// Adpapted for browser+node from https://github.com/joeferner/node-bplist-parser/blob/master/bplistParser.js
import plainTextPlist from 'plist'
import bigInt from 'big-integer'
import { Buffer } from 'buffer/'


// const fs = require('fs');
// const bigInt = require('big-integer')
// const bufferApi = require('buffer')
const debug = false

export const maxObjectSize = 100 * 1000 * 1000; // 100Meg
export const maxObjectCount = 32768;

// EPOCH = new SimpleDateFormat("yyyy MM dd zzz").parse("2001 01 01 GMT").getTime();
// ...but that's annoying in a static initializer because it can throw exceptions, ick.
// So we just hardcode the correct value.
const EPOCH = 978307200000;

// UID object definition
const UID = function(id) {
    this.UID = id;
};

export function parsePlistBuffer ( fileBuffer , callback) {
    return new Promise(function(resolve, reject) {
        function tryParseBuffer(buffer) {
            let err = null;
            let result;
            try {
                result = parseBuffer(buffer);
                resolve(result);
            } catch (ex) {
                err = ex;
                reject(err);
            } finally {
                if (callback) callback(err, result);
            }
        }

        return tryParseBuffer( fileBuffer )

        // if (Buffer.isBuffer(fileNameOrBuffer)) {

        // }
        // fs.readFile(fileNameOrBuffer, function(err, data) {
        //     if (err) {
        //         reject(err);
        //         return callback(err);
        //     }
        //     tryParseBuffer(data);
        // });
    });
};

export function parseFileSync (fileNameOrBuffer) {
    // if (!Buffer.isBuffer(fileNameOrBuffer)) {
    //     fileNameOrBuffer = fs.readFileSync(fileNameOrBuffer);
    // }
    return parseBuffer(fileNameOrBuffer);
};

function parseBuffer ( buffer ) {
    // check header
    const header = buffer.slice(0, 'bplist'.length).toString('utf8');



    const isPlainTextPlist = header.includes('<?xml')

    if ( isPlainTextPlist ) {
        // console.log( 'isPlainTextPlist', isPlainTextPlist )

        return plainTextPlist.parse( buffer.toString('utf8') )
    }

    if (header !== 'bplist') {
        throw new Error("Invalid binary plist. Expected 'bplist' at offset 0.");
    }

    // Handle trailer, last 32 bytes of the file
    const trailer = buffer.slice(buffer.length - 32, buffer.length);
    // 6 null bytes (index 0 to 5)
    const offsetSize = trailer.readUInt8(6);
    if (debug) {
        console.log("offsetSize: " + offsetSize);
    }
    const objectRefSize = trailer.readUInt8(7);
    if (debug) {
        console.log("objectRefSize: " + objectRefSize);
    }
    const numObjects = readUInt64BE(trailer, 8);
    if (debug) {
        console.log("numObjects: " + numObjects);
    }
    const topObject = readUInt64BE(trailer, 16);
    if (debug) {
        console.log("topObject: " + topObject);
    }
    const offsetTableOffset = readUInt64BE(trailer, 24);
    if (debug) {
        console.log("offsetTableOffset: " + offsetTableOffset);
    }

    if (numObjects > maxObjectCount) {
        throw new Error("maxObjectCount exceeded");
    }

    // Handle offset table
    const offsetTable = [];

    for (let i = 0; i < numObjects; i++) {
        const offsetBytes = buffer.slice(offsetTableOffset + i * offsetSize, offsetTableOffset + (i + 1) * offsetSize);
        offsetTable[i] = readUInt(offsetBytes, 0);
        if (debug) {
            console.log("Offset for Object #" + i + " is " + offsetTable[i] + " [" + offsetTable[i].toString(16) + "]");
        }
    }

