
+)
+
+const HashLength uint = 64
+
+type User struct {
+	Name       string `json:"username"`
+	SecretHash string `json:"secret_hash"`
+	Created    uint64
+}
+
+// Used to declare connection/disconnection messages in chat
+var UserSystem User = User{
+	Name:       "System",
+	SecretHash: "_",
+	Created:    0,
+}
+
+// Get existing user from database by unique name
+func (db *DB) GetUser(name string) (User, error) {
+	command := fmt.Sprintf("SELECT * FROM %s WHERE username=\"%s\"", UsersTablename, name)
+	result := db.QueryRow(command)
+	err := result.Err()
+	if err != nil {
+		return User{}, err
+	}
+
+	user := User{}
+	err = result.Scan(&user.Name, &user.SecretHash)
+	if err != nil {
+		return User{}, err
+	}
+
+	return user, nil
+}
+
+// Create a new user with a unique name
+func (db *DB) CreateUser(user *User) error {
+	command := fmt.Sprintf("INSERT INTO %s (username, secret_hash) VALUES (?, ?)", UsersTablename)
+	_, err := db.Exec(command, user.Name, user.SecretHash)
+	if err != nil {
+		return err
+	}
+
+	log.Info("created user \"%s\"", user.Name)
+
+	return nil
+}
+
+// Tells if the user already exists in the db
+func (db *DB) DoesUserExist(name string) bool {
+	_, err := db.GetUser(name)
+	if err != nil {
+		return false
+	}
+
+	return true
+}
+
+// func (db *DB) GetAllUsers() (*[]User, error) {
+// 	command := fmt.Sprintf("SELECT * FROM %s", UsersTablename)
+// 	rows, err := db.Query(command)
+// 	if err != nil {
+// 		return nil, err
+// 	}
+
+// 	var users []User
+
+// 	for rows.Next() {
+// 		var user User
+// 		rows.Scan(&user.Name, &user.SecretHash)
+// 		users = append(users, user)
+// 	}
+
+// 	return &users, nil
+// }
+
+// Used to send validation check results for user credentials to frontend
+type UserCredentialsValidation struct {
+	Valid bool `json:"valid"`
+}

src/api/websocket.go

@@ -0,0 +1,107 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package api
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/gorilla/websocket"
+	"unbewohnte.xyz/gochat/log"
+)
+
+// Websocket connection paired with the owner
+type WS struct {
+	Socket *websocket.Conn
+	User   User
+}
+
+// All existing websockets wrapper
+type WSHolder struct {
+	Sockets []*WS
+}
+
+// Untrack user's websocket from broadcast
+func (holder *WSHolder) Remove(username string) {
+	var indexToRemove int
+	for index, socket := range holder.Sockets {
+		if socket.User.Name == username {
+			indexToRemove = index
+			break
+		}
+	}
+
+	if len(holder.Sockets) >= 2 {
+		holder.Sockets = append(holder.Sockets[:indexToRemove], holder.Sockets[indexToRemove+1:]...)
+	} else {
+		holder.Sockets = append(holder.Sockets[:indexToRemove])
+	}
+}
+
+// Tell the websocket that it is no longer connected
+func Disconnect(ws *websocket.Conn) {
+	ws.WriteControl(websocket.CloseMessage, nil, time.Now().Add(time.Second*1))
+	ws.Close()
+}
+
+// Handle all incoming messages from this websocket, redirecting messages to specified output
+func (holder *WSHolder) HandleNewWebSocketMessages(ws *WS, output chan Message) {
+	for {
+		msgType, contents, err := ws.Socket.ReadMessage()
+		if err != nil {
+			log.Error("could not read message from websocket: %s", err)
+			Disconnect(ws.Socket)
+			holder.Remove(ws.User.Name)
+
+			disconnectionMessage := Message{
+				From:     UserSystem,
+				Contents: fmt.Sprintf("%s has disconnected", ws.User.Name),
+			}
+			output <- disconnectionMessage
+			break
+		}
+
+		switch msgType {
+		case websocket.CloseMessage:
+			ws.Socket.Close()
+			holder.Remove(ws.User.Name)
+
+			disconnectionMessage := Message{
+				From:     UserSystem,
+				Contents: fmt.Sprintf("%s has disconnected", ws.User.Name),
+			}
+			output <- disconnectionMessage
+
+		case websocket.TextMessage:
+			var newMessage Message
+			err = json.Unmarshal(contents, &newMessage)
+			if err != nil {
+				log.Error("error unmarshaling text message from \"%s\"'s websocket: %s", ws.User.Name, err)
+				break
+			}
+
+			if len(newMessage.Contents) < 1 {
+				break
+			}
+
+			newMessage.From = ws.User
+			output <- newMessage
+		}
+
+	}
+}

