#include "encoding.hh"

#include <algorithm>

#define CUBECTYPE(s, p, d, a, A, u, U) \
    0, U, U, U, U, U, U, U, U, s, s, s, s, s, U, U, \
    U, U, U, U, U, U, U, U, U, U, U, U, U, U, U, U, \
    s, p, p, p, p, p, p, p, p, p, p, p, p, p, p, p, \
    d, d, d, d, d, d, d, d, d, d, p, p, p, p, p, p, \
    p, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, \
    A, A, A, A, A, A, A, A, A, A, A, p, p, p, p, p, \
    p, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, \
    a, a, a, a, a, a, a, a, a, a, a, p, p, p, p, U, \
    U, u, u, u, u, u, u, u, u, u, u, u, u, u, u, u, \
    u, u, u, u, u, u, u, u, u, u, u, u, u, u, u, U, \
    u, U, u, U, u, U, u, U, u, U, u, U, u, U, u, U, \
    u, U, u, U, u, U, u, U, u, U, u, U, u, U, u, U, \
    u, U, u, U, u, U, u, U, U, u, U, u, U, u, U, U, \
    U, U, U, U, U, U, U, U, U, U, U, U, U, U, U, U, \
    U, U, U, U, u, u, u, u, u, u, u, u, u, u, u, u, \
    u, u, u, u, u, u, u, u, u, u, u, u, u, u, U, u

extern const unsigned char cubectype[256] =
{
    CUBECTYPE(CT_SPACE,
              CT_PRINT,
              CT_PRINT|CT_DIGIT,
              CT_PRINT|CT_ALPHA|CT_LOWER,
              CT_PRINT|CT_ALPHA|CT_UPPER,
              CT_PRINT|CT_UNICODE|CT_ALPHA|CT_LOWER,
              CT_PRINT|CT_UNICODE|CT_ALPHA|CT_UPPER)
};
extern const int cube2unichars[256] =
{
    0, 192, 193, 194, 195, 196, 197, 198, 199, 9, 10, 11, 12, 13, 200, 201,
    202, 203, 204, 205, 206, 207, 209, 210, 211, 212, 213, 214, 216, 217, 218, 219,
    32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
    48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
    64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
    80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
    96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
    112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 220,
    221, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237,
    238, 239, 241, 242, 243, 244, 245, 246, 248, 249, 250, 251, 252, 253, 255, 0x104,
    0x105, 0x106, 0x107, 0x10C, 0x10D, 0x10E, 0x10F, 0x118, 0x119, 0x11A, 0x11B, 0x11E, 0x11F, 0x130, 0x131, 0x141,
    0x142, 0x143, 0x144, 0x147, 0x148, 0x150, 0x151, 0x152, 0x153, 0x158, 0x159, 0x15A, 0x15B, 0x15E, 0x15F, 0x160,
    0x161, 0x164, 0x165, 0x16E, 0x16F, 0x170, 0x171, 0x178, 0x179, 0x17A, 0x17B, 0x17C, 0x17D, 0x17E, 0x404, 0x411,
    0x413, 0x414, 0x416, 0x417, 0x418, 0x419, 0x41B, 0x41F, 0x423, 0x424, 0x426, 0x427, 0x428, 0x429, 0x42A, 0x42B,
    0x42C, 0x42D, 0x42E, 0x42F, 0x431, 0x432, 0x433, 0x434, 0x436, 0x437, 0x438, 0x439, 0x43A, 0x43B, 0x43C, 0x43D,
    0x43F, 0x442, 0x444, 0x446, 0x447, 0x448, 0x449, 0x44A, 0x44B, 0x44C, 0x44D, 0x44E, 0x44F, 0x454, 0x490, 0x491
};
extern const int uni2cubeoffsets[8] =
{
    0, 256, 658, 658, 512, 658, 658, 658
};
extern const unsigned char uni2cubechars[878] =
{
    0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 10, 11, 12, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
    64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
    96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    1, 2, 3, 4, 5, 6, 7, 8, 14, 15, 16, 17, 18, 19, 20, 21, 0, 22, 23, 24, 25, 26, 27, 0, 28, 29, 30, 31, 127, 128, 0, 129,
    130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 0, 146, 147, 148, 149, 150, 151, 0, 152, 153, 154, 155, 156, 157, 0, 158,
    0, 0, 0, 0, 159, 160, 161, 162, 0, 0, 0, 0, 163, 164, 165, 166, 0, 0, 0, 0, 0, 0, 0, 0, 167, 168, 169, 170, 0, 0, 171, 172,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 173, 174, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 175, 176, 177, 178, 0, 0, 179, 180, 0, 0, 0, 0, 0, 0, 0, 181, 182, 183, 184, 0, 0, 0, 0, 185, 186, 187, 188, 0, 0, 189, 190,
    191, 192, 0, 0, 193, 194, 0, 0, 0, 0, 0, 0, 0, 0, 195, 196, 197, 198, 0, 0, 0, 0, 0, 0, 199, 200, 201, 202, 203, 204, 205, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 17, 0, 0, 206, 83, 73, 21, 74, 0, 0, 0, 0, 0, 0, 0, 65, 207, 66, 208, 209, 69, 210, 211, 212, 213, 75, 214, 77, 72, 79, 215,
    80, 67, 84, 216, 217, 88, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 97, 228, 229, 230, 231, 101, 232, 233, 234, 235, 236, 237, 238, 239, 111, 240,
    112, 99, 241, 121, 242, 120, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 0, 141, 0, 0, 253, 115, 105, 145, 106, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 254, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
extern const unsigned char cubelowerchars[256] =
{
    0, 130, 131, 132, 133, 134, 135, 136, 137, 9, 10, 11, 12, 13, 138, 139,
    140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155,
    32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
    48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
    64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
    112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 91, 92, 93, 94, 95,
    96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
    112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 156,
    157, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
    144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 160,
    160, 162, 162, 164, 164, 166, 166, 168, 168, 170, 170, 172, 172, 105, 174, 176,
    176, 178, 178, 180, 180, 182, 182, 184, 184, 186, 186, 188, 188, 190, 190, 192,
    192, 194, 194, 196, 196, 198, 198, 158, 201, 201, 203, 203, 205, 205, 206, 207,
    208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
    224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
    240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};
extern const unsigned char cubeupperchars[256] =
{
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
    16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
    32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
    48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
    64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
    80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
    96, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
    80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 123, 124, 125, 126, 127,
    128, 129, 1, 2, 3, 4, 5, 6, 7, 8, 14, 15, 16, 17, 18, 19,
    20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 127, 128, 199, 159,
    159, 161, 161, 163, 163, 165, 165, 167, 167, 169, 169, 171, 171, 173, 73, 175,
    175, 177, 177, 179, 179, 181, 181, 183, 183, 185, 185, 187, 187, 189, 189, 191,
    191, 193, 193, 195, 195, 197, 197, 199, 200, 200, 202, 202, 204, 204, 206, 207,
    208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
    224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
    240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};

