import * as fs from 'fs';
import * as LooksSameStub from 'looks-same';
import { Image } from './image-utils';
import { ScreenshotLocations } from './file-utils';
import Diagnostics from './diagnostics';
import { takeScreenshot } from './take-screenshot';
import { buildTextMask } from './build-text-mask';
import type { DiffOptions, IComparerOptions, SelectorType } from './options';

function looksSame(item1: Image, item2: Image, options: DiffOptions): Promise<{ equal?: boolean }> {
  return new Promise((resolve, reject) => {
    LooksSameStub(item1.getBuffer(), item2.getBuffer(), options, (error, result) => {
      if (error) {
        reject(error);
      } else {
        resolve(result);
      }
    });
  });
}

export async function tryGetValidScreenshot(
  t: TestController,
  element: SelectorType,
  options: IComparerOptions,
  locations: ScreenshotLocations,
  diag: Diagnostics,
) : Promise<{
    equal: boolean;
    screenshot: Image | null;
    patchedByMaskScreenshot: Image | null;
    textMask: Image | null;
  }> {
  let equal = false;
  let attempt = 0;
  let currentScreenshot: Image | null = null;
  let patchedByMaskScreenshot: Image | null = null;
  let textMask: Image | null = null;

  if (!locations.source.exists('file')) {
    await takeScreenshot(t, element, locations.temp.filePath);
    throw new Error('etalon file not found');
  }
  const sourceScreenshot = locations.source.read('file');
  const emptyImage = sourceScreenshot.as((x) => x.fill({ r: 0, g: 0, b: 0 }));
  while (!equal && attempt < options.attempts) {
    diag.log(`Starting attempt ${attempt}`);
    diag.pushPrefix(`attempt${attempt}-`);
    if (attempt > 0) {
      // eslint-disable-next-line @typescript-eslint/no-loop-func
      const patchFileName = (fn) => `${fn}_${attempt}`;
      fs.unlinkSync(locations.temp.filePath);
      locations.temp.patchFileName(patchFileName);
      locations.tempText.patchFileName(patchFileName);
    }
    await takeScreenshot(t, element, locations.temp.filePath);
    let mask = locations.source.tryRead('mask');

    currentScreenshot = locations.temp.read('file');
    diag.log('0 temp clean ', currentScreenshot);

    textMask = await buildTextMask(options, attempt, t, element, locations, diag, currentScreenshot, emptyImage, sourceScreenshot);

    if (textMask) {
      if (mask) { mask.and(textMask); } else { mask = textMask; }
    }
    patchedByMaskScreenshot = currentScreenshot.as((x) => x.replace(sourceScreenshot, mask));
    equal = (await looksSame(
      sourceScreenshot,
      patchedByMaskScreenshot,
      options.looksSameComparisonOptions,
    )).equal;
    diag.log('6 result', { equal });

    if (!equal && attempt < options.attempts) {
      await t.wait(options.attemptTimeout);
    }

    attempt += 1;
    diag.popPrefix();
  }
  return {
    equal, screenshot: currentScreenshot, patchedByMaskScreenshot, textMask,
  };
}