#include <string.h>
#include <vendor/hde.hpp>

static unsigned char hde32_table[] = {
    0xa3, 0xa8, 0xa3, 0xa8, 0xa3, 0xa8, 0xa3, 0xa8, 0xa3, 0xa8, 0xa3, 0xa8, 0xa3, 0xa8, 0xa3, 0xa8, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
    0xaa, 0xaa, 0xac, 0xaa, 0xb2, 0xaa, 0x9f, 0x9f, 0x9f, 0x9f, 0xb5, 0xa3, 0xa3, 0xa4, 0xaa, 0xaa, 0xba, 0xaa, 0x96, 0xaa, 0xa8, 0xaa,
    0xc3, 0xc3, 0x96, 0x96, 0xb7, 0xae, 0xd6, 0xbd, 0xa3, 0xc5, 0xa3, 0xa3, 0x9f, 0xc3, 0x9c, 0xaa, 0xaa, 0xac, 0xaa, 0xbf, 0x03, 0x7f,
    0x11, 0x7f, 0x01, 0x7f, 0x01, 0x3f, 0x01, 0x01, 0x90, 0x82, 0x7d, 0x97, 0x59, 0x59, 0x59, 0x59, 0x59, 0x7f, 0x59, 0x59, 0x60, 0x7d,
    0x7f, 0x7f, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59, 0x9a, 0x88, 0x7d, 0x59, 0x50, 0x50, 0x50, 0x50,
    0x59, 0x59, 0x59, 0x59, 0x61, 0x94, 0x61, 0x9e, 0x59, 0x59, 0x85, 0x59, 0x92, 0xa3, 0x60, 0x60, 0x59, 0x59, 0x59, 0x59, 0x59, 0x59,
    0x59, 0x59, 0x59, 0x59, 0x59, 0x9f, 0x01, 0x03, 0x01, 0x04, 0x03, 0xd5, 0x03, 0xcc, 0x01, 0xbc, 0x03, 0xf0, 0x10, 0x10, 0x10, 0x10,
    0x50, 0x50, 0x50, 0x50, 0x14, 0x20, 0x20, 0x20, 0x20, 0x01, 0x01, 0x01, 0x01, 0xc4, 0x02, 0x10, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01,
    0xc0, 0xc2, 0x10, 0x11, 0x02, 0x03, 0x11, 0x03, 0x03, 0x04, 0x00, 0x00, 0x14, 0x00, 0x02, 0x00, 0x00, 0xc6, 0xc8, 0x02, 0x02, 0x02,
    0x02, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0xff, 0xca, 0x01, 0x01, 0x01, 0x00, 0x06, 0x00, 0x04, 0x00, 0xc0, 0xc2,
    0x01, 0x01, 0x03, 0x01, 0xff, 0xff, 0x01, 0x00, 0x03, 0xc4, 0xc4, 0xc6, 0x03, 0x01, 0x01, 0x01, 0xff, 0x03, 0x03, 0x03, 0xc8, 0x40,
    0x00, 0x0a, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x7f, 0x00, 0x33, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xbf, 0xff, 0xff,
    0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0xff, 0xff, 0x00, 0x00, 0x00, 0xbf, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7f, 0x00, 0x00, 0xff, 0x4a, 0x4a, 0x4a, 0x4a,
    0x4b, 0x52, 0x4a, 0x4a, 0x4a, 0x4a, 0x4f, 0x4c, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x55, 0x45, 0x40, 0x4a, 0x4a, 0x4a,
    0x45, 0x59, 0x4d, 0x46, 0x4a, 0x5d, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x4a, 0x61, 0x63,
    0x67, 0x4e, 0x4a, 0x4a, 0x6b, 0x6d, 0x4a, 0x4a, 0x45, 0x6d, 0x4a, 0x4a, 0x44, 0x45, 0x4a, 0x4a, 0x00, 0x00, 0x00, 0x02, 0x0d, 0x06,
    0x06, 0x06, 0x06, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x06, 0x06, 0x06, 0x00, 0x06, 0x06, 0x02, 0x06, 0x00, 0x0a, 0x0a, 0x07, 0x07, 0x06,
    0x02, 0x05, 0x05, 0x02, 0x02, 0x00, 0x00, 0x04, 0x04, 0x04, 0x04, 0x00, 0x00, 0x00, 0x0e, 0x05, 0x06, 0x06, 0x06, 0x01, 0x06, 0x00,
    0x00, 0x08, 0x00, 0x10, 0x00, 0x18, 0x00, 0x20, 0x00, 0x28, 0x00, 0x30, 0x00, 0x80, 0x01, 0x82, 0x01, 0x86, 0x00, 0xf6, 0xcf, 0xfe,
    0x3f, 0xab, 0x00, 0xb0, 0x00, 0xb1, 0x00, 0xb3, 0x00, 0xba, 0xf8, 0xbb, 0x00, 0xc0, 0x00, 0xc1, 0x00, 0xc7, 0xbf, 0x62, 0xff, 0x00,
    0x8d, 0xff, 0x00, 0xc4, 0xff, 0x00, 0xc5, 0xff, 0x00, 0xff, 0xff, 0xeb, 0x01, 0xff, 0x0e, 0x12, 0x08, 0x00, 0x13, 0x09, 0x00, 0x16,
    0x08, 0x00, 0x17, 0x09, 0x00, 0x2b, 0x09, 0x00, 0xae, 0xff, 0x07, 0xb2, 0xff, 0x00, 0xb4, 0xff, 0x00, 0xb5, 0xff, 0x00, 0xc3, 0x01,
    0x00, 0xc7, 0xff, 0xbf, 0xe7, 0x08, 0x00, 0xf0, 0x02, 0x00 //
};

