#include "os.h"

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

// Function to check if a string ends with a specific suffix (case insensitive)
int ends_with_wav(const char *str) {
  size_t len = strlen(str);
  if (len < 4) return 0;
    
  const char *suffix = str + len - 4;
  return (strcasecmp(suffix, ".wav") == 0);
}

// Function to extract the example name from folder format: "example name[2048-44.1khz-32bit]"
char* extract_example_name(const char *folder_name) {
  char *result = malloc(strlen(folder_name) + 1);
  if (!result) return NULL;
    
  strcpy(result, folder_name);
    
  // Find the opening bracket and terminate the string there
  char *bracket = strchr(result, '[');
  if (bracket) {
    *bracket = '\0';
  }
    
  // Remove trailing whitespace
  int len = strlen(result);
  while (len > 0 && (result[len-1] == ' ' || result[len-1] == '\t')) {
    result[--len] = '\0';
  }
    
  return result;
}

char* scan_for_wav(const char *directory_path) {
    DIR *dir;
    struct dirent *entry;
    struct stat statbuf;
    char full_path[1024];
    char *result = NULL;
    size_t result_size = 0;
    size_t result_capacity = 1024;
    int first_entry = 1;
    
    // Initialize result buffer
    result = malloc(result_capacity);
    if (!result) return NULL;
    result[0] = '\0';
    
    // Open directory
    dir = opendir(directory_path);
    if (!dir) {
        free(result);
        return NULL;
    }
    
    // Iterate through directory entries
    while ((entry = readdir(dir)) != NULL) {
        // Skip . and .. entries
        if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
            continue;
        }
        
        // Create full path
        snprintf(full_path, sizeof(full_path), "%s/%s", directory_path, entry->d_name);
        
        // Check if it's a directory
        if (stat(full_path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
            // This is a subdirectory, scan for WAV files in it
            DIR *subdir;
            struct dirent *subentry;
            
            subdir = opendir(full_path);
            if (!subdir) continue;
            
            // Extract example name from folder name
            char *example_name = extract_example_name(entry->d_name);
            if (!example_name) {
                closedir(subdir);
                continue;
            }
            
            // Look for WAV files in subdirectory
            while ((subentry = readdir(subdir)) != NULL) {
                if (ends_with_wav(subentry->d_name)) {
                    // Calculate needed space for new entry (full path)
                    size_t needed_space = strlen(full_path) + 1 + strlen(subentry->d_name) + 2; // +2 for ';' and '\0'
                    if (!first_entry) needed_space += 1; // for semicolon separator
                    
                    // Resize buffer if needed
                    while (result_size + needed_space >= result_capacity) {
                        result_capacity *= 2;
                        char *new_result = realloc(result, result_capacity);
                        if (!new_result) {
                            free(result);
                            free(example_name);
                            closedir(subdir);
                            closedir(dir);
                            return NULL;
                        }
                        result = new_result;
                    }
                    
                    // Add separator if not first entry
                    if (!first_entry) {
                        strcat(result, ";");
                        result_size += 1;
                    }
                    
                    // Add the full path
                    strcat(result, full_path);
                    strcat(result, "/");
                    strcat(result, subentry->d_name);
                    result_size += strlen(full_path) + 1 + strlen(subentry->d_name);
                    
                    first_entry = 0;
                }
            }
            
            free(example_name);
            closedir(subdir);
        }
    }
    
    closedir(dir);
    
    // If no WAV files found, return empty string
    if (result_size == 0) {
        strcpy(result, "");
    }
    
    return result;
}


// Main function to scan directory and return formatted string
char* scan_for_wav_pretty(const char *directory_path) {
  DIR *dir;
  struct dirent *entry;
  struct stat statbuf;
  char full_path[1024];
  char *result = NULL;
  size_t result_size = 0;
  size_t result_capacity = 1024;
  int first_entry = 1;
    
  // Initialize result buffer
  result = malloc(result_capacity);
  if (!result) return NULL;
  result[0] = '\0';
    
  // Open directory
  dir = opendir(directory_path);
  if (!dir) {
    free(result);
    return NULL;
  }
    
  // Iterate through directory entries
  while ((entry = readdir(dir)) != NULL) {
    // Skip . and .. entries
    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
      continue;
    }
        
    // Create full path
    snprintf(full_path, sizeof(full_path), "%s/%s", directory_path, entry->d_name);
        
    // Check if it's a directory
    if (stat(full_path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
      // This is a subdirectory, scan for WAV files in it
      DIR *subdir;
      struct dirent *subentry;
            
      subdir = opendir(full_path);
      if (!subdir) continue;
            
      // Extract example name from folder name
      char *example_name = extract_example_name(entry->d_name);
      if (!example_name) {
        closedir(subdir);
        continue;
      }
            
      // Look for WAV files in subdirectory
      while ((subentry = readdir(subdir)) != NULL) {
        if (ends_with_wav(subentry->d_name)) {
          // Calculate needed space for new entry
          size_t needed_space = strlen(example_name) + 1 + strlen(subentry->d_name) + 2; // +2 for ';' and '\0'
          if (!first_entry) needed_space += 1; // for semicolon separator
                    
          // Resize buffer if needed
          while (result_size + needed_space >= result_capacity) {
            result_capacity *= 2;
            char *new_result = realloc(result, result_capacity);
            if (!new_result) {
              free(result);
              free(example_name);
              closedir(subdir);
              closedir(dir);
              return NULL;
            }
            result = new_result;
          }
                    
          // Add separator if not first entry
          if (!first_entry) {
            strcat(result, ";");
            result_size += 1;
          }
                    
          // Add the formatted entry
          strcat(result, example_name);
          strcat(result, "/");
          strcat(result, subentry->d_name);
          result_size += strlen(example_name) + 1 + strlen(subentry->d_name);
                    
          first_entry = 0;
        }
      }
            
      free(example_name);
      closedir(subdir);
    }
  }
    
  closedir(dir);
    
  // If no WAV files found, return empty string
  if (result_size == 0) {
    strcpy(result, "");
  }
    
  return result;
}

/* // Example usage */
/* int main() { */
/*   const char *test_dir = "/path/to/your/directory"; */
/*   char *result = scan_wav_directory(test_dir); */
    
/*   if (result) { */
/*     printf("Found WAV files: %s\n", result); */
/*     free(result); */
/*   } else { */
/*     printf("Error scanning directory or no WAV files found.\n"); */
/*   } */
    
/*   return 0; */
/* } */