src/go.mod

@@ -0,0 +1,8 @@
+module unbewohnte.xyz/gochat
+
+go 1.17
+
+require (
+	github.com/gorilla/websocket v1.5.0 // indirect
+	github.com/mattn/go-sqlite3 v1.14.12 // indirect
+)

src/go.sum

@@ -0,0 +1,4 @@
+github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc=
+github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/mattn/go-sqlite3 v1.14.12 h1:TJ1bhYJPV44phC+IMu1u2K/i5RriLTPe+yc68XDJ1Z0=
+github.com/mattn/go-sqlite3 v1.14.12/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=

src/log/log.go

@@ -0,0 +1,55 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package log
+
+import (
+	"io"
+	"log"
+	"os"
+)
+
+// 3 basic loggers in global space
+var (
+	infoLog    *log.Logger
+	warningLog *log.Logger
+	errorLog   *log.Logger
+)
+
+func init() {
+	infoLog = log.New(os.Stdout, "[INFO] ", log.Ldate|log.Ltime)
+	warningLog = log.New(os.Stdout, "[WARNING] ", log.Ldate|log.Ltime)
+	errorLog = log.New(os.Stdout, "[ERROR] ", log.Ldate|log.Ltime|log.Lshortfile)
+}
+
+// Set up loggers to write to the given writer
+func SetOutput(writer io.Writer) {
+	infoLog.SetOutput(writer)
+	warningLog.SetOutput(writer)
+	errorLog.SetOutput(writer)
+}
+
+func Info(format string, a ...interface{}) {
+	infoLog.Printf(format, a...)
+}
+
+func Warning(format string, a ...interface{}) {
+	warningLog.Printf(format, a...)
+}
+
+func Error(format string, a ...interface{}) {
+	errorLog.Printf(format, a...)
+}

src/main.go

@@ -0,0 +1,74 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"unbewohnte.xyz/gochat/log"
+	"unbewohnte.xyz/gochat/server"
+)
+
+const version string = "0.1.0"
+
+func main() {
+	// set up logging
+	exePath, err := os.Executable()
+	if err != nil {
+		log.Error("could not lookup executable's path: %s", err)
+	}
+
+	exeDirPath := filepath.Dir(exePath)
+	logsDirPath := filepath.Join(exeDirPath, "logs")
+
+	err = os.MkdirAll(logsDirPath, os.ModePerm)
+	if err != nil {
+		log.Error("could not create logs directory: %s", err)
+	}
+
+	logsFile, err := os.Create(filepath.Join(logsDirPath, "latest.log"))
+	if err != nil {
+		log.Error("could not create logs file: %s", err)
+	}
+
+	if err == nil {
+		log.SetOutput(io.MultiWriter(os.Stdout, logsFile))
+	} else {
+		log.SetOutput(os.Stdout)
+	}
+
+	// work out launch flags
+	var port uint
+	flag.UintVar(&port, "port", 8080, "Set working port")
+	flag.Usage = func() {
+		fmt.Printf("gochat v%s\n\nFlags\nport [uint] -> specify a port number (default: 8080)\n\n(c) Unbewohnte (Kasyanov Nikolay Alexeyevich)\n", version)
+	}
+	flag.Parse()
+
+	const dbFilename string = "gochat.db"
+	dbPath := filepath.Join(exeDirPath, dbFilename)
+
+	server, err := server.New(exeDirPath, dbPath, port)
+	if err != nil {
+		log.Error("could not create a new server instance: %s", err)
+	}
+	server.Start()
+}

src/page/page.go

@@ -0,0 +1,32 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package page
+
+import (
+	"html/template"
+	"path/filepath"
+)
+
+// Parse files in pagesDir and return a ready-to-render template
+func Get(pagesDir string, base string, pagename string) (*template.Template, error) {
+	page, err := template.ParseFiles(filepath.Join(pagesDir, base), filepath.Join(pagesDir, pagename))
+	if err != nil {
+		return nil, err
+	}
+
+	return page, nil
+}

