/*
 * FSM table generator:
 *  Generate FSM tables as ".c" files from FSM functions.
 *
 * 23.03.2016 (dd.mm.yyyy)
 */

// TOP

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>

#define ArrayCount(a) (sizeof(a)/sizeof(*a))

#include "4cpp_lexer_fsms.h"

Whitespace_FSM
whitespace_skip_fsm(Whitespace_FSM wfsm, char c){
    if (wfsm.pp_state != LSPP_default){
        if (c == '\n') wfsm.pp_state = LSPP_default;
    }
    if (!(c == ' ' || c == '\n' || c == '\t' || c == '\r' || c == '\f' || c == '\v')){
        wfsm.white_done = 1;
    }
    return(wfsm);
}

Lex_FSM
int_fsm(Lex_FSM fsm, char c){
    switch (fsm.int_state){
        case LSINT_default:
        switch (c){
            case 'u': case 'U': fsm.int_state = LSINT_u; break;
            case 'l': fsm.int_state = LSINT_l; break;
            case 'L': fsm.int_state = LSINT_L; break;
            default: fsm.emit_token = 1; break;
        }
        break;

        case LSINT_u:
        switch (c){
            case 'l': fsm.int_state = LSINT_ul; break;
            case 'L': fsm.int_state = LSINT_uL; break;
            default: fsm.emit_token = 1; break;
        }
        break;

        case LSINT_l:
        switch (c){
            case 'l': fsm.int_state = LSINT_ll; break;
            case 'U': case 'u': fsm.int_state = LSINT_extra; break;
            default: fsm.emit_token = 1; break;
        }
        break;

        case LSINT_L:
        switch (c){
            case 'L': fsm.int_state = LSINT_ll; break;
            case 'U': case 'u': fsm.int_state = LSINT_extra; break;
            default: fsm.emit_token = 1; break;
        }
        break;

        case LSINT_ul:
        switch (c){
            case 'l': fsm.int_state = LSINT_extra; break;
            default: fsm.emit_token = 1; break;
        }
        break;

        case LSINT_uL:
        switch (c){
            case 'L': fsm.int_state = LSINT_extra; break;
            default: fsm.emit_token = 1; break;
        }
        break;

        case LSINT_ll:
        switch (c){
            case 'u': case 'U': fsm.int_state = LSINT_extra; break;
            default: fsm.emit_token = 1; break;
        }
        break;

        case LSINT_extra:
        fsm.emit_token = 1;
        break;
    }
    return(fsm);
}

Lex_FSM
main_fsm(Lex_FSM fsm, unsigned char pp_state, unsigned char c){
    if (c == 0) fsm.emit_token = 1;
    else
        switch (pp_state){
        case LSPP_error:
        fsm.state = LS_error_message;
        if (c == '\n') fsm.emit_token = 1;
        break;

        case LSPP_include:
        switch (fsm.state){
            case LSINC_default:
            switch (c){
                case '"': fsm.state = LSINC_quotes; break;
                case '<': fsm.state = LSINC_pointy; break;
                default: fsm.state = LSINC_junk; break;
            }
            break;

            case LSINC_quotes:
            if (c == '"') fsm.emit_token = 1;
            break;

            case LSINC_pointy:
            if (c == '>') fsm.emit_token = 1;
            break;

            case LSINC_junk:
            if (c == '\n') fsm.emit_token = 1;
            break;
        }
        break;

        default:
        switch (fsm.state){
            case LS_default:
            if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_'){
                fsm.state = LS_identifier;
            }
            else if (c >= '1' && c <= '9'){
                fsm.state = LS_number;
            }
            else if (c == '0'){
                fsm.state = LS_number0;
            }
            else switch (c){
                case '\'': fsm.state = LS_char; break;
                case '"': fsm.state = LS_string; break;

                case '/': fsm.state = LS_comment_pre; break;

                case '.': fsm.state = LS_dot; break;

                case '<': fsm.state = LS_less; break;
                case '>': fsm.state = LS_more; break;

                case '-': fsm.state = LS_minus; break;

                case '&': fsm.state = LS_and; break;
                case '|': fsm.state = LS_or; break;

                case '+': fsm.state = LS_plus; break;

                case ':': fsm.state = LS_colon; break;

                case '*': fsm.state = LS_star; break;

                case '%': fsm.state = LS_modulo; break;
                case '^': fsm.state = LS_caret; break;

                case '=': fsm.state = LS_eq; break;
                case '!': fsm.state = LS_bang; break;

                case '#': fsm.state = LS_pound; break;

#define OperCase(op,type) case op: fsm.emit_token = 1; break;
                OperCase('{', CPP_TOKEN_BRACE_OPEN);
                OperCase('}', CPP_TOKEN_BRACE_CLOSE);

