#include "token.h"

KeyValuePair TokenTypeMappings[TOKENTYPE_MAPPINGS_COUNT] = {
    { "(", LParen}, { ")", RParen}, { ",", Comma }, { ".", Dot },
    { "-", Minus }, { "+", Plus }, { ";", Semicolon }, { "/", Slash}, { "*", Star },
    { "!", Bang }, { "!=", Bang_Equal }, { "=", Equal }, { "==", Equal_Equal },
    { ">", Greater }, { ">=", Greater_Equal }, { "<", Less }, { "<=", Less_Equal },
    { "and", AND }, { "class", CLASS }, { "else", ELSE },
    { "false", FALSE }, { "for", FOR }, { "fun", FUN },
    { "if", IF }, { "nil", NIL }, { "or", OR },
    { "print", PRINT }, { "return", RETURN }, { "super", SUPER },
    { "this", THIS }, { "true", TRUE }, { "var", VAR }, { "while", WHILE },
    { "", EndOF }
};

const char* GetLexemeMapping(TokenType);

Token* CreateToken(const char* lexeme, void* literal, int line, TokenType type) {
    Token* token = calloc(1, sizeof(Token));
    
    if (!token) {
        fprintf(stderr, "Failed to calloc token. %s", strerror(errno));
        return NULL;
    }

    if (lexeme) {
        token->literal = literal;
        token->lexeme = lexeme;
    }
    else { 
        const char* mapping_result = GetLexemeMapping(type);
        
        if (!mapping_result) {
            fprintf(stderr, "Failed to get the mapping for %s\n", lexeme);
            free(token);
            return NULL;
        }

        token->literal = mapping_result;
        token->lexeme = mapping_result;
    }

    token->line = line;
    token->type = type;

    return token;
}

const char* GetLexemeMapping(TokenType type) {
    for (int i = 0; i < TOKENTYPE_MAPPINGS_COUNT; i++) {
        if (TokenTypeMappings[i].type == type) return TokenTypeMappings[i].lexeme;
    }

    return NULL;
}

void FreeToken(Token* token) {
    if (!token) return;

    if (token->type == String || token->type == Number || token->type == Identifier) free((void *) token->lexeme);

    free(token);
}