import * as Long from 'long';
import {HTTPAssets} from '../enums/HTTPAssets';

export class Utils
{
    static StringToBuffer(str: string): Buffer
    {
        return Buffer.from(str + '\0', 'utf8');
    }
    static BufferToStringSimple(buf: Buffer, startPos?: number): string
    {
        if (buf.length === 0)
        {
            return '';
        }
        if (buf[buf.length - 1] === 0)
        {
            return buf.slice(0, buf.length - 1).toString('utf8');
        }
        else
        {
            return buf.toString('utf8');
        }
    }
    static BufferToString(buf: Buffer, startPos?: number):
    {
        readLength: number,
        result: string
    }
    {
        if (buf.length === 0)
        {
            return {
                readLength: 0,
                result: ''
            };
        }
        if (startPos === undefined)
        {
            startPos = 0;
        }

        let foundNull = -1;
        for (let x = startPos; x <= buf.length; x++)
        {
            if (buf[x] === 0)
            {
                foundNull = x;
                break;
            }
        }
        if (foundNull === -1)
        {
            console.error('BufferToString: Null terminator not found after ' + (buf.length - startPos) + ' bytes. Buffer length: ' + buf.length + ', startPos: ' + startPos);
            foundNull = buf.length - 1;
        }
        return {
            readLength: (foundNull - startPos) + 1,
            result: buf.slice(startPos, foundNull).toString('utf8')
        }
    }

    static RegionCoordinatesToHandle(regionX: number, regionY: number): Long
    {
        regionX = Math.floor(regionX / 256) * 256;
        regionY = Math.floor( regionY / 256) * 256;
        return new Long(regionY, regionX);
    }

    static HTTPAssetTypeToInventoryType(HTTPAssetType: string)
    {
        switch (HTTPAssetType)
        {
            case HTTPAssets.ASSET_TEXTURE:
                return 'texture';
            case HTTPAssets.ASSET_SOUND:
                return 'sound';
            case HTTPAssets.ASSET_ANIMATION:
                return 'animation';
            case HTTPAssets.ASSET_GESTURE:
                return 'gesture';
            case HTTPAssets.ASSET_LANDMARK:
                return 'landmark';
            case HTTPAssets.ASSET_CALLINGCARD:
                return 'callcard';
            case HTTPAssets.ASSET_SCRIPT:
                return 'script';
            case HTTPAssets.ASSET_CLOTHING:
                return 'wearable';
            case HTTPAssets.ASSET_OBJECT:
                return 'object';
            case HTTPAssets.ASSET_NOTECARD:
                return 'notecard';
            case HTTPAssets.ASSET_CATEGORY:
                return 'category';
            case HTTPAssets.ASSET_LSL_TEXT:
                return 'script';
            case HTTPAssets.ASSET_LSL_BYTECODE:
                return 'script';
            case HTTPAssets.ASSET_BODYPART:
                return 'wearable';
            case HTTPAssets.ASSET_MESH:
                return 'mesh';
            default:
                return '';
        }
    }

    static UInt16ToFloat(val: number, lower: number, upper: number)
    {
        const ONE_OVER_U16_MAX = 1.0 / 65535;
        let fval = val * ONE_OVER_U16_MAX;
        const delta = upper - lower;
        fval *= delta;
        fval += lower;

        const maxError = delta * ONE_OVER_U16_MAX;
        if (Math.abs(fval) < maxError)
        {
            fval = 0.0;
        }
        return fval;
    }
    static Base64EncodeString(str: string): string
    {
        const buff = new Buffer(str, 'utf8');
        return buff.toString('base64');
    }
    static Base64DecodeString(str: string): string
    {
        const buff = new Buffer(str, 'base64');
        return buff.toString('utf8');
    }
}