    // Parses an object inside the currently parsed binary property list.
    // For the format specification check
    // <a href="https://www.opensource.apple.com/source/CF/CF-635/CFBinaryPList.c">
    // Apple's binary property list parser implementation</a>.
    function parseObject(tableOffset) {
        const offset = offsetTable[tableOffset];
        const type = buffer[offset];
        const objType = (type & 0xF0) >> 4; //First  4 bits
        const objInfo = (type & 0x0F); //Second 4 bits
        switch (objType) {
        case 0x0:
            return parseSimple();
        case 0x1:
            return parseInteger();
        case 0x8:
            return parseUID();
        case 0x2:
            return parseReal();
        case 0x3:
            return parseDate();
        case 0x4:
            return parseData();
        case 0x5: // ASCII
            return parsePlistString();
        case 0x6: // UTF-16
            return parsePlistString(true);
        case 0xA:
            return parseArray();
        case 0xD:
            return parseDictionary();
        default:
            throw new Error("Unhandled type 0x" + objType.toString(16));
        }

        function parseSimple() {
            //Simple
            switch (objInfo) {
            case 0x0: // null
                return null;
            case 0x8: // false
                return false;
            case 0x9: // true
                return true;
            case 0xF: // filler byte
                return null;
            default:
                throw new Error("Unhandled simple type 0x" + objType.toString(16));
            }
        }

        function bufferToHexString(buffer) {
            let str = '';
            let i;
            for (i = 0; i < buffer.length; i++) {
                if (buffer[i] != 0x00) {
                    break;
                }
            }
            for (; i < buffer.length; i++) {
                const part = '00' + buffer[i].toString(16);
                str += part.substr(part.length - 2);
            }
            return str;
        }

        function parseInteger() {
            const length = Math.pow(2, objInfo);
            if (length < maxObjectSize) {
                const data = buffer.slice(offset + 1, offset + 1 + length);
                if (length === 16) {
                    const str = bufferToHexString(data);
                    return bigInt(str, 16);
                }
                return data.reduce((acc, curr) => {
                    acc <<= 8;
                    acc |= curr & 255;
                    return acc;
                });
            }
            throw new Error("Too little heap space available! Wanted to read " + length + " bytes, but only " + maxObjectSize + " are available.");

        }

        function parseUID() {
            const length = objInfo + 1;
            if (length < maxObjectSize) {
                return new UID(readUInt(buffer.slice(offset + 1, offset + 1 + length)));
            }
            throw new Error("Too little heap space available! Wanted to read " + length + " bytes, but only " + maxObjectSize + " are available.");
        }

        function parseReal() {
            const length = Math.pow(2, objInfo);
            if (length < maxObjectSize) {
                const realBuffer = buffer.slice(offset + 1, offset + 1 + length);
                if (length === 4) {
                    return realBuffer.readFloatBE(0);
                }
                if (length === 8) {
                    return realBuffer.readDoubleBE(0);
                }
            } else {
                throw new Error("Too little heap space available! Wanted to read " + length + " bytes, but only " + maxObjectSize + " are available.");
            }
        }

        function parseDate() {
            if (objInfo != 0x3) {
                console.error("Unknown date type :" + objInfo + ". Parsing anyway...");
            }
            const dateBuffer = buffer.slice(offset + 1, offset + 9);
            return new Date(EPOCH + (1000 * dateBuffer.readDoubleBE(0)));
        }

        function parseData() {
            let dataoffset = 1;
            let length = objInfo;
            if (objInfo == 0xF) {
                const int_type = buffer[offset + 1];
                const intType = (int_type & 0xF0) / 0x10;
                if (intType != 0x1) {
                    console.error("0x4: UNEXPECTED LENGTH-INT TYPE! " + intType);
                }
                const intInfo = int_type & 0x0F;
                const intLength = Math.pow(2, intInfo);
                dataoffset = 2 + intLength;
                if (intLength < 3) {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                } else {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                }
            }
            if (length < maxObjectSize) {
                return buffer.slice(offset + dataoffset, offset + dataoffset + length);
            }
            throw new Error("Too little heap space available! Wanted to read " + length + " bytes, but only " + maxObjectSize + " are available.");
        }

