Add initial prototype of NixOS module

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

flake.lock

@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1766736597,
+        "narHash": "sha256-BASnpCLodmgiVn0M1MU2Pqyoz0aHwar/0qLkp7CjvSQ=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "f560ccec6b1116b22e6ed15f4c510997d99d5852",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-25.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,29 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+        let
+	  pkgs = import nixpkgs { inherit system; };
+	  joann-pupper-bot = pkgs.crystal.buildCrystalPackage {
+	    pname = "joann-pupper-bot";
+	    version = "0.1.0";
+	    src = ./.;
+            lockFile = ./shard.lock;
+	    shardsFile = ./shards.nix;
+	    format = "shards";
+	    buildInputs = [pkgs.sqlite];
+	  };
+        in
+          {
+            packages = { inherit joann-pupper-bot; };
+            defaultPackage = joann-pupper-bot;
+          }
+    ) // {
+      nixosModules.joann-pupper-bot = import ./module.nix;
+    };
+}

module.nix

@@ -0,0 +1,71 @@
+{ config, lib, pkgs, ... }:
+with lib;
+let cfg = config.services.joann-pupper-bot; in {
+  options.services.joann-pupper-bot = {
+    enable = mkEnableOption "Joann's Pupper Bot";
+    user = mkOption {
+      type = types.str;
+      default = "joann-pupper-bot";
+      example = "myuser";
+      description = "Which user should be running Joann's Pupper Bot";
+    };
+    group = mkOption {
+      type = types.str;
+      default = "joann-pupper-bot";
+      example = "mygroup";
+      description = "Which group should be running Joann's Pupper Bot";
+    };
+    stateDir = mkOption {
+      type = types.str;
+      default = "/var/lib/joann-pupper-bot";
+      description = "Which directory the bot should use for storage";
+    };
+    config.token = mkOption {
+      type = types.str;
+      description = "Bot token used for Telegram";
+    };
+    config.subreddits = mkOption {
+      type = types.listOf types.str;
+      description = "Which subreddits to draw images from";
+      default = ["rarepuppers"];
+    };
+    config.sendCron = mkOption {
+      type = types.str;
+      description = "cron-style string determining when images should be sent";
+      default = "*/30 8-21 * * *";
+    };
+    config.refreshCron = mkOption {
+      type = types.str;
+      description = "cron-style string determining when the bot polls Reddit for new images";
+      default = "*/15 * * * *";
+    };
+    config.recipients = mkOption {
+      type = types.listOf types.int;
+      description = "Telegram chat IDs for each of the image recipients";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.tmpfiles.rules = [
+      "d '${cfg.stateDir}' 0750 ${cfg.user} ${cfg.group} - -"
+    ];
+    systemd.services.joann-pupper-bot = {
+      description = "Joann's Pupper Bot";
+      wantedBy = [ "multi-user.target" ];
+
+      preStart =
+        let
+          yml = generators.toYAML {} cfg.config;
+          configFile = pkgs.writeText "config.yaml" yml;
+        in
+        ''
+          cp -f '${configFile}' '${cfg.stateDir}'/config.yaml
+        '';
+
+      serviceConfig = {
+	Type = "oneshot";
+        ExecStart = "/bin/sh -c :";
+      };
+    };
+  };
+}

shard.lock

@@ -0,0 +1,22 @@
+version: 2.0
+shards:
+  cron_parser:
+    git: https://github.com/kostya/cron_parser.git
+    version: 0.4.0
+
+  cron_scheduler:
+    git: https://github.com/kostya/cron_scheduler.git
+    version: 0.4.0
+
+  db:
+    git: https://github.com/crystal-lang/crystal-db.git
+    version: 0.14.0
+
+  sqlite3:
+    git: https://github.com/crystal-lang/crystal-sqlite3.git
+    version: 0.22.0
+
+  telepathy:
+    git: https://dev.danilafe.com/Crystal-Bots/telepathy
+    version: 0.2.0
+

shard.yml

@@ -10,8 +10,12 @@ targets:
 
 dependencies:
   telepathy:
-    git: http://dev.danilafe.com/Crystal-Bots/telepathy
+    git: https://dev.danilafe.com/Crystal-Bots/telepathy
+  cron_scheduler:
+    github: kostya/cron_scheduler
+  sqlite3:
+    github: crystal-lang/crystal-sqlite3
 
