#include "../includes/tokenizer.h"
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>

Token* GetNextToken(char *);
TokenType GetOperatorType(char);
char* SplitOnBasicGrammar(char*);
int TokenIsNumeric(const char*);
Token* CreateToken(TokenType, char*);

List* TokenizeString(const char *file_path) {
    FILE *file;
    char* line = NULL;
    size_t len = 0;
    ssize_t bytes_read;

    file = fopen(file_path, "r");

    if (!file) {
        printf("Failed to open '%s' for reading.\n", file_path);
        return NULL;
    }

    while((bytes_read = getline(&line, &len, file)) != -1) {
        Token* token = GetNextToken(line);

        while (token) {
            if (!token) break;

            if(token->type == TK_Number)  {
                printf("Found number: '%s'\n", token->value);
            }
            else {
                printf("Found text: '%s'\n", token->value);
            }

            free(token->value);
            free(token);

            token = GetNextToken(NULL);
        }
    }

    fclose(file);

    if (line) free(line);

    return NULL;
}

Token* GetNextToken(char *string) {
    char* string_token = SplitOnBasicGrammar(string);
    
    while (strlen(string_token) != 0) {
        
        if (TokenIsNumeric(string_token)) return CreateToken(TK_Number, string_token);

        return CreateToken(TK_Text, string_token);
    }
    
    free(string_token);

    return NULL;
}

Token* CreateToken(TokenType type, char* value) {
    Token* token = calloc(1, sizeof(Token));

    if (!token) return NULL;

    token->type = type;
    token->value = value;

    return token;
}

int TokenIsNumeric(const char* token) {
    if (!token) return 0;
    
    unsigned long length = strlen(token);

    if (length == 0) return 0;

    for(int i = 0; i < length; i++) {
        if (!isdigit(token[i])) return 0;
    }

    return 1;
}

char* SplitOnBasicGrammar(char* line) {
    static char* string;
    static unsigned long position;

    if (line) {
        string = line;
        position = 0;
    }

    char* token = calloc(1, strlen(string) + 1);
    int parsing_string = 0;

    for (int i = 0; position < strlen(string); i++, position++) {
        
        if (parsing_string) {
            if (string[position] == '\n') break;
            if (string[position] == '"') break;

            token[i] = string[position];

            continue;
        }

        if (string[position] == ';') break;

        if (string[position] == '"') {
            parsing_string = 1;
            i--;
            continue;
        }

        if (string[position] == ' ') {
            while(string[position] == ' ') {
                position++;
            }

            if (strlen(token) != 0) break;
        }

        if (string[position] == ',') {
            if (strlen(token) == 0) {
                token[0] = string[position];
                position++;
            }

            break;
        }
        
        if (string[position] != '\n') token[i] = string[position];
    }

    return token;
}

TokenType GetOperatorType(char c) {
    switch (c){
        case '+':
        return TK_Add;
        case '-':
        return TK_Sub;
        case '*':
        return TK_Mul;
        case '/':
        return TK_Div;
        case '^':
        return TK_Power;
        case ':':
        return TK_Colon;
        case '(':
        return TK_LParam;
        case ')':
        return TK_RParam;
        case '[':
        return TK_LBracket;
        case ']':
        return TK_RBracket;
    };

    return TK_Invalid;
}