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/// @file xed-enc-lang.cpp
/// @author Mark Charney   <mark.charney@intel.com>

// This is an example of how to use the encoder from scratch in the context
// of parsing a string from the command line.  


#include <iostream>
#include <iomanip>
#include <vector>
#include <sstream>
#include <cassert>
extern "C" {
#include "xed-interface.h"
#include "xed-portability.h"
#include "xed-examples-util.h"
}
#include "xed-enc-lang.H"




using namespace std;
static char xed_enc_lang_toupper(char c) {
    if (c >= 'a' && c <= 'z')
        return c-'a'+'A';
    return c;
}

static string upcase(string s) {
    string t = "";
    xed_uint_t len = static_cast<xed_uint_t>(s.size());
    xed_uint_t i;
    for(i=0 ; i < len ; i++ ) 
        t = t + xed_enc_lang_toupper(s[i]);
    return t;
}

unsigned int
xed_split_args(const string& sep, 
               const string& input, 
               vector<string>& output_array)
{
    // returns the number of args
    // rip off the separator characters and split the src string based on separators.
    
    // find the string between last_pos and pos. pos is after last_pos
    string::size_type last_pos = input.find_first_not_of(sep, 0);
    string::size_type pos = input.find_first_of(sep, last_pos);  
    if (CLIENT_VERBOSE3)
        printf("input %s\tlast_pos " XED_FMT_U " pos " XED_FMT_U "\n", 
               input.c_str() , STATIC_CAST(xed_uint_t,last_pos), STATIC_CAST(xed_uint_t,pos));
    int i=0;
    while( pos != string::npos && last_pos != string::npos ) 
    {
        string a = input.substr(last_pos, pos-last_pos);
        output_array.push_back(a); 
        if (CLIENT_VERBOSE3)
            printf("\t\tlast_pos " XED_FMT_U " pos " XED_FMT_U " i %d\n", 
                   STATIC_CAST(xed_uint_t,last_pos),
                   STATIC_CAST(xed_uint_t,pos),
                   i);
        last_pos = input.find_first_not_of(sep, pos);
        pos = input.find_first_of(sep, last_pos);  
        i++;
    }
    if (last_pos != string::npos && pos == string::npos)
    {
        if (CLIENT_VERBOSE3)
            printf("\t\tGetting last substring at " XED_FMT_U "\n", STATIC_CAST(xed_uint_t,last_pos));
        string a = input.substr(last_pos); // get the rest of the string
        output_array.push_back(a);
        i++;
    }
    if (CLIENT_VERBOSE3)
        printf("\t returning %d\n",i);
    return i;
}

vector<string> 
tokenize(const string& s,
	 const string& delimiter) {
    vector<string> v;
    (void) xed_split_args(delimiter, s, v);
    return v;
}


void slash_split(const string& src,
                 string& first, // output
                 string&  second) //output
{
  string::size_type p = src.find("/");
  if (p == string::npos) {
    first = src;
    second = "";
  }
  else {
    first = src.substr(0,p);
    second = src.substr(p+1);
  }
}

class immed_parser_t {
  public:
    xed_bool_t valid;
    string immed;
    unsigned int width_bits;
    xed_uint64_t immed_val;
    string tok0;

    immed_parser_t(const string& s, 
                   const string& arg_tok0) //CONS
        : valid(false),
          tok0(arg_tok0)
    {
        vector<string> vs = tokenize(s,"(),");
        if (vs.size() == 2) {
            if (vs[0] == tok0) {
                string immed_str = vs[1];
                immed_val = convert_ascii_hex_to_int(immed_str.c_str());
                width_bits = static_cast<unsigned int>(immed_str.size()*4); // nibbles to bits
                valid = true;
            }
        }
    }

    void
    print(ostream& o) const {
        o << tok0 
          << "(" ;
        if (valid) 
            o << hex << immed_val << dec;
        else 
            o << "???";
        o << ")";
    }

};

ostream& operator<<(ostream& o, const immed_parser_t& x) 
{
    x.print(o);
    return o;
}


class seg_parser_t
{
  public:
    xed_bool_t valid;
    xed_reg_enum_t segment_reg;
    string segment;

    seg_parser_t(const string& s) // CONS
        : valid(false),
          segment_reg(XED_REG_INVALID)
    {
        vector<string> vs = tokenize(s,"(),");
        xed_uint_t ntokens = static_cast<xed_uint_t>(vs.size());
        cerr << "ntokens " << ntokens << ": " ;
        for(unsigned int i=0;i<ntokens;i++) cerr  << '[' << vs[i] << "] ";
        cerr << endl;
        if (ntokens == 2 && vs[0] == "SEG") {
            segment = vs[1];
            segment_reg = str2xed_reg_enum_t(segment.c_str());
            if (segment_reg != XED_REG_INVALID && xed_reg_class(segment_reg) == XED_REG_CLASS_SR) {
                valid=true;
            }
        }
    }

