// @flow
import * as React from "react";
import map from "lodash/map";
import mapValues from "lodash/mapValues";
import filter from "lodash/filter";
import keys from "lodash/keys";
import merge from "lodash/merge";
import throttle from "lodash/throttle";

import type { Config, Control, Topics } from "config/flowtypes";

import {
  ThemeProvider, withStyles
} from "@mui/styles";
import { createTheme } from "@mui/material/styles";
import * as Colors from "@mui/material/colors";
import Snackbar from "@mui/material/Snackbar";
import IconButton from "@mui/material/IconButton";
import Typography from "@mui/material/Typography";

import SideBar from "components/SideBar";
import ControlMap from "components/ControlMap";
import TopBar from "components/TopBar";
import UiItemList from "components/UiItemList";

import MqttContext from "mqtt/context";
import connectMqtt from "../connectMqtt";

export type AppProps = {
  config: Config
};

export type AppState = {
  selectedControl: ?Control,
  drawerOpened: boolean,
  mqttState: State,
  mqttSend: (topic: string, value: Buffer) => void,
  mqttConnected: boolean,
  search: string,
  error: ?string
};

/*
 *const App = (props: AppProps) => {
 *  const topics = Array.isArray(props.config.topics) ?
 *      Object.assign({}, ...props.config.topics) : props.config.topics;
 *  const [mqttConnected, setMqttConnected] = useState(false);
 *};
 */

class App extends React.PureComponent<AppProps & Classes, AppState> {
  controlMap: React.Node

  constructor(props: AppProps & Classes) {
    super(props);
    this.state = {
      selectedControl: null,
      drawerOpened: false,
      mqttState: mapValues(this.topics, (topic) => topic.defaultValue),
      mqttSend: connectMqtt(props.config.space.mqtt, {
        onMessage: this.receiveMessage.bind(this),
        onConnect: () => this.setState({ mqttConnected: true }),
        onReconnect: () => this.setState({ mqttConnected: false }),
        onDisconnect: () => this.setState({ mqttConnected: false }),
        subscribe: map(
          filter(keys(this.topics), (x) => this.topics[x].state != null),
          (x) => (this.topics[x].state != null ? this.topics[x].state.name : "")
        )
      }),
      mqttConnected: false,
      search: "",
      error: null
    };
  }

  controlMap = (search: string) =>
    <ControlMap width={1000} height={700} zoom={0}
      layers={this.props.config.layers}
      controls={this.props.config.controls}
      onChangeControl={this.changeControl}
      search={search}
    />;

  get topics(): Topics {
    return Array.isArray(this.props.config.topics) ?
      Object.assign({}, ...this.props.config.topics) : this.props.config.topics;
  }

  static styles(theme) {
    return {
      contentElement: {
        transition: theme.transitions.create(["width"], {
          easing: theme.transitions.easing.sharp,
          duration: theme.transitions.duration.leavingScreen
        })
      },
      contentElementShifted: {
        width: "calc(100% - 340px)",
        transition: theme.transitions.create(["width"], {
          easing: theme.transitions.easing.easeOut,
          duration: theme.transitions.duration.enteringScreen
        })
      }
    };
  }

  receiveMessage(rawTopic: string, message: Buffer) {
    try {
      const topics = filter(
        keys(this.topics),
        (k) => this.topics[k].state != null &&
          this.topics[k].state.name === rawTopic
      );
      if (topics.length === 0) {
        return;
      }
      for (let i in topics) {
        const topic = topics[i];
        const stateTopic = this.topics[topic].state;
        const typeConversion = stateTopic?.type?.from ?? stateTopic?.type;
        const val = (typeConversion ?? ((x: Buffer) => x.toString()))(message);
        this.setMqttStateDebounced(
          {mqttState: Object.assign({},
            merge(this.state.mqttState, { [topic]: val}))});
      }
    } catch (err) {
      this.setState({ error: err.toString() });
    }
  }

  setMqttStateDebounced = throttle(this.setState, 16);

  changeControl = (control: ?Control = null) => {
    this.setState({selectedControl: control, drawerOpened: control != null});
  }

  closeDrawer = () => {
    this.setState({drawerOpened: false});
  }

  changeState = (topic: string, val: string) => {
    try {
      const commandTopic = this.topics[topic].command;
      if (commandTopic == null) {
        return;
      }
      const rawTopic = commandTopic.name;
      const typeConversion = commandTopic?.type?.to ?? commandTopic.type;
      const value = (typeConversion ?? Buffer.from)(val);
      this.state.mqttSend(rawTopic, value);
    } catch (err) {
      this.setState({ error: err.toString() });
    }
  }

  render() {
    return (
      <MqttContext.Provider value={{
        state: this.state.mqttState,
        changeState: this.changeState
      }}>
        <div className={
          this.state.drawerOpened
            ? this.props.classes.contentElementShifted
            : this.props.classes.contentElement
        }>
          <TopBar connected={this.state.mqttConnected}
            onSearch={(s) => this.setState({ search: s })} />
          {this.controlMap(this.state.search)}
        </div>
        <SideBar open={this.state.drawerOpened}
          control={this.state.selectedControl}
          onCloseRequest={this.closeDrawer}
          icon={this.state.selectedControl == null ? null :
            this.state.selectedControl.icon.render(this.state.mqttState)}
        >
          {this.state.selectedControl == null
            || <UiItemList controls={this.state.selectedControl.ui} />}
        </SideBar>
        <Snackbar
          anchorOrigin={{
            vertical: "bottom",
            horizontal: "center"
          }}
          open={this.state.error != null}
          autoHideDuration={6000}
          onClose={() => this.setState({ error: null })}
          ContentProps={{
            "aria-describedby": "errormsg"
          }}
          message={
            <Typography color="error" id="errormsg">
              {this.state.error}
            </Typography>}
          action={
            <IconButton
              key="close"
              aria-label="Close"
              color="inherit"
              onClick={() => this.setState({ error: null })}>
              <i className="mdi mdi-close" />
            </IconButton>
          } />
      </MqttContext.Provider>
    );
  }
}

const generateTheme = (config: Config) =>
  createTheme({
    palette: {
      primary: Colors[config.space.color]
    }
  });

export default (props: AppProps) => {
  const StyledApp = withStyles(App.styles)(App);
  return (
    <ThemeProvider theme={generateTheme(props.config)}>
      <StyledApp {...props} />
    </ThemeProvider>
  );
};