                OperCase('[', CPP_TOKEN_BRACKET_OPEN);
                OperCase(']', CPP_TOKEN_BRACKET_CLOSE);

                OperCase('(', CPP_TOKEN_PARENTHESE_OPEN);
                OperCase(')', CPP_TOKEN_PARENTHESE_CLOSE);

                OperCase('~', CPP_TOKEN_TILDE);
                OperCase(',', CPP_TOKEN_COMMA);
                OperCase(';', CPP_TOKEN_SEMICOLON);
                OperCase('?', CPP_TOKEN_TERNARY_QMARK);

                OperCase('@', CPP_TOKEN_JUNK);
                OperCase('$', CPP_TOKEN_JUNK);
                OperCase('\\', CPP_TOKEN_JUNK);
#undef OperCase
            }
            break;

            case LS_identifier:
            if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')){
                fsm.emit_token = 1;
            }
            break;

            case LS_pound:
            if (pp_state == LSPP_default){
                if (c == ' ' || c == '\t' || c == '\r' || c == '\f' || c == '\v'){
                    fsm.state = LS_pound;
                }
                else if (c == '\n'){
                    fsm.emit_token = 1;
                }
                else{
                    fsm.state = LS_pp;
                }
            }
            else{
                switch (c){
                    case '#': fsm.emit_token = 1; break;
                    default: fsm.emit_token = 1; break;
                }
            }
            break;

            case LS_pp:
            if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')){
                fsm.emit_token = 1;
            }
            break;

            case LS_char:
            case LS_char_multiline:
            switch(c){
                case '\'': fsm.emit_token = 1; break;
                case '\\': fsm.state = LS_char_slashed; break;
            }
            break;

            case LS_char_slashed:
            switch (c){
                case '\r': case '\f': case '\v': break;
                case '\n': fsm.state = LS_char_multiline; break;
                default: fsm.state = LS_char; break;
            }
            break;

            case LS_string:
            case LS_string_multiline:
            switch(c){
                case '\"': fsm.emit_token = 1; break;
                case '\\': fsm.state = LS_string_slashed; break;
            }
            break;

            case LS_string_slashed:
            switch (c){
                case '\r': case '\f': case '\v': break;
                case '\n': fsm.state = LS_string_multiline; break;
                default: fsm.state = LS_string; break;
            }
            break;

            case LS_number:
            if (c >= '0' && c <= '9'){
                fsm.state = LS_number;
            }
            else{
                switch (c){
                    case '.': fsm.state = LS_float; break;
                    default: fsm.emit_token = 1; break;
                }
            }
            break;

            case LS_number0:
            if (c >= '0' && c <= '9'){
                fsm.state = LS_number;
            }
            else if (c == 'x'){
                fsm.state = LS_hex;
            }
            else if (c == '.'){
                fsm.state = LS_float;
            }
            else{
                fsm.emit_token = 1;
            }
            break;

            case LS_float:
            if (!(c >= '0' && c <= '9')){
                switch (c){
                    case 'e': fsm.state = LS_crazy_float0; break;
                    default: fsm.emit_token = 1; break;
                }
            }
            break;

            case LS_crazy_float0:
            {
                if ((c >= '0' && c <= '9') || c == '-'){
                    fsm.state = LS_crazy_float1;
                }
                else{
                    fsm.emit_token = 1;
                }
            }
            break;

            case LS_crazy_float1:
            {
                if (!(c >= '0' && c <= '9')){
                    fsm.emit_token = 1;
                }
            }
            break;

            case LS_hex:
            if (!(c >= '0' && c <= '9' || c >= 'a' && c <= 'f' || c >= 'A' && c <= 'F')){
                fsm.emit_token = 1;
            }
            break;

            case LS_dot:
            if (c >= '0' && c <= '9'){
                fsm.state = LS_float;
            }
            else
                switch (c){
                case '.': fsm.state = LS_ellipsis; break;
                case '*': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_ellipsis: fsm.emit_token = 1; break;

            case LS_less:
            switch (c){
                case '<': fsm.state = LS_less_less; break;
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_less_less:
            switch (c){
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_more:
            switch (c){
                case '>': fsm.state = LS_more_more; break;
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_more_more:
            switch (c){
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_comment_pre:
            switch (c){
                case '/': fsm.state = LS_comment; break;
                case '*': fsm.state = LS_comment_block; break;
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_comment:
            switch (c){
                case '\\': fsm.state = LS_comment_slashed; break;
                case '\n': fsm.emit_token = 1; break;
            }
            break;

            case LS_comment_slashed:
            switch (c){
                case '\r': case '\f': case '\v': break;
                default: fsm.state = LS_comment; break;
            }
            break;

