/**
 *  @file  operator-append.cc
 *  @brief  Implementation of the APPEND command.
 *  @author Andreas Aardal Hanssen
 *  @date 2002-2005
 */

#include "depot.h"
#include "iodevice.h"
#include "iofactory.h"
#include "mailbox.h"
#include "operators.h"
#include "pendingupdates.h"
#include "recursivedescent.h"
#include "session.h"

#include <algorithm>
#include <string>

#include <fcntl.h>

using namespace Binc;
using std::string;

AppendOperator::AppendOperator() {}

AppendOperator::~AppendOperator() {}

const string AppendOperator::getName() const
{
  return "APPEND";
}

Session::State AppendOperator::getState() const
{
  return Session::State(Session::State::AUTHENTICATED | Session::State::SELECTED);
}

Operator::ProcessResult AppendOperator::process(Depot &depot, Request &command)
{
  constexpr auto NO = ProcessResult::NO;
  constexpr auto ABORT = ProcessResult::ABORT;
  constexpr auto BAD = ProcessResult::BAD;

  Session &session = Session::getInstance();

  const string &srcmailbox = command.getMailbox();
  const string &canonmailbox = toCanonMailbox(srcmailbox);
  Mailbox *mailbox = nullptr;

  if ((mailbox = depot.get(canonmailbox)) == nullptr) {
    session.setResponseCode("TRYCREATE");
    session.setLastError("invalid destination mailbox " + toImapString(srcmailbox));
    return NO;
  }

  // mask all passed flags together
  unsigned int newflags = (unsigned int)Message::F_NONE;
  std::vector<string>::const_iterator f_i = command.flags.begin();
  while (f_i != command.flags.end()) {
    if (*f_i == "\\Deleted") newflags |= Message::F_DELETED;
    if (*f_i == "\\Answered") newflags |= Message::F_ANSWERED;
    if (*f_i == "\\Seen") newflags |= Message::F_SEEN;
    if (*f_i == "\\Draft") newflags |= Message::F_DRAFT;
    if (*f_i == "\\Flagged") newflags |= Message::F_FLAGGED;
    ++f_i;
  }

  int mday, year, hour, minute, second;
  char month[4];

  struct tm mytm;
  if (command.getDate() != "") {
    sscanf(command.getDate().c_str(),
           "%2i-%3s-%4i %2i:%2i:%2i",
           &mday,
           month,
           &year,
           &hour,
           &minute,
           &second);

    month[3] = '\0';
    string monthstr = month;
    lowercase(monthstr);
    mytm.tm_sec = second;
    mytm.tm_min = minute;
    mytm.tm_hour = hour;
    mytm.tm_year = year - 1900;
    mytm.tm_mday = mday;
    if (monthstr == "jan")
      mytm.tm_mon = 0;
    else if (monthstr == "feb")
      mytm.tm_mon = 1;
    else if (monthstr == "mar")
      mytm.tm_mon = 2;
    else if (monthstr == "apr")
      mytm.tm_mon = 3;
    else if (monthstr == "may")
      mytm.tm_mon = 4;
    else if (monthstr == "jun")
      mytm.tm_mon = 5;
    else if (monthstr == "jul")
      mytm.tm_mon = 6;
    else if (monthstr == "aug")
      mytm.tm_mon = 7;
    else if (monthstr == "sep")
      mytm.tm_mon = 8;
    else if (monthstr == "oct")
      mytm.tm_mon = 9;
    else if (monthstr == "nov")
      mytm.tm_mon = 10;
    else if (monthstr == "dec")
      mytm.tm_mon = 11;
    mytm.tm_isdst = -1;
  }

  // Read number of characters in literal. Literal is required here.
  char c;
  if (!bincClient.readChar(&c)) return ABORT;

  if (c != '{') {
    session.setLastError("expected literal");
    return BAD;
  }

  string nr;
  bool literalPlus = false;
  while (1) {
    if (!bincClient.readChar(&c)) {
      session.setLastError("unexcepted EOF");
      return BAD;
    }

    if (c == '}') break;

