my new youtube and minecraft block script

scripts/yt-block/app.nix

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+{ pkgs
+, ...
+}: let
+  python = pkgs.python3.withPackages (ps: with ps; [pkgs.python311Pacakges.cryptography]);
+	python_script = pkgs.writeText (builtins.readFile ./main.py);
+in pkgs.writeShellApplication {
+  name = "yt-block";
+  text = ''
+    ${python}/bin/python ${python_script}
+  '';
+}

scripts/yt-block/main.py

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+
+import hashlib
+import datetime
+import sys
+from cryptography.fernet import Fernet
+import os
+import json
+import base64
+import subprocess
+
+YT_TIME_MAX = 90 # in min
+STATE_FILE = "/etc/yt_block_state"
+
+DEFAULT_STATE = {
+        "yt_time_left": 0,
+        "yt_time_current": 0,
+        "date": "2024-07-15",
+}
+
+YT_HOSTS = [
+    [ "127.0.0.1", "youtube.com" ],
+    [ "127.0.0.1", "www.youtube.com" ],
+    [ "::1", "www.youtube.com" ],
+    [ "::1", "youtube.com" ],
+]
+
+def main():
+    if sys.argv[1] == "g" or sys.argv[1] == "guard":
+        cmd_guard()
+        return
+
+    if sys.argv[1] == "r" or sys.argv[1] == "request":
+        cmd_request()
+        return
+
+    if sys.argv[1] == "i" or sys.argv[1] == "info":
+        cmd_info()
+        return
+    
+    print("unknown command!!!!")
+    
+
+def cmd_guard():
+    pwd = get_pwd()
+
+    state = read_state(pwd)
+
+    # if it's after 22:00 block yt and kill all minecraft processes
+    now = datetime.datetime.now()
+    if now.hour >= 22:
+        block_yt()
+        kill_mc()
+
+    # if date is not today, set time_left to YT_TIME_LIMIT
+    date_from_state = datetime.datetime.strptime(state["date"], "%Y-%m-%d")
+    if now.date() != date_from_state.date():
+        state["yt_time_left"] = YT_TIME_MAX
+        state["date"] = now.strftime("%Y-%m-%d")
+
+
+    # if time_current in state is 0, block yt
+    if state["yt_time_current"] == 0:
+        block_yt()
+
+    # if time_current in state is 0, block yt
+    if state["yt_time_current"] >= 0:
+        unblock_yt()
+
+    # decrement time_current
+    state["yt_time_current"] -= 1
+
+    write_state(state, pwd)
+
+def cmd_request():
+    pwd = get_pwd()
+
+    state = read_state(pwd)
+
+    time_to_request = int(sys.argv[2])
+
+    if time_to_request > state["yt_time_left"]:
+        print("Trying to request more time, than is left")
+        exit(1)
+
+    state["yt_time_left"] -= time_to_request
+    state["yt_time_current"] = time_to_request +1 # +1 because we are running guard now as well....
+
+    write_state(state, pwd)
+
+    # run gurad now as well ... so that changes take effect immediately
+    cmd_guard()
+
+
+def cmd_info():
+    pwd = get_pwd()
+
+    state = read_state(pwd)
+
+    kill_mc()
+
+    print("YouTube")
+    print("time_left:", state["yt_time_left"])
+    print("time_current:", state["yt_time_current"])
+
+
+
+
+def get_pwd():
+    with open("/etc/machine-id", "r") as f:
+        pwd = f.read()
+
+
+    for i in range(0, 7):
+        my_string_bits = pwd.encode('utf-8')
+        secret_thing = hashlib.sha256(my_string_bits)
+        pwd = secret_thing.hexdigest()
+
+    pwd = pwd[0:32]
+    pwd_bytes =pwd.encode('ascii')
+    pwd_base64_bytes = base64.b64encode(pwd_bytes)
+    return pwd_base64_bytes
+
+
+def read_state(pwd):
+    fernet = Fernet(pwd)
+
+    if not os.path.exists(STATE_FILE):
+        with open(STATE_FILE, "wb") as file:
+            encrypted = fernet.encrypt(json.dumps(DEFAULT_STATE).encode())
+            file.write(encrypted)
+
+        return DEFAULT_STATE
+
+    with open(STATE_FILE, "rb") as file:
+        state_encrypted = file.read()
+        state_string = fernet.decrypt(state_encrypted)
+        state = json.loads(state_string)
+
+    return state
+
+
+def write_state(state, pwd):
+    fernet = Fernet(pwd)
+
+    with open(STATE_FILE, "wb") as file:
+        state_string = json.dumps(state)
+        state_encrypted = fernet.encrypt(state_string.encode())
+        file.write(state_encrypted)
+
+
+def get_hosts():
+    with open(f"/etc/hosts", "r") as file:
+        hosts = []
+        for line in file.readlines():
+            if line == "\n":
+                continue
+            split = line.split(" ")
+            try:
+                hosts.append([split[1].strip(), split[0].strip()])
+            except:
+                print("error with geting hosts from /etc/hosts: ", split)
+    return hosts
+
+
+def write_hosts(hosts):
+    with open("/etc/hosts", "w") as file:
+        lines = []
+        for entry in hosts:
+            lines.append(entry[1] + " " + entry[0])
+
+        file.write("\n".join(lines) + "\n")
+
+
+def block_yt():
+    hosts = get_hosts()
+    for entry in YT_HOSTS:
+        hosts.append(entry)
+
+    write_hosts(hosts)
+
+def unblock_yt():
+    hosts = get_hosts()
+    new_hosts = []
+    for entry in hosts:
+        if entry[0] == "youtube.com" or entry[0] == "www.youtube.com":
+            continue
+        else:
+            new_hosts.append(entry)
+
+    write_hosts(new_hosts)
+
+def kill_mc():
+    output = subprocess.check_output(['bash', '-c', "ps fax | grep minecraft"])
+    for line in output.decode().split("\n"):
+        if line.find("java") != -1:
+            kill_line(line)
+
+def kill_line(line):
+    pid = int(line.split(" ")[1])
+    os.system(f"kill {pid}")
+
+if __name__ == "__main__":
+    main()

scripts/yt-block/module.nix

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+{ pkgs, ... }:
+let 
+	yt_block = pkgs.callPackage ./app.nix {};
+in {
+	systemd.services.yt-block = {
+		 enable = true;
+		 description = "Block Youtube";
+		 serviceConfig = {
+			Restart = "always";
+			RestartSec = "60s";
+			ExecStart = "${yt_block}/bin/yt_block guard";
+		 };
+		 wantedBy = [ "multi-user.target" ];
+	};
+  	environment.systemPackages = [ yt_block ];
+}