#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/stat.h>

#include "platform.h"
#include "config.h"

int ensure_directory_exists(const char *path) {
    struct stat st;
    
    if (stat(path, &st) == 0) {
        /* Path exists, check if it's a directory */
#if defined(__MSDOS__) || defined(__DOS__)
        /* DOS/Turbo C: use bit test because S_ISDIR macro may be missing */
        if ((st.st_mode & S_IFMT) == S_IFDIR) {
            return 1;
        }
#else
        /* Unix/Linux/Windows modern: use standard POSIX macro */
        if (S_ISDIR(st.st_mode)) {
            return 1;
        }
#endif
        else {
            fprintf(stderr, "Error: %s exists but is not a directory\n", path);
            return 0;
        }
    }
    
    /* Directory doesn't exist, try to create it */
    if (mkdir_portable(path) != 0) {
        fprintf(stderr, "Error: Cannot create directory %s\n", path);
        return 0;
    }
    return 1;
}

int get_cnotes_path(char *buffer, size_t bufsize) {
    const char *custom_path;
    const char *home;
    size_t len;

    /* First check for CNOTES_PATH environment variable override */
    custom_path = getenv(CNOTES_PATH_ENV);
    if (custom_path != NULL && strlen(custom_path) > 0) {
        if (strlen(custom_path) >= bufsize) {
            fprintf(stderr, "Error: Path too long\n");
            return 0;
        }
        strcpy(buffer, custom_path);
        return 1;
    }

    /* Fall back to HOME_ENV + CNOTES_DIR */
    home = getenv(HOME_ENV);
    if (home == NULL) {
        fprintf(stderr, "Error: %s environment variable not set\n", HOME_ENV);
        fprintf(stderr, "Hint: Set %s to specify notes directory\n", CNOTES_PATH_ENV);
        return 0;
    }

    /* Build path: $HOME/CNOTES_DIR (or just $HOME if CNOTES_DIR is empty) */
    len = strlen(home);
    if (strlen(CNOTES_DIR) == 0) {
        /* DOS mode: use home directory directly */
        if (len >= bufsize) {
            fprintf(stderr, "Error: Path too long\n");
            return 0;
        }
        strcpy(buffer, home);
    } else {
        /* Unix/Windows: append CNOTES_DIR to home */
        if (len + strlen(CNOTES_DIR) + 2 > bufsize) {
            fprintf(stderr, "Error: Path too long\n");
            return 0;
        }
        sprintf(buffer, "%s" PATH_SEP_STR "%s", home, CNOTES_DIR);
    }
    return 1;
}

int write_entry(const char *category, const char *message) {
    char dir_path[512];
    char file_path[600];
    FILE *file;
    time_t now;
    struct tm *tm_info;
    char date[11];
    char time_str[6];
    char padded_category[CATEGORY_LENGTH + 1];
    char truncated_message[FREETEXT_MAX_LENGTH + 1];
    int i;
    
    /* Get current date and time */
    now = time(NULL);
    if (now == -1) {
        fprintf(stderr, "Error: Cannot get current time\n");
        return 0;
    }
    
    tm_info = localtime(&now);
    if (tm_info == NULL) {
        fprintf(stderr, "Error: Cannot convert time\n");
        return 0;
    }
    
    /* Format date as YYYY-MM-DD */
    strftime(date, sizeof(date), "%Y-%m-%d", tm_info);
    
    /* Format time as HH:MM */
    strftime(time_str, sizeof(time_str), "%H:%M", tm_info);
    
    /* Pad category to 10 characters */
    strncpy(padded_category, category, CATEGORY_LENGTH);
    padded_category[CATEGORY_LENGTH] = '\0';
    for (i = (int)strlen(padded_category); i < CATEGORY_LENGTH; i++) {
        padded_category[i] = ' ';
    }
    padded_category[CATEGORY_LENGTH] = '\0';
    
    /* Truncate message to 80 characters */
    strncpy(truncated_message, message, FREETEXT_MAX_LENGTH);
    truncated_message[FREETEXT_MAX_LENGTH] = '\0';
    
    /* Get cnotes directory path */
    if (!get_cnotes_path(dir_path, sizeof(dir_path))) {
        return 0;
    }
    
    /* Ensure directory exists */
    if (!ensure_directory_exists(dir_path)) {
        return 0;
    }
    
    /* Build full file path */
    sprintf(file_path, "%s" PATH_SEP_STR "%s", dir_path, CNOTES_FILE);
    
    /* Open file in append mode */
    file = fopen(file_path, "a");
    if (file == NULL) {
        fprintf(stderr, "Error: Cannot open file %s\n", file_path);
        return 0;
    }
    
    /* Write entry */
    fprintf(file, "%s,%s,%s,\"%s\"\n", 
            date, time_str, padded_category, truncated_message);
    
    fclose(file);
    
    printf("Entry added to %s\n", file_path);
    return 1;
}

void print_usage(const char *prog_name) {
    fprintf(stderr, "Usage: %s [-c category] message\n", prog_name);
    fprintf(stderr, "  -c category  Optional category (max 10 chars, default: %s)\n", 
            DEFAULT_CATEGORY);
    fprintf(stderr, "  message      Required message text (max 80 chars). Wrapped in double-quotes.\n");
}

int main(int argc, char *argv[]) {
    const char *category;
    const char *message;
    int i;
    
    category = DEFAULT_CATEGORY;
    message = NULL;
    
    /* Parse command-line arguments */
    i = 1;
    while (i < argc) {
        if (strcmp(argv[i], "-c") == 0) {
            if (i + 1 >= argc) {
                fprintf(stderr, "Error: -c option requires an argument\n");
                print_usage(argv[0]);
                return 1;
            }
            category = argv[i + 1];
            i += 2;
        } else {
            message = argv[i];
            i++;
            break;  /* Only take first non-option as message */
        }
    }
    
    /* Validate arguments */
    if (message == NULL || strlen(message) == 0) {
        fprintf(stderr, "Error: Message is required\n");
        print_usage(argv[0]);
        return 1;
    }
    
    /* Write entry */
    if (!write_entry(category, message)) {
        return 1;
    }
    
    return 0;
}