From 9eb699ea3b82c1474d8bbfb0a7a7832fb4482093 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Mon, 7 Jun 2021 07:04:49 +0000
Subject: [PATCH] Add plugin subscription types

---
 src/plugin/plugin.cr        | 18 ++++++++
 src/plugin/subscriptions.cr | 87 +++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100644 src/plugin/subscriptions.cr

diff --git a/src/plugin/plugin.cr b/src/plugin/plugin.cr
index be08d6f..f6fd2a7 100644
--- a/src/plugin/plugin.cr
+++ b/src/plugin/plugin.cr
@@ -2,6 +2,8 @@ require "duktape/runtime"
 require "myhtml"
 require "xml"
 
+require "./subscriptions"
+
 class Plugin
   class Error < ::Exception
   end
@@ -131,6 +133,22 @@ class Plugin
     @info.not_nil!
   end
 
+  def subscribe(subscription : Subscription)
+    list = SubscriptionList.new info.dir
+    list << subscription
+    list.save
+  end
+
+  def list_subscriptions
+    SubscriptionList.new(info.dir).ary
+  end
+
+  def unsubscribe(id : String)
+    list = SubscriptionList.new info.dir
+    list.reject &.id.== id
+    list.save
+  end
+
   def initialize(id : String)
     Plugin.build_info_ary
 
diff --git a/src/plugin/subscriptions.cr b/src/plugin/subscriptions.cr
new file mode 100644
index 0000000..daca785
--- /dev/null
+++ b/src/plugin/subscriptions.cr
@@ -0,0 +1,87 @@
+require "uuid"
+
+enum FilterType
+  String
+  NumMin
+  NumMax
+  DateMin
+  DateMax
+  Array
+
+  def self.from_string(str)
+    case str
+    when "string"
+      String
+    when "number-min"
+      NumMin
+    when "number-max"
+      NumMax
+    when "date-min"
+      DateMin
+    when "date-max"
+      DateMax
+    when "array"
+      Array
+    else
+      raise "Unknown filter type with string #{str}"
+    end
+  end
+end
+
+struct Filter
+  include JSON::Serializable
+
+  property key : String
+  property value : String | Int32 | Int64 | Float32 | Nil
+  property type : FilterType
+
+  def initialize(@key, @value, @type)
+  end
+
+  def self.from_json(str) : Filter
+    json = JSON.parse str
+    key = json["key"].as_s
+    type = FilterType.from_string json["type"].as_s
+    _value = json["value"]
+    value = _value.as_s? || _value.as_i32? || _value.as_i64? ||
+            _value.as_f32? || nil
+    self.new key, value, type
+  end
+end
+
+struct Subscription
+  include JSON::Serializable
+
+  property id : String
+  property plugin_id : String
+  property name : String
+  property created_at : Int64
+  property last_checked : Int64
+  property filters = [] of Filter
+
+  def initialize(@plugin_id, @name)
+    @id = UUID.random.to_s
+    @created_at = Time.utc.to_unix
+    @last_checked = Time.utc.to_unix
+  end
+end
+
+struct SubscriptionList
+  @dir : String
+  @path : String
+
+  getter ary = [] of Subscription
+
+  forward_missing_to @ary
+
+  def initialize(@dir)
+    @path = Path[@dir, "subscriptions.json"]
+    if File.exists? @path
+      @ary = Array(Subscription).from_json File.read @path
+    end
+  end
+
+  def save
+    File.write @path, @ary.to_json
+  end
+end