import { BadRequestException, Injectable, Logger } from '@nestjs/common';
import { Floor } from 'src/objects/building/entities/floor.entity';
import { PlanRenderer } from './renderer';
import { FloorDocument } from './renderer/renderer.interfaces';
import fs from 'fs';
import { join } from 'path';
import { isValidLayer } from './renderer/plan-validators';

@Injectable()
export class PlanRendererService {
  public validateFloorDocument(floorDocument: FloorDocument) {
    const valid =
      floorDocument?.layers &&
      !isNaN(floorDocument.height) &&
      !isNaN(floorDocument.width) &&
      floorDocument.height > 0 &&
      floorDocument.width > 0 &&
      Array.isArray(floorDocument.layers) &&
      floorDocument.layers.every(isValidLayer);

    if (!valid)
      throw new BadRequestException(
        'Floor plan JSON is incorrect or malformed',
      );
  }

  public renderFloor(floor: Floor) {
    const plan = JSON.parse(floor.plan || '{}') as FloorDocument;
    this.validateFloorDocument(plan);

    if (plan.layers.every(({ contents }) => !contents.length)) return;

    const filename = `floorplan-${floor.id}.png`;
    const output = fs.createWriteStream(
      join(process.cwd(), 'usercontent', filename),
    );

    const pngStream = PlanRenderer.renderFloorDocument(plan);
    pngStream.pipe(output);
    output.on('finish', () =>
      Logger.log(`Floor plan for ID:${plan.id} has been rendered`),
    );
    floor.planImage = filename;
  }
}