import { injectable, inject } from 'inversify';
import { Emitter } from '@theia/core/lib/common/event';
import { ILogger } from '@theia/core/lib/common/logger';
import { CommandService } from '@theia/core/lib/common/command';
import { MessageService } from '@theia/core/lib/common/message-service';
import { FrontendApplicationContribution } from '@theia/core/lib/browser/frontend-application';
import { RecursiveRequired } from '../../common/types';
import {
  Port,
  Board,
  BoardsService,
  BoardsPackage,
  AttachedBoardsChangeEvent,
  BoardWithPackage,
} from '../../common/protocol';
import { BoardsConfig } from './boards-config';
import { naturalCompare } from '../../common/utils';
import { NotificationCenter } from '../notification-center';
import { ArduinoCommands } from '../arduino-commands';
import { StorageWrapper } from '../storage-wrapper';

@injectable()
export class BoardsServiceProvider implements FrontendApplicationContribution {
  @inject(ILogger)
  protected logger: ILogger;

  @inject(MessageService)
  protected messageService: MessageService;

  @inject(BoardsService)
  protected boardsService: BoardsService;

  @inject(CommandService)
  protected commandService: CommandService;

  @inject(NotificationCenter)
  protected notificationCenter: NotificationCenter;

  protected readonly onBoardsConfigChangedEmitter =
    new Emitter<BoardsConfig.Config>();
  protected readonly onAvailableBoardsChangedEmitter = new Emitter<
    AvailableBoard[]
  >();

  /**
   * Used for the auto-reconnecting. Sometimes, the attached board gets disconnected after uploading something to it.
   * It happens with certain boards on Windows. For example, the `MKR1000` boards is selected on post `COM5` on Windows,
   * perform an upload, the board automatically disconnects and reconnects, but on another port, `COM10`.
   * We have to listen on such changes and auto-reconnect the same board on another port.
   * See: https://arduino.slack.com/archives/CJJHJCJSJ/p1568645417013000?thread_ts=1568640504.009400&cid=CJJHJCJSJ
   */
  protected latestValidBoardsConfig:
    | RecursiveRequired<BoardsConfig.Config>
    | undefined = undefined;
  protected latestBoardsConfig: BoardsConfig.Config | undefined = undefined;
  protected _boardsConfig: BoardsConfig.Config = {};
  protected _attachedBoards: Board[] = []; // This does not contain the `Unknown` boards. They're visible from the available ports only.
  protected _availablePorts: Port[] = [];
  protected _availableBoards: AvailableBoard[] = [];

  /**
   * Unlike `onAttachedBoardsChanged` this even fires when the user modifies the selected board in the IDE.\
   * This even also fires, when the boards package was not available for the currently selected board,
   * and the user installs the board package. Note: installing a board package will set the `fqbn` of the
   * currently selected board.\
   * This even also emitted when the board package for the currently selected board was uninstalled.
   */
  readonly onBoardsConfigChanged = this.onBoardsConfigChangedEmitter.event;
  readonly onAvailableBoardsChanged =
    this.onAvailableBoardsChangedEmitter.event;

  onStart(): void {
    this.notificationCenter.onAttachedBoardsChanged(
      this.notifyAttachedBoardsChanged.bind(this)
    );
    this.notificationCenter.onPlatformInstalled(
      this.notifyPlatformInstalled.bind(this)
    );
    this.notificationCenter.onPlatformUninstalled(
      this.notifyPlatformUninstalled.bind(this)
    );

    Promise.all([
      this.boardsService.getAttachedBoards(),
      this.boardsService.getAvailablePorts(),
      this.loadState(),
    ]).then(([attachedBoards, availablePorts]) => {
      this._attachedBoards = attachedBoards;
      this._availablePorts = availablePorts;
      this.reconcileAvailableBoards().then(() => this.tryReconnect());
    });
  }

  protected notifyAttachedBoardsChanged(
    event: AttachedBoardsChangeEvent
  ): void {
    if (!AttachedBoardsChangeEvent.isEmpty(event)) {
      this.logger.info('Attached boards and available ports changed:');
      this.logger.info(AttachedBoardsChangeEvent.toString(event));
      this.logger.info('------------------------------------------');
    }
    this._attachedBoards = event.newState.boards;
    this._availablePorts = event.newState.ports;
    this.reconcileAvailableBoards().then(() => this.tryReconnect());
  }

