export class Bzip2Error extends Error {
  public name: string = 'Bzip2Error';
  public message: string;
  public stack = (new Error()).stack;

  constructor(messageArg: string) {
    super();
    this.message = messageArg;
  }
}

var messageArg = {
  Error: function(message) {throw new Bzip2Error(message);}
};

export class Bzip2 {
  public Bzip2Error = Bzip2Error;
  public crcTable =
  [
   0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
   0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
   0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
   0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
   0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
   0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
   0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
   0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
   0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
   0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
   0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
   0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
   0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
   0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
   0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
   0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
   0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
   0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
   0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
   0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
   0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
   0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
   0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
   0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
   0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
   0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
   0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
   0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
   0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
   0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
   0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
   0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
   0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
   0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
   0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
   0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
   0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
   0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
   0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
   0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
   0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
   0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
   0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
   0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
   0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
   0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
   0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
   0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
   0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
   0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
   0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
   0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
   0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
   0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
   0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
   0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
   0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
   0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
   0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
   0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
   0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
   0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
   0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
   0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
  ];

  array = function(bytes) {
    var bit = 0, byte = 0;
    var BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
    return function(n) {
        var result = 0;
        while(n > 0) {
            var left = 8 - bit;
            if (n >= left) {
                result <<= left;
                result |= (BITMASK[left] & bytes[byte++]);
                bit = 0;
                n -= left;
            } else {
                result <<= n;
                result |= ((bytes[byte] & (BITMASK[n] << (8 - n - bit))) >> (8 - n - bit));
                bit += n;
                n = 0;
            }
        }
        return result;
    }
  }

  simple = function(srcbuffer, stream) {
    var bits = this.array(srcbuffer);
    var size = this.header(bits);
    var ret = false;
    var bufsize = 100000 * size;
    var buf = new Int32Array(bufsize);
    
    do {
        ret = this.decompress(bits, stream, buf, bufsize);        
    } while(!ret);
  }

  header = function(bits) {
    this.byteCount = new Int32Array(256);
    this.symToByte = new Uint8Array(256);
    this.mtfSymbol = new Int32Array(256);
    this.selectors = new Uint8Array(0x8000);
  
    if (bits(8*3) != 4348520) messageArg.Error("No magic number found");
  
    var i = bits(8) - 48;
    if (i < 1 || i > 9) messageArg.Error("Not a BZIP archive");
    return i;
  };

  decompress = function(bits, stream, buf, bufsize, streamCRC) {
    var MAX_HUFCODE_BITS = 20;
    var MAX_SYMBOLS = 258;
    var SYMBOL_RUNA = 0;
    var SYMBOL_RUNB = 1;
    var GROUP_SIZE = 50;
    var crc = 0 ^ (-1);
    
    for(var h = '', i = 0; i < 6; i++) h += bits(8).toString(16);
    if (h == "177245385090") {
      var finalCRC = bits(32)|0;
      if (finalCRC !== streamCRC) messageArg.Error("Error in bzip2: crc32 do not match");
      // align stream to byte
      bits(null);
      return null; // reset streamCRC for next call
    }
    if (h != "314159265359") messageArg.Error("eek not valid bzip data");
    var crcblock = bits(32)|0; // CRC code
    if (bits(1)) messageArg.Error("unsupported obsolete version");
    var origPtr = bits(24);
    if (origPtr > bufsize) messageArg.Error("Initial position larger than buffer size");
    var t = bits(16);
    var symTotal = 0;
    for (i = 0; i < 16; i++) {
        if (t & (1 << (15 - i))) {
            var k = bits(16);
            for(j = 0; j < 16; j++) {
                if (k & (1 << (15 - j))) {
                    this.symToByte[symTotal++] = (16 * i) + j;
                }
            }
        }
    }
  
    var groupCount = bits(3);
    if (groupCount < 2 || groupCount > 6) messageArg.Error("another error");
    var nSelectors = bits(15);
    if (nSelectors == 0) messageArg.Error("meh");
    for(var i = 0; i < groupCount; i++) this.mtfSymbol[i] = i;
  
    for(var i = 0; i < nSelectors; i++) {
        for(var j = 0; bits(1); j++) if (j >= groupCount) messageArg.Error("whoops another error");
        var uc = this.mtfSymbol[j];
        for(var k: any = j-1; k>=0; k--) {
            this.mtfSymbol[k+1] = this.mtfSymbol[k];
        }
        this.mtfSymbol[0] = uc;
        this.selectors[i] = uc;
    }
  
    var symCount = symTotal + 2;
    var groups = [];
    var length = new Uint8Array(MAX_SYMBOLS),
    temp = new Uint16Array(MAX_HUFCODE_BITS+1);
  
    var hufGroup;
  
