"use strict"

var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k
    var desc = Object.getOwnPropertyDescriptor(m, k)
    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
      desc = { enumerable: true, get: function() { return m[k] } }
    }
    Object.defineProperty(o, k2, desc)
}) : (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k
    o[k2] = m[k]
}))

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    Object.defineProperty(o, "default", { enumerable: true, value: v })
}) : function(o, v) {
    o["default"] = v
})

var __importStar = (this && this.__importStar) || function (mod) {
    if (mod && mod.__esModule) return mod
    var result = {}
    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k)
    __setModuleDefault(result, mod)
    return result
}

Object.defineProperty(exports, "__esModule", { value: true })

const util_1 = require("util")
const zlib_1 = require("zlib")
const constants = __importStar(require("./constants"))
const jid_utils_1 = require("./jid-utils")
const inflatePromise = util_1.promisify(zlib_1.inflate)

const decompressingIfRequired = async (buffer) => {
    if (2 & buffer.readUInt8()) {
        buffer = await inflatePromise(buffer.slice(1))
    }
    else { // nodes with no compression have a 0x00 prefix, we remove that
        buffer = buffer.slice(1)
    }
    return buffer
}

const decodeDecompressedBinaryNode = (buffer, opts, indexRef = { index: 0 }) => {
    const { DOUBLE_BYTE_TOKENS, SINGLE_BYTE_TOKENS, TAGS } = opts
    const checkEOS = (length) => {
        if (indexRef.index + length > buffer.length) {
            throw new Error('end of stream')
        }
    }
    
    const next = () => {
        const value = buffer[indexRef.index]
        indexRef.index += 1
        return value
    }
    
    const readByte = () => {
        checkEOS(1)
        return next()
    }
    
    const readBytes = (n) => {
        checkEOS(n)
        const value = buffer.slice(indexRef.index, indexRef.index + n)
        indexRef.index += n
        return value
    }
    
    const readStringFromChars = (length) => {
        return readBytes(length).toString('utf-8')
    }
    
    const readInt = (n, littleEndian = false) => {
        checkEOS(n)
        let val = 0
        for (let i = 0; i < n; i++) {
            const shift = littleEndian ? i : n - 1 - i
            val |= next() << (shift * 8)
        }
        return val
    }
    
    const readInt20 = () => {
        checkEOS(3)
        return ((next() & 15) << 16) + (next() << 8) + next()
    }
    
    const unpackHex = (value) => {
        if (value >= 0 && value < 16) {
            return value < 10 ? '0'.charCodeAt(0) + value : 'A'.charCodeAt(0) + value - 10
        }
        throw new Error('invalid hex: ' + value)
    }
    
    const unpackNibble = (value) => {
        if (value >= 0 && value <= 9) {
            return '0'.charCodeAt(0) + value
        }
        switch (value) {
            case 10:
                return '-'.charCodeAt(0)
            case 11:
                return '.'.charCodeAt(0)
            case 15:
                return '\0'.charCodeAt(0)
            default:
                throw new Error('invalid nibble: ' + value)
        }
    }
    
    const unpackByte = (tag, value) => {
        if (tag === TAGS.NIBBLE_8) {
            return unpackNibble(value)
        }
        else if (tag === TAGS.HEX_8) {
            return unpackHex(value)
        }
        else {
            throw new Error('unknown tag: ' + tag)
        }
    }
    
    const readPacked8 = (tag) => {
        const startByte = readByte()
        let value = ''
        for (let i = 0; i < (startByte & 127); i++) {
            const curByte = readByte()
            value += String.fromCharCode(unpackByte(tag, (curByte & 0xf0) >> 4))
            value += String.fromCharCode(unpackByte(tag, curByte & 0x0f))
        }
        if (startByte >> 7 !== 0) {
            value = value.slice(0, -1)
        }
        return value
    }
    
    const isListTag = (tag) => {
        return tag === TAGS.LIST_EMPTY || tag === TAGS.LIST_8 || tag === TAGS.LIST_16
    }
    