-crystal: 0.24.1
+crystal: 1.0.0
 
 license: MIT

shards.nix

@@ -0,0 +1,27 @@
+{
+  "cron_parser" = {
+    url = "https://github.com/kostya/cron_parser.git";
+    rev = "v0.4.0";
+    sha256 = "17fgg2nvyx99v05l10h6cnxfr7swz8yaxhmnk4l47kg2spi8w90a";
+  };
+  "cron_scheduler" = {
+    url = "https://github.com/kostya/cron_scheduler.git";
+    rev = "v0.4.0";
+    sha256 = "0jd0maw1h87hjgjpqhbwxb4yz83g8shlrwfivyf0sd6x3l5lspns";
+  };
+  "db" = {
+    url = "https://github.com/crystal-lang/crystal-db.git";
+    rev = "v0.14.0";
+    sha256 = "1s67fs5abzgg2yyjsm2la967mk881i91h8jdnal072fb9qh9wr58";
+  };
+  "sqlite3" = {
+    url = "https://github.com/crystal-lang/crystal-sqlite3.git";
+    rev = "v0.22.0";
+    sha256 = "1lc8ixnzjx8nsp96qj9yxmfk7g334id8v87g3h5bwgkhkbx5ghqn";
+  };
+  "telepathy" = {
+    url = "https://dev.danilafe.com/Crystal-Bots/telepathy";
+    rev = "v0.2.0";
+    sha256 = "1zhjlpa31vldgd9f6l1hdfj7a97hlqkxkvxzisfs2zfnvc86aiyc";
+  };
+}

src/joann-pupper-bot.cr

@@ -1,67 +1,18 @@
 require "./joann-pupper-bot/*"
-require "logger"
-require "telepathy"
-require "time"
+require "option_parser"
 
-# Chat IDs
-chatid_joann = 215301902
-chatid_daniel = 220888832
+config_file = "./config.yaml"
 
-# Configuration
-subreddit = "rarepuppers"
-chatid = chatid_daniel
-delay = 1.hours
-active_hours = 7..24
-bot_token = "599474797:AAEmjQNO32uqurI16blS9FT4OoO7GdUZ6h0"
-
-# Setup
-completed = [] of String
-logger = Logger.new(STDOUT)
-bot = Telepathy::Bot.new bot_token
-
-# Commands.
-bot.command "ping" do |update, args|
-    bot.send_message(update.message.as(Telepathy::Message).chat.id, "pong")
+OptionParser.parse do |parser|
+  parser.banner = "Usage: joann-pupper-bot [arguments]"
+  parser.on("-c", "--config=CONFIG", "Select config file") do |c|
+    config_file = c
   end
-
-bot.command "pupper" do |update, args|
-    url_tuple = get_reddit_post(subreddit, completed)
-    if url_tuple
-        url, title = url_tuple
-        command_chatid = update.message.as(Telepathy::Message).chat.id
-        logger.info "Using URL #{url} for request from #{command_chatid}"
-        bot.send_photo(command_chatid, url, title)
-    else
-        logger.error "Unable to find a post to send."
+  parser.on("-h", "--help", "Show this message") do
+    puts parser
+    exit
   end
 end
 
-spawn do
-    loop do
-        time = Time.now
-        url_tuple = get_reddit_post(subreddit, completed) if (active_hours.includes? time.hour)
-        if url_tuple
-            url, title = url_tuple
-            logger.info "Sending regular picture to #{chatid}."
-            bot.send_photo(chatid.to_i64, url, title)
-        else
-            logger.error "Unable to find a post to send. (Or it's quiet hours)"
-        end
-        sleep delay
-    end
-end
-
-# Code to stop the bot on time.
-end_channel = Channel(Nil).new(1)
-
-bot.poll_end do
-    end_channel.send nil
-end
-
-Signal::INT.trap do
-    logger.info "Shutting down bot..."
-    bot.end_poll
-end
-
-bot.poll
-end_channel.receive
+botc = PupperBot.new(BotConfiguration.from_yaml(File.open(config_file)))
+sleep