size_t decodeutf8(unsigned char *dstbuf, size_t dstlen, const unsigned char *srcbuf, size_t srclen, size_t *carry)
{
    unsigned char *dst = dstbuf, *dstend = &dstbuf[dstlen];
    const unsigned char *src = srcbuf, *srcend = &srcbuf[srclen];
    if(dstbuf == srcbuf)
    {
        int len = std::min(dstlen, srclen);
        for(const unsigned char *end4 = &srcbuf[len&~3]; src < end4; src += 4) if(*(const int *)src & 0x80808080) goto decode;
        for(const unsigned char *end = &srcbuf[len]; src < end; src++) if(*src & 0x80) goto decode;
        if(carry) *carry += len;
        return len;
    }

decode:
    dst += src - srcbuf;
    while(src < srcend && dst < dstend)
    {
        int c = *src++;
        if(c < 0x80) *dst++ = c;
        else if(c >= 0xC0)
        {
            int uni;
            if(c >= 0xE0)
            {
                if(c >= 0xF0)
                {
                    if(c >= 0xF8)
                    {
                        if(c >= 0xFC)
                        {
                            if(c >= 0xFE) continue;
                            uni = c&1; if(srcend - src < 5) break;
                            c = *src; if((c&0xC0) != 0x80) continue; src++; uni = (uni<<6) | (c&0x3F);
                        }
                        else { uni = c&3; if(srcend - src < 4) break; }
                        c = *src; if((c&0xC0) != 0x80) continue; src++; uni = (uni<<6) | (c&0x3F);
                    }
                    else { uni = c&7; if(srcend - src < 3) break; }
                    c = *src; if((c&0xC0) != 0x80) continue; src++; uni = (uni<<6) | (c&0x3F);
                }
                else { uni = c&0xF; if(srcend - src < 2) break; }
                c = *src; if((c&0xC0) != 0x80) continue; src++; uni = (uni<<6) | (c&0x3F);
            }
            else { uni = c&0x1F; if(srcend - src < 1) break; }
            c = *src; if((c&0xC0) != 0x80) continue; src++; uni = (uni<<6) | (c&0x3F);
            c = uni2cube(uni);
            if(!c) continue;
            *dst++ = c;
        }
    }
    if(carry) *carry += src - srcbuf;
    return dst - dstbuf;
}

size_t encodeutf8(unsigned char *dstbuf, size_t dstlen, const unsigned char *srcbuf, size_t srclen, size_t *carry)
{
    unsigned char *dst = dstbuf, *dstend = &dstbuf[dstlen];
    const unsigned char *src = srcbuf, *srcend = &srcbuf[srclen];
    if(src < srcend && dst < dstend) do
    {
        int uni = cube2uni(*src);
        if(uni <= 0x7F)
        {
            if(dst >= dstend) goto done;
            const unsigned char *end = std::min(srcend, &src[dstend-dst]);
            do
            {
                if(uni == '\f')
                {
                    if(++src >= srcend) goto done;
                    goto uni1;
                }
                *dst++ = uni;
                if(++src >= end) goto done;
                uni = cube2uni(*src);
            }
            while(uni <= 0x7F);
        }
        if(uni <= 0x7FF) { if(dst + 2 > dstend) goto done; *dst++ = 0xC0 | (uni>>6); goto uni2; }
        else if(uni <= 0xFFFF) { if(dst + 3 > dstend) goto done; *dst++ = 0xE0 | (uni>>12); goto uni3; }
        else if(uni <= 0x1FFFFF) { if(dst + 4 > dstend) goto done; *dst++ = 0xF0 | (uni>>18); goto uni4; }
        else if(uni <= 0x3FFFFFF) { if(dst + 5 > dstend) goto done; *dst++ = 0xF8 | (uni>>24); goto uni5; }
        else if(uni <= 0x7FFFFFFF) { if(dst + 6 > dstend) goto done; *dst++ = 0xFC | (uni>>30); goto uni6; }
        else goto uni1;
    uni6: *dst++ = 0x80 | ((uni>>24)&0x3F);
    uni5: *dst++ = 0x80 | ((uni>>18)&0x3F);
    uni4: *dst++ = 0x80 | ((uni>>12)&0x3F);
    uni3: *dst++ = 0x80 | ((uni>>6)&0x3F);
    uni2: *dst++ = 0x80 | (uni&0x3F);
    uni1:;
    }
    while(++src < srcend);

done:
    if(carry) *carry += src - srcbuf;
    return dst - dstbuf;
}