/*
 * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import 'dart:async';
import 'dart:typed_data';

import 'package:image/image.dart' as im;

import 'color.dart';

/// Represents a bitmap image
class PdfRasterBase {
  /// Create a bitmap image
  const PdfRasterBase(
    this.width,
    this.height,
    this.alpha,
    this.pixels,
  );

  factory PdfRasterBase.fromImage(im.Image image) {
    final data = image
        .convert(format: im.Format.uint8, numChannels: 4, noAnimation: true)
        .toUint8List();
    return PdfRasterBase(image.width, image.height, true, data);
  }

  factory PdfRasterBase.fromPng(Uint8List png) {
    final img = im.PngDecoder().decode(png)!;
    return PdfRasterBase.fromImage(img);
  }

  static im.Image shadowRect(
    double width,
    double height,
    double spreadRadius,
    double blurRadius,
    PdfColor color,
  ) {
    final shadow = im.Image(
      width: (width + spreadRadius * 2).round(),
      height: (height + spreadRadius * 2).round(),
      format: im.Format.uint8,
      numChannels: 4,
    );

    im.fillRect(
      shadow,
      x1: spreadRadius.round(),
      y1: spreadRadius.round(),
      x2: (spreadRadius + width).round(),
      y2: (spreadRadius + height).round(),
      color: im.ColorUint8(4)
        ..r = color.red * 255
        ..g = color.green * 255
        ..b = color.blue * 255
        ..a = color.alpha * 255,
    );

    return im.gaussianBlur(shadow, radius: blurRadius.round());
  }

  static im.Image shadowEllipse(
    double width,
    double height,
    double spreadRadius,
    double blurRadius,
    PdfColor color,
  ) {
    final shadow = im.Image(
      width: (width + spreadRadius * 2).round(),
      height: (height + spreadRadius * 2).round(),
      format: im.Format.uint8,
      numChannels: 4,
    );

    im.fillCircle(
      shadow,
      x: (spreadRadius + width / 2).round(),
      y: (spreadRadius + height / 2).round(),
      radius: (width / 2).round(),
      color: im.ColorUint8(4)
        ..r = color.red * 255
        ..g = color.green * 255
        ..b = color.blue * 255
        ..a = color.alpha * 255,
    );

    return im.gaussianBlur(shadow, radius: blurRadius.round());
  }

  /// The width of the image
  final int width;

  /// The height of the image
  final int height;

  /// The alpha channel is used
  final bool alpha;

  /// The raw RGBA pixels of the image
  final Uint8List pixels;

  @override
  String toString() => 'Image ${width}x$height ${width * height * 4} bytes';

  /// Convert to a PNG image
  Future<Uint8List> toPng() async {
    final img = asImage();
    return im.PngEncoder().encode(img);
  }

  /// Returns the image as an [Image] object from the pub:image library
  im.Image asImage() {
    return im.Image.fromBytes(
      width: width,
      height: height,
      bytes: pixels.buffer,
      bytesOffset: pixels.offsetInBytes,
      format: im.Format.uint8,
      numChannels: 4,
    );
  }
}