#include "wordle.h"

// TODO: Use enums for error codes

char* get_flag_from_argument(char* argument) {
    char* flag = (char*)malloc(sizeof(char) * (strlen(argument) + 1));
    if (!strcpy(flag, argument)) {
        fprintf(stderr, "Could not parse argument \"%s\", exiting...\n",
                argument);
        exit(E_ARGS);
    }
    return flag;
}

int add_to_used_flags(
        char* flag, char usedFlags[MAX_FLAGS][5], int* usedFlagIndex) {
    // Make sure command has not already been used
    for (int i = 0; i < (*usedFlagIndex) + 1; i++) {
        if (strcmp(usedFlags[i], flag) == 0) {
            return 0;
        }
    }

    // Add command to used commands to make sure there are no
    // duplicates
    strcpy(usedFlags[*usedFlagIndex], flag);
    (*usedFlagIndex)++;
    return 1;
}

int check_valid_value(char* value) {
    for (int i = 0; i < strlen(value); i++) {
        if (!isdigit(value[i])) {
            return 0;
        }
    }
    return 1;
}

void update_file_path_from_argument(char** filePath, char* argument) {
    *filePath =
            (char*)realloc(*filePath, sizeof(char) * (strlen(argument) + 1));
    if (!strcpy(*filePath, argument)) {
        fprintf(stderr, "Could not parse file path, exiting...\n");
        exit(1);
    }
}

int get_valid_command_arguments(int argc, char* argv[], int* wordLength,
        int* maxGuesses, char** filePath) {
    char usedFlags[MAX_FLAGS][5];
    int usedFlagIndex = 0;
    char* flag = NULL;

    for (int i = 1; i < argc; i++) {
        flag = get_flag_from_argument(argv[i]);
        if (flag[0] == '-') {
            int value = 0;

            // Check conditions and move index to argument index
            if (!add_to_used_flags(flag, usedFlags, &usedFlagIndex) ||
                    (++i) >= argc) {
                free(flag);
                return 0;
            }

            // Check if the argument is a valid integer
            value = atoi(argv[i]);
            if (!check_valid_value(argv[i]) || !value || value < MIN_RANGE ||
                    value > MAX_RANGE) {
                return 0;
            }

            // If the option matches, update its corresponding value
            if (strcmp(flag, "-len") == 0) {
                *wordLength = value;
            } else if (strcmp(flag, "-max") == 0) {
                *maxGuesses = value;
            } else {
                free(flag);
                return 0;
            }
        } else if (i == argc - 1) {
            update_file_path_from_argument(filePath, argv[i]);
        } else {
            free(flag);
            return 0;
        }
    }
    if (flag) {
        free(flag);
    }
    return 1;
}

int check_invalid_word(char* word, int wordLength) {
    if (strlen(word) != wordLength) {
        return 1;
    }

    for (int i = 0; i < strlen(word); i++) {
        if (!isalpha(word[i])) {
            return 2;
        }
    }
    return 0;
}

void free_dictionary(Dictionary* dictionary) {
    for (int i = 0; i < dictionary->size; i++) {
        free(dictionary->contents[i]);
    }
    free(dictionary->contents);
}

void insert_word_into_dictionary(Dictionary* dictionary, char* word) {
    // Increase dictionary size
    dictionary->size++;
    dictionary->contents = (char**)realloc(
            dictionary->contents, sizeof(char*) * dictionary->size);

    // Allocate space and insert new word
    dictionary->contents[dictionary->size - 1] =
            (char*)malloc(sizeof(char) * (strlen(word) + 1));
    strcpy(dictionary->contents[dictionary->size - 1], word);
}

Dictionary get_new_dictionary() {
    Dictionary dictionary;
    dictionary.size = 0;
    dictionary.contents = (char**)malloc(sizeof(char*));
    return dictionary;
}

Dictionary get_dictionary_from_buffer(FILE* buffer) {
    Dictionary dictionary = get_new_dictionary();

    char line[MAX_GUESS_LENGTH] = {'\0'};
    while (fgets(line, MAX_GUESS_LENGTH, buffer)) {
        // Remove newline
        line[strcspn(line, "\n")] = '\0';

        if (check_invalid_word(line, strlen(line))) {
            continue;
        }
        string_lowercase(line);

        // Won't check if word in already as lookup times would be huge
        insert_word_into_dictionary(&dictionary, line);
    }
    return dictionary;
}

Dictionary get_dictionary_words_of_length(
        Dictionary dictionary, int wordLength) {
    Dictionary sizedDictionary = get_new_dictionary();
    for (int i = 0; i < dictionary.size; i++) {
        if (strlen(dictionary.contents[i]) == wordLength) {
            insert_word_into_dictionary(
                    &sizedDictionary, dictionary.contents[i]);
        }
    }
    return sizedDictionary;
}

int check_word_in_dictionary(Dictionary dictionary, char* word) {
    if (dictionary.size == 0) {
        return 0;
    }

    for (int i = 0; i < dictionary.size; i++) {
        if (strcmp(dictionary.contents[i], word) == 0) {
            return 1;
        }
    }
    return 0;
}

char* get_blank_wordle(int wordLength) {
    char* wordleWord = (char*)malloc(sizeof(char) * (wordLength + 1));
    memset(wordleWord, '-', wordLength);
    wordleWord[wordLength] = '\0';
    return wordleWord;
}

char* get_wordle_format(char* guessedWord, char* answer) {
    char* modifiedAnswer = (char*)malloc(sizeof(char) * (strlen(answer) + 1));
    char* wordleWord = get_blank_wordle(strlen(answer));

    strcpy(modifiedAnswer, answer);

