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

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

#include <string>

using namespace Binc;
using std::string;
using std::vector;

constexpr auto ACCEPT = Parser::ParseResult::ACCEPT;
constexpr auto ERROR = Parser::ParseResult::ERROR;
constexpr auto REJECT = Parser::ParseResult::REJECT;

namespace {
  void outputFlags(const Message &message)
  {
    bincClient << "FLAGS ";

    bincClient << "(";
    int flags = message.getStdFlags();
    vector<string> flagv;
    if (flags & Message::F_SEEN) flagv.push_back("\\Seen");
    if (flags & Message::F_ANSWERED) flagv.push_back("\\Answered");
    if (flags & Message::F_DELETED) flagv.push_back("\\Deleted");
    if (flags & Message::F_DRAFT) flagv.push_back("\\Draft");
    if (flags & Message::F_RECENT) flagv.push_back("\\Recent");
    if (flags & Message::F_FLAGGED) flagv.push_back("\\Flagged");

    for (auto k = flagv.begin(); k != flagv.end(); ++k) {
      if (k != flagv.begin()) bincClient << " ";
      bincClient << *k;
    }

    vector<string> customFlags = message.getCustomFlags();
    for (auto it = customFlags.begin(); it != customFlags.end(); ++it) {
      if (flagv.size() > 0 || it != customFlags.begin()) bincClient << " ";
      bincClient << *it;
    }

    bincClient << ")";
  }

}

FetchOperator::FetchOperator() {}

FetchOperator::~FetchOperator() {}

const string FetchOperator::getName() const
{
  return "FETCH";
}

Session::State FetchOperator::getState() const
{
  return Session::SELECTED;
}

Operator::ProcessResult FetchOperator::process(Depot &depot, Request &request)
{
  Session &session = Session::getInstance();

  bool updateFlags = false;
  Request req = request;

  Mailbox *mailbox = depot.getSelected();

  // If this is a UID FETCH, check if the UID attribute is fetched. If
  // it is not, then add it to the list of fetch attributes.
  vector<BincImapParserFetchAtt>::const_iterator f_i;
  bool uidfetched = false;
  if (request.getUidMode()) {
    f_i = request.fatt.begin();
    while (f_i != request.fatt.end()) {
      if ((*f_i).type == "UID") {
        uidfetched = true;
        break;
      }
      f_i++;
    }

    if (!uidfetched) {
      BincImapParserFetchAtt b;
      b.type = "UID";
      req.fatt.push_back(b);
    }
  }

  // Convert macros ALL, FULL and FAST
  f_i = request.fatt.begin();
  while (f_i != request.fatt.end()) {
    const string &type = (*f_i).type;
    if (type == "ALL") {
      req.fatt.push_back(BincImapParserFetchAtt("FLAGS"));
      req.fatt.push_back(BincImapParserFetchAtt("INTERNALDATE"));
      req.fatt.push_back(BincImapParserFetchAtt("RFC822.SIZE"));
      req.fatt.push_back(BincImapParserFetchAtt("ENVELOPE"));
    } else if (type == "FULL") {
      req.fatt.push_back(BincImapParserFetchAtt("FLAGS"));
      req.fatt.push_back(BincImapParserFetchAtt("INTERNALDATE"));
      req.fatt.push_back(BincImapParserFetchAtt("RFC822.SIZE"));
      req.fatt.push_back(BincImapParserFetchAtt("ENVELOPE"));
      req.fatt.push_back(BincImapParserFetchAtt("BODY"));
    } else if (type == "FAST") {
      req.fatt.push_back(BincImapParserFetchAtt("FLAGS"));
      req.fatt.push_back(BincImapParserFetchAtt("INTERNALDATE"));
      req.fatt.push_back(BincImapParserFetchAtt("RFC822.SIZE"));
    }

