/**
 *  @file depot.cc
 *  @brief Implementation of the Depot class.
 *  @author Andreas Aardal Hanssen
 *  @date 2002-2005
 */

#include "depot.h"

#include "convert.h"
#include "iodevice.h"
#include "iofactory.h"
#include "mailbox.h"
#include "status.h"

#include <cstddef>
#include <map>
#include <string>

#include <errno.h>

#include <unistd.h>

using namespace Binc;
using std::endl;
using std::string;

DepotFactory::DepotFactory() {}

DepotFactory::~DepotFactory()
{
  for (auto i : depots)
    delete i;
}

Depot *DepotFactory::get(const string &name) const
{
  for (const auto i : depots)
    if (i->getName() == name) return i;

  return nullptr;
}

void DepotFactory::assign(Depot *depot)
{
  depots.push_back(depot);
}

DepotFactory &DepotFactory::getInstance()
{
  static DepotFactory depotfactory;
  return depotfactory;
}

Depot::Depot() : Depot("") {}

Depot::Depot(const std::string &name)
  : enditerator(nullptr, nullptr)
  , defaultmailbox(nullptr)
  , selectedmailbox(nullptr)
  , name(name)
  , delimiter('/')
{}

const string &Depot::getLastError() const
{
  return lastError;
}

void Depot::setLastError(const string &error) const
{
  lastError = error;
}

void Depot::assign(Mailbox *m)
{
  for (const auto i : backends)
    if (i == m) break;

  backends.push_back(m);
}

Mailbox *Depot::get(const string &s_in) const
{
  for (const auto i : backends)
    if (i->isMailbox(mailboxToFilename(s_in))) return i;

  setLastError("No such mailbox " + toImapString(s_in));
  return nullptr;
}

bool Depot::setSelected(Mailbox *m)
{
  for (const auto i : backends) {
    if (i == m) {
      selectedmailbox = m;
      return true;
    }
  }

  setLastError("Attempted to select unregistered Mailbox type in Depot");
  return false;
}

const string &Depot::getName() const
{
  return name;
}

const string &Depot::getPersonalNamespace() const
{
  return personalNamespace;
}

const string &Depot::getOthersNamespace() const
{
  return othersNamespace;
}

const string &Depot::getSharedNamespace() const
{
  return sharedNamespace;
}

void Depot::setDelimiter(char c)
{
  delimiter = c;
}

char Depot::getDelimiter() const
{
  return delimiter;
}

bool Depot::setDefaultType(const string &name)
{
  for (const auto i : backends) {
    if (i->getTypeName() == name) {
      defaultmailbox = i;
      return true;
    }
  }

  setLastError("attempt to default to unregistered Mailbox type " + name);
  return false;
}

Mailbox *Depot::getSelected() const
{
  return selectedmailbox;
}

void Depot::resetSelected()
{
  selectedmailbox = nullptr;
}

Mailbox *Depot::getDefault() const
{
  return defaultmailbox;
}

bool Depot::createMailbox(const string &s_in) const
{
  const string &mailboxname = mailboxToFilename(toCanonMailbox(s_in));
  if (mailboxname.empty()) {
    setLastError("invalid mailbox name");
    return false;
  }

  Mailbox *mailbox = getDefault();
  if (mailbox == nullptr) {
    setLastError("no default mailbox defined");
    return false;
  }

  bool result = mailbox->createMailbox(mailboxname, 0777);
  if (result) {
    return true;
  } else {
    setLastError(mailbox->getLastError());
    return false;
  }
}

bool Depot::deleteMailbox(const string &s_in) const
{
  const string &mailboxname = mailboxToFilename(toCanonMailbox(s_in));

  Mailbox *mailbox = get(s_in);
  if (mailbox == nullptr) {
    setLastError(s_in + ": no such mailbox");
    return false;
  }

  bool result = mailbox->deleteMailbox(mailboxname);
  if (result) {
    return true;
  } else {
    setLastError(mailbox->getLastError());
    return false;
  }
}

bool Depot::renameMailbox(const string &s_in, const string &t_in) const
{
  const string &source = mailboxToFilename(s_in);
  const string &dest = mailboxToFilename(t_in);

  int nrenamed = 0;
  const iterator e = end();
  for (iterator i = begin("."); i != e; ++i) {
    string entry = *i;

    if (entry.substr(0, source.length()) == source) {
      string sourcename, destname;

      if (entry.length() == source.length()) {
        sourcename = source;
        destname = dest;
      } else if (entry.length() > source.length() && entry[source.length()] == '.') {
        sourcename = entry;
        destname = dest + entry.substr(source.length());
      } else {
        continue;
      }

      if (rename(sourcename.c_str(), destname.c_str()) != 0) {
        bincWarning << "error renaming " << sourcename << " to " << destname << ": "
                    << strerror(errno) << endl;
      } else {
        nrenamed++;
      }