            case LS_comment_block:
            switch (c){
                case '*': fsm.state = LS_comment_block_ending; break;
            }
            break;

            case LS_comment_block_ending:
            switch (c){
                case '*': fsm.state = LS_comment_block_ending; break;
                case '/': fsm.emit_token = 1; break;
                default: fsm.state = LS_comment_block; break;
            }
            break;

            case LS_minus:
            switch (c){
                case '>': fsm.state = LS_arrow; break;
                case '-': fsm.emit_token = 1; break;
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_arrow:
            switch (c){
                case '*': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_and:
            switch (c){
                case '&': fsm.emit_token = 1; break;
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_or:
            switch (c){
                case '|': fsm.emit_token = 1; break;
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_plus:
            switch (c){
                case '+': fsm.emit_token = 1; break;
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_colon:
            switch (c){
                case ':': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_star:
            switch (c){
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_modulo:
            switch (c){
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_caret:
            switch (c){
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_eq:
            switch (c){
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;

            case LS_bang:
            switch (c){
                case '=': fsm.emit_token = 1; break;
                default: fsm.emit_token = 1; break;
            }
            break;
        }
        break;
    }
    return(fsm);
}

void
begin_table(FILE *file, char *type, char *group_name, char *table_name){
    fprintf(file, "unsigned %s %s_%s[] = {\n", type, group_name, table_name);
}

void
begin_table(FILE *file, char *type, char *table_name){
    fprintf(file, "unsigned %s %s[] = {\n", type, table_name);
}

void
begin_ptr_table(FILE *file, char *type, char *table_name){
    fprintf(file, "unsigned %s * %s[] = {\n", type, table_name);
}

void
do_table_item(FILE *file, unsigned short item){
    fprintf(file, "%2d,", (int)item);
}

void
do_table_item_direct(FILE *file, char *item, char *tail){
    fprintf(file, "%s%s,", item, tail);
}

void
end_row(FILE *file){
    fprintf(file, "\n");
}

void
end_table(FILE *file){
    fprintf(file, "};\n\n");
}

struct FSM_Tables{
    unsigned char *full_transition_table;
    unsigned char *marks;
    unsigned char *eq_class;
    unsigned char *eq_class_rep;
    unsigned char *reduced_transition_table;
    
    unsigned char eq_class_counter;
    unsigned short state_count;
};

void
do_table_reduction(FSM_Tables *table, unsigned short state_count){
    {
        table->eq_class_counter = 0;
        unsigned char *c_line = table->full_transition_table;
        for (unsigned short c = 0; c < 256; ++c){
            if (table->marks[c] == 0){
                table->eq_class[c] = table->eq_class_counter;
                table->eq_class_rep[table->eq_class_counter] = (unsigned char)c;
                unsigned char *c2_line = c_line + state_count;
                for (unsigned short c2 = c + 1; c2 < 256; ++c2){
                    if (memcmp(c_line, c2_line, state_count) == 0){
                        table->marks[c2] = 1;
                        table->eq_class[c2] = table->eq_class_counter;
                    }
                    c2_line += state_count;
                }
                ++table->eq_class_counter;
            }
            c_line += state_count;
        }
    }

    table->reduced_transition_table = (unsigned char*)malloc(state_count * table->eq_class_counter);
    {
        unsigned char *r_line = table->reduced_transition_table;
        for (unsigned short eq = 0; eq < table->eq_class_counter; ++eq){
            unsigned char *u_line = table->full_transition_table + state_count * table->eq_class_rep[eq];
            memcpy(r_line, u_line, state_count);
            r_line += state_count;
        }
    }
}

FSM_Tables
generate_whitespace_skip_table(){
	unsigned char state_count = LSPP_count;
    FSM_Tables table;
    table.full_transition_table = (unsigned char*)malloc(state_count * 256);
    table.marks = (unsigned char*)malloc(state_count * 256);
    table.eq_class = (unsigned char*)malloc(state_count * 256);
    table.eq_class_rep = (unsigned char*)malloc(state_count * 256);
    table.state_count = state_count;
    memset(table.marks, 0, 256);
    
    int i = 0;
    Whitespace_FSM wfsm = {0};
    Whitespace_FSM new_wfsm;
    for (unsigned short c = 0; c < 256; ++c){
        for (unsigned char state = 0; state < state_count; ++state){
            wfsm.pp_state = state;
            wfsm.white_done = 0;
            new_wfsm = whitespace_skip_fsm(wfsm, (unsigned char)c);
            table.full_transition_table[i++] = new_wfsm.pp_state + state_count*new_wfsm.white_done;
        }
    }
    
    do_table_reduction(&table, state_count);
    
