import sharp = require("sharp");
import { createReadStream, createWriteStream } from "fs";

// Test samples taken from the official documentation

const input: Buffer = new Buffer(0);
const readableStream: NodeJS.ReadableStream = createReadStream(input);
const writableStream: NodeJS.WritableStream = createWriteStream(input);

sharp(input)
    .extractChannel('green')
    .toFile('input_green.jpg', (err, info) => {
        // info.channels === 1
        // input_green.jpg contains the green channel of the input image
    });

sharp('3-channel-rgb-input.png')
    .bandbool(sharp.bool.and)
    .toFile('1-channel-output.png', (err, info) => {
        // The output will be a single channel image where each pixel `P = R & G & B`.
        // If `I(1,1) = [247, 170, 14] = [0b11110111, 0b10101010, 0b00001111]`
        // then `O(1,1) = 0b11110111 & 0b10101010 & 0b00001111 = 0b00000010 = 2`.
    });

sharp('input.png')
    .rotate(180)
    .resize(300)
    .flatten({ background: "#ff6600" })
    .composite([{ input: 'overlay.png',  gravity: sharp.gravity.southeast }])
    .sharpen()
    .withMetadata()
    .webp({
        quality: 90
    })
    .toBuffer()
    .then((outputBuffer: Buffer) => {
        // outputBuffer contains upside down, 300px wide, alpha channel flattened
        // onto orange background, composited with overlay.png with SE gravity,
        // sharpened, with metadata, 90% quality WebP image data. Phew!
    });

sharp('input.jpg')
    .resize(300, 200)
    .toFile('output.jpg', (err: Error) => {
        // output.jpg is a 300 pixels wide and 200 pixels high image
        // containing a scaled and cropped version of input.jpg
    });

sharp({
    create: {
        width: 300,
        height: 200,
        channels: 4,
        background: { r: 255, g: 0, b: 0, alpha: 128 }
    }
})
.png()
.toBuffer();

let transformer = sharp()
    .resize(300)
    .on('info', (info: sharp.OutputInfo) => {
        console.log('Image height is ' + info.height);
    });
readableStream.pipe(transformer).pipe(writableStream);

console.log(sharp.format);
console.log(sharp.versions);

sharp.queue.on('change', (queueLength: number) => {
    console.log(`Queue contains ${queueLength} task(s)`);
});

let pipeline: sharp.Sharp = sharp().rotate();
pipeline.clone().resize(800, 600).pipe(writableStream);
pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(writableStream);
readableStream.pipe(pipeline);
// firstWritableStream receives auto-rotated, resized readableStream
// secondWritableStream receives auto-rotated, extracted region of readableStream

const image: sharp.Sharp = sharp(input);
image
    .metadata()
    .then<Buffer|undefined>((metadata: sharp.Metadata) => {
        if (metadata.width) {
            return image
                .resize(Math.round(metadata.width / 2))
                .webp()
                .toBuffer();
        }
    })
    .then((data: Buffer) => {
        // data contains a WebP image half the width and height of the original JPEG
    });

pipeline = sharp()
    .rotate()
    .resize(undefined, 200)
    .toBuffer((err: Error, outputBuffer: Buffer, info: sharp.OutputInfo) => {
        // outputBuffer contains 200px high JPEG image data,
        // auto-rotated using EXIF Orientation tag
        // info.width and info.height contain the dimensions of the resized image
    });
readableStream.pipe(pipeline);

sharp(input)
    .extract({ left: 0, top: 0, width: 100, height: 100 })
    .toFile("output", (err: Error) => {
        // Extract a region of the input image, saving in the same format.
    });

sharp(input)
    .extract({ left: 0, top: 0, width: 100, height: 100 })
    .resize(200, 200)
    .extract({ left: 0, top: 0, width: 100, height: 100 })
    .toFile("output", (err: Error) => {
        // Extract a region, resize, then extract from the resized image
    });