      Mailbox *mailbox;
      if ((mailbox = get(filenameToMailbox(sourcename))) != nullptr)
        mailbox->bumpUidValidity(filenameToMailbox(sourcename));
      if ((mailbox = get(filenameToMailbox(destname))) != nullptr)
        mailbox->bumpUidValidity(filenameToMailbox(destname));
    }
  }

  if (nrenamed == 0) {
    setLastError("An error occurred when renaming " + toImapString(s_in) + " to "
                 + toImapString(t_in)
                 + ". Try creating a new mailbox,"
                   " then copy over all messages."
                   " Finally, delete the original mailbox");
    return false;
  } else {
    return true;
  }
}

bool Depot::getStatus(const std::string &s_in, Status &dest) const
{
  const string mailbox = toCanonMailbox(s_in);
  Mailbox *m = get(mailbox);
  if (m == nullptr) {
    setLastError("Unrecognized mailbox: " + toImapString(s_in));
    return false;
  }

  int statusid = m->getStatusID(mailboxToFilename(mailbox));
  if (mailboxstatuses.find(mailbox) != mailboxstatuses.end()) {
    dest = mailboxstatuses[mailbox];
    if (dest.getStatusID() == statusid) return true;
  }

  if (!m->getStatus(mailboxToFilename(mailbox), dest)) {
    setLastError(m->getLastError());
    return false;
  }

  dest.setStatusID(statusid);
  mailboxstatuses[mailbox] = dest;
  return true;
}

std::vector<string> Depot::getSubscriptions() const
{
  return subscribed;
}

void Depot::subscribeTo(const string mailbox)
{
  for (const auto &i : subscribed)
    if (i == mailbox) return;

  subscribed.push_back(mailbox);
}

bool Depot::unsubscribeTo(const string mailbox)
{
  for (auto i = subscribed.begin(); i != subscribed.end(); ++i) {
    if (*i == mailbox) {
      subscribed.erase(i);
      return true;
    }
  }

  return false;
}

void Depot::loadSubscribes()
{
  // drop all existing subscribed folders.
  subscribed.clear();

  // try loading the .subscribed file
  bool ok = false;
  FILE *fp = fopen(".subscribed", "r");
  std::map<string, bool> addedEntries;
  if (fp) {
    int c;
    string current;
    while ((c = fgetc(fp)) != EOF) {
      if (c == '\n') {
        if (current != "") {
          if (current == "INBOX") current = ".";

          if (current.substr(0, 5) == "INBOX") current = current.substr(5);

          if (addedEntries.find(current) == addedEntries.end()) {
            subscribed.push_back(filenameToMailbox(current));
            addedEntries[current] = true;
          }
          current = "";
        }
      } else {
        current += c;
      }
    }

    fclose(fp);
    ok = true;
  }

  if (!ok) {
    subscribed.push_back("INBOX");
    saveSubscribes();
  }
}

bool Depot::saveSubscribes() const
{
  // create a safe file name
  string ftemplate = ".subscribed-tmp-XXXXXX";

  int fd = mkstemp(ftemplate.data());
  if (fd == -1) {
    bincWarning << "unable to create temporary file \"" << ftemplate << "\"" << endl;
    return false;
  }

  std::map<string, bool> addedEntries;
  for (const auto &i : subscribed) {
    if (addedEntries.find(i) == addedEntries.end()) {
      addedEntries[i] = true;
      string w = mailboxToFilename(i) + "\n";
      if (write(fd, w.c_str(), w.length()) != (ssize_t)w.length()) {
        bincWarning << "failed to write to " << ftemplate << ": " << strerror(errno) << endl;
        break;
      }
    }
  }

  if ((fsync(fd) && (errno != EROFS || errno != EINVAL)) || close(fd)) {
    bincWarning << "failed to close " << ftemplate << ": " << strerror(errno) << endl;
    return false;
  }

  if (rename(ftemplate.c_str(), ".subscribed") != 0) {
    bincWarning << "failed to rename " << ftemplate << " to .subscribed: " << strerror(errno)
                << endl;
    return false;
  }

  return true;
}

Depot::iterator::iterator()
{
  dirp = nullptr;
  ref = new int;
  *ref = 1;
}

Depot::iterator::iterator(DIR *dp, struct dirent *sp)
{
  dirp = dp;
  direntp = sp;

  ref = new int;
  *ref = 1;
}

Depot::iterator::iterator(const iterator &copy)
{
  if (*copy.ref != 0) ++(*copy.ref);

  ref = copy.ref;
  dirp = copy.dirp;
  direntp = copy.direntp;
}

Depot::iterator::~iterator()
{
  deref();
}

Depot::iterator &Depot::iterator::operator=(const iterator &copy)
{
  if (*copy.ref != 0) ++(*copy.ref);

  deref();

  ref = copy.ref;
  dirp = copy.dirp;
  direntp = copy.direntp;

  return *this;
}

void Depot::iterator::deref()
{
  // decrease existing copy ref if there is one
  if (*ref != 0 && --(*ref) == 0) {
    if (dirp) {
      closedir(dirp);
      dirp = nullptr;
    }

    delete ref;
    ref = nullptr;
  }
}

string Depot::iterator::operator*() const
{
  if (direntp == nullptr) return "";

  return direntp->d_name;
}

void Depot::iterator::operator++()
{
  direntp = readdir(dirp);
}

bool Depot::iterator::operator==(Depot::iterator i) const
{
  return direntp == i.direntp;
}

bool Depot::iterator::operator!=(Depot::iterator i) const
{
  return direntp != i.direntp;
}