    for(var j = 0; j < groupCount; j++) {
        t = bits(5); //lengths
        for(var i = 0; i < symCount; i++) {
            while(true){
                if (t < 1 || t > MAX_HUFCODE_BITS) messageArg.Error("I gave up a while ago on writing error messages");
                if (!bits(1)) break;
                if (!bits(1)) t++;
                else t--;
            }
            length[i] = t;
        }
        var  minLen,  maxLen;
        minLen = maxLen = length[0];
        for(var i = 1; i < symCount; i++) {
            if (length[i] > maxLen) maxLen = length[i];
            else if (length[i] < minLen) minLen = length[i];
        }
        hufGroup = groups[j] = {};
        hufGroup.permute = new Int32Array(MAX_SYMBOLS);
        hufGroup.limit = new Int32Array(MAX_HUFCODE_BITS + 1);
        hufGroup.base = new Int32Array(MAX_HUFCODE_BITS + 1);
  
        hufGroup.minLen = minLen;
        hufGroup.maxLen = maxLen;
        var base = hufGroup.base;
        var limit = hufGroup.limit;
        var pp = 0;
        for(var i: number = minLen; i <= maxLen; i++)
        for(var t: any = 0; t < symCount; t++)
        if (length[t] == i) hufGroup.permute[pp++] = t;
        for(i = minLen; i <= maxLen; i++) temp[i] = limit[i] = 0;
        for(i = 0; i < symCount; i++) temp[length[i]]++;
        pp = t = 0;
        for(i = minLen; i < maxLen; i++) {
            pp += temp[i];
            limit[i] = pp - 1;
            pp <<= 1;
            base[i+1] = pp - (t += temp[i]);
        }
        limit[maxLen] = pp + temp[maxLen] - 1;
        base[minLen] = 0;
    }
  
    for(var i = 0; i < 256; i++) { 
        this.mtfSymbol[i] = i;
        this.byteCount[i] = 0;
    }
    var runPos, count, symCount: number, selector;
    runPos = count = symCount = selector = 0;    
    while(true) {
        if (!(symCount--)) {
            symCount = GROUP_SIZE - 1;
            if (selector >= nSelectors) messageArg.Error("meow i'm a kitty, that's an error");
            hufGroup = groups[this.selectors[selector++]];
            base = hufGroup.base;
            limit = hufGroup.limit;
        }
        i = hufGroup.minLen;
        j = bits(i);
        while(true) {
            if (i > hufGroup.maxLen) messageArg.Error("rawr i'm a dinosaur");
            if (j <= limit[i]) break;
            i++;
            j = (j << 1) | bits(1);
        }
        j -= base[i];
        if (j < 0 || j >= MAX_SYMBOLS) messageArg.Error("moo i'm a cow");
        var nextSym = hufGroup.permute[j];
        if (nextSym == SYMBOL_RUNA || nextSym == SYMBOL_RUNB) {
            if (!runPos){
                runPos = 1;
                t = 0;
            }
            if (nextSym == SYMBOL_RUNA) t += runPos;
            else t += 2 * runPos;
            runPos <<= 1;
            continue;
        }
        if (runPos) {
            runPos = 0;
            if (count + t > bufsize) messageArg.Error("Boom.");
            uc = this.symToByte[this.mtfSymbol[0]];
            this.byteCount[uc] += t;
            while(t--) buf[count++] = uc;
        }
        if (nextSym > symTotal) break;
        if (count >= bufsize) messageArg.Error("I can't think of anything. Error");
        i = nextSym - 1;
        uc = this.mtfSymbol[i];
        for(var k: any = i-1; k>=0; k--) {
            this.mtfSymbol[k+1] = this.mtfSymbol[k];
        }
        this.mtfSymbol[0] = uc
        uc = this.symToByte[uc];
        this.byteCount[uc]++;
        buf[count++] = uc;
    }
    if (origPtr < 0 || origPtr >= count) messageArg.Error("I'm a monkey and I'm throwing something at someone, namely you");
    var j = 0;
    for(var i = 0; i < 256; i++) {
        k = j + this.byteCount[i];
        this.byteCount[i] = j;
        j = k;
    }
    for(var i = 0; i < count; i++) {
        uc = buf[i] & 0xff;
        buf[this.byteCount[uc]] |= (i << 8);
        this.byteCount[uc]++;
    }
    var pos = 0, current = 0, run = 0;
    if (count) {
        pos = buf[origPtr];
        current = (pos & 0xff);
        pos >>= 8;
        run = -1;
    }
    count = count;
    var copies, previous, outbyte;
    while(count) {
        count--;
        previous = current;
        pos = buf[pos];
        current = pos & 0xff;
        pos >>= 8;
        if (run++ == 3) {
            copies = current;
            outbyte = previous;
            current = -1;
        } else {
            copies = 1;
            outbyte = current;
        }
        while(copies--) {
            crc = ((crc << 8) ^ this.crcTable[((crc>>24) ^ outbyte) & 0xFF])&0xFFFFFFFF; // crc32
            stream(outbyte);
        }
        if (current != previous) run = 0;
    }
  
    crc = (crc ^ (-1)) >>> 0;
    if ((crc|0) != (crcblock|0)) messageArg.Error("Error in bzip2: crc32 do not match");
    streamCRC = (crc ^ ((streamCRC << 1) | (streamCRC >>> 31))) & 0xFFFFFFFF;
    return streamCRC;
  };
};