#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <error.h>
#include <stdbool.h>
#include <ctype.h>

#define MAX_LINE_WIDTH 256

enum CMD_CODES{
    UCI          = 0,
    DEBUG        = 1,
    ISREADY      = 2,
    SETOPTION    = 3,
    REGISTER     = 4,
    UCINEWGAME   = 5,
    POSITION     = 6,
    GO           = 7,
    STOP         = 8,
    PONDERHIT    = 9,
    QUIT         = 10
};

const char* CMDS[] = {
    "uci",
    "debug",
    "isready",
    "setoption name",
    "register",
    "ucinewgame",
    "position",
    "go",
    "stop",
    "ponderhit",
    "quit"
};
#define NUM_CMDS (sizeof (CMDS) / sizeof (const char *))

typedef enum{
    CHECK,
    SPIN,
    COMBO,
    BUTTON,
    STRING
} option_type;


typedef void button_handler();
typedef union {
    bool check;
    int spin;
    // maybe I could store an array of strings for combo, 
    // and just have the first one be the one that gets modified, 
    // the others being the possible variants
    char* combo;
    button_handler* button_handler;
    char* string;
} option_data;

typedef struct {
    char* name;
    option_type type;
    option_data data;
} option;

option options[] = {
    {"Ponder", CHECK, false},
    {"OwnBook", CHECK, true}
};

void _uci(char* parse_condition){
    send_id();
    send_opts();
    send_uciok();
}

void _debug(char* parse_condition){
    if(strcmp("on", parse_condition)){
        debug_mode = false;
    }else if(strcmp("off", parse_condition)){
        debug_mode = true;
    }else{
        printf("Warning: debug command without [ on | off ]");
    }
}

void _isready(char* parse_condition){
    while(true){
        if(ready){
            send_readyok();
            break;
        }
    }
}

void _setoption(char* parse_condition){
    int value_pos = find_value_pos();
    //bit exessive, but oh well *shrugs*
    char option_str[value_pos];
    strncpy(option_str, parse_condition, value_pos-1);
    char values_str[MAX_LINE_WIDTH];
    strncpy(values_str, &parse_condition[value_pos+6], MAX_LINE_WIDTH);
    for(int i = 0; i < value_pos-1; i++){
        option_str[i] = tolower(option_str[i]);
    }
    for(int i = 0; i < sizeof(options)/sizeof(option); i++){
        if(strncmp(options[i].name, option_str, value_pos-1) == 0){
            switch(options[i].type){
                case CHECK:
                    options[i].data = parse_check(values_str);
                case SPIN:
                    options[i].data = parse_spin(values_str);
                case COMBO:
                    // This is missing the info of what the possible strings are, to ensure that it's a valid string. 
                    // Integrating this into my rather neat data structure seems pain, so for now it won't get done
                    options[i].data = parse_combo(values_str);
                case BUTTON:
                    // Function pointer syntax is hard. This is meant to be a function call to the function pointer in data.
                    // (this feels cursed as hell, but seemed like the only way to actually implement this x.x)
                    *((button_handler*) options[i].data)();
                case STRING:
                    //this should really just be a quick verification of the termination
                    options[i].data = parse_string(values_str);
            }
        }
    }
}
void _register(char* parse_condition){}
void _ucinewgame(char* parse_condition){}
void _position(char* parse_condition){}
void _go(char* parse_condition){}
void _stop(char* parse_condition){
    run = false;
}
void _ponderhit(char* parse_condition){
    ponder = true;
}
void _quit(char* parse_condition){
    //letting the OS do the cleanup .-.
    //TODO: merge any threads together, and cleanly exit, rather than this mess x.x
    exit(1);
}

//reads a line of the input and parses it as UCI GUI->ENGINE communication
void parse_line(){
    char* parse_buff [MAX_LINE_WIDTH];
    char* parse_pos = parse_buff;
    if(!fgets(parse_buff, MAX_LINE_WIDTH, stdin)){
        perror("failed reading input");
        exit(-1);
    }
    int active_command;
    for(active_command = 0; active_command<NUM_CMDS; active_command++){
        if(strncmp(CMDS[active_command], parse_pos, strlen(CMDS[active_command])) == 0){
            break;
        }
    }
    parse_pos+=(strlen(CMDS[active_command])+1);
    switch(active_command){
        case UCI:
            _uci(parse_pos);
            break;
        case DEBUG:
            _debug(parse_pos);
            break;
        case ISREADY:
            _isready(parse_pos);
            break;
        case SETOPTION:
            _setoption(parse_pos);
            break;
        case REGISTER:
            _register(parse_pos);
            break;
        case UCINEWGAME:
            _ucinewgame(parse_pos);
            break;
        case POSITION:
            _position(parse_pos);
            break;
        case GO:
            _go(parse_pos);
            break;
        case STOP:
            _stop(parse_pos);
            break;
        case PONDERHIT:
            _ponderhit(parse_pos);
            break;
        case QUIT:
            _quit(parse_pos);
            break;
    }
}