};

class mem_bis_parser_t 
{
    // parse: MEM[length]([segment:]base,index,scale[,displacement])
    // parse: AGEN(base,index,scale[,displacement])
    // The displacement is optional
    // The length of the memop is usually optional 
    //   but required for x87 ops, for example.
  public:
    xed_bool_t valid;
    xed_bool_t mem;

    xed_bool_t agen;
    xed_bool_t disp_valid;
    string segment;
    string base;
    string index;
    string scale;
    string disp; //displacement
    xed_reg_enum_t segment_reg;
    xed_reg_enum_t base_reg;
    xed_reg_enum_t index_reg;
    xed_uint8_t scale_val;


    xed_int64_t disp_val;
    unsigned int disp_width_bits;

    unsigned int mem_len;

    void
    print(ostream& o) const {
        if (agen) 
            o << "AGEN"; 
        if (mem) 
            o << "MEM"; 
        if (mem_len) 
            o << setw(1) << mem_len;
        o << "(";
        if (segment_reg != XED_REG_INVALID)
            o << segment_reg << ":";
        o << base_reg;
        o << "," << index_reg 
          << "," 
          << (unsigned int) scale_val;
        if (disp_valid) 
            o <<  "," << disp;
        o << ")";
     
    }
  
    mem_bis_parser_t(const string& s) //CONS
        : valid(false),
          disp_valid(false),
          base("INVALID"),
          index("INVALID"),
          scale("1"),
          segment_reg(XED_REG_INVALID),
          base_reg(XED_REG_INVALID),
          index_reg(XED_REG_INVALID),
          disp_val(0),
          disp_width_bits(0),
          mem_len(0)
    {

        mem = false;
        agen = false;
        vector<string> vs = tokenize(s,"(),");
        xed_uint_t ntokens = static_cast<xed_uint_t>(vs.size());
        if (ntokens >= 2 && ntokens <= 5) {
            if (vs[0] == "AGEN") {
                agen = true;
            }
            else if (vs[0].substr(0,3) == "MEM") {
                mem = true;
                if (vs[0].size() > 3) {
                    string len = vs[0].substr(3);
                    mem_len = strtol(len.c_str(),0,0);
                    //printf("mem_len  = " XED_FMT_U "\n", mem_len);
                }
            }
            else             {
                return;
            }

            segment = "INVALID";
            string seg_and_base = upcase(vs[1]);
            vector<string> sb = tokenize(seg_and_base,":");
            int seg_and_base_tokens = STATIC_CAST(int,sb.size());
            if (seg_and_base_tokens == 1) {
                segment = "INVALID";
                base = sb[0];
            }
            else if (seg_and_base_tokens == 2) {
                if (agen) {
                    xedex_derror("AGENs cannot have segment overrides");
                }
                segment = sb[0];
                base = sb[1];
            }
            else            {
                printf("seg_and_base_tokens = %d\n",seg_and_base_tokens);
                xedex_derror("Bad segment-and-base specifier.");
            }

            if (base == "-" || base == "NA") {
                base = "INVALID";
            }
            if (ntokens > 2) {
                index = upcase(vs[2]);
                if (index == "-" || index == "NA") {
                    index = "INVALID";
                }
            }

            if (ntokens > 3) {
                scale = vs[3];
                if (scale == "-" || scale == "NA") {
                    scale = "1";
                }
            }
            if (scale == "1" || scale == "2" || scale == "4" || scale == "8") {
                valid=true;
                scale_val = STATIC_CAST(xed_uint8_t,strtol(scale.c_str(), 0, 10));
                segment_reg = str2xed_reg_enum_t(segment.c_str());
                base_reg = str2xed_reg_enum_t(base.c_str());
                index_reg = str2xed_reg_enum_t(index.c_str());

                // look for a displacement
                if (ntokens == 5 && vs[4] != "-") {
                    disp = vs[4];
                    disp_valid = true;
                    unsigned int nibbles = STATIC_CAST(int,disp.size());
                    if (nibbles & 1) {
                        // ensure an even number of nibbles
                        string zero("0");
                        disp = zero + disp;
                        nibbles++;
                    }
                    disp_val = convert_ascii_hex_to_int(disp.c_str());
                    disp_width_bits = nibbles*4; // nibbles to bits
                }
            }

        }
    
    }
};

ostream& operator<<(ostream& o, const mem_bis_parser_t& x) {
  x.print(o);
  return o;
}

xed_encoder_request_t parse_encode_request(ascii_encode_request_t& areq) {
    unsigned int i;
    xed_encoder_request_t req;
    xed_encoder_request_zero_set_mode(&req,&(areq.dstate)); // calls xed_encoder_request_zero()

    /* This is the important function here. This encodes an instruction from scratch.
       