unsigned int hde32_disasm(const void *code, hde32s *hs) {
    uint8_t x, c, *p = (uint8_t *) code, cflags, opcode, pref = 0;
    uint8_t *ht = hde32_table, m_mod, m_reg, m_rm, disp_size = 0;

    memset(hs, 0, sizeof(hde32s));

    for (x = 16; x; x--)
        switch (c = *p++) {
        case 0xf3:
            hs->p_rep = c;
            pref |= PRE_F3;
            break;
        case 0xf2:
            hs->p_rep = c;
            pref |= PRE_F2;
            break;
        case 0xf0:
            hs->p_lock = c;
            pref |= PRE_LOCK;
            break;
        case 0x26:
        case 0x2e:
        case 0x36:
        case 0x3e:
        case 0x64:
        case 0x65:
            hs->p_seg = c;
            pref |= PRE_SEG;
            break;
        case 0x66:
            hs->p_66 = c;
            pref |= PRE_66;
            break;
        case 0x67:
            hs->p_67 = c;
            pref |= PRE_67;
            break;
        default: goto pref_done;
        }
pref_done:

    hs->flags = (uint32_t) pref << 23;

    if (!pref)
        pref |= PRE_NONE;

    if ((hs->opcode = c) == 0x0f) {
        hs->opcode2 = c = *p++;
        ht += DELTA_OPCODES;
    } else if (c >= 0xa0 && c <= 0xa3) {
        if (pref & PRE_67)
            pref |= PRE_66;
        else
            pref &= ~PRE_66;
    }

    opcode = c;
    cflags = ht[ht[opcode / 4] + (opcode % 4)];

    if (cflags == C_ERROR) {
        hs->flags |= F_ERROR | F_ERROR_OPCODE;
        cflags = 0;
        if ((opcode & -3) == 0x24)
            cflags++;
    }

    x = 0;
    if (cflags & C_GROUP) {
        uint16_t t;
        t = *(uint16_t *) (ht + (cflags & 0x7f));
        cflags = (uint8_t) t;
        x = (uint8_t) (t >> 8);
    }

    if (hs->opcode2) {
        ht = hde32_table + DELTA_PREFIXES;
        if (ht[ht[opcode / 4] + (opcode % 4)] & pref)
            hs->flags |= F_ERROR | F_ERROR_OPCODE;
    }

    if (cflags & C_MODRM) {
        hs->flags |= F_MODRM;
        hs->modrm = c = *p++;
        hs->modrm_mod = m_mod = c >> 6;
        hs->modrm_rm = m_rm = c & 7;
        hs->modrm_reg = m_reg = (c & 0x3f) >> 3;

        if (x && ((x << m_reg) & 0x80))
            hs->flags |= F_ERROR | F_ERROR_OPCODE;

        if (!hs->opcode2 && opcode >= 0xd9 && opcode <= 0xdf) {
            uint8_t t = opcode - 0xd9;
            if (m_mod == 3) {
                ht = hde32_table + DELTA_FPU_MODRM + t * 8;
                t = ht[m_reg] << m_rm;
            } else {
                ht = hde32_table + DELTA_FPU_REG;
                t = ht[t] << m_reg;
            }
            if (t & 0x80)
                hs->flags |= F_ERROR | F_ERROR_OPCODE;
        }

        if (pref & PRE_LOCK) {
            if (m_mod == 3) {
                hs->flags |= F_ERROR | F_ERROR_LOCK;
            } else {
                uint8_t *table_end, op = opcode;
                if (hs->opcode2) {
                    ht = hde32_table + DELTA_OP2_LOCK_OK;
                    table_end = ht + DELTA_OP_ONLY_MEM - DELTA_OP2_LOCK_OK;
                } else {
                    ht = hde32_table + DELTA_OP_LOCK_OK;
                    table_end = ht + DELTA_OP2_LOCK_OK - DELTA_OP_LOCK_OK;
                    op &= -2;
                }
                for (; ht != table_end; ht++)
                    if (*ht++ == op) {
                        if (!((*ht << m_reg) & 0x80))
                            goto no_lock_error;
                        else
                            break;
                    }
                hs->flags |= F_ERROR | F_ERROR_LOCK;
            no_lock_error:;
            }
        }

