28 files changed, 1072 insertions, 1 deletions
diff --git a/src/utils/dirname.cpp b/src/utils/dirname.cpp
new file mode 100644
index 0000000..71c9c38
--- /dev/null
+++ b/src/utils/dirname.cpp
@@ -0,0 +1,16 @@
+#include <utils/dirname.hpp>
+
+namespace utils
+{
+    std::string dirname(const std::string filename)
+    {
+      if (filename.empty())
+        return "./";
+      if (filename == ".." || filename == ".")
+        return filename;
+      auto pos = filename.rfind('/');
+      if (pos == std::string::npos)
+        return "./";
+      return filename.substr(0, pos + 1);
+    }
+}
diff --git a/src/utils/dirname.hpp b/src/utils/dirname.hpp
new file mode 100644
index 0000000..c1df81b
--- /dev/null
+++ b/src/utils/dirname.hpp
@@ -0,0 +1,6 @@
+#include <string>
+
+namespace utils
+{
+std::string dirname(const std::string filename);
+}
diff --git a/src/utils/encoding.cpp b/src/utils/encoding.cpp
new file mode 100644
index 0000000..cff0039
--- /dev/null
+++ b/src/utils/encoding.cpp
@@ -0,0 +1,254 @@
+#include <utils/encoding.hpp>
+
+#include <utils/scopeguard.hpp>
+
+#include <stdexcept>
+
+#include <cassert>
+#include <string.h>
+#include <iconv.h>
+#include <cerrno>
+
+#include <map>
+#include <bitset>
+
+/**
+ * The UTF-8-encoded character used as a place holder when a character conversion fails.
+ * This is U+FFFD � "replacement character"
+ */
+static const char* invalid_char = "\xef\xbf\xbd";
+static const size_t invalid_char_len = 3;
+
+namespace utils
+{
+  /**
+   * Based on http://en.wikipedia.org/wiki/UTF-8#Description
+   */
+  std::size_t get_next_codepoint_size(const unsigned char c)
+  {
+    if ((c & 0b11111000) == 0b11110000)          // 4 bytes:  11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+      return 4;
+    else if ((c & 0b11110000) == 0b11100000)     // 3 bytes:  1110xxx 10xxxxxx 10xxxxxx
+      return 3;
+    else if ((c & 0b11100000) == 0b11000000)     // 2 bytes:  110xxxxx 10xxxxxx
+      return 2;
+    return 1;                                    // 1 byte:  0xxxxxxx
+  }
+
+  bool is_valid_utf8(const char* s)
+  {
+    if (!s)
+      return false;
+
+    const unsigned char* str = reinterpret_cast<const unsigned char*>(s);
+
+    while (*str)
+      {
+        const auto codepoint_size = get_next_codepoint_size(str[0]);
+        if (codepoint_size == 4)
+          {
+            if (!str[1] || !str[2] || !str[3]
+                || ((str[1] & 0b11000000) != 0b10000000)
+                || ((str[2] & 0b11000000) != 0b10000000)
+                || ((str[3] & 0b11000000) != 0b10000000))
+              return false;
+          }
+        else if (codepoint_size == 3)
+          {
+            if (!str[1] || !str[2]
+                || ((str[1] & 0b11000000) != 0b10000000)
+                || ((str[2] & 0b11000000) != 0b10000000))
+              return false;
+          }
+        else if (codepoint_size == 2)
+          {
+            if (!str[1] ||
+                ((str[1] & 0b11000000) != 0b10000000))
+              return false;
+          }
+        else if ((str[0] & 0b10000000) != 0)
+          return false;
+        str += codepoint_size;
+      }
+    return true;
+  }
+
+  std::string remove_invalid_xml_chars(const std::string& original)
+  {
+    // The given string MUST be a valid utf-8 string
+    std::vector<char> res(original.size(), '\0');
+
+    // pointer where we write valid chars
+    char* r = res.data();
+
+    const char* str = original.c_str();
+    std::bitset<20> codepoint;
+
+    while (*str)
+      {
+        // 4 bytes:  11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+        if ((str[0] & 0b11111000) == 0b11110000)
+          {
+            codepoint  = ((str[0] & 0b00000111) << 18);
+            codepoint |= ((str[1] & 0b00111111) << 12);
+            codepoint |= ((str[2] & 0b00111111) << 6 );
+            codepoint |= ((str[3] & 0b00111111) << 0 );
+            if (codepoint.to_ulong() <= 0x10FFFF)
+              {
+                ::memcpy(r, str, 4);
+                r += 4;
+              }
+            str += 4;
+          }
+        // 3 bytes:  1110xxx 10xxxxxx 10xxxxxx
+        else if ((str[0] & 0b11110000) == 0b11100000)
+          {
+            codepoint  = ((str[0] & 0b00001111) << 12);
+            codepoint |= ((str[1] & 0b00111111) << 6);
+            codepoint |= ((str[2] & 0b00111111) << 0 );
+            if (codepoint.to_ulong() <= 0xD7FF ||
+                (codepoint.to_ulong() >= 0xE000 && codepoint.to_ulong() <= 0xFFFD))
+              {
+                ::memcpy(r, str, 3);
+                r += 3;
+              }
+            str += 3;
+          }
+        // 2 bytes:  110xxxxx 10xxxxxx