  protected notifyPlatformInstalled(event: { item: BoardsPackage }): void {
    this.logger.info('Boards package installed: ', JSON.stringify(event));
    const { selectedBoard } = this.boardsConfig;
    const { installedVersion, id } = event.item;
    if (selectedBoard) {
      const installedBoard = event.item.boards.find(
        ({ name }) => name === selectedBoard.name
      );
      if (
        installedBoard &&
        (!selectedBoard.fqbn || selectedBoard.fqbn === installedBoard.fqbn)
      ) {
        this.logger.info(
          `Board package ${id}[${installedVersion}] was installed. Updating the FQBN of the currently selected ${selectedBoard.name} board. [FQBN: ${installedBoard.fqbn}]`
        );
        this.boardsConfig = {
          ...this.boardsConfig,
          selectedBoard: installedBoard,
        };
        return;
      }
      // The board name can change after install.
      // This logic handles it "gracefully" by unselecting the board, so that we can avoid no FQBN is set error.
      // https://github.com/arduino/arduino-cli/issues/620
      // https://github.com/arduino/arduino-pro-ide/issues/374
      if (
        BoardWithPackage.is(selectedBoard) &&
        selectedBoard.packageId === event.item.id &&
        !installedBoard
      ) {
        this.messageService
          .warn(
            `Could not find previously selected board '${selectedBoard.name}' in installed platform '${event.item.name}'. Please manually reselect the board you want to use. Do you want to reselect it now?`,
            'Reselect later',
            'Yes'
          )
          .then(async (answer) => {
            if (answer === 'Yes') {
              this.commandService.executeCommand(
                ArduinoCommands.OPEN_BOARDS_DIALOG.id,
                selectedBoard.name
              );
            }
          });
        this.boardsConfig = {};
        return;
      }
      // Trigger a board re-set. See: https://github.com/arduino/arduino-cli/issues/954
      // E.g: install `adafruit:avr`, then select `adafruit:avr:adafruit32u4` board, and finally install the required `arduino:avr`
      this.boardsConfig = this.boardsConfig;
    }
  }

  protected notifyPlatformUninstalled(event: { item: BoardsPackage }): void {
    this.logger.info('Boards package uninstalled: ', JSON.stringify(event));
    const { selectedBoard } = this.boardsConfig;
    if (selectedBoard && selectedBoard.fqbn) {
      const uninstalledBoard = event.item.boards.find(
        ({ name }) => name === selectedBoard.name
      );
      if (uninstalledBoard && uninstalledBoard.fqbn === selectedBoard.fqbn) {
        // We should not unset the FQBN, if the selected board is an attached, recognized board.
        // Attach Uno and install AVR, select Uno. Uninstall the AVR core while Uno is selected. We do not want to discard the FQBN of the Uno board.
        // Dev note: We cannot assume the `selectedBoard` is a type of `AvailableBoard`.
        // When the user selects an `AvailableBoard` it works, but between app start/stops,
        // it is just a FQBN, so we need to find the `selected` board among the `AvailableBoards`
        const selectedAvailableBoard = AvailableBoard.is(selectedBoard)
          ? selectedBoard
          : this._availableBoards.find((availableBoard) =>
              Board.sameAs(availableBoard, selectedBoard)
            );
        if (
          selectedAvailableBoard &&
          selectedAvailableBoard.selected &&
          selectedAvailableBoard.state === AvailableBoard.State.recognized
        ) {
          return;
        }
        this.logger.info(
          `Board package ${event.item.id} was uninstalled. Discarding the FQBN of the currently selected ${selectedBoard.name} board.`
        );
        const selectedBoardWithoutFqbn = {
          name: selectedBoard.name,
          // No FQBN
        };
        this.boardsConfig = {
          ...this.boardsConfig,
          selectedBoard: selectedBoardWithoutFqbn,
        };
      }
    }
  }