    // First parse, match all exact matches
    for (int i = 0; i < strlen(answer); i++) {
        if (guessedWord[i] == modifiedAnswer[i]) {
            wordleWord[i] = toupper(modifiedAnswer[i]);
            modifiedAnswer[i] = '-';
        }
    }

    // Second parse, match everything else
    for (int i = 0; i < strlen(answer); i++) {
        // If the character has already been matched
        if (wordleWord[i] != '-') {
            continue;
        }

        // Sourced with inspiration from:
        // https://stackoverflow.com/questions/1479386/
        const char* ptr;
        if ((ptr = strchr(modifiedAnswer, guessedWord[i]))) {
            int characterIndex = ptr - modifiedAnswer;

            wordleWord[i] = tolower(guessedWord[i]);
            modifiedAnswer[characterIndex] = '-';
        }
    }
    free(modifiedAnswer);
    return wordleWord;
}

void string_lowercase(char* string) {
    for (int i = 0; i < strlen(string); i++) {
        string[i] = tolower(string[i]);
    }
}

char* get_guessed_word_from_input(void) {
    char* guessedWord = (char*)malloc(sizeof(char) * MAX_GUESS_LENGTH);

    char buffer[MAX_GUESS_LENGTH];
    if (fgets(buffer, MAX_GUESS_LENGTH, stdin)) {
        // Remove newline character
        buffer[strcspn(buffer, "\n")] = '\0';
        if (strlen(buffer) == 0) {
            // Words cannot be smaller than 3 so this is a quick and
            // dirty hack
            strcpy(buffer, "a");
        }
        guessedWord = (char*)realloc(
                guessedWord, sizeof(char) * (strlen(buffer) + 1));
        strcpy(guessedWord, buffer);
    } else {
        free(guessedWord);
        return NULL;
    }

    return guessedWord;
}

void prompt_invalid_guess(int invalidType, int wordLength) {
    if (invalidType == 1) {
        printf("Words must be %d letters long - try again.\n", wordLength);
    } else if (invalidType == 2) {
        printf("Words must contain only letters - try again.\n");
    }
}

void print_attempt_prompt(int guessesRemaining, int wordLength) {
    if (guessesRemaining > 1) {
        printf("Enter a %d letter word (%d attempts remaining):\n", wordLength,
                guessesRemaining);
    } else if (guessesRemaining == 1) {
        printf("Enter a %d letter word (last attempt):\n", wordLength);
    }
}

// TODO: split this into smaller functions
int game_loop(
        int wordLength, int maxGuesses, char* answer, Dictionary dictionary) {
    int gameWon = 0;
    int guessesRemaining = maxGuesses;
    printf(WELCOME_MESSAGE);
    while (!gameWon && guessesRemaining >= 1) {
        int invalidGuess = 1;

        // Print prompt
        print_attempt_prompt(guessesRemaining, wordLength);

        // Get user input, break on EOF
        char* guessedWord = get_guessed_word_from_input();
        if (!guessedWord) {
            free(guessedWord);
            break;
        }

        // Check if word is valid
        invalidGuess = check_invalid_word(guessedWord, wordLength);
        if (invalidGuess) {
            prompt_invalid_guess(invalidGuess, wordLength);
            free(guessedWord);
            continue;
        }

        string_lowercase(guessedWord);

        // If the guessed word is correct
        if (strcmp(guessedWord, answer) == 0) {
            printf("Correct!\n");
            gameWon = 1;
            free(guessedWord);
            return E_OK;
        }

        if (!check_word_in_dictionary(dictionary, guessedWord)) {
            printf("Word not found in the dictionary - try again.\n");
            free(guessedWord);
            continue;
        }

        char* wordleWord = get_wordle_format(guessedWord, answer);
        printf("%s\n", wordleWord);

        free(wordleWord);
        free(guessedWord);
        guessesRemaining--;
    }
    fprintf(stderr, "Bad luck - the word is \"%s\".\n", answer);
    return E_LOST;
}

void get_answer(char** answer, int wordLength) {
    char* tmpAnswer = get_random_word(wordLength);
    *answer = (char*)realloc(*answer, sizeof(char) * (strlen(tmpAnswer) + 1));
    strcpy(*answer, tmpAnswer);
    free(tmpAnswer);
}

int main(int argc, char* argv[]) {
    char* answer = NULL;
    int wordLength = DEFAULT_WORD_LENGTH;
    int maxGuesses = DEFAULT_MAX_GUESSES;
    char* filePath = (char*)malloc(
            sizeof(char) * (strlen(DEFAULT_DICTIONARY_PATH) + 1));
    strcpy(filePath, DEFAULT_DICTIONARY_PATH);

    // clang-format off
    if (argc > 6 || !get_valid_command_arguments(
            argc, argv, &wordLength, &maxGuesses, &filePath)) {
        fprintf(stderr, USAGE_MESSAGE);
        return E_ARGS;
    }
    // clang-format on

    FILE* dictionaryBuffer = fopen(filePath, "r");
    if (!dictionaryBuffer) {
        fprintf(stderr, FILE_ERROR, filePath);
        return E_FILE;
    }
    free(filePath);

    get_answer(&answer, wordLength);

    // Load dictionary and get words of the required word length
    Dictionary dictionary = get_dictionary_from_buffer(dictionaryBuffer);
    Dictionary sizedDictionary =
            get_dictionary_words_of_length(dictionary, wordLength);

    fclose(dictionaryBuffer);

    int gameResult =
            game_loop(wordLength, maxGuesses, answer, sizedDictionary);

    free(answer);
    free_dictionary(&dictionary);
    free_dictionary(&sizedDictionary);

    return gameResult;
}