    ++f_i;
  }

  int mode;
  if (req.getUidMode())
    mode = Mailbox::UID_MODE;
  else
    mode = Mailbox::SQNR_MODE;

  for (Mailbox::iterator i = mailbox->begin(req.bset, Mailbox::SKIP_EXPUNGED | mode);
       i != mailbox->end();
       ++i)
  {
    Message &message = *i;

    bincClient << "* " << i.getSqnr() << " FETCH (";
    bool hasprinted = false;
    f_i = req.fatt.begin();
    while (f_i != req.fatt.end()) {
      BincImapParserFetchAtt fatt = *f_i;

      string prefix = "";
      if (hasprinted) prefix = " ";

      if (fatt.type == "FLAGS") {
        // FLAGS
        hasprinted = true;
        bincClient << prefix;

        outputFlags(message);
      } else if (fatt.type == "UID") {
        // UID
        hasprinted = true;
        bincClient << prefix << "UID " << message.getUID();
      } else if (fatt.type == "RFC822.SIZE") {
        // RFC822.SIZE
        hasprinted = true;
        bincClient << prefix << "RFC822.SIZE " << message.getSize(true);
      } else if (fatt.type == "ENVELOPE") {
        // ENVELOPE
        hasprinted = true;
        bincClient << prefix << "ENVELOPE ";
        message.printEnvelope();
      } else if (fatt.type == "BODYSTRUCTURE") {
        // BODYSTRUCTURE
        hasprinted = true;
        bincClient << prefix << "BODYSTRUCTURE ";
        message.printBodyStructure(true);
      } else if (fatt.type == "BODY" && !fatt.hassection) {
        // BODY with no section
        hasprinted = true;
        session.addBody();
        bincClient << prefix << "BODY ";
        message.printBodyStructure(false);
      } else if (fatt.type == "INTERNALDATE") {
        // INTERNALDATE
        hasprinted = true;
        bincClient << prefix << "INTERNALDATE ";

        time_t iDate = message.getInternalDate();
        struct tm *_tm = gmtime(&iDate);
        char internal[64];
        string iDateStr;
        if (strftime(internal, sizeof(internal), "%d-%b-%Y %H:%M:%S %z", _tm) != 0) {
          if (internal[0] == '0') internal[0] = ' ';
          iDateStr = internal;
        } else {
          iDateStr = "NIL";
        }

        bincClient << toImapString(iDateStr);
      } else if (fatt.type == "BODY" || fatt.type == "BODY.PEEK") {
        // BODY & BODY.PEEK
        hasprinted = true;
        session.addBody();

        bincClient << prefix;
        bool peek = (fatt.type == "BODY.PEEK");
        bincClient << fatt.toString();

        bool includeheaders = true;
        bool fullheader = false;
        bool bodyfetch = false;

        if (fatt.section != "" || fatt.sectiontext == "" || fatt.sectiontext == "TEXT") {
          bodyfetch = true;
          fullheader = true;
        }

        if (fatt.sectiontext == "HEADER.FIELDS.NOT") includeheaders = false;

        if (fatt.sectiontext == "HEADER" || fatt.sectiontext == "HEADER.FIELDS"
            || fatt.sectiontext == "HEADER.FIELDS.NOT" || fatt.sectiontext == "MIME")
        {
          vector<string> v;

          if (fatt.sectiontext == "MIME") {
            v.push_back("content-type");
            v.push_back("content-transfer-encoding");
            v.push_back("content-disposition");
            v.push_back("content-description");
          } else {
            v = fatt.headerlist;
          }

          string dummy;
          unsigned int size = fullheader ? message.getHeaderSize(fatt.section,
                                                                 v,
                                                                 true,
                                                                 fatt.offsetstart,
                                                                 fatt.offsetlength,
                                                                 fatt.sectiontext == "MIME")
                                         : message.getHeaderSize(fatt.section,
                                                                 fatt.headerlist,
                                                                 includeheaders,
                                                                 fatt.offsetstart,
                                                                 fatt.offsetlength,
                                                                 fatt.sectiontext == "MIME");

          bincClient << "{" << size << "}\r\n";

          if (fullheader) {
            message.printHeader(fatt.section,
                                v,
                                true,
                                fatt.offsetstart,
                                fatt.offsetlength,
                                fatt.sectiontext == "MIME");
          } else {
            message.printHeader(fatt.section,
                                fatt.headerlist,
                                includeheaders,
                                fatt.offsetstart,
                                fatt.offsetlength,
                                fatt.sectiontext == "MIME");
          }
        } else {
          unsigned int size;
          if ((fatt.sectiontext == "" || fatt.sectiontext == "TEXT") && fatt.section == "")
            size = message.getDocSize(fatt.offsetstart,
                                      fatt.offsetlength,
                                      fatt.sectiontext == "TEXT");
          else
            size = message.getBodySize(fatt.section, fatt.offsetstart, fatt.offsetlength);

          bincClient << "{" << size << "}\r\n";

          if ((fatt.sectiontext == "" || fatt.sectiontext == "TEXT") && fatt.section == "")
            message.printDoc(fatt.offsetstart, fatt.offsetlength, fatt.sectiontext == "TEXT");
          else
            message.printBody(fatt.section, fatt.offsetstart, fatt.offsetlength);
        }

