import { WidgetDAO } from "@/consumer/dao";
import { TracingLogger } from "@/consumer/log";
import { Widget, WidgetT, WidgetRequestT } from "@/shared/schema";

export class ConsumerRequestProcessor implements WidgetRequestProcessor {
  private widgetDao: WidgetDAO;
  private logger: TracingLogger;

  constructor(widgetDao: WidgetDAO, logger: TracingLogger) {
    this.widgetDao = widgetDao;
    this.logger = logger;
  }

  public async processRequest(widgetRequest: WidgetRequestT) {
    this.logger.info(
      `processing RequestId=(${widgetRequest.requestId}) with WidgetRequestType=(${widgetRequest.type})`
    );
    switch (widgetRequest.type) {
      case "create":
        await this.createWidget(widgetRequest);
        break;
      case "delete":
        await this.deleteWidget(widgetRequest);
        break;
      case "update":
        await this.updateWidget(widgetRequest);
        break;
      default:
        this.logger.warn(
          `received WidgetRequestType=(${widgetRequest.type})... don't know what to do!`
        );
        break;
    }
  }

  private async createWidget(widgetRequest: WidgetRequestT) {
    this.logger.info(`creating new Widget=(${widgetRequest.widgetId})`);
    const widget = this.widgetFromWidgetRequest(widgetRequest);

    const currentWidget = await this.widgetDao.retrieve(widget);

    if (!currentWidget) {
      await this.widgetDao.save(widget);
    } else {
      this.logger.warn(
        `received creation request for Widget=(${widget.id}) but it already exists... skipping`
      );
    }
  }

  private async deleteWidget(widgetRequest: WidgetRequestT) {
    this.logger.info(`deleting Widget=(${widgetRequest.widgetId})`);
    const widget = this.widgetFromWidgetRequest(widgetRequest);

    const currentWidget = await this.widgetDao.retrieve(widget);

    if (currentWidget) {
      await this.widgetDao.delete(widget);
    } else {
      this.logger.warn(
        `received deletion request for Widget=(${widget.id}) but it did not exist... skipping`
      );
    }
  }

  private async updateWidget(widgetRequest: WidgetRequestT) {
    this.logger.info(`updating Widget=(${widgetRequest.widgetId})`);
    const widget = this.widgetFromWidgetRequest(widgetRequest);

    const currentWidget = await this.widgetDao.retrieve(widget);
    if (!currentWidget) {
      this.logger.warn(
        `attempted to retrieve Widget=(${widgetRequest.widgetId}) to update, but it doesn't exist! skipping...`
      );
      return;
    }

    const immutableKeys = ["id", "owner"] as unknown as (keyof WidgetT)[];

    for (const key of Object.keys(widget) as unknown as (keyof WidgetT)[]) {
      const isImmutable = immutableKeys.includes(key);
      if (!isImmutable && widget[key] === "") {
        delete widget[key];
        delete currentWidget[key];
      } else if (isImmutable && widget[key] !== currentWidget[key]) {
        this.logger.warn(
          `cannot change ${key} on Widget=(${widget.id}). skipping...`
        );
        return;
      }
    }

    const otherAttributeMap = new Map<string, string>();
    [
      ...(currentWidget.otherAttributes ?? []),
      ...(widget.otherAttributes ?? []),
    ].forEach(({ name, value }) => {
      if (value != null) otherAttributeMap.set(name, value);
      if (value == "") otherAttributeMap.delete(name);
    });
    const otherAttributes = Array.from(otherAttributeMap.entries()).map(
      ([name, value]) => {
        return { name, value };
      }
    );

    const newWidget: WidgetT = {
      ...currentWidget,
      ...widget,
    };

    if (otherAttributes.length) {
      newWidget.otherAttributes = otherAttributes;
    }

    await this.widgetDao.save(newWidget);
  }

  private widgetFromWidgetRequest(widgetRequest: WidgetRequestT): WidgetT {
    const widget: Record<string, any> = {
      id: widgetRequest.widgetId,
      owner: widgetRequest.owner,
    };

    if (widgetRequest.label !== undefined) widget.label = widgetRequest.label;
    if (widgetRequest.description !== undefined)
      widget.description = widgetRequest.description;
    if (widgetRequest.otherAttributes?.length)
      widget.otherAttributes = widgetRequest.otherAttributes;

    return Widget.parse(widget);
  }
}