    You must set:
    the machine mode (machine width, addressing widths)
    the effective operand width
    the iclass
    for some instructions you need to specify prefixes (like REP or LOCK).
    the operands:
           operand kind (XED_OPERAND_{AGEN,MEM0,MEM1,IMM0,IMM1,RELBR,PTR,REG0...REG15}
           operand order 
                    xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_*);
                    where the operand_index is a sequential index starting at zero.

           operand details 
                     FOR MEMOPS: base,segment,index,scale,displacement for memops, 
                  FOR REGISTERS: register name
                 FOR IMMEDIATES: immediate values
       
     */
    

    switch(xed_state_get_machine_mode(&(areq.dstate))) {
        // set the default width.
      case XED_MACHINE_MODE_LONG_64:
        xed_encoder_request_set_effective_operand_width(&req, 32);
        xed_encoder_request_set_effective_address_size(&req, 64);
        break;

      case XED_MACHINE_MODE_LEGACY_32:
      case XED_MACHINE_MODE_LONG_COMPAT_32:
        xed_encoder_request_set_effective_operand_width(&req, 32);
        xed_encoder_request_set_effective_address_size(&req, 32);
        break;

      case XED_MACHINE_MODE_LEGACY_16:
      case XED_MACHINE_MODE_LONG_COMPAT_16:
        xed_encoder_request_set_effective_operand_width(&req, 16);
        xed_encoder_request_set_effective_address_size(&req, 16);
        break;

      default:
        assert(0);
    }

    //FIXME: allow changing the effective address size from the above defaults.

    vector<string> tokens = tokenize(areq.command," ");
    // first token has the operand and our temporary hack for the immediate

    string first, second;
    unsigned int token_index = 0;

    while(token_index < tokens.size()) {
        slash_split(tokens[token_index], first, second);
        if (CLIENT_VERBOSE3)
            printf( "[%s][%s][%s]\n", tokens[0].c_str(), first.c_str(), second.c_str());

        if (token_index == 0 && first == "REP") {
            xed_encoder_request_set_rep(&req);
            token_index++;
            continue;
        }
        else if (token_index == 0 && first == "REPNE") {
            xed_encoder_request_set_repne(&req);
            token_index++;
            continue;
        }
  
        token_index++;
        break;
    }

    // we can attempt to override the mode 
    if (second == "8") 
        xed_encoder_request_set_effective_operand_width(&req, 8);
    else if (second == "16") 
        xed_encoder_request_set_effective_operand_width(&req, 16);
    else if (second == "32") 
        xed_encoder_request_set_effective_operand_width(&req, 32);
    else if (second == "64") 
        xed_encoder_request_set_effective_operand_width(&req, 64);

    first = upcase(first);
    xed_iclass_enum_t iclass =  str2xed_iclass_enum_t(first.c_str());
    if (iclass == XED_ICLASS_INVALID) {
        ostringstream os;
        os << "Bad instruction name: " << first;
        xedex_derror(os.str().c_str());
    }
    xed_encoder_request_set_iclass(&req, iclass );

    xed_uint_t memop = 0;
    xed_uint_t regnum = 0;
    // put the operands in the request. Loop through tokens 
    // (skip the opcode iclass, handled above)
    xed_uint_t operand_index = 0;
    for( i=token_index; i < tokens.size(); i++, operand_index++ ) {
        string str_res_reg, second_x;
        slash_split(tokens[i], str_res_reg, second_x);
        str_res_reg = upcase(str_res_reg);
        // prune the AGEN or MEM(base,index,scale[,displacement]) text from str_res_reg
        // FIXME: add MEM(immed) for the OC1_A and OC1_O types????
        mem_bis_parser_t mem_bis(str_res_reg);
        if (mem_bis.valid) {
            if (mem_bis.mem) {
                if (memop == 0) {
                    // Tell XED that we have a memory operand
                    xed_encoder_request_set_mem0(&req);
                    // Tell XED that the mem0 operand is the next operand:
                    xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_MEM0);
                }
                else {
                    xed_encoder_request_set_mem1(&req);
                    // Tell XED that the mem1 operand is the next operand:
                    xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_MEM1);
                }
                memop++;
            }
            else if (mem_bis.agen) {
                // Tell XED we have an AGEN
                xed_encoder_request_set_agen(&req);
                // The AGEN is the next operand
                xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_AGEN);
            }
            else 
                assert(mem_bis.agen || mem_bis.mem);

            xed_reg_class_enum_t rc = xed_gpr_reg_class(mem_bis.base_reg);
            xed_reg_class_enum_t rci = xed_gpr_reg_class(mem_bis.index_reg);
            if (mem_bis.base_reg != XED_REG_INVALID && mem_bis.index_reg != XED_REG_INVALID) 
                if (rc != rci) {
                    ostringstream os;
                    os << "The base and index regs do not agree on the address size" << endl;
                    xedex_derror(os.str().c_str()); // dies
                }
            
            if (rc == XED_REG_CLASS_GPR32 || rci == XED_REG_CLASS_GPR32) 
                xed_encoder_request_set_effective_address_size(&req, 32);