  protected async tryReconnect(): Promise<boolean> {
    if (this.latestValidBoardsConfig && !this.canUploadTo(this.boardsConfig)) {
      for (const board of this.availableBoards.filter(
        ({ state }) => state !== AvailableBoard.State.incomplete
      )) {
        if (
          this.latestValidBoardsConfig.selectedBoard.fqbn === board.fqbn &&
          this.latestValidBoardsConfig.selectedBoard.name === board.name &&
          Port.sameAs(this.latestValidBoardsConfig.selectedPort, board.port)
        ) {
          this.boardsConfig = this.latestValidBoardsConfig;
          return true;
        }
      }
      // If we could not find an exact match, we compare the board FQBN-name pairs and ignore the port, as it might have changed.
      // See documentation on `latestValidBoardsConfig`.
      for (const board of this.availableBoards.filter(
        ({ state }) => state !== AvailableBoard.State.incomplete
      )) {
        if (
          this.latestValidBoardsConfig.selectedBoard.fqbn === board.fqbn &&
          this.latestValidBoardsConfig.selectedBoard.name === board.name
        ) {
          this.boardsConfig = {
            ...this.latestValidBoardsConfig,
            selectedPort: board.port,
          };
          return true;
        }
      }
    }
    return false;
  }

  set boardsConfig(config: BoardsConfig.Config) {
    this.doSetBoardsConfig(config);
    this.saveState().finally(() =>
      this.reconcileAvailableBoards().finally(() =>
        this.onBoardsConfigChangedEmitter.fire(this._boardsConfig)
      )
    );
  }

  get boardsConfig(): BoardsConfig.Config {
    return this._boardsConfig;
  }

  protected doSetBoardsConfig(config: BoardsConfig.Config): void {
    this.logger.info('Board config changed: ', JSON.stringify(config));
    this._boardsConfig = config;
    this.latestBoardsConfig = this._boardsConfig;
    if (this.canUploadTo(this._boardsConfig)) {
      this.latestValidBoardsConfig = this._boardsConfig;
    }
  }

  async searchBoards({
    query,
    cores,
  }: {
    query?: string;
    cores?: string[];
  }): Promise<BoardWithPackage[]> {
    const boards = await this.boardsService.searchBoards({ query });
    return boards;
  }

  /**
   * `true` if the `config.selectedBoard` is defined; hence can compile against the board. Otherwise, `false`.
   */
  canVerify(
    config: BoardsConfig.Config | undefined = this.boardsConfig,
    options: { silent: boolean } = { silent: true }
  ): config is BoardsConfig.Config & { selectedBoard: Board } {
    if (!config) {
      return false;
    }

    if (!config.selectedBoard) {
      if (!options.silent) {
        this.messageService.warn('No boards selected.', {
          timeout: 3000,
        });
      }
      return false;
    }

    return true;
  }

  /**
   * `true` if `canVerify`, the board has an FQBN and the `config.selectedPort` is also set, hence can upload to board. Otherwise, `false`.
   */
  canUploadTo(
    config: BoardsConfig.Config | undefined = this.boardsConfig,
    options: { silent: boolean } = { silent: true }
  ): config is RecursiveRequired<BoardsConfig.Config> {
    if (!this.canVerify(config, options)) {
      return false;
    }

    const { name } = config.selectedBoard;
    if (!config.selectedPort) {
      if (!options.silent) {
        this.messageService.warn(`No ports selected for board: '${name}'.`, {
          timeout: 3000,
        });
      }
      return false;
    }

    if (!config.selectedBoard.fqbn) {
      if (!options.silent) {
        this.messageService.warn(
          `The FQBN is not available for the selected board ${name}. Do you have the corresponding core installed?`,
          { timeout: 3000 }
        );
      }
      return false;
    }

