#include "StringUtils.h"

#include <algorithm>
#include <cstring>

namespace StringUtils {

std::string sanitizeFilename(const std::string& name, size_t maxLength) {
  std::string result;
  result.reserve(name.size());

  for (char c : name) {
    // Replace invalid filename characters with underscore
    if (c == '/' || c == '\\' || c == ':' || c == '*' || c == '?' || c == '"' || c == '<' || c == '>' || c == '|') {
      result += '_';
    } else if (c >= 32 && c < 127) {
      // Keep printable ASCII characters
      result += c;
    }
    // Skip non-printable characters
  }

  // Trim leading/trailing spaces and dots
  size_t start = result.find_first_not_of(" .");
  if (start == std::string::npos) {
    return "book";  // Fallback if name is all invalid characters
  }
  size_t end = result.find_last_not_of(" .");
  result = result.substr(start, end - start + 1);

  // Limit filename length
  if (result.length() > maxLength) {
    result.resize(maxLength);
  }

  return result.empty() ? "book" : result;
}

bool checkFileExtension(const std::string& fileName, const char* extension) {
  if (fileName.length() < strlen(extension)) {
    return false;
  }

  const std::string fileExt = fileName.substr(fileName.length() - strlen(extension));
  for (size_t i = 0; i < fileExt.length(); i++) {
    if (tolower(fileExt[i]) != tolower(extension[i])) {
      return false;
    }
  }
  return true;
}

bool checkFileExtension(const String& fileName, const char* extension) {
  if (fileName.length() < strlen(extension)) {
    return false;
  }

  String localFile(fileName);
  String localExtension(extension);
  localFile.toLowerCase();
  localExtension.toLowerCase();
  return localFile.endsWith(localExtension);
}

void sortFileList(std::vector<std::string>& entries) {
  std::sort(begin(entries), end(entries), [](const std::string& str1, const std::string& str2) {
    bool isDir1 = str1.back() == '/';
    bool isDir2 = str2.back() == '/';
    if (isDir1 != isDir2) return isDir1;

    const char* s1 = str1.c_str();
    const char* s2 = str2.c_str();

    while (*s1 && *s2) {
      if (isdigit(*s1) && isdigit(*s2)) {
        while (*s1 == '0') s1++;
        while (*s2 == '0') s2++;

        int len1 = 0, len2 = 0;
        while (isdigit(s1[len1])) len1++;
        while (isdigit(s2[len2])) len2++;

        if (len1 != len2) return len1 < len2;

        for (int i = 0; i < len1; i++) {
          if (s1[i] != s2[i]) return s1[i] < s2[i];
        }

        s1 += len1;
        s2 += len2;
      } else {
        char c1 = tolower(*s1);
        char c2 = tolower(*s2);
        if (c1 != c2) return c1 < c2;
        s1++;
        s2++;
      }
    }

    return *s1 == '\0' && *s2 != '\0';
  });
}

}  // namespace StringUtils