+        else if (((str[0]) & 0b11100000) == 0b11000000)
+          {
+            // All 2 bytes char are valid, don't even bother calculating
+            // the codepoint
+            ::memcpy(r, str, 2);
+            r += 2;
+            str += 2;
+          }
+        // 1 byte:  0xxxxxxx
+        else if ((str[0] & 0b10000000) == 0)
+          {
+            codepoint = ((str[0] & 0b01111111));
+            if (codepoint.to_ulong() == 0x09 ||
+                codepoint.to_ulong() == 0x0A ||
+                codepoint.to_ulong() == 0x0D ||
+                codepoint.to_ulong() >= 0x20)
+              {
+                ::memcpy(r, str, 1);
+                r += 1;
+              }
+            str += 1;
+          }
+        else
+          throw std::runtime_error("Invalid UTF-8 passed to remove_invalid_xml_chars");
+      }
+    return {res.data(), static_cast<size_t>(r - res.data())};
+  }
+
+  std::string convert_to_utf8(const std::string& str, const char* charset)
+  {
+    std::string res;
+
+    const iconv_t cd = iconv_open("UTF-8", charset);
+    if (cd == (iconv_t)-1)
+      throw std::runtime_error("Cannot convert into UTF-8");
+
+    // Make sure cd is always closed when we leave this function
+    const auto sg = utils::make_scope_guard([&cd](){ iconv_close(cd); });
+
+    size_t inbytesleft = str.size();
+
+    // iconv will not attempt to modify this buffer, but some plateform
+    // require a char** anyway
+#ifdef ICONV_SECOND_ARGUMENT_IS_CONST
+    const char* inbuf_ptr = str.c_str();
+#else
+    char* inbuf_ptr = const_cast<char*>(str.c_str());
+#endif
+
+    size_t outbytesleft = str.size() * 4;
+    char* outbuf = new char[outbytesleft];
+    char* outbuf_ptr = outbuf;
+
+    // Make sure outbuf is always deleted when we leave this function
+    const auto sg2 = utils::make_scope_guard([outbuf](){ delete[] outbuf; });
+
+    bool done = false;
+    while (done == false)
+      {
+        size_t error = iconv(cd, &inbuf_ptr, &inbytesleft, &outbuf_ptr, &outbytesleft);
+        if ((size_t)-1 == error)
+          {
+            switch (errno)
+              {
+              case EILSEQ:
+                // Invalid byte found. Insert a placeholder instead of the
+                // converted character, jump one byte and continue
+                memcpy(outbuf_ptr, invalid_char, invalid_char_len);
+                outbuf_ptr += invalid_char_len;
+                inbytesleft--;
+                inbuf_ptr++;
+                break;
+              case EINVAL:
+                // A multibyte sequence is not terminated, but we can't
+                // provide any more data, so we just add a placeholder to
+                // indicate that the character is not properly converted,
+                // and we stop the conversion
+                memcpy(outbuf_ptr, invalid_char, invalid_char_len);
+                outbuf_ptr += invalid_char_len;
+                outbuf_ptr++;
+                done = true;
+                break;
+              case E2BIG:  // This should never happen
+              default:     // This should happen even neverer
+                done = true;
+                break;
+              }
+          }
+        else
+          {
+            // The conversion finished without any error, stop converting
+            done = true;
+          }
+      }
+    // Terminate the converted buffer, and copy that buffer it into the
+    // string we return
+    *outbuf_ptr = '\0';
+    res = outbuf;
+    return res;
+  }
+
+}
+
+namespace xep0106
+{
+  static const std::map<const char, const std::string> encode_map = {
+    {' ', "\\20"},
+    {'"', "\\22"},
+    {'&', "\\26"},
+    {'\'',"\\27"},
+    {'/', "\\2f"},
+    {':', "\\3a"},
+    {'<', "\\3c"},
+    {'>', "\\3e"},
+    {'@', "\\40"},
+  };
+
+  void decode(std::string& s)
+  {
+    std::string::size_type pos;
+    for (const auto& pair: encode_map)
+      while ((pos = s.find(pair.second)) != std::string::npos)
+        s.replace(pos, pair.second.size(),
+                  1, pair.first);
+  }
+
+  void encode(std::string& s)
+  {
+    std::string::size_type pos;
+    while ((pos = s.find_first_of(" \"&'/:<>@")) != std::string::npos)
+      {
+        auto it = encode_map.find(s[pos]);
+        assert(it != encode_map.end());
+        s.replace(pos, 1, it->second);
+      }
+  }
+}
diff --git a/src/utils/encoding.hpp b/src/utils/encoding.hpp
new file mode 100644
index 0000000..b707a0c
--- /dev/null
+++ b/src/utils/encoding.hpp
@@ -0,0 +1,43 @@
+#pragma once
+
+
+#include <string>
+
+namespace utils
+{
+  /**
+   * Return the size, in bytes, of the next UTF-8 codepoint, based on
+   * the given char.