        // set the \Seen flag if .PEEK is not used.
        if (!peek) {
          if ((message.getStdFlags() & Message::F_SEEN) == 0)
            message.setStdFlag(Message::F_SEEN);
        }
      } else if (fatt.type == "RFC822") {
        bincClient << prefix;
        hasprinted = true;
        session.addBody();
        bincClient << fatt.toString();
        unsigned int size = message.getDocSize(fatt.offsetstart, fatt.offsetlength);
        bincClient << " {" << size << "}\r\n";
        message.printDoc(fatt.offsetstart, fatt.offsetlength);

        // set the \Seen flag
        if ((message.getStdFlags() & Message::F_SEEN) == 0)
          message.setStdFlag(Message::F_SEEN);

      } else if (fatt.type == "RFC822.HEADER") {
        bincClient << prefix;
        hasprinted = true;
        bincClient << fatt.toString();
        vector<string> v;
        string dummy;
        unsigned int size = message.getHeaderSize("",
                                                  v,
                                                  true,
                                                  fatt.offsetstart,
                                                  fatt.offsetlength);
        bincClient << " {" << size << "}\r\n";
        message.printHeader("", v, true, fatt.offsetstart, fatt.offsetlength);
      } else if (fatt.type == "RFC822.TEXT") {
        // RFC822.TEXT
        bincClient << prefix;
        hasprinted = true;
        session.addBody();

        bincClient << fatt.toString();

        bool bodyfetch = false;
        bodyfetch = true;

        unsigned int size;
        if (fatt.sectiontext == "" && fatt.section == "")
          size = message.getDocSize(fatt.offsetstart, fatt.offsetlength, true);
        else
          size = message.getBodySize(fatt.section, fatt.offsetstart, fatt.offsetlength);

        bincClient << " {" << size << "}\r\n";

        if (fatt.sectiontext == "" && fatt.section == "")
          message.printDoc(fatt.offsetstart, fatt.offsetlength, true);
        else
          message.printBody(fatt.section, fatt.offsetstart, fatt.offsetlength);

        // set the \Seen flag
        if ((message.getStdFlags() & Message::F_SEEN) == 0)
          message.setStdFlag(Message::F_SEEN);

      } else {
        // Unrecognized fetch_att, this is stopped by the parser
        // so we never get here.
      }

      f_i++;
    }

    // FIXME: how are parse error passed back?

    bincClient << ")" << std::endl;

    if (message.hasFlagsChanged()) {
      updateFlags = true;
      bincClient << "* " << i.getSqnr() << " FETCH (";
      outputFlags(message);
      bincClient << ")" << std::endl;
      message.setFlagsUnchanged();
    }
  }

  if (updateFlags) mailbox->updateFlags();

  pendingUpdates(mailbox,
                 PendingUpdates::FLAGS | PendingUpdates::EXISTS | PendingUpdates::EXPUNGE
                     | PendingUpdates::RECENT,
                 true);

  return Operator::ProcessResult::OK;
}

Parser::ParseResult FetchOperator::parse(Request &c_in, Parser &p)
{
  Session &session = Session::getInstance();

  Parser::ParseResult res;
  if ((res = p.expectSPACE()) != ACCEPT) {
    session.setLastError("Expected SPACE after FETCH");
    return res;
  }

  if ((res = p.expectSet(c_in.getSet())) != ACCEPT) {
    session.setLastError("Expected sequence set after FETCH SPACE");
    return res;
  }

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

  BincImapParserFetchAtt f;

  if ((res = p.expectThisString("ALL")) == ACCEPT) {
    f.type = "ALL";
    c_in.fatt.push_back(f);
  } else if ((res = p.expectThisString("FULL")) == ACCEPT) {
    f.type = "FULL";
    c_in.fatt.push_back(f);
  } else if ((res = p.expectThisString("FAST")) == ACCEPT) {
    f.type = "FAST";
    c_in.fatt.push_back(f);
  } else if ((res = expectFetchAtt(f, p)) == ACCEPT) {
    c_in.fatt.push_back(f);
  } else if ((res = p.expectThisString("(")) == ACCEPT) {
    while (1) {
      BincImapParserFetchAtt ftmp;
      if ((res