Finish plugin functionalities

src/plugin/plugin.cr

@@ -1,6 +1,7 @@
 require "duktape/runtime"
 require "myhtml"
 require "http"
+require "xml"
 
 class Plugin
   class Error < ::Exception
@@ -15,70 +16,164 @@ class Plugin
   class SyntaxError < Error
   end
 
-  {% for name in ["id", "title", "author", "version", "placeholder"] %}
-    getter {{name.id}} = ""
-  {% end %}
-  getter wait_seconds : UInt64 = 0
-  getter filename
+  struct Info
+    {% for name in ["id", "title", "author", "version", "placeholder"] %}
+      getter {{name.id}} = ""
+    {% end %}
+    getter wait_seconds : UInt64 = 0
+    getter dir : String
 
-  def self.list
-    dir = Config.current.plugin_path
-    Dir.mkdir_p dir unless Dir.exists? dir
+    def initialize(@dir)
+      info_path = File.join @dir, "info.json"
 
-    Dir.children(dir)
-      .select do |f|
-        fp = File.join dir, f
-        File.file?(fp) && File.extname(fp) == ".js"
+      unless File.exists? info_path
+        raise MetadataError.new "File `info.json` not found in the " \
+                                "plugin directory #{dir}"
       end
-      .map do |f|
-        File.basename f, ".js"
+
+      json = JSON.parse File.read info_path
+
+      begin
+        {% for name in ["id", "title", "author", "version", "placeholder"] %}
+          @{{name.id}} = json[{{name}}].as_s
+        {% end %}
+        @wait_seconds = json["wait_seconds"].as_i.to_u64
+
+        unless @id.alphanumeric_underscore?
+          raise "Plugin ID can only contain alphanumeric characters and " \
+                "underscores"
+        end
+      rescue e
+        raise MetadataError.new "Failed to retrieve metadata from plugin " \
+                                "at #{@dir}. Error: #{e.message}"
       end
+    end
   end
 
-  def initialize(@filename : String)
+  struct State
+    @hash = {} of String => String
+
+    def initialize(@path : String)
+      unless File.exists? @path
+        save
+      end
+
+      json = JSON.parse File.read @path
+      json.as_h.each do |k, v|
+        @hash[k] = v.as_s
+      end
+    end
+
+    def []?(key)
+      @hash[key]?
+    end
+
+    def []=(key, val : String)
+      @hash[key] = val
+    end
+
+    def save
+      File.write @path, @hash.to_pretty_json
+    end
+  end
+
+  @@info_ary = [] of Info
+  @info : Info?
+
+  getter js_path = ""
+  getter state_path = ""
+
+  def self.build_info_ary
+    return unless @@info_ary.empty?
+
     dir = Config.current.plugin_path
     Dir.mkdir_p dir unless Dir.exists? dir
 
-    @path = File.join dir, "#{filename}.js"
-    unless File.exists? @path
-      raise Error.new "Plugin script not found at #{@path}"
+    Dir.each_child dir do |f|
+      path = File.join dir, f
+      next unless File.directory? path
+
+      begin
+        @@info_ary << Info.new path
+      rescue e : MetadataError
+        Logger.warn e
+      end
+    end
+  end
+
+  def self.list
+    self.build_info_ary
+
+    @@info_ary.map &.title
+  end
+
+  def info
+    @info.not_nil!
+  end
+
+  def self.new_from_id(id : String)
+    self.build_info_ary
+
+    info = @@info_ary.find { |i| i.id == id }
+    raise Error.new "Plugin with id #{id} not found" unless info
+    self.new info.title
+  end
+
+  def initialize(title : String)
+    Plugin.build_info_ary
+
+    @info = @@info_ary.find { |i| i.title == title }
+    if @info.nil?
+      raise Error.new "Plugin with title #{title} not found"
+    end
+
+    @js_path = File.join info.dir, "main.js"
+    @state_path = File.join info.dir, "state.json"
+
+    unless File.exists? @js_path
+      raise Error.new "Plugin script not found at #{@js_path}"
     end
 
     @rt = Duktape::Runtime.new do |sbx|
       sbx.push_global_object
 
-      sbx.del_prop_string -1, "print"
-      sbx.del_prop_string -1, "alert"
-      sbx.del_prop_string -1, "console"
+      sbx.push_pointer @state_path.as(Void*)
+      path = sbx.require_pointer(-1).as String
+      sbx.pop
+      sbx.push_string path
+      sbx.put_prop_string -2, "state_path"
 
       def_helper_functions sbx
     end
 
-    eval File.read @path
+    eval File.read @js_path
+  end
 
-    begin
-      data = eval_json "metadata"
-      {% for name in ["id", "title", "author", "version", "placeholder"] %}
-        @{{name.id}} = data[{{name}}].as_s
-      {% end %}
-      @wait_seconds = data["wait_seconds"].as_i.to_u64
-    rescue e
-      raise MetadataError.new "Failed to retrieve metadata from plugin " \
-                              "at #{@path}. Error: #{e.message}"
-    end
+  macro check_fields(ary)
+    {% for field in ary %}
+      unless json[{{field}}]?
+        raise "Field `{{field.id}}` is missing from the function outputs"
+      end
+    {% end %}
   end
 
   def search(query : String)
     json = eval_json "search('#{query}')"
     begin
-      ary = json.as_a
+      check_fields ["title", "chapters"]
+
+      ary = json["chapters"].as_a
       ary.each do |obj|
         id = obj["id"]?
         raise "Field `id` missing from `search` outputs" if id.nil?
 
-        unless id.to_s.chars.all? &.number?
-          raise "The `id` values must be numeric" unless id
+        unless id.to_s.alphanumeric_underscore?
+          raise "The `id` field can only contain alphanumeric characters and " \
+                "underscores"
         end
+
+        title = obj["title"]?
+        raise "Field `title` missing from `search` outputs" if title.nil?
       end
     rescue e
       raise Error.new e.message
@@ -89,12 +184,11 @@ class Plugin
   def select_chapter(id : String)
     json = eval_json "selectChapter('#{id}')"
     begin
-      {% for field in ["title", "pages"] %}
-        unless json[{{field}}]?
-          raise "Field `{{field.id}}` is missing from the " \
-                "`selectChapter` outputs"
-        end
-      {% end %}
+      check_fields ["title", "pages"]
+
+      if json["title"].to_s.empty?
+        raise "The `title` field of the chapter can not be empty"
+      end
     rescue e
       raise Error.new e.message
     end
@@ -105,12 +199,7 @@ class Plugin
     json = eval_json "nextPage()"
     return if json.size == 0
     begin
-      {% for field in ["filename", "url"] %}
-        unless json[{{field}}]?
-          raise "Field `{{field.id}}` is missing from the " \
-                "`nextPage` outputs"
-        end
-      {% end %}
+      check_fields ["filename", "url"]
     rescue e
       raise Error.new e.message
     end
@@ -173,16 +262,28 @@ class Plugin
       env = Duktape::Sandbox.new ptr
       html = env.require_string 0
 
-      myhtml = Myhtml::Parser.new html
-      root = myhtml.root
-
-      str = ""
-      str = root.inner_text if root
+      str = XML.parse(html).inner_text
 
       env.push_string str
       env.call_success
     end
-    sbx.put_prop_string -2, "innerText"
+    sbx.put_prop_string -2, "text"
+
+    sbx.push_proc 2 do |ptr|
+      env = Duktape::Sandbox.new ptr
+      html = env.require_string 0
+      name = env.require_string 1
+
+      begin
+        attr = XML.parse(html).first_element_child.not_nil![name]
+        env.push_string attr
+      rescue
+        env.push_undefined
+      end
+
+      env.call_success
+    end
+    sbx.put_prop_string -2, "attribute"
 
     sbx.push_proc 1 do |ptr|
       env = Duktape::Sandbox.new ptr
@@ -193,6 +294,32 @@ class Plugin
     end
     sbx.put_prop_string -2, "raise"
 
+    sbx.push_proc LibDUK::VARARGS do |ptr|
+      env = Duktape::Sandbox.new ptr
+      key = env.require_string 0
+
+      env.get_global_string "state_path"
+      state_path = env.require_string -1
+      env.pop
+      state = State.new state_path
+
+      if env.get_top == 2
+        val = env.require_string 1
+        state[key] = val
+        state.save
+      else
+        val = state[key]?
+        if val
+          env.push_string val
+        else
+          env.push_undefined
+        end
+      end
+
+      env.call_success
+    end
+    sbx.put_prop_string -2, "state"
+
     sbx.put_prop_string -2, "mango"
   end
 end