+   */
+  std::size_t get_next_codepoint_size(const unsigned char c);
+  /**
+   * Returns true if the given null-terminated string is valid utf-8.
+   *
+   * Based on http://en.wikipedia.org/wiki/UTF-8#Description
+   */
+  bool is_valid_utf8(const char* s);
+  /**
+   * Remove all invalid codepoints from the given utf-8-encoded string.
+   * The value returned is a copy of the string, without the removed chars.
+   *
+   * See http://www.w3.org/TR/xml/#charsets for the list of valid characters
+   * in XML.
+   */
+  std::string remove_invalid_xml_chars(const std::string& original);
+  /**
+   * Convert the given string (encoded is "encoding") into valid utf-8.
+   * If some decoding fails, insert an utf-8 placeholder character instead.
+   */
+  std::string convert_to_utf8(const std::string& str, const char* charset);
+}
+
+namespace xep0106
+{
+  /**
+   * Decode and encode inplace.
+   */
+  void decode(std::string&);
+  void encode(std::string&);
+}
+
+
diff --git a/src/utils/get_first_non_empty.cpp b/src/utils/get_first_non_empty.cpp
new file mode 100644
index 0000000..5b3bedb
--- /dev/null
+++ b/src/utils/get_first_non_empty.cpp
@@ -0,0 +1,11 @@
+#include <utils/get_first_non_empty.hpp>
+
+bool is_empty(const std::string& val)
+{
+  return val.empty();
+}
+
+bool is_empty(const int& val)
+{
+  return val == 0;
+}
diff --git a/src/utils/get_first_non_empty.hpp b/src/utils/get_first_non_empty.hpp
new file mode 100644
index 0000000..a38f5fb
--- /dev/null
+++ b/src/utils/get_first_non_empty.hpp
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <string>
+
+bool is_empty(const std::string& val);
+bool is_empty(const int& val);
+
+template <typename T>
+T get_first_non_empty(T&& last)
+{
+  return last;
+}
+
+template <typename T, typename... Args>
+T get_first_non_empty(T&& first, Args&&... args)
+{
+  if (!is_empty(first))
+    return first;
+  return get_first_non_empty(std::forward<Args>(args)...);
+}
diff --git a/src/utils/optional_bool.hpp b/src/utils/optional_bool.hpp
new file mode 100644
index 0000000..59bbbab
--- /dev/null
+++ b/src/utils/optional_bool.hpp
@@ -0,0 +1,35 @@
+#pragma once
+
+#include <string>
+
+struct OptionalBool
+{
+  OptionalBool() = default;
+
+  OptionalBool(bool value):
+  is_set(true), value(value) {}
+
+  void set_value(bool value)
+  {
+    this->is_set = true;
+    this->value = value;
+  }
+
+  void unset()
+  {
+    this->is_set = false;
+  }
+
+  std::string to_string()
+  {
+    if (this->is_set == false)
+      return "unset";
+    else if (this->value)
+      return "true";
+    else
+      return "false";
+  }
+
+  bool is_set{false};
+  bool value{false};
+};
diff --git a/src/utils/reload.cpp b/src/utils/reload.cpp
index 348c5b5..fdca9bc 100644
--- a/src/utils/reload.cpp
+++ b/src/utils/reload.cpp
@@ -26,7 +26,7 @@ void reload_process()
 #ifdef USE_DATABASE
   try {
       open_database();
-    } catch (const litesql::DatabaseError&) {
+    } catch (...) {
       log_warning("Re-using the previous database.");
     }
 #endif
diff --git a/src/utils/revstr.cpp b/src/utils/revstr.cpp
new file mode 100644
index 0000000..87fd801
--- /dev/null
+++ b/src/utils/revstr.cpp
@@ -0,0 +1,9 @@
+#include <utils/revstr.hpp>
+
+namespace utils
+{
+  std::string revstr(const std::string& original)
+  {
+    return {original.rbegin(), original.rend()};
+  }
+}
diff --git a/src/utils/revstr.hpp b/src/utils/revstr.hpp
new file mode 100644
index 0000000..8e521ea
--- /dev/null
+++ b/src/utils/revstr.hpp
@@ -0,0 +1,11 @@
+#pragma once
+
+
+#include <string>
+
+namespace utils
+{
+  std::string revstr(const std::string& original);
+}
+
+
diff --git a/src/utils/scopeguard.hpp b/src/utils/scopeguard.hpp
new file mode 100644
index 0000000..e697fc3
--- /dev/null
+++ b/src/utils/scopeguard.hpp
@@ -0,0 +1,98 @@
+#pragma once
+
+#include <functional>
+#include <memory>