        if (hs->opcode2) {
            switch (opcode) {
            case 0x20:
            case 0x22:
                m_mod = 3;
                if (m_reg > 4 || m_reg == 1)
                    goto error_operand;
                else
                    goto no_error_operand;
            case 0x21:
            case 0x23:
                m_mod = 3;
                if (m_reg == 4 || m_reg == 5)
                    goto error_operand;
                else
                    goto no_error_operand;
            }
        } else {
            switch (opcode) {
            case 0x8c:
                if (m_reg > 5)
                    goto error_operand;
                else
                    goto no_error_operand;
            case 0x8e:
                if (m_reg == 1 || m_reg > 5)
                    goto error_operand;
                else
                    goto no_error_operand;
            }
        }

        if (m_mod == 3) {
            uint8_t *table_end;
            if (hs->opcode2) {
                ht = hde32_table + DELTA_OP2_ONLY_MEM;
                table_end = ht + sizeof(hde32_table) - DELTA_OP2_ONLY_MEM;
            } else {
                ht = hde32_table + DELTA_OP_ONLY_MEM;
                table_end = ht + DELTA_OP2_ONLY_MEM - DELTA_OP_ONLY_MEM;
            }
            for (; ht != table_end; ht += 2)
                if (*ht++ == opcode) {
                    if ((*ht++ & pref) && !((*ht << m_reg) & 0x80))
                        goto error_operand;
                    else
                        break;
                }
            goto no_error_operand;
        } else if (hs->opcode2) {
            switch (opcode) {
            case 0x50:
            case 0xd7:
            case 0xf7:
                if (pref & (PRE_NONE | PRE_66))
                    goto error_operand;
                break;
            case 0xd6:
                if (pref & (PRE_F2 | PRE_F3))
                    goto error_operand;
                break;
            case 0xc5: goto error_operand;
            }
            goto no_error_operand;
        } else
            goto no_error_operand;

    error_operand:
        hs->flags |= F_ERROR | F_ERROR_OPERAND;
    no_error_operand:

        c = *p++;
        if (m_reg <= 1) {
            if (opcode == 0xf6)
                cflags |= C_IMM8;
            else if (opcode == 0xf7)
                cflags |= C_IMM_P66;
        }

        switch (m_mod) {
        case 0:
            if (pref & PRE_67) {
                if (m_rm == 6)
                    disp_size = 2;
            } else if (m_rm == 5)
                disp_size = 4;
            break;
        case 1: disp_size = 1; break;
        case 2:
            disp_size = 2;
            if (!(pref & PRE_67))
                disp_size <<= 1;
            break;
        }

        if (m_mod != 3 && m_rm == 4 && !(pref & PRE_67)) {
            hs->flags |= F_SIB;
            p++;
            hs->sib = c;
            hs->sib_scale = c >> 6;
            hs->sib_index = (c & 0x3f) >> 3;
            if ((hs->sib_base = c & 7) == 5 && !(m_mod & 1))
                disp_size = 4;
        }

        p--;
        switch (disp_size) {
        case 1:
            hs->flags |= F_DISP8;
            hs->disp.disp8 = *p;
            break;
        case 2:
            hs->flags |= F_DISP16;
            hs->disp.disp16 = *(uint16_t *) p;
            break;
        case 4:
            hs->flags |= F_DISP32;
            hs->disp.disp32 = *(uint32_t *) p;
            break;
        }
        p += disp_size;
    } else if (pref & PRE_LOCK)
        hs->flags |= F_ERROR | F_ERROR_LOCK;

    if (cflags & C_IMM_P66) {
        if (cflags & C_REL32) {
            if (pref & PRE_66) {
                hs->flags |= F_IMM16 | F_RELATIVE;
                hs->imm.imm16 = *(uint16_t *) p;
                p += 2;
                goto disasm_done;
            }
            goto rel32_ok;
        }
        if (pref & PRE_66) {
            hs->flags |= F_IMM16;
            hs->imm.imm16 = *(uint16_t *) p;
            p += 2;
        } else {
            hs->flags |= F_IMM32;
            hs->imm.imm32 = *(uint32_t *) p;
            p += 4;
        }
    }

    if (cflags & C_IMM16) {
        if (hs->flags & F_IMM32) {
            hs->flags |= F_IMM16;
            hs->disp.disp16 = *(uint16_t *) p;
        } else if (hs->flags & F_IMM16) {
            hs->flags |= F_2IMM16;
            hs->disp.disp16 = *(uint16_t *) p;
        } else {
            hs->flags |= F_IMM16;
            hs->imm.imm16 = *(uint16_t *) p;
        }
        p += 2;
    }
    if (cflags & C_IMM8) {
        hs->flags |= F_IMM8;
        hs->imm.imm8 = *p++;
    }

    if (cflags & C_REL32) {
    rel32_ok:
        hs->flags |= F_IMM32 | F_RELATIVE;
        hs->imm.imm32 = *(uint32_t *) p;
        p += 4;
    } else if (cflags & C_REL8) {
        hs->flags |= F_IMM8 | F_RELATIVE;
        hs->imm.imm8 = *p++;
    }

disasm_done:

    if ((hs->len = (uint8_t) (p - (uint8_t *) code)) > 15) {
        hs->flags |= F_ERROR | F_ERROR_LENGTH;
        hs->len = 15;
    }

    return (unsigned int) hs->len;
}