src/server/server.go

@@ -0,0 +1,126 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package server
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"unbewohnte.xyz/gochat/api"
+	"unbewohnte.xyz/gochat/log"
+	"unbewohnte.xyz/gochat/page"
+)
+
+// Server structure that glues api logic and http/websocket server together
+type Server struct {
+	workingDir       string
+	http             *http.Server
+	db               *api.DB
+	websockets       *api.WSHolder
+	incomingMessages chan api.Message
+}
+
+// Create a new configured and ready-to-launch server
+func New(workingDir string, dbPath string, port uint) (*Server, error) {
+	var server = Server{
+		workingDir:       workingDir,
+		websockets:       &api.WSHolder{},
+		incomingMessages: make(chan api.Message),
+	}
+
+	err := api.CreateDB(dbPath)
+	if err != nil {
+		log.Error("could not create database: %s", err)
+		os.Exit(1)
+	}
+
+	db, err := api.OpenDB(dbPath)
+	if err != nil {
+		log.Error("could not open database: %s", err)
+		os.Exit(1)
+	}
+	server.db = db
+
+	// set up routes and handlers
+	const (
+		pagesDirName   string = "pages"
+		staticDirName  string = "static"
+		scriptsDirName string = "scripts"
+	)
+
+	pagesDirPath := filepath.Join(workingDir, pagesDirName)
+
+	serveMux := http.NewServeMux()
+
+	serveMux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir(filepath.Join(workingDir, staticDirName)))))
+	serveMux.Handle("/scripts/", http.StripPrefix("/scripts/", http.FileServer(http.Dir(filepath.Join(workingDir, scriptsDirName)))))
+
+	serveMux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+		switch req.URL.Path {
+		case "/":
+			requestedPage, err := page.Get(pagesDirPath, "base.html", "index.html")
+			if err != nil {
+				log.Error("error getting page on route %s: %s", req.URL.Path, err)
+				http.Error(w, "internal server error", http.StatusInternalServerError)
+			}
+			requestedPage.ExecuteTemplate(w, "index.html", nil)
+
+		default:
+			if strings.HasPrefix(req.URL.Path, api.RouteBase) {
+				return
+			}
+
+			requestedPage, err := page.Get(pagesDirPath, "base.html", req.URL.Path[1:]+".html")
+			if err != nil {
+				log.Error("error getting page on route %s: %s", req.URL.Path, err)
+				http.Error(w, "internal server error", http.StatusInternalServerError)
+			}
+			requestedPage.ExecuteTemplate(w, req.URL.Path[1:]+".html", nil)
+		}
+	})
+
+	// user api endpoint
+	serveMux.HandleFunc(api.RouteUsers, server.HandlerUsers)
+	// ws api endpoint
+	serveMux.HandleFunc(api.RouteWebsockets, server.HandlerWebsockets)
+
+	httpServer := http.Server{
+		Addr:         fmt.Sprintf(":%d", port),
+		Handler:      serveMux,
+		ReadTimeout:  time.Second * 5,
+		WriteTimeout: time.Second * 5,
+	}
+	server.http = &httpServer
+
+	return &server, nil
+}
+
+// Fire up the server
+func (s *Server) Start() {
+	defer s.db.ShutDown()
+	go s.BroadcastMessages()
+
+	// fire up a server
+	err := s.http.ListenAndServe()
+	if err != nil {
+		log.Error("FATAL server error: %s", err)
+	}
+}

src/server/userHandler.go

@@ -0,0 +1,128 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package server
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"unbewohnte.xyz/gochat/api"
+	"unbewohnte.xyz/gochat/log"
+)
+
+// User creation/credentials validation http handler
+func (s *Server) HandlerUsers(w http.ResponseWriter, req *http.Request) {
+	switch req.Method {
+	case http.MethodPost:
+		// unmarshal incoming json
+		requestBody, err := io.ReadAll(req.Body)
+		if err != nil {
+			http.Error(w, "", http.StatusInternalServerError)
+			return
+		}
+
+		var newUser api.User
+		err = json.Unmarshal(requestBody, &newUser)
+		if err != nil {
+			log.Error("could not unmarshal new user json: %s", err)
+			http.Error(w, "invalid user json", http.StatusBadRequest)
+			return
+		}
+
+		// check if this all is genuine
+		if len(newUser.Name) <= 1 || uint(len(newUser.SecretHash)) != api.HashLength {
+			log.Error("could not create a new user: incoming name or secret hash is invalid")
+			http.Error(w, "invalid user json", http.StatusBadRequest)
+			return
+		}
+
+		if s.db.DoesUserExist(newUser.Name) {
+			// already have !
+			http.Error(w, "already exists", http.StatusBadRequest)
+			return
+		}
+
+		// add user to db
+		err = s.db.CreateUser(&newUser)
+		if err != nil {
+			http.Error(w, "", http.StatusInternalServerError)
+			log.Error("could not create a new user \"%s\": %s", newUser.Name, err)
+			return
+		}
+
+		log.Info("successfully created a new user: \"%s\"", newUser.Name)
+
+		w.WriteHeader(http.StatusOK)
+
+	case http.MethodGet:
+		// TODO(redo to make it return true or false whether user credentials are okay or not)
+		headerUserData := api.GetUserAuthHeaderData(req)
+
+		if s.db.DoesUserExist(headerUserData.Name) {
+			response := api.UserCredentialsValidation{}
+
+			userDB, _ := s.db.GetUser(headerUserData.Name)
+
+			if userDB.SecretHash != headerUserData.SecretHash {
+				// passwords do not match
+				response.Valid = false
+			} else {
+				response.Valid = true
+			}
+
+			responseBytes, err := json.Marshal(&response)
+			if err != nil {
+				log.Error("could not marshal user credentials validation response: %s", err)
+				http.Error(w, "", http.StatusInternalServerError)
+				return
+			}
+
+			w.Write(responseBytes)
+
+		} else {
+			// does not even exist
+			responseBytes, err := json.Marshal(&api.UserCredentialsValidation{
+				Valid: false,
+			})
+			if err != nil {
+				log.Error("could not marshal user credentials validation response: %s", err)
+				http.Error(w, "", http.StatusInternalServerError)
+				return
+			}
+
+			w.Write(responseBytes)
+		}
+
+		// users, err := db.getAllUsers()
+		// if err != nil {
+		// 	http.Error(w, "", http.StatusInternalServerError)
+		// 	return
+		// }
+
+		// w.Header().Add("Content-type", "application/json")
+		// userBytes, err := json.Marshal(*users)
+		// if err != nil {
+		// 	break
+		// }
+
+		// w.Write(userBytes)
+
+	default:
+		http.Error(w, "wrong method", http.StatusMethodNotAllowed)
+	}
+}