Depot::iterator Depot::begin(const string &path) const
{
  Depot::iterator i;

  if ((i.dirp = opendir(path.c_str())) == nullptr) {
    bincWarning << "opendir on " << path << " failed" << endl;
    setLastError("opendir on " + path + " failed");
    return end();
  }

  ++i;
  return i;
}

const Depot::iterator &Depot::end() const
{
  return enditerator;
}

MaildirPPDepot::MaildirPPDepot() : Depot("Maildir++")
{
  privateNamespace = "INBOX";
  privateNamespace += getDelimiter();
}

MaildirPPDepot::~MaildirPPDepot() {}

const string &MaildirPPDepot::getPersonalNamespace() const
{
  return privateNamespace;
}

string MaildirPPDepot::mailboxToFilename(const string &m) const
{
  string prefix = "INBOX";
  prefix += delimiter;

  string mm = m;
  trim(mm, string(&delimiter, 1));
  string tmp = mm;
  uppercase(tmp);
  if (tmp != "INBOX" && tmp.substr(0, 6) != prefix) {
    setLastError("With a Maildir++ depot, you must create all"
                 " mailboxes under INBOX. Try creating"
                 " "
                 + prefix + mm + " .");
    return "";
  }

  string twodelim;
  twodelim += delimiter;
  twodelim += delimiter;

  if (mm == "INBOX") {
    return ".";
  } else if (mm.length() <= 6) {
    setLastError("With a Maildir++ depot, you must create all"
                 " mailboxes under INBOX.");
    return "";
  } else if (mm.substr(0, 6) != prefix) {
    setLastError("With a Maildir++ depot, you must create all"
                 " mailboxes under INBOX.");
    return "";
  } else if (mm.find(twodelim) != string::npos) {
    setLastError("Invalid character combination " + twodelim + " in mailbox name");
    return "";
  } else if (mm != "" && delimiter != '.' && mm.substr(1).find('.') != string::npos) {
    setLastError("Invalid character '.' in mailbox name");
    return "";
  } else {
    string tmp = mm.substr(6);
    for (auto &i : tmp)
      if (i == delimiter) i = '.';

    return "." + tmp;
  }
}

string MaildirPPDepot::filenameToMailbox(const string &m) const
{
  if (m == ".") {
    return "INBOX";
  } else if (delimiter != '.' && m.find(delimiter) != string::npos) {
    return "";
  } else if (m != "" && m[0] == '.') {
    string tmp = m;
    for (auto &i : tmp)
      if (i == '.') i = delimiter;

    return "INBOX" + tmp;
  } else {
    return "";
  }
}

IMAPdirDepot::IMAPdirDepot() : Depot("IMAPdir") {}

IMAPdirDepot::~IMAPdirDepot() {}

string IMAPdirDepot::mailboxToFilename(const string &m) const
{
  string tmp;
  string mm = m;
  trim(mm, string(&delimiter, 1));

  string twodelim;
  twodelim += delimiter;
  twodelim += delimiter;

  if (mm.find(twodelim) != string::npos) {
    setLastError("Invalid character combination " + twodelim + " in mailbox name");
    return "";
  }

  for (auto i = mm.cbegin(); i != mm.cend(); ++i) {
    if (*i == delimiter)
      tmp += '.';
    else if (*i == '\\')
      tmp += "\\\\";
    else if (*i == '.')
      if (i == mm.cbegin())
        tmp += ".";
      else
        tmp += "\\.";
    else
      tmp += *i;
  }

  return tmp;
}

string IMAPdirDepot::filenameToMailbox(const string &m) const
{
  string tmp;
  bool escape = false;

  // hide the magic "." mailbox.
  if (m == "." || m == "..") return "";

  for (auto i = m.cbegin(); i != m.cend(); ++i) {
    if (*i == '.') {
      if (i != m.cbegin() && !escape)
        tmp += delimiter;
      else if (i == m.cbegin() || escape)
        tmp += '.';
      escape = false;
    } else if (*i == '\\') {
      if (!escape) {
        escape = true;
      } else {
        tmp += '\\';
        escape = false;
      }
    } else if (*i == delimiter) {
      return "";
    } else if (escape) {
      return "";
    } else {
      tmp += *i;
      escape = false;
    }
  }

  return tmp;
}