src/joann-pupper-bot/bot.cr

@@ -0,0 +1,83 @@
+require "log"
+require "telepathy"
+require "time"
+require "sqlite3"
+require "cron_scheduler"
+
+EXTENSIONS = ["png", "jpeg", "jpg"]
+LOGGER = Log.for("joann-pupper-bot")
+
+class PupperBot
+   @db : DB::Database
+
+  def initialize(@configuration : BotConfiguration)
+    @telegram_bot = Telepathy::Bot.new @configuration.token
+    @db = DB.open "sqlite3://#{@configuration.database}"
+    initialize_db
+    update_database
+    initialize_timers
+    initialize_telegram
+    send_broadcast
+  end
+
+  private def initialize_db
+    @db.exec "create table if not exists posts(id integer primary key, title text, url text unique)"
+    @db.exec "create table if not exists recepient_posts(recepient integer, post integer, foreign key(post) references posts(id))"
+  end
+
+  private def initialize_timers
+    CronScheduler.define do
+      at(@configuration.send_cron) { send_broadcast }
+      at(@configuration.refresh_cron) { update_database }
+    end
+  end
+
+  private def initialize_telegram
+    @telegram_bot.command "ping" do |update, args|
+      @telegram_bot.send_message(update.message.as(Telepathy::Message).chat.id, "pong")
+    end
+
+    @telegram_bot.command "pupper" do |update, args|
+      command_chatid = update.message.as(Telepathy::Message).chat.id
+      send_single command_chatid
+    end
+
+    @telegram_bot.poll
+  end
+
+  def send_single(chatid)
+    unsent_query = "select id, title, url from posts where not exists (select * from recepient_posts where recepient=? and post=id) limit 1"
+
+    unless to_send = @db.query_one? unsent_query, chatid, as: { Int64, String, String }
+      LOGGER.info { "Unable to find a post to send to #{chatid}." }
+      return
+    end
+
+    id, title, url = to_send
+    LOGGER.info { "Using URL #{url} for request from #{chatid}" }
+    @db.exec "insert into recepient_posts(recepient, post) values(?, ?)", chatid, id
+    @telegram_bot.send_photo(chatid, url, title)
+  end
+
+  def send_broadcast
+    @configuration.recipients.each do |recepient|
+      send_single recepient
+    end
+  end
+
+  def update_database
+    unless response = RedditResponse.from_subreddits(@configuration.subreddits)
+      LOGGER.info { "Unable to find more posts for the database" }
+      return
+    end
+
+    posts = response.data.posts_matching { |post| EXTENSIONS.any? { |it| post.url.ends_with? it } }
+    posts.each do |post|
+      LOGGER.info { "Trying to save post #{post.title} #{post.url}" }
+      begin
+        @db.exec "insert into posts(title, url) values(?, ?)", post.title, post.url
+      rescue
+      end
+    end
+  end
+end

src/joann-pupper-bot/config.cr

@@ -0,0 +1,23 @@
+require "yaml"
+
+class BotConfiguration
+  include YAML::Serializable
+
+  @[YAML::Field(key: "token")]
+  property token : String
+
+  @[YAML::Field(key: "database")]
+  property database : String = "./data.sqlite"
+
+  @[YAML::Field(key: "subreddits")]
+  property subreddits : Array(String) = ["rarepuppers"]
+
+  @[YAML::Field(key: "send_cron")]
+  property send_cron : String = "*/30 8-21 * * *"
+
+  @[YAML::Field(key: "refresh_cron")]
+  property refresh_cron : String = "*/15 * * * *"
+
+  @[YAML::Field(key: "recipients")]
+  property recipients : Array(Int64)
+end

src/joann-pupper-bot/reddit.cr

@@ -1,27 +1,63 @@
 require "http/client"
 require "json"
 
-def get_reddit_json(subreddit)
-    request_url = "https://www.reddit.com/r/#{subreddit}/hot.json?limit=30"
+class RedditWrapper(T)
+  include JSON::Serializable
+
+  @[JSON::Field(key: "kind")]
+  property kind : String
+
+  @[JSON::Field(key: "data")]
+  property data : T
+end
+
+class RedditChild
+  include JSON::Serializable
+
+  @[JSON::Field(key: "url")]
+  property url : String
+
+  @[JSON::Field(key: "name")]
+  property name : String
+
+  @[JSON::Field(key: "title")]
+  property title : String
+end
+
+class RedditResponse
+  include JSON::Serializable
+
+  @[JSON::Field(key: "modhash")]
+  property modhash : String
+
+  @[JSON::Field(key: "dist")]
+  property dist : Int32
+
+  @[JSON::Field(key: "children")]
+  property children : Array(RedditWrapper(RedditChild))
+
+  def self.from_subreddits(subreddits : Array(String))
+    request_url = URI.new scheme: "https", host: "www.reddit.com", path: "/r/#{subreddits.join "+"}/hot.json", query: "limit=30"
     response = HTTP::Client.get(request_url, headers: HTTP::Headers {
       "User-agent" => "Joann-Pupper-Bot"
     })
-    response.body?.try { |body| JSON.parse(body) }
-end
 
-def filter_reddit_json(json, completed)
-    json["data"]["children"]
-        .as_a
-        .map(&.["data"])
-        .select do |it| 
-            url = it["url"].as_s
-            name = it["name"].as_s
-            !completed.includes?(name) && (url.ends_with?(".png") || url.ends_with?(".jpg"))
+    return nil unless body = response.body?
+
+    begin
+      RedditWrapper(RedditResponse).from_json body
+    rescue e
+      nil
     end
   end
 
-def get_reddit_post(subreddit, completed)
-    json = get_reddit_json(subreddit)
-    post = json.try { |json| filter_reddit_json(json, completed).first? }
-    post.try { |post| completed.push(post["name"].as_s); { post["url"].as_s, post["title"].as_s } }
+  def self.from_subreddit(subreddit)
+    from_subreddits [subreddit]
+  end
+
+  def posts_matching(&block)
+    children
+      .map(&.data)
+      .select { |it| yield it }
+  end
 end