    return true;
  }

  get availableBoards(): AvailableBoard[] {
    return this._availableBoards;
  }

  async waitUntilAvailable(
    what: Board & { port: Port },
    timeout?: number
  ): Promise<void> {
    const find = (needle: Board & { port: Port }, haystack: AvailableBoard[]) =>
      haystack.find(
        (board) =>
          Board.equals(needle, board) && Port.equals(needle.port, board.port)
      );
    const timeoutTask =
      !!timeout && timeout > 0
        ? new Promise<void>((_, reject) =>
            setTimeout(
              () => reject(new Error(`Timeout after ${timeout} ms.`)),
              timeout
            )
          )
        : new Promise<void>(() => {
            /* never */
          });
    const waitUntilTask = new Promise<void>((resolve) => {
      let candidate = find(what, this.availableBoards);
      if (candidate) {
        resolve();
        return;
      }
      const disposable = this.onAvailableBoardsChanged((availableBoards) => {
        candidate = find(what, availableBoards);
        if (candidate) {
          disposable.dispose();
          resolve();
        }
      });
    });
    return await Promise.race([waitUntilTask, timeoutTask]);
  }

  protected async reconcileAvailableBoards(): Promise<void> {
    const attachedBoards = this._attachedBoards;
    const availablePorts = this._availablePorts;
    // Unset the port on the user's config, if it is not available anymore.
    if (
      this.boardsConfig.selectedPort &&
      !availablePorts.some((port) =>
        Port.sameAs(port, this.boardsConfig.selectedPort)
      )
    ) {
      this.doSetBoardsConfig({
        selectedBoard: this.boardsConfig.selectedBoard,
        selectedPort: undefined,
      });
      this.onBoardsConfigChangedEmitter.fire(this._boardsConfig);
    }
    const boardsConfig = this.boardsConfig;
    const currentAvailableBoards = this._availableBoards;
    const availableBoards: AvailableBoard[] = [];
    const availableBoardPorts = availablePorts.filter(Port.isBoardPort);
    const attachedSerialBoards = attachedBoards.filter(({ port }) => !!port);

    for (const boardPort of availableBoardPorts) {
      let state = AvailableBoard.State.incomplete; // Initial pessimism.
      let board = attachedSerialBoards.find(({ port }) =>
        Port.sameAs(boardPort, port)
      );
      if (board) {
        state = AvailableBoard.State.recognized;
      } else {
        // If the selected board is not recognized because it is a 3rd party board: https://github.com/arduino/arduino-cli/issues/623
        // We still want to show it without the red X in the boards toolbar: https://github.com/arduino/arduino-pro-ide/issues/198#issuecomment-599355836
        const lastSelectedBoard = await this.getLastSelectedBoardOnPort(
          boardPort
        );
        if (lastSelectedBoard) {
          board = {
            ...lastSelectedBoard,
            port: boardPort,
          };
          state = AvailableBoard.State.guessed;
        }
      }
      if (!board) {
        availableBoards.push({
          name: 'Unknown',
          port: boardPort,
          state,
        });
      } else {
        const selected = BoardsConfig.Config.sameAs(boardsConfig, board);
        availableBoards.push({
          ...board,
          state,
          selected,
          port: boardPort,
        });
      }
    }

    if (
      boardsConfig.selectedBoard &&
      !availableBoards.some(({ selected }) => selected)
    ) {
      availableBoards.push({
        ...boardsConfig.selectedBoard,
        port: boardsConfig.selectedPort,
        selected: true,
        state: AvailableBoard.State.incomplete,
      });
    }

    const sortedAvailableBoards = availableBoards.sort(AvailableBoard.compare);
    let hasChanged =
      sortedAvailableBoards.length !== currentAvailableBoards.length;
    for (let i = 0; !hasChanged && i < sortedAvailableBoards.length; i++) {
      hasChanged =
        AvailableBoard.compare(
          sortedAvailableBoards[i],
          currentAvailableBoards[i]
        ) !== 0;
    }
    if (hasChanged) {
      this._availableBoards = sortedAvailableBoards;
      this.onAvailableBoardsChangedEmitter.fire(this._availableBoards);
    }
  }

  protected async getLastSelectedBoardOnPort(
    port: Port | string | undefined
  ): Promise<Board | undefined> {
    if (!port) {
      return undefined;
    }
    const key = this.getLastSelectedBoardOnPortKey(port);
    return this.getData<Board>(key);
  }