        function parsePlistString(isUtf16) {
            isUtf16 = isUtf16 || 0;
            let enc = "utf8";
            let length = objInfo;
            let stroffset = 1;
            if (objInfo == 0xF) {
                const int_type = buffer[offset + 1];
                const intType = (int_type & 0xF0) / 0x10;
                if (intType != 0x1) {
                    console.error("UNEXPECTED LENGTH-INT TYPE! " + intType);
                }
                const intInfo = int_type & 0x0F;
                const intLength = Math.pow(2, intInfo);
                stroffset = 2 + intLength;
                if (intLength < 3) {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                } else {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                }
            }
            // length is String length -> to get byte length multiply by 2, as 1 character takes 2 bytes in UTF-16
            length *= (isUtf16 + 1);
            if (length < maxObjectSize) {
                let plistString = Buffer.from(buffer.slice(offset + stroffset, offset + stroffset + length));
                if (isUtf16) {
                    plistString = swapBytes(plistString);
                    enc = "ucs2";
                }
                return plistString.toString(enc);
            }
            throw new Error("Too little heap space available! Wanted to read " + length + " bytes, but only " + maxObjectSize + " are available.");
        }

        function parseArray() {
            let length = objInfo;
            let arrayoffset = 1;
            if (objInfo == 0xF) {
                const int_type = buffer[offset + 1];
                const intType = (int_type & 0xF0) / 0x10;
                if (intType != 0x1) {
                    console.error("0xa: UNEXPECTED LENGTH-INT TYPE! " + intType);
                }
                const intInfo = int_type & 0x0F;
                const intLength = Math.pow(2, intInfo);
                arrayoffset = 2 + intLength;
                if (intLength < 3) {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                } else {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                }
            }
            if (length * objectRefSize > maxObjectSize) {
                throw new Error("Too little heap space available!");
            }
            const array = [];
            for (let i = 0; i < length; i++) {
                const objRef = readUInt(buffer.slice(offset + arrayoffset + i * objectRefSize, offset + arrayoffset + (i + 1) * objectRefSize));
                array[i] = parseObject(objRef);
            }
            return array;
        }

        function parseDictionary() {
            let length = objInfo;
            let dictoffset = 1;
            if (objInfo == 0xF) {
                const int_type = buffer[offset + 1];
                const intType = (int_type & 0xF0) / 0x10;
                if (intType != 0x1) {
                    console.error("0xD: UNEXPECTED LENGTH-INT TYPE! " + intType);
                }
                const intInfo = int_type & 0x0F;
                const intLength = Math.pow(2, intInfo);
                dictoffset = 2 + intLength;
                if (intLength < 3) {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                } else {
                    length = readUInt(buffer.slice(offset + 2, offset + 2 + intLength));
                }
            }
            if (length * 2 * objectRefSize > maxObjectSize) {
                throw new Error("Too little heap space available!");
            }
            if (debug) {
                console.log("Parsing dictionary #" + tableOffset);
            }
            const dict = {};
            for (let i = 0; i < length; i++) {
                const keyRef = readUInt(buffer.slice(offset + dictoffset + i * objectRefSize, offset + dictoffset + (i + 1) * objectRefSize));
                const valRef = readUInt(buffer.slice(offset + dictoffset + (length * objectRefSize) + i * objectRefSize, offset + dictoffset + (length * objectRefSize) + (i + 1) * objectRefSize));
                const key = parseObject(keyRef);
                const val = parseObject(valRef);
                if (debug) {
                    console.log("  DICT #" + tableOffset + ": Mapped " + key + " to " + val);
                }
                dict[key] = val;
            }
            return dict;
        }
    }

    return parseObject(topObject)
};

function readUInt(buffer, start) {
    start = start || 0;

    let l = 0;
    for (let i = start; i < buffer.length; i++) {
        l <<= 8;
        l |= buffer[i] & 0xFF;
    }
    return l;
}

// we're just going to toss the high order bits because javascript doesn't have 64-bit ints
function readUInt64BE(buffer, start) {
    const data = buffer.slice(start, start + 8);
    return data.readUInt32BE(4, 8);
}

function swapBytes(buffer) {
    const len = buffer.length;
    for (let i = 0; i < len; i += 2) {
        const a = buffer[i];
        buffer[i] = buffer[i + 1];
        buffer[i + 1] = a;
    }
    return buffer;
}