    // Support LITERAL+
    if (c == '+' && !literalPlus) {
      literalPlus = true;
      continue;
    }

    if (!isdigit(c)) {
      session.setLastError("unexcepted non-digit character");
      return BAD;
    }

    if (literalPlus) {
      session.setLastError("expected '}'");
      return BAD;
    }

    nr += c;
  }

  int nchars = atoi(nr.c_str());
  if (nchars < 0) {
    session.setLastError("expected positive size of appended message");
    return BAD;
  }

  if (!bincClient.readChar(&c)) return ABORT;

  if (c != '\r') {
    session.setLastError("expected CR");
    return BAD;
  }

  if (!bincClient.readChar(&c)) return ABORT;

  if (c != '\n') {
    session.setLastError("expected LF");
    return BAD;
  }

  time_t newtime = (command.getDate() != "") ? mktime(&mytm) : time(nullptr);
  if (newtime == -1) newtime = time(nullptr);
  Message *dest = mailbox->createMessage(depot.mailboxToFilename(canonmailbox), newtime);
  if (!dest) {
    session.setLastError(mailbox->getLastError());
    return NO;
  }

  if (!literalPlus) {
    bincClient << "+ go ahead with " << nchars << " characters" << std::endl;
    bincClient.flush();
  }

  bincClient.clearFlags(IODevice::HasInputLimit);

  while (nchars > 0) {
    // Read in chunks of 8192, followed by an optional chunk at the
    // end which is < 8192 bytes.
    string s;
    int bytesToRead = nchars > 8192 ? 8192 : nchars;
    if (!bincClient.readStr(&s, bytesToRead)) {
      mailbox->rollBackNewMessages();
      session.setLastError(bincClient.getLastErrorString());
      return NO;
    }

    // Write the chunk to the message.
    if (!dest->appendChunk(s)) {
      mailbox->rollBackNewMessages();
      session.setLastError(dest->getLastError());
      return NO;
    }

    // Update the message count.
    nchars -= s.size();
  }

  // Read the trailing CRLF after the message data.
  if (!bincClient.readChar(&c)) return ABORT;

  if (c != '\r') {
    mailbox->rollBackNewMessages();
    session.setLastError("expected CR");
    return BAD;
  }

  if (!bincClient.readChar(&c)) return ABORT;

  if (c != '\n') {
    mailbox->rollBackNewMessages();
    session.setLastError("expected LF");
    return BAD;
  }

  // Commit the message.
  dest->close();
  dest->setStdFlag(newflags);
  dest->setInternalDate(mktime(&mytm));

  if (!mailbox->commitNewMessages(depot.mailboxToFilename(canonmailbox))) {
    session.setLastError("failed to commit after successful APPEND: "
                         + mailbox->getLastError());
    return NO;
  }

  if (mailbox == depot.getSelected()) {
    pendingUpdates(mailbox,
                   PendingUpdates::EXISTS | PendingUpdates::RECENT | PendingUpdates::FLAGS,
                   true,
                   false,
                   true);
  }

  return ProcessResult::OK;
}

Parser::ParseResult AppendOperator::parse(Request &c_in)
{
  constexpr auto ACCEPT = Parser::ParseResult::ACCEPT;

  Session &session = Session::getInstance();
  Parser::ParseResult res;

  if (c_in.getUidMode()) return Parser::ParseResult::REJECT;

  if ((res = expectSPACE()) != ACCEPT) {
    session.setLastError("Expected SPACE after APPEND");
    return res;
  }

  string mailbox;
  if ((res = expectMailbox(mailbox)) != ACCEPT) {
    session.setLastError("Expected mailbox after APPEND SPACE");
    return res;
  }

  c_in.setMailbox(mailbox);

  if ((res = expectSPACE()) != ACCEPT) {
    session.setLastError("Expected SPACE after APPEND SPACE mailbox");
    return res;
  }

  if ((res = expectThisString("(")) == ACCEPT) {
    if ((res = expectFlag(c_in.getFlags())) == ACCEPT) {
      while (1) {
        if ((res = expectSPACE()) != ACCEPT) break;
        if ((res = expectFlag(c_in.getFlags())) != ACCEPT) {
          session.setLastError("expected a flag after the '('");
          return res;
        }
      }
    }

    if ((res = expectThisString(")")) != ACCEPT) {
      session.setLastError("expected a ')'");
      return res;
    }

    if ((res = expectSPACE()) != ACCEPT) {
      session.setLastError("expected a SPACE after the flag list");
      return res;
    }
  }

  string date;
  if ((res = expectDateTime(date)) == ACCEPT) {
    if ((res = expectSPACE()) != ACCEPT) {
      session.setLastError("expected a SPACE after date_time");
      return res;
    }
  }

  c_in.setDate(date);
  c_in.setName("APPEND");
  return ACCEPT;
}