            // fill in the memory fields
            xed_encoder_request_set_base0(&req, mem_bis.base_reg);
            xed_encoder_request_set_index(&req, mem_bis.index_reg);
            xed_encoder_request_set_scale(&req, mem_bis.scale_val);
            xed_encoder_request_set_seg0(&req, mem_bis.segment_reg);

            if (mem_bis.mem_len) 
                xed_encoder_request_set_memory_operand_length(&req, mem_bis.mem_len ); // BYTES
            if (mem_bis.disp_valid)
                xed_encoder_request_set_memory_displacement(&req,
                                                            mem_bis.disp_val,
                                                            mem_bis.disp_width_bits/8);
            continue;
        }

        seg_parser_t seg_parser(str_res_reg);
        if (seg_parser.valid) {
            printf("Setting segment to %s\n", xed_reg_enum_t2str(seg_parser.segment_reg));
            xed_encoder_request_set_seg0(&req, seg_parser.segment_reg);
            xed_encoder_request_set_operand_order(&req, operand_index, XED_OPERAND_SEG0);
            continue;
        }

        immed_parser_t imm(str_res_reg, "IMM");
        if (imm.valid) {
            if (CLIENT_VERBOSE3) 
                printf("Setting immediate value to " XED_FMT_LX "\n", imm.immed_val);
            xed_encoder_request_set_uimm0_bits(&req, 
                                               imm.immed_val,
                                               imm.width_bits);
            xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_IMM0);
            continue;
        }
        immed_parser_t simm(str_res_reg, "SIMM");
        if (simm.valid) {
            if (CLIENT_VERBOSE3) 
                printf("Setting immediate value to " XED_FMT_LX "\n", simm.immed_val);
            xed_encoder_request_set_simm(&req, 
                                         STATIC_CAST(xed_int32_t,simm.immed_val),
                                         simm.width_bits/8); //FIXME
            xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_IMM0);
            continue;
        }
        immed_parser_t imm2(str_res_reg, "IMM2");
        if (imm2.valid) {
            if (imm2.width_bits != 8)
                xedex_derror("2nd immediate must be just 1 byte long");
            xed_encoder_request_set_uimm1(&req, imm2.immed_val);
            xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_IMM1);
            continue;
        }

        immed_parser_t disp(str_res_reg, "BRDISP");
        if (disp.valid) {
            if (CLIENT_VERBOSE3) 
                printf("Setting  displacement value to " XED_FMT_LX "\n", disp.immed_val);
            xed_encoder_request_set_branch_displacement(&req,
                                                        STATIC_CAST(xed_uint32_t,disp.immed_val),
                                                        disp.width_bits/8); //FIXME
            xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_RELBR);
            xed_encoder_request_set_relbr(&req);
            continue;
        }

        immed_parser_t ptr_disp(str_res_reg, "PTR");
        if (ptr_disp.valid) {
            if (CLIENT_VERBOSE3) 
                printf("Setting pointer displacement value to " XED_FMT_LX "\n", ptr_disp.immed_val);
            xed_encoder_request_set_branch_displacement(&req,
                                                        STATIC_CAST(xed_uint32_t,ptr_disp.immed_val),
                                                        ptr_disp.width_bits/8); //FIXME
            xed_encoder_request_set_operand_order(&req,operand_index, XED_OPERAND_PTR);
            xed_encoder_request_set_ptr(&req);
            continue;
        }

        xed_reg_enum_t reg = str2xed_reg_enum_t(str_res_reg.c_str());
        if (reg == XED_REG_INVALID) {
            ostringstream os;
            os << "Bad register name: " << str_res_reg << " on operand " << i;
            xedex_derror(os.str().c_str()); // dies
        }
        // The registers operands aer numbered starting from the first one
        // as XED_OPERAND_REG0. We incremenet regnum (below) every time we add a
        // register operands.
        xed_operand_enum_t r = STATIC_CAST(xed_operand_enum_t,XED_OPERAND_REG0 + regnum);
        // store the register identifer in the operand storage field
        xed_encoder_request_set_reg(&req, r, reg);
        // store the operand storage field name in the encode-order array
        xed_encoder_request_set_operand_order(&req, operand_index, r);
        regnum++;
    } // for loop

    return req;
}