+#include <vector>
+
+/**
+ * A class to be used to make sure some functions are called when the scope
+ * is left, because they will be called in the ScopeGuard's destructor.  It
+ * can for example be used to delete some pointer whenever any exception is
+ * called.  Example:
+
+ * {
+ *  ScopeGuard scope;
+ *  int* number = new int(2);
+ *  scope.add_callback([number]() { delete number; });
+ *  // Do some other stuff with the number. But these stuff might throw an exception:
+ *  throw std::runtime_error("Some error not caught here, but in our caller");
+ *  return true;
+ * }
+
+ * In this example, our pointer will always be deleted, even when the
+ * exception is thrown.  If we want the functions to be called only when the
+ * scope is left because of an unexpected exception, we can use
+ * ScopeGuard::disable();
+ */
+
+namespace utils
+{
+
+class ScopeGuard
+{
+public:
+  /**
+   * The constructor can take a callback. But additional callbacks can be
+   * added later with add_callback()
+   */
+  explicit ScopeGuard(std::function<void()>&& func):
+    enabled(true)
+  {
+    this->add_callback(std::move(func));
+  }
+
+  ScopeGuard(const ScopeGuard&) = delete;
+  ScopeGuard& operator=(ScopeGuard&&) = delete;
+  ScopeGuard(ScopeGuard&&) = delete;
+  ScopeGuard& operator=(const ScopeGuard&) = delete;
+
+  /**
+   * default constructor, the scope guard is enabled but empty, use
+   * add_callback()
+   */
+  explicit ScopeGuard():
+    enabled(true)
+  {
+  }
+  /**
+   * Call all callbacks in the desctructor, unless it has been disabled.
+   */
+  ~ScopeGuard()
+  {
+    if (this->enabled)
+      for (auto& func: this->callbacks)
+        func();
+  }
+  /**
+   * Add a callback to be called in our destructor, one scope guard can be
+   * used for more than one task, if needed.
+   */
+  void add_callback(std::function<void()>&& func)
+  {
+    this->callbacks.emplace_back(std::move(func));
+  }
+  /**
+   * Disable that scope guard, nothing will be done when the scope is
+   * exited.
+   */
+  void disable()
+  {
+    this->enabled = false;
+  }
+
+private:
+  bool enabled;
+  std::vector<std::function<void()>> callbacks;
+
+};
+
+template<typename F>
+auto make_scope_guard(F f)
+{
+  static struct Empty {} empty;
+  auto deleter = [f = std::move(f)](Empty*) { f(); };
+  return std::unique_ptr<Empty, decltype(deleter)>{&empty, std::move(deleter)};
+}
+
+}
+
diff --git a/src/utils/sha1.cpp b/src/utils/sha1.cpp
new file mode 100644
index 0000000..2e6efc2
--- /dev/null
+++ b/src/utils/sha1.cpp
@@ -0,0 +1,40 @@
+#include <utils/sha1.hpp>
+
+#include <biboumi.h>
+
+#ifdef BOTAN_FOUND
+# include <botan/version.h>
+# include <botan/hash.h>
+# include <botan/hex.h>
+# include <botan/exceptn.h>
+#endif
+#ifdef GCRYPT_FOUND
+# include <gcrypt.h>
+# include <vector>
+# include <iomanip>
+# include <sstream>
+#endif
+
+std::string sha1(const std::string& input)
+{
+#ifdef BOTAN_FOUND
+# if BOTAN_VERSION_CODE < BOTAN_VERSION_CODE_FOR(1,11,34)
+  auto sha1 = Botan::HashFunction::create("SHA-1");
+  if (!sha1)
+    throw Botan::Algorithm_Not_Found("SHA-1");
+# else
+  auto sha1 = Botan::HashFunction::create_or_throw("SHA-1");
+# endif
+  sha1->update(input);
+  return Botan::hex_encode(sha1->final(), false);
+#endif
+#ifdef GCRYPT_FOUND
+  const auto hash_length = gcry_md_get_algo_dlen(GCRY_MD_SHA1);
+  std::vector<uint8_t> output(hash_length, {});
+  gcry_md_hash_buffer(GCRY_MD_SHA1, output.data(), input.data(), input.size());
+  std::ostringstream digest;
+  for (std::size_t i = 0; i < hash_length; i++)
+    digest << std::hex << std::setfill('0') << std::setw(2) << static_cast<int>(output[i]);
+  return digest.str();
+#endif
+}
diff --git a/src/utils/sha1.hpp b/src/utils/sha1.hpp
new file mode 100644
index 0000000..6c551ac
--- /dev/null
+++ b/src/utils/sha1.hpp
@@ -0,0 +1,5 @@
