export default class Image {
    width: number;
    height: number;
    data: Uint8Array;

    constructor(
        width: number,
        height: number,
        data = new Uint8Array(width * height * 4)
    ) {
        this.width = width;
        this.height = height;
        this.data = data;
    }

    getImageCrop(
        x: number,
        y: number,
        image: Image,
        x1: number,
        y1: number,
        x2: number,
        y2: number
    ) {
        const width = x2 - x1;
        for (let j = 0; j < y2 - y1; j++) {
            const destIndex = (y + j) * this.width * 4 + x * 4;
            const srcIndex = (y1 + j) * image.width * 4 + x1 * 4;
            this.data.set(
                image.data.subarray(srcIndex, srcIndex + width * 4),
                destIndex
            );
        }
    }

    padToTileSize(tileSize: number) {
        let newWidth = this.width;
        let newHeight = this.height;
        if (this.width < tileSize) {
            newWidth = tileSize;
        }
        if (this.height < tileSize) {
            newHeight = tileSize;
        }
        if (newWidth === this.width && newHeight === this.height) {
            return;
        }
        const newData = new Uint8Array(newWidth * newHeight * 4);
        for (let y = 0; y < this.height; y++) {
            const srcStart = y * this.width * 4;
            const destStart = y * newWidth * 4;
            newData.set(
                this.data.subarray(srcStart, srcStart + this.width * 4),
                destStart
            );
        }
        if (newWidth > this.width) {
            const rightColumnIndex = (this.width - 1) * 4;
            for (let y = 0; y < this.height; y++) {
                const destRowStart = y * newWidth * 4;
                const srcPixelIndex = y * this.width * 4 + rightColumnIndex;
                const padPixel = this.data.subarray(srcPixelIndex, srcPixelIndex + 4);
                for (let x = this.width; x < newWidth; x++) {
                    const destPixelIndex = destRowStart + x * 4;
                    newData.set(padPixel, destPixelIndex);
                }
            }
        }
        if (newHeight > this.height) {
            const bottomRowStart = (this.height - 1) * newWidth * 4;
            const bottomRow = newData.subarray(
                bottomRowStart,
                bottomRowStart + newWidth * 4
            );
            for (let y = this.height; y < newHeight; y++) {
                const destRowStart = y * newWidth * 4;
                newData.set(bottomRow, destRowStart);
            }
        }
        this.width = newWidth;
        this.height = newHeight;
        this.data = newData;
    }

    cropToOriginalSize(width: number, height: number) {
        const newData = new Uint8Array(width * height * 4);
        for (let y = 0; y < height; y++) {
            const srcStart = y * this.width * 4;
            const destStart = y * width * 4;
            newData.set(
                this.data.subarray(srcStart, srcStart + width * 4),
                destStart
            );
        }
        this.width = width;
        this.height = height;
        this.data = newData;
    }
}