src/server/websocketHandler.go

@@ -0,0 +1,89 @@
+/*
+gochat - A dead simple real time webchat.
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+This file is a part of gochat
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package server
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gorilla/websocket"
+	"unbewohnte.xyz/gochat/api"
+	"unbewohnte.xyz/gochat/log"
+)
+
+// Websocket creation handler
+func (s *Server) HandlerWebsockets(w http.ResponseWriter, req *http.Request) {
+	upgrader := websocket.Upgrader{}
+	socket, err := upgrader.Upgrade(w, req, nil)
+	if err != nil {
+		http.Error(w, "could not upgrade to a websocket", http.StatusInternalServerError)
+		return
+	}
+
+	var authInfo api.User
+	err = socket.ReadJSON(&authInfo)
+	if err != nil {
+		log.Error("%s did not send auth info on websocket connection at all: %s", socket.RemoteAddr(), err)
+		api.Disconnect(socket)
+		return
+	}
+
+	if !s.db.DoesUserExist(authInfo.Name) {
+		log.Error("%s sent an invalid authentication data on websocket: user does not exist", socket.RemoteAddr())
+		api.Disconnect(socket)
+		return
+	}
+
+	userDB, _ := s.db.GetUser(authInfo.Name)
+
+	if authInfo.SecretHash != userDB.SecretHash {
+		log.Error("%s did not send valid password hash on websocket", socket.RemoteAddr())
+		api.Disconnect(socket)
+		return
+	}
+
+	newWS := api.WS{
+		Socket: socket,
+		User:   authInfo,
+	}
+
+	// add this new authorized socket to the broadcast
+	s.websockets.Sockets = append(s.websockets.Sockets, &newWS)
+
+	log.Info("A new websocket connection has been established with %s as \"%s\"", newWS.Socket.RemoteAddr(), newWS.User.Name)
+	go s.websockets.HandleNewWebSocketMessages(&newWS, s.incomingMessages)
+
+	newConnectionMessage := api.Message{
+		From:     api.UserSystem,
+		Contents: fmt.Sprintf("%s has connected", newWS.User.Name),
+	}
+	s.incomingMessages <- newConnectionMessage
+}
+
+// Send incoming messages from each websocket to all connected ones
+func (s *Server) BroadcastMessages() {
+	for {
+		message, ok := <-s.incomingMessages
+		if !ok {
+			break
+		}
+
+		for _, ws := range s.websockets.Sockets {
+			ws.Socket.WriteJSON(&message)
+		}
+	}
+}

static/style.css

@@ -0,0 +1,57 @@
+@viewport {
+    width: device-width;
+    zoom: 1.0;
+} 
+
+body {
+    margin: auto;
+    margin-top: 5ch;
+    margin-bottom: 10ch;
+    background-color: #232729;
+    max-width: 120ch;
+    padding-left: 2ch;
+    padding-right: 2ch;
+
+
+    font-size: 1.1em;
+
+    word-wrap: break-word;
+    color: #bbbbbb;
+}
+
+a {
+    text-decoration: none;
+    color: #bbbbbb;
+}
+
+a:hover {
+    color: azure;
+}
+
+nav {
+    white-space: nowrap;
+    display: inline-block;
+}
+
+#wrapper {
+    display: flex;
+    flex-flow: column wrap;
+    justify-content: center;
+    row-gap: 3ch;
+}
+
+#chatbox {
+    flex: 1 0 90%;
+    width: auto;
+    height: 60ch;
+
+    max-width: 80ch;
+    max-height: 150ch;
+
+    overflow-y: scroll;
+    border: 1px solid #bbbbbb;
+}
+
+#error_output {
+    color: firebrick;
+}