+#pragma once
+
+#include <string>
+
+std::string sha1(const std::string& input);
diff --git a/src/utils/split.cpp b/src/utils/split.cpp
new file mode 100644
index 0000000..80f8dae
--- /dev/null
+++ b/src/utils/split.cpp
@@ -0,0 +1,19 @@
+#include <utils/split.hpp>
+#include <sstream>
+
+namespace utils
+{
+  std::vector<std::string> split(const std::string& s, const char delim, const bool allow_empty)
+  {
+    std::vector<std::string> ret;
+    std::stringstream ss(s);
+    std::string item;
+    while (std::getline(ss, item, delim))
+      {
+        if (item.empty() && !allow_empty)
+          continue ;
+        ret.emplace_back(std::move(item));
+      }
+    return ret;
+  }
+}
diff --git a/src/utils/split.hpp b/src/utils/split.hpp
new file mode 100644
index 0000000..3755ef8
--- /dev/null
+++ b/src/utils/split.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+
+#include <string>
+#include <vector>
+
+namespace utils
+{
+  std::vector<std::string> split(const std::string &s, const char delim, const bool allow_empty=true);
+}
+
+
diff --git a/src/utils/string.cpp b/src/utils/string.cpp
new file mode 100644
index 0000000..635e71a
--- /dev/null
+++ b/src/utils/string.cpp
@@ -0,0 +1,28 @@
+#include <utils/string.hpp>
+#include <utils/encoding.hpp>
+
+bool to_bool(const std::string& val)
+{
+  return (val == "1" || val == "true");
+}
+
+std::vector<std::string> cut(const std::string& val, const std::size_t size)
+{
+  std::vector<std::string> res;
+  std::string::size_type pos = 0;
+  while (pos < val.size())
+    {
+      // Get the number of chars, <= size, that contain only whole
+      // UTF-8 codepoints.
+      std::size_t s = 0;
+      auto codepoint_size = utils::get_next_codepoint_size(val[pos + s]);
+      while (s + codepoint_size <= size && pos + s < val.size())
+        {
+          s += codepoint_size;
+          codepoint_size = utils::get_next_codepoint_size(val[pos + s]);
+        }
+      res.emplace_back(val.substr(pos, s));
+      pos += s;
+    }
+  return res;
+}
diff --git a/src/utils/string.hpp b/src/utils/string.hpp
new file mode 100644
index 0000000..071ce2c
--- /dev/null
+++ b/src/utils/string.hpp
@@ -0,0 +1,8 @@
+#pragma once
+
+
+#include <vector>
+#include <string>
+
+bool to_bool(const std::string& val);
+std::vector<std::string> cut(const std::string& val, const std::size_t size);
diff --git a/src/utils/system.cpp b/src/utils/system.cpp
new file mode 100644
index 0000000..d821dec
--- /dev/null
+++ b/src/utils/system.cpp
@@ -0,0 +1,21 @@
+#include <logger/logger.hpp>
+#include <utils/system.hpp>
+#include <sys/utsname.h>
+#include <cstring>
+
+using namespace std::string_literals;
+
+namespace utils
+{
+std::string get_system_name()
+{
+  struct utsname uts{};
+  const int res = ::uname(&uts);
+  if (res == -1)
+    {
+      log_error("uname failed: ", std::strerror(errno));
+      return "Unknown";
+    }
+  return uts.sysname + " "s + uts.release;
+}
+}
+\ No newline at end of file
diff --git a/src/utils/system.hpp b/src/utils/system.hpp
new file mode 100644
index 0000000..7ea1677
--- /dev/null
+++ b/src/utils/system.hpp
@@ -0,0 +1,8 @@
+#pragma once
+
+#include <string>
+
+namespace utils
+{
+std::string get_system_name();
+}
+\ No newline at end of file
diff --git a/src/utils/time.cpp b/src/utils/time.cpp
new file mode 100644
index 0000000..bc2c18d
--- /dev/null
+++ b/src/utils/time.cpp
@@ -0,0 +1,80 @@
+#include <utils/time.hpp>
+#include <ctime>
+
+#include <sstream>
+#include <iomanip>
+#include <locale>
+
+#include "biboumi.h"
+
+namespace utils
+{
+std::string to_string(const std::time_t& timestamp)
+{
+  constexpr std::size_t stamp_size = 21;
+  char date_buf[stamp_size];
+  if (std::strftime(date_buf, stamp_size, "%FT%TZ", std::gmtime(&timestamp)) != stamp_size - 1)
+    return "";
+  return {std::begin(date_buf), std::end(date_buf) - 1};