    return(table);
}

FSM_Tables
generate_int_table(){
	unsigned char state_count = LSINT_count;
    FSM_Tables table;
    table.full_transition_table = (unsigned char*)malloc(state_count * 256);
    table.marks = (unsigned char*)malloc(state_count * 256);
    table.eq_class = (unsigned char*)malloc(state_count * 256);
    table.eq_class_rep = (unsigned char*)malloc(state_count * 256);
    table.state_count = state_count;
    memset(table.marks, 0, 256);
    
    int i = 0;
    Lex_FSM fsm = {0};
    Lex_FSM new_fsm;
    for (unsigned short c = 0; c < 256; ++c){
        for (unsigned char state = 0; state < state_count; ++state){
            fsm.int_state = state;
            fsm.emit_token = 0;
            new_fsm = int_fsm(fsm, (unsigned char)c);
            table.full_transition_table[i++] = new_fsm.int_state + state_count*new_fsm.emit_token;
        }
    }
        
    do_table_reduction(&table, state_count);

    return(table);
}

FSM_Tables
generate_fsm_table(unsigned char pp_state){
    unsigned char state_count = LS_count;
    FSM_Tables table;
    table.full_transition_table = (unsigned char*)malloc(state_count * 256);
    table.marks = (unsigned char*)malloc(state_count * 256);
    table.eq_class = (unsigned char*)malloc(state_count * 256);
    table.eq_class_rep = (unsigned char*)malloc(state_count * 256);
    table.state_count = state_count;
    memset(table.marks, 0, 256);
    
    int i = 0;
    Lex_FSM fsm = {0};
    Lex_FSM new_fsm;
    for (unsigned short c = 0; c < 256; ++c){
        for (unsigned char state = 0; state < state_count; ++state){
            fsm.state = state;
            fsm.emit_token = 0;
            new_fsm = main_fsm(fsm, pp_state, (unsigned char)c);
            table.full_transition_table[i++] = new_fsm.state + state_count*new_fsm.emit_token;
        }
    }
    
    do_table_reduction(&table, state_count);
    
    return(table);
}

void
render_fsm_table(FILE *file, FSM_Tables tables, char *group_name){
    begin_table(file, "short", group_name, "eq_classes");
    for (unsigned short c = 0; c < 256; ++c){
        do_table_item(file, tables.eq_class[c]*tables.state_count);
    }
    end_row(file);
    end_table(file);

    fprintf(file, "const int num_%s_eq_classes = %d;\n\n", group_name, tables.eq_class_counter);

    int i = 0;
    begin_table(file, "char", group_name, "table");
    for (unsigned short c = 0; c < tables.eq_class_counter; ++c){
        for (unsigned char state = 0; state < tables.state_count; ++state){
            do_table_item(file, tables.reduced_transition_table[i++]);
        }
        end_row(file);
    }
    end_table(file);
}

struct PP_Names{
    unsigned char pp_state;
    char *name;
};

PP_Names pp_names[] = {
    {LSPP_default, "main_fsm"},
    {LSPP_include, "pp_include_fsm"},
    {LSPP_macro_identifier, "pp_macro_fsm"},
    {LSPP_identifier, "pp_identifier_fsm"},
    {LSPP_body_if, "pp_body_if_fsm"},
    {LSPP_body, "pp_body_fsm"},
    {LSPP_number, "pp_number_fsm"},
    {LSPP_error, "pp_error_fsm"},
    {LSPP_junk, "pp_junk_fsm"},
};

int main(){
    FILE *file;
    file = fopen("4cpp_lexer_tables.c", "wb");
    
    FSM_Tables wtables = generate_whitespace_skip_table();
    render_fsm_table(file, wtables, "whitespace_fsm");
    
    FSM_Tables itables = generate_int_table();
    render_fsm_table(file, itables, "int_fsm");
    
    begin_table(file, "char", "multiline_state_table");
    for (unsigned char state = 0; state < LS_count; ++state){
        do_table_item(file, (state == LS_string_multiline || state == LS_char_multiline));
    }
    end_row(file);
    end_table(file);
        
    for (int i = 0; i < ArrayCount(pp_names); ++i){
        assert(i == pp_names[i].pp_state);
        FSM_Tables tables = generate_fsm_table(pp_names[i].pp_state);
        render_fsm_table(file, tables, pp_names[i].name);
    }
    
    begin_ptr_table(file, "short", "get_eq_classes");
    for (int i = 0; i < ArrayCount(pp_names); ++i){
        do_table_item_direct(file, pp_names[i].name, "_eq_classes");
        end_row(file);
    }
    end_table(file);
    
    begin_ptr_table(file, "char", "get_table");
    for (int i = 0; i < ArrayCount(pp_names); ++i){
        do_table_item_direct(file, pp_names[i].name, "_table");
        end_row(file);
    }
    end_table(file);
    
    fclose(file);
    return(0);
}

// BOTTOM