  protected async saveState(): Promise<void> {
    // We save the port with the selected board name/FQBN, to be able to guess a better board name.
    // Required when the attached board belongs to a 3rd party boards package, and neither the name, nor
    // the FQBN can be retrieved with a `board list` command.
    // https://github.com/arduino/arduino-cli/issues/623
    const { selectedBoard, selectedPort } = this.boardsConfig;
    if (selectedBoard && selectedPort) {
      const key = this.getLastSelectedBoardOnPortKey(selectedPort);
      await this.setData(key, selectedBoard);
    }
    await Promise.all([
      this.setData('latest-valid-boards-config', this.latestValidBoardsConfig),
      this.setData('latest-boards-config', this.latestBoardsConfig),
    ]);
  }

  protected getLastSelectedBoardOnPortKey(port: Port | string): string {
    // TODO: we lose the port's `protocol` info (`serial`, `network`, etc.) here if the `port` is a `string`.
    return `last-selected-board-on-port:${
      typeof port === 'string' ? port : Port.toString(port)
    }`;
  }

  protected async loadState(): Promise<void> {
    const storedLatestValidBoardsConfig = await this.getData<
      RecursiveRequired<BoardsConfig.Config>
    >('latest-valid-boards-config');
    if (storedLatestValidBoardsConfig) {
      this.latestValidBoardsConfig = storedLatestValidBoardsConfig;
      if (this.canUploadTo(this.latestValidBoardsConfig)) {
        this.boardsConfig = this.latestValidBoardsConfig;
      }
    } else {
      // If we could not restore the latest valid config, try to restore something, the board at least.
      let storedLatestBoardsConfig = await this.getData<
        BoardsConfig.Config | undefined
      >('latest-boards-config');
      // Try to get from the URL if it was not persisted.
      if (!storedLatestBoardsConfig) {
        storedLatestBoardsConfig = BoardsConfig.Config.getConfig(
          new URL(window.location.href)
        );
      }
      if (storedLatestBoardsConfig) {
        this.latestBoardsConfig = storedLatestBoardsConfig;
        this.boardsConfig = this.latestBoardsConfig;
      }
    }
  }

  private setData<T>(key: string, value: T): Promise<void> {
    return this.commandService.executeCommand(
      StorageWrapper.Commands.SET_DATA.id,
      key,
      value
    );
  }

  private getData<T>(key: string): Promise<T | undefined> {
    return this.commandService.executeCommand<T>(
      StorageWrapper.Commands.GET_DATA.id,
      key
    );
  }
}

/**
 * Representation of a ready-to-use board, either the user has configured it or was automatically recognized by the CLI.
 * An available board was not necessarily recognized by the CLI (e.g.: it is a 3rd party board) or correctly configured but ready for `verify`.
 * If it has the selected board and a associated port, it can be used for `upload`. We render an available board for the user
 * when it has the `port` set.
 */
export interface AvailableBoard extends Board {
  readonly state: AvailableBoard.State;
  readonly selected?: boolean;
  readonly port?: Port;
}

export namespace AvailableBoard {
  export enum State {
    /**
     * Retrieved from the CLI via the `board list` command.
     */
    'recognized',
    /**
     * Guessed the name/FQBN of the board from the available board ports (3rd party).
     */
    'guessed',
    /**
     * We do not know anything about this board, probably a 3rd party. The user has not selected a board for this port yet.
     */
    'incomplete',
  }

  export function is(board: any): board is AvailableBoard {
    return Board.is(board) && 'state' in board;
  }

  export function hasPort(
    board: AvailableBoard
  ): board is AvailableBoard & { port: Port } {
    return !!board.port;
  }

  export const compare = (left: AvailableBoard, right: AvailableBoard) => {
    if (left.selected && !right.selected) {
      return -1;
    }
    if (right.selected && !left.selected) {
      return 1;
    }
    let result = naturalCompare(left.name, right.name);
    if (result !== 0) {
      return result;
    }
    if (left.fqbn && right.fqbn) {
      result = naturalCompare(left.fqbn, right.fqbn);
      if (result !== 0) {
        return result;
      }
    }
    if (left.port && right.port) {
      result = Port.compare(left.port, right.port);
      if (result !== 0) {
        return result;
      }
    }
    if (!!left.selected && !right.selected) {
      return -1;
    }
    if (!!right.selected && !left.selected) {
      return 1;
    }
    return left.state - right.state;
  };
}