+}
+
+std::time_t parse_datetime(const std::string& stamp)
+{
+  static const char* format = "%Y-%m-%dT%H:%M:%S";
+  std::tm t = {};
+#ifdef HAS_GET_TIME
+  std::istringstream ss(stamp);
+  ss.imbue(std::locale("C"));
+
+  std::string remainings;
+  ss >> std::get_time(&t, format) >> remainings;
+  if (ss.fail())
+    return -1;
+#else
+                                             /* Y   -   m   -   d   T   H   :   M   :   S */
+  constexpr std::size_t stamp_size_without_tz = 4 + 1 + 2 + 1 + 2 + 1 + 2 + 1 + 2 + 1 + 2;
+  if (!strptime(stamp.data(), format, &t)) {
+    return -1;
+  }
+  const std::string remainings(stamp.data() + stamp_size_without_tz);
+#endif
+
+  if (remainings.empty())
+    return -1;
+
+  std::string timezone;
+  // Skip optional fractions of seconds
+  if (remainings[0] == '.')
+    {
+      const auto pos = remainings.find_first_not_of(".0123456789");
+      timezone = remainings.substr(pos);
+    }
+  else
+    timezone = std::move(remainings);
+
+  if (timezone.compare(0, 1, "Z") != 0)
+    {
+      std::stringstream tz_ss;
+      tz_ss << timezone;
+      int multiplier = -1;
+      char prefix;
+      int hours;
+      char sep;
+      int minutes;
+      tz_ss >> prefix >> hours >> sep >> minutes;
+      if (tz_ss.fail())
+        return -1;
+      if (prefix == '-')
+        multiplier = +1;
+      else if (prefix != '+')
+        return -1;
+
+      t.tm_hour += multiplier * hours;
+      t.tm_min += multiplier * minutes;
+    }
+  return ::timegm(&t);
+}
+
+}
+
+
diff --git a/src/utils/time.hpp b/src/utils/time.hpp
new file mode 100644
index 0000000..c71cd9c
--- /dev/null
+++ b/src/utils/time.hpp
@@ -0,0 +1,10 @@
+#pragma once
+
+#include <ctime>
+#include <string>
+
+namespace utils
+{
+std::string to_string(const std::time_t& timestamp);
+std::time_t parse_datetime(const std::string& stamp);
+}
+\ No newline at end of file
diff --git a/src/utils/timed_events.cpp b/src/utils/timed_events.cpp
new file mode 100644
index 0000000..26ded82
--- /dev/null
+++ b/src/utils/timed_events.cpp
@@ -0,0 +1,48 @@
+#include <utility>
+#include <utils/timed_events.hpp>
+
+TimedEvent::TimedEvent(std::chrono::steady_clock::time_point&& time_point,
+                       std::function<void()> callback, std::string name):
+  time_point(time_point),
+  callback(std::move(callback)),
+  repeat(false),
+  repeat_delay(0),
+  name(std::move(name))
+{
+}
+
+TimedEvent::TimedEvent(std::chrono::milliseconds&& duration,
+                       std::function<void()> callback, std::string name):
+  time_point(std::chrono::steady_clock::now() + duration),
+  callback(std::move(callback)),
+  repeat(true),
+  repeat_delay(duration),
+  name(std::move(name))
+{
+}
+
+bool TimedEvent::is_after(const TimedEvent& other) const
+{
+  return this->is_after(other.time_point);
+}
+
+bool TimedEvent::is_after(const std::chrono::steady_clock::time_point& time_point) const
+{
+  return this->time_point > time_point;
+}
+
+std::chrono::milliseconds TimedEvent::get_timeout() const
+{
+  auto diff = std::chrono::duration_cast<std::chrono::milliseconds>(this->time_point - std::chrono::steady_clock::now());
+  return std::max(diff, 0ms);
+}
+
+void TimedEvent::execute() const
+{
+  this->callback();
+}
+
+const std::string& TimedEvent::get_name() const
+{
+  return this->name;
+}
diff --git a/src/utils/timed_events.hpp b/src/utils/timed_events.hpp
new file mode 100644
index 0000000..fa0fc50
--- /dev/null
+++ b/src/utils/timed_events.hpp
@@ -0,0 +1,137 @@
+#pragma once
+
+#include <functional>
+#include <string>
+#include <chrono>
+#include <vector>
+
+using namespace std::literals::chrono_literals;
+
+namespace utils {
+static constexpr std::chrono::milliseconds no_timeout = std::chrono::milliseconds(-1);
+}
+
+class TimedEventsManager;
+
+/**
+ * A callback with an associated date.