// Resize to 140 pixels wide, then add 10 transparent pixels
// to the top, left and right edges and 20 to the bottom edge
sharp(input)
    .resize(140, null, { background: { r: 0, g: 0, b: 0, alpha: 0 } })
    .extend({ top: 10, bottom: 20, left: 10, right: 10 });

sharp(input)
    .convolve({
        width: 3,
        height: 3,
        kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
    })
    .raw()
    .toBuffer((err: Error, data: Buffer, info: sharp.OutputInfo) => {
        // data contains the raw pixel data representing the convolution
        // of the input image with the horizontal Sobel operator
    });

sharp('input.tiff')
    .png()
    .tile({
        size: 512
    })
    .toFile('output.dz', (err: Error, info: sharp.OutputInfo) => {
        // output.dzi is the Deep Zoom XML definition
        // output_files contains 512x512 tiles grouped by zoom level
    });

sharp(input)
    .resize(200, 300, {
        fit: "contain",
        position: "north",
        kernel: sharp.kernel.lanczos2,
        background: "white"
    })
    .toFile('output.tiff')
    .then(() => {
        // output.tiff is a 200 pixels wide and 300 pixels high image
        // containing a lanczos2/nohalo scaled version, embedded on a white canvas,
        // of the image data in inputBuffer
    });

transformer = sharp()
    .resize(200, 200, {
        fit: "cover",
        position: sharp.strategy.entropy
    })
    .on('error', (err: Error) => {
        console.log(err);
    });
// Read image data from readableStream
// Write 200px square auto-cropped image data to writableStream
readableStream.pipe(transformer).pipe(writableStream);

sharp('input.gif')
    .resize(200, 300, {
        fit: "contain",
        position: "north",
        background: { r: 0, g: 0, b: 0, alpha: 0 }
    })
    .toFormat(sharp.format.webp)
    .toBuffer((err: Error, outputBuffer: Buffer) => {
        if (err) {
            throw err;
        }
        // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
        // containing a scaled version, embedded on a transparent canvas, of input.gif
    });

sharp(input)
    .resize(200, 200, { fit: "inside" })
    .toFormat('jpeg')
    .toBuffer()
    .then((outputBuffer: Buffer) => {
        // outputBuffer contains JPEG image data no wider than 200 pixels and no higher
        // than 200 pixels regardless of the inputBuffer image dimensions
    });

sharp(input)
    .resize(100, 100)
    .toBuffer({ resolveWithObject: false })
    .then((outputBuffer: Buffer) => {
        // Resolves with a Buffer object when resolveWithObject is false
    });

sharp(input)
    .resize(100, 100)
    .toBuffer({ resolveWithObject: true })
    .then((object: { data: Buffer, info: sharp.OutputInfo }) => {
        // Resolve with an object containing data Buffer and an OutputInfo object
        // when resolveWithObject is true
    });

const stats = sharp.cache();

sharp.cache({ items: 200 });
sharp.cache({ files: 0 });
sharp.cache(false);

const threads = sharp.concurrency(); // 4
sharp.concurrency(2); // 2
sharp.concurrency(0); // 4

const counters = sharp.counters(); // { queue: 2, process: 4 }

let simd: boolean = sharp.simd();
// simd is `true` if SIMD is currently enabled

simd = sharp.simd(true);
// attempts to enable the use of SIMD, returning true if available

const vipsVersion: string = sharp.versions.vips;

if (sharp.versions.cairo) {
    const cairoVersion: string = sharp.versions.cairo;
}

sharp('input.gif')
    .linear(1)
    .linear(1, 0)
    .linear(null, 0)

    .recomb([
        [0.3588, 0.7044, 0.1368],
        [0.2990, 0.5870, 0.1140],
        [0.2392, 0.4696, 0.0912],
    ])

    .modulate({ brightness: 2 })
    .modulate({ hue: 180 })
    .modulate({ brightness: 0.5, saturation: 0.5, hue: 90 })
;