module React
  module ReduxComponent
    module NativeComponentConstructor
      # for should_component_update we apply ruby semantics for comparing props
      # to do so, we convert the props to ruby hashes and then compare
      # this makes sure, that for example rubys Nil object gets handled properly
      def self.extended(base)
        component_name = base.to_s
        # language=JS
        %x{
          base.react_component = class extends React.Component {
            constructor(props) {
              super(props);
              if (base.$default_state_defined()) {
                this.state = Object.assign({}, base.$state().$to_n(), { isomorfeus_store: Opal.Isomorfeus.store.native.getState() });
              } else {
                this.state = { isomorfeus_store: Opal.Isomorfeus.store.native.getState() };
              };
              if (typeof this.state.isomorfeus_store.component_class_state[#{component_name}] === "undefined") {
                this.state.isomorfeus_store.component_class_state[#{component_name}] = {};
              };
              this.__ruby_instance = base.$new(this);
              this.__object_id = this.__ruby_instance.$object_id().$to_s();
              if (!this.state.isomorfeus_store.component_state) {
                this.state.isomorfeus_store.component_state = {};
                if (base.$default_instance_store_defined()) {
                  this.state.isomorfeus_store.component_state[this.__object_id] = base.$store.$to_n();
                } else {
                  this.state.isomorfeus_store.component_state[this.__object_id] = {};
                }
              };
              var event_handlers = #{base.event_handlers};
              for (var i = 0; i < event_handlers.length; i++) {
                this[event_handlers[i]] = this[event_handlers[i]].bind(this);
              }
              var defined_refs = #{base.defined_refs};
              for (var ref in defined_refs) {
                if (defined_refs[ref] != null) {
                  this[ref] = function(element) {
                    #{`this.__ruby_instance`.instance_exec(React::Ref.new(`element`), `defined_refs[ref]`)}
                  }
                  this[ref] = this[ref].bind(this);
                } else {
                  this[ref] = React.createRef();
                }
              }
              this.listener = this.listener.bind(this);
              this.unsubscriber = Opal.Isomorfeus.store.native.subscribe(this.listener);
            }
            data_access() {
              return this.state.isomorfeus_store
            }
            static get displayName() {
              return #{component_name};
            }
            listener() {
              var next_state = Object.assign({}, this.state, { isomorfeus_store: Opal.Isomorfeus.store.native.getState() });
              if (this.scu_for_used_store_paths(this, this.state.isomorfeus_store, next_state.isomorfeus_store)) { this.setState(next_state); }
            }
            register_used_store_path(path) {
              this.used_store_paths.push(path);
            }
            componentWillUnmount() {
              if (typeof this.unsubscriber === "function") { this.unsubscriber(); };
            }
            shouldComponentUpdate(next_props, next_state) {
              var next_props_keys = Object.keys(next_props);
              var this_props_keys = Object.keys(this.props);
              if (next_props_keys.length !== this_props_keys.length) { return true; }

              var next_state_keys = Object.keys(next_state);
              var this_state_keys = Object.keys(this.state);
              if (next_state_keys.length !== this_state_keys.length) { return true; }

              for (var property in next_props) {
                if (next_props.hasOwnProperty(property)) {
                  if (!this.props.hasOwnProperty(property)) { return true; };
                  if (property == "children") { if (next_props.children !== this.props.children) { return true; }}
                  else if (typeof next_props[property] !== "undefined" && typeof next_props[property]['$!='] !== "undefined" && typeof this.props[property] !== "undefined" && typeof this.props[property]['$!='] !== "undefined") {
                    if (#{ !! (`next_props[property]` != `this.props[property]`) }) { return true; };
                  } else if (next_props[property] !== this.props[property]) { return true; };
                }
              }
              for (var property in next_state) {
                if (property === "isomorfeus_store") {
                  var res = this.scu_for_used_store_paths(this, this.state.isomorfeus_store, next_state.isomorfeus_store);
                  if (res) { return true; }
                }
                if (next_state.hasOwnProperty(property)) {
                  if (!this.state.hasOwnProperty(property)) { return true; };
                  if (typeof next_state[property]['$!='] !== "undefined" && typeof this.state[property]['$!='] !== "undefined") {
                    if (#{ !! (`next_state[property]` != `this.state[property]`) }) { return true };
                  } else if (next_state[property] !== this.state[property]) { return true };
                }
              }
              return false;
            }
            scu_for_used_store_paths(self, current_state, next_state) {
              var unique_used_store_paths = self.used_store_paths.filter(function(elem, pos) {
                return (self.used_store_paths.indexOf(elem) === pos);
              });
              var used_length = unique_used_store_paths.length;
              var store_path;
              var current_value;
              var next_value;
              for (var i = 0; i < used_length; i++) {
                store_path = unique_used_store_paths[i];
                current_value = store_path.reduce(function(prev, curr) { return prev && prev[curr]; }, current_state);
                next_value = store_path.reduce(function(prev, curr) { return prev && prev[curr]; }, next_state);
                if (current_value !== next_value) { return true; };
              }
              return false;
            }
          }
        }
      end
    end
  end
end