+ */
+
+class TimedEvent
+{
+  friend class TimedEventsManager;
+public:
+  /**
+   * An event the occurs only once, at the given time_point
+   */
+  explicit TimedEvent(std::chrono::steady_clock::time_point&& time_point,
+                      std::function<void()> callback, std::string name="");
+  explicit TimedEvent(std::chrono::milliseconds&& duration,
+                      std::function<void()> callback, std::string name="");
+
+  explicit TimedEvent(TimedEvent&&) = default;
+  TimedEvent& operator=(TimedEvent&&) = default;
+  ~TimedEvent() = default;
+
+  TimedEvent(const TimedEvent&) = delete;
+  TimedEvent& operator=(const TimedEvent&) = delete;
+
+  /**
+   * Whether or not this event happens after the other one.
+   */
+  bool is_after(const TimedEvent& other) const;
+  bool is_after(const std::chrono::steady_clock::time_point& time_point) const;
+  /**
+   * Return the duration difference between now and the event time point.
+   * If the difference would be negative (i.e. the event is expired), the
+   * returned value is 0 instead. The value cannot then be negative.
+   */
+  std::chrono::milliseconds get_timeout() const;
+  void execute() const;
+  const std::string& get_name() const;
+
+private:
+  /**
+   * The next time point at which the event is executed.
+   */
+  std::chrono::steady_clock::time_point time_point;
+  /**
+   * The function to execute.
+   */
+  std::function<void()> callback;
+  /**
+   * Whether or not this events repeats itself until it is destroyed.
+   */
+  bool repeat;
+  /**
+   * This value is added to the time_point each time the event is executed,
+   * if repeat is true. Otherwise it is ignored.
+   */
+  std::chrono::milliseconds repeat_delay;
+  /**
+   * A name that is used to identify that event. If you want to find your
+   * event (for example if you want to cancel it), the name should be
+   * unique.
+   */
+  std::string name;
+};
+
+/**
+ * A class managing a list of TimedEvents.
+ * They are sorted, new events can be added, removed, fetch, etc.
+ */
+
+class TimedEventsManager
+{
+public:
+  ~TimedEventsManager() = default;
+
+  TimedEventsManager(const TimedEventsManager&) = delete;
+  TimedEventsManager(TimedEventsManager&&) = delete;
+  TimedEventsManager& operator=(const TimedEventsManager&) = delete;
+  TimedEventsManager& operator=(TimedEventsManager&&) = delete;
+
+  /**
+   * Return the unique instance of this class
+   */
+  static TimedEventsManager& instance();
+  /**
+   * Add an event to the list of managed events. The list is sorted after
+   * this call.
+   */
+  void add_event(TimedEvent&& event);
+  /**
+   * Returns the duration, in milliseconds, between now and the next
+   * available event. If the event is already expired (the duration is
+   * negative), 0 is returned instead (as in “it's not too late, execute it
+   * now”)
+   * Returns a negative value if no event is available.
+   */
+  std::chrono::milliseconds get_timeout() const;
+  /**
+   * Execute all the expired events (if their expiration time is exactly
+   * now, or before now). The event is then removed from the list. If the
+   * event does repeat, its expiration time is updated and it is reinserted
+   * in the list at the correct position.
+   * Returns the number of executed events.
+   */
+  std::size_t execute_expired_events();
+  /**
+   * Remove (and thus cancel) all the timed events with the given name.
+   * Returns the number of canceled events.
+   */
+  std::size_t cancel(const std::string& name);
+  /**
+   * Return the number of managed events.
+   */
+  std::size_t size() const;
+  /**
+   * Return a pointer to the first event with the given name. If none
+   * is found, returns nullptr.
