// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import type * as Common from '../../../../core/common/common.js';
import type * as Platform from '../../../../core/platform/platform.js';
import * as TextUtils from '../../../../models/text_utils/text_utils.js';

import {ResourceSourceFrame} from './ResourceSourceFrame.js';

export class BinaryResourceViewFactory {
  private base64content: string;
  private readonly contentUrl: Platform.DevToolsPath.UrlString;
  private readonly resourceType: Common.ResourceType.ResourceType;
  private arrayPromise: Promise<Uint8Array>|null;
  private hexPromise: Promise<TextUtils.ContentProvider.DeferredContent>|null;
  private utf8Promise: Promise<TextUtils.ContentProvider.DeferredContent>|null;
  constructor(
      base64content: string, contentUrl: Platform.DevToolsPath.UrlString,
      resourceType: Common.ResourceType.ResourceType) {
    this.base64content = base64content;
    this.contentUrl = contentUrl;
    this.resourceType = resourceType;
    this.arrayPromise = null;
    this.hexPromise = null;
    this.utf8Promise = null;
  }

  private async fetchContentAsArray(): Promise<Uint8Array> {
    if (!this.arrayPromise) {
      this.arrayPromise = new Promise(async resolve => {
        const fetchResponse = await fetch('data:;base64,' + this.base64content);
        resolve(new Uint8Array(await fetchResponse.arrayBuffer()));
      });
    }
    return await this.arrayPromise;
  }

  async hex(): Promise<TextUtils.ContentProvider.DeferredContent> {
    if (!this.hexPromise) {
      const content = await this.fetchContentAsArray();
      const hexString = BinaryResourceViewFactory.uint8ArrayToHexString(content);
      return {content: hexString, isEncoded: false};
    }

    return this.hexPromise;
  }

  async base64(): Promise<TextUtils.ContentProvider.DeferredContent> {
    return {content: this.base64content, isEncoded: true};
  }

  async utf8(): Promise<TextUtils.ContentProvider.DeferredContent> {
    if (!this.utf8Promise) {
      this.utf8Promise = new Promise(async resolve => {
        const content = await this.fetchContentAsArray();
        const utf8String = new TextDecoder('utf8').decode(content);
        resolve({content: utf8String, isEncoded: false});
      });
    }

    return this.utf8Promise;
  }

  createBase64View(): ResourceSourceFrame {
    return new ResourceSourceFrame(
        TextUtils.StaticContentProvider.StaticContentProvider.fromString(
            this.contentUrl, this.resourceType, this.base64content),
        this.resourceType.canonicalMimeType(), {lineNumbers: false, lineWrapping: true});
  }

  createHexView(): ResourceSourceFrame {
    const hexViewerContentProvider =
        new TextUtils.StaticContentProvider.StaticContentProvider(this.contentUrl, this.resourceType, async () => {
          const contentAsArray = await this.fetchContentAsArray();
          const content = BinaryResourceViewFactory.uint8ArrayToHexViewer(contentAsArray);
          return {content, isEncoded: false};
        });
    return new ResourceSourceFrame(
        hexViewerContentProvider, this.resourceType.canonicalMimeType(), {lineNumbers: false, lineWrapping: false});
  }

  createUtf8View(): ResourceSourceFrame {
    const utf8fn = this.utf8.bind(this);
    const utf8ContentProvider =
        new TextUtils.StaticContentProvider.StaticContentProvider(this.contentUrl, this.resourceType, utf8fn);
    return new ResourceSourceFrame(
        utf8ContentProvider, this.resourceType.canonicalMimeType(), {lineNumbers: true, lineWrapping: true});
  }

  static uint8ArrayToHexString(uint8Array: Uint8Array): string {
    let output = '';
    for (let i = 0; i < uint8Array.length; i++) {
      output += BinaryResourceViewFactory.numberToHex(uint8Array[i], 2);
    }
    return output;
  }

  static numberToHex(number: number, padding: number): string {
    let hex = number.toString(16);
    while (hex.length < padding) {
      hex = '0' + hex;
    }
    return hex;
  }

  static uint8ArrayToHexViewer(array: Uint8Array): string {
    let output = '';
    let line = 0;

    while ((line * 16) < array.length) {
      const lineArray = array.slice(line * 16, (line + 1) * 16);

      // line number
      output += BinaryResourceViewFactory.numberToHex(line, 8) + ':';

      // hex
      let hexColsPrinted = 0;
      for (let i = 0; i < lineArray.length; i++) {
        if (i % 2 === 0) {
          output += ' ';
          hexColsPrinted++;
        }
        output += BinaryResourceViewFactory.numberToHex(lineArray[i], 2);
        hexColsPrinted += 2;
      }

      // hex-ascii padding
      while (hexColsPrinted < 42) {
        output += ' ';
        hexColsPrinted++;
      }

      // ascii
      for (let i = 0; i < lineArray.length; i++) {
        const code = lineArray[i];
        if (code >= 32 && code <= 126) {
          // printable ascii character
          output += String.fromCharCode(code);
        } else {
          // non-printable
          output += '.';
        }
      }

      output += '\n';
      line++;
    }
    return output;
  }
}