    const readListSize = (tag) => {
        switch (tag) {
            case TAGS.LIST_EMPTY:
                return 0
            case TAGS.LIST_8:
                return readByte()
            case TAGS.LIST_16:
                return readInt(2)
            default:
                throw new Error('invalid tag for list size: ' + tag)
        }
    }
    
    const readJidPair = () => {
        const i = readString(readByte())
        const j = readString(readByte())
        if (j) {
            return (i || '') + '@' + j
        }
        throw new Error('invalid jid pair: ' + i + ', ' + j)
    }
    
    const readAdJid = () => {
        const agent = readByte()
        const device = readByte()
        const user = readString(readByte())
        return jid_utils_1.jidEncode(user, agent === 0 ? 's.whatsapp.net' : 'lid', device)
    }
    
    const readString = (tag) => {
        if (tag >= 1 && tag < SINGLE_BYTE_TOKENS.length) {
            return SINGLE_BYTE_TOKENS[tag] || ''
        }
        switch (tag) {
            case TAGS.DICTIONARY_0:
            case TAGS.DICTIONARY_1:
            case TAGS.DICTIONARY_2:
            case TAGS.DICTIONARY_3:
                return getTokenDouble(tag - TAGS.DICTIONARY_0, readByte())
            case TAGS.LIST_EMPTY:
                return ''
            case TAGS.BINARY_8:
                return readStringFromChars(readByte())
            case TAGS.BINARY_20:
                return readStringFromChars(readInt20())
            case TAGS.BINARY_32:
                return readStringFromChars(readInt(4))
            case TAGS.JID_PAIR:
                return readJidPair()
            case TAGS.AD_JID:
                return readAdJid()
            case TAGS.HEX_8:
            case TAGS.NIBBLE_8:
                return readPacked8(tag)
            default:
                throw new Error('invalid string with tag: ' + tag)
        }
    }
    
    const readList = (tag) => {
        const items = []
        const size = readListSize(tag)
        for (let i = 0; i < size; i++) {
            items.push(decodeDecompressedBinaryNode(buffer, opts, indexRef))
        }
        return items
    }
    
    const getTokenDouble = (index1, index2) => {
        const dict = DOUBLE_BYTE_TOKENS[index1]
        if (!dict) {
            throw new Error(`Invalid double token dict (${index1})`)
        }
        const value = dict[index2]
        if (typeof value === 'undefined') {
            throw new Error(`Invalid double token (${index2})`)
        }
        return value
    }
    
    const listSize = readListSize(readByte())
    const header = readString(readByte())
    
    if (!listSize || !header.length) {
        throw new Error('invalid node')
    }
    
    const attrs = {}
    
    let data
    
    if (listSize === 0 || !header) {
        throw new Error('invalid node')
    }
    
    // read the attributes in
    const attributesLength = (listSize - 1) >> 1
    for (let i = 0; i < attributesLength; i++) {
        const key = readString(readByte())
        const value = readString(readByte())
        attrs[key] = value
    }
    
    if (listSize % 2 === 0) {
        const tag = readByte()
        if (isListTag(tag)) {
            data = readList(tag)
        }
        else {
            let decoded
            switch (tag) {
                case TAGS.BINARY_8:
                    decoded = readBytes(readByte())
                    break
                case TAGS.BINARY_20:
                    decoded = readBytes(readInt20())
                    break
                case TAGS.BINARY_32:
                    decoded = readBytes(readInt(4))
                    break
                default:
                    decoded = readString(tag)
                    break
            }
            data = decoded
        }
    }
    return {
        tag: header,
        attrs,
        content: data
    }
}

const decodeBinaryNode = async (buff) => {
    const decompBuff = await decompressingIfRequired(buff)
    return decodeDecompressedBinaryNode(decompBuff, constants)
}

module.exports = {
  decompressingIfRequired, 
  decodeDecompressedBinaryNode, 
  decodeBinaryNode
}