+   */
+  const TimedEvent* find_event(const std::string& name) const;
+
+private:
+  std::vector<TimedEvent> events;
+  explicit TimedEventsManager() = default;
+};
diff --git a/src/utils/timed_events_manager.cpp b/src/utils/timed_events_manager.cpp
new file mode 100644
index 0000000..75e6338
--- /dev/null
+++ b/src/utils/timed_events_manager.cpp
@@ -0,0 +1,87 @@
+#include <utils/timed_events.hpp>
+
+#include <algorithm>
+
+TimedEventsManager& TimedEventsManager::instance()
+{
+  static TimedEventsManager inst;
+  return inst;
+}
+
+void TimedEventsManager::add_event(TimedEvent&& event)
+{
+  for (auto it = this->events.begin(); it != this->events.end(); ++it)
+    {
+      if (it->is_after(event))
+        {
+          this->events.emplace(it, std::move(event));
+          return;
+        }
+    }
+  this->events.emplace_back(std::move(event));
+}
+
+std::chrono::milliseconds TimedEventsManager::get_timeout() const
+{
+  if (this->events.empty())
+    return utils::no_timeout;
+  return this->events.front().get_timeout();
+}
+
+std::size_t TimedEventsManager::execute_expired_events()
+{
+  std::size_t count = 0;
+  const auto now = std::chrono::steady_clock::now();
+  for (auto it = this->events.begin(); it != this->events.end();)
+    {
+      if (!it->is_after(now))
+        {
+          TimedEvent copy(std::move(*it));
+          it = this->events.erase(it);
+          ++count;
+          copy.execute();
+          if (copy.repeat)
+            {
+              copy.time_point += copy.repeat_delay;
+              this->add_event(std::move(copy));
+            }
+          continue;
+        }
+      else
+        break;
+    }
+  return count;
+}
+
+std::size_t TimedEventsManager::cancel(const std::string& name)
+{
+  std::size_t res = 0;
+  for (auto it = this->events.begin(); it != this->events.end();)
+    {
+      if (it->get_name() == name)
+        {
+          it = this->events.erase(it);
+          res++;
+        }
+      else
+        ++it;
+    }
+  return res;
+}
+
+
+
+std::size_t TimedEventsManager::size() const
+{
+  return this->events.size();
+}
+
+const TimedEvent* TimedEventsManager::find_event(const std::string& name) const
+{
+  const auto it = std::find_if(this->events.begin(), this->events.end(), [&name](const TimedEvent& o) {
+    return o.get_name() == name;
+  });
+  if (it == this->events.end())
+    return nullptr;
+  return &*it;
+}
diff --git a/src/utils/tolower.cpp b/src/utils/tolower.cpp
new file mode 100644
index 0000000..3e518bd
--- /dev/null
+++ b/src/utils/tolower.cpp
@@ -0,0 +1,13 @@
+#include <utils/tolower.hpp>
+
+namespace utils
+{
+  std::string tolower(const std::string& original)
+  {
+    std::string res;
+    res.reserve(original.size());
+    for (const char c: original)
+      res += static_cast<char>(std::tolower(c));
+    return res;
+  }
+}
diff --git a/src/utils/tolower.hpp b/src/utils/tolower.hpp
new file mode 100644
index 0000000..650e05d
--- /dev/null
+++ b/src/utils/tolower.hpp
@@ -0,0 +1,11 @@
+#pragma once
+
+
+#include <string>
+
+namespace utils
+{
+  std::string tolower(const std::string& original);
+}
+
+
diff --git a/src/utils/xdg.cpp b/src/utils/xdg.cpp
new file mode 100644
index 0000000..b0fa7be
--- /dev/null
+++ b/src/utils/xdg.cpp
@@ -0,0 +1,29 @@
+#include <utils/xdg.hpp>
+#include <cstdlib>
+
+#include "biboumi.h"
+
+std::string xdg_path(const std::string& filename, const char* env_var)
+{
+  const char* xdg_home = ::getenv(env_var);
+  if (xdg_home && xdg_home[0] == '/')
+    return std::string{xdg_home} + "/" PROJECT_NAME "/" + filename;
+  else
+    {
+      const char* home = ::getenv("HOME");
+      if (home)
+        return std::string{home} + "/" ".config" "/" PROJECT_NAME "/" + filename;
+      else
+        return filename;
+    }
+}
+
+std::string xdg_config_path(const std::string& filename)
+{
+  return xdg_path(filename, "XDG_CONFIG_HOME");
+}
+
+std::string xdg_data_path(const std::string& filename)
+{
+  return xdg_path(filename, "XDG_DATA_HOME");
+}
diff --git a/src/utils/xdg.hpp b/src/utils/xdg.hpp
new file mode 100644
index 0000000..7be6922
--- /dev/null
+++ b/src/utils/xdg.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+
+#include <string>
+
+/**
+ * Returns a path for the given filename, according to the XDG base
+ * directory specification, see
+ * http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
+ */
+std::string xdg_config_path(const std::string& filename);
+std::string xdg_data_path(const std::string& filename);