fix: replace user_agent_parser with UserAgent + pre compiled regexes

app/controllers/click.cr

@@ -1,7 +1,3 @@
-require "user_agent_parser"
-
-UserAgent.load_regexes(File.read("data/uap_core_regexes.yaml"))
-
 module App::Controllers
   struct ClickController
     include App::Models
@@ -26,14 +22,14 @@ module App::Controllers
             user_agent_str = env.request.headers["User-Agent"]?
             referer = env.request.headers["Referer"]?.try { |r| URI.parse(r).host rescue r } || env.params.query["utm_source"]? || "Direct"
 
-            ua_parser = user_agent_str ? UserAgent.new(user_agent_str) : nil
+            family, _, _, os = user_agent_str ? UserAgent.parse(user_agent_str) : {nil, nil, nil, nil}
 
             click = App::Models::Click.new
             click.link_id = link_id
             click.country = client_ip ? IpLookup.country(client_ip) : nil
             click.user_agent = user_agent_str
-            click.browser = ua_parser.try(&.family)
-            click.os = ua_parser.try(&.os.try(&.family))
+            click.browser = family
+            click.os = os.try &.[0]  # Access the first element of the os tuple (the family)
             click.referer = referer
 
             Database.insert(click)

app/lib/ua_parser.cr

@@ -0,0 +1,123 @@
+require "yaml"
+require "semantic_version"
+
+module App::Lib
+  struct UserAgent
+    REGEXES_PATH = "data/uap_core_regexes.yaml"
+
+    @@regexes_cache : YAML::Any? = nil
+    @@compiled_regexes = {} of String => Array(Tuple(Regex, YAML::Any))
+    @@mutex = Mutex.new
+
+    private def self.load_regexes
+      @@mutex.synchronize do
+        if @@regexes_cache.nil?
+          begin
+            regexes_yaml = File.read(REGEXES_PATH)
+            @@regexes_cache = YAML.parse(regexes_yaml)
+
+            # Pre-compile all regexes for better performance
+            ["user_agent_parsers", "os_parsers", "device_parsers"].each do |parser_type|
+              @@compiled_regexes[parser_type] = [] of Tuple(Regex, YAML::Any)
+
+              @@regexes_cache.not_nil![parser_type].as_a.each do |parser|
+                regex_str = parser["regex"].as_s
+                options = parser["regex_flag"]?.try(&.as_s) == "i" ?
+                  Regex::Options::IGNORE_CASE : Regex::Options::None
+
+                begin
+                  compiled_regex = Regex.new(regex_str, options)
+                  @@compiled_regexes[parser_type] << {compiled_regex, parser}
+                rescue
+                  # Skip invalid regexes
+                end
+              end
+            end
+          rescue ex
+            # If loading fails, set an empty cache to prevent repeated failures
+            @@regexes_cache = YAML.parse("{}")
+            @@compiled_regexes = {} of String => Array(Tuple(Regex, YAML::Any))
+          end
+        end
+      end
+    end
+
+    def self.parse(user_agent_string : String)
+      return {nil, nil, nil, nil} if user_agent_string.empty?
+
+      # Load regexes only once and cache them
+      load_regexes
+
+      family = nil
+      version = nil
+      device = nil
+      os = nil
+
+      @@compiled_regexes["user_agent_parsers"]?.try &.each do |regex_tuple|
+        regex, parser = regex_tuple
+        match = regex.match(user_agent_string)
+        next unless match
+
+        family = match[1]? || nil
+        v1 = (match[2]? || "0").to_i
+        v2 = (match[3]? || "0").to_i
+        v3 = (match[4]? || "0").to_i
+
+        # Apply replacements if defined
+        if replacement = parser["family_replacement"]?
+          family = replacement.as_s.gsub("$1", family.to_s)
+        end
+
+        version = SemanticVersion.new(v1, v2, v3)
+        break
+      end
+
+      @@compiled_regexes["os_parsers"]?.try &.each do |regex_tuple|
+        regex, parser = regex_tuple
+        match = regex.match(user_agent_string)
+        next unless match
+
+        os_family = match[1]? || nil
+        os_v1 = (match[2]? || "0").to_i
+        os_v2 = (match[3]? || "0").to_i
+        os_v3 = (match[4]? || "0").to_i
+
+        # Apply replacements if defined
+        if replacement = parser["os_replacement"]?
+          os_family = replacement.as_s.gsub("$1", os_family.to_s)
+        end
+
+        os = {os_family, SemanticVersion.new(os_v1, os_v2, os_v3)}
+        break
+      end
+
+      @@compiled_regexes["device_parsers"]?.try &.each do |regex_tuple|
+        regex, parser = regex_tuple
+        match = regex.match(user_agent_string)
+        next unless match
+
+        model = match[1]? || nil
+        device_name = model
+        brand = nil
+
+        # Apply replacements if defined
+        if device_replacement = parser["device_replacement"]?
+          device_name = device_replacement.as_s.gsub("$1", device_name.to_s)
+        end
+
+        if model_replacement = parser["model_replacement"]?
+          model = model_replacement.as_s.gsub("$1", model.to_s)
+        end
+
+        if brand_replacement = parser["brand_replacement"]?
+          brand = brand_replacement.as_s
+        end
+
+        device = {model, brand, device_name}
+        break
+      end
+
+      {family, version, device, os}
+    end
+  end
+end

shard.lock

@@ -1,9 +1,5 @@
 version: 2.0
 shards:
-  async:
-    git: https://github.com/protoncr/async.git
-    version: 0.2.0
-
   backtracer:
     git: https://github.com/sija/backtracer.cr.git
     version: 1.2.2
@@ -60,7 +56,3 @@ shards:
     git: https://github.com/crystal-lang/crystal-sqlite3.git
     version: 0.19.0
 
-  user_agent_parser:
-    git: https://github.com/busyloop/user_agent_parser.git
-    version: 2.0.1
-

shard.yml

@@ -20,8 +20,6 @@ dependencies:
   micrate:
     github: amberframework/micrate
     version: 0.15.1
-  user_agent_parser:
-    github: busyloop/user_agent_parser
   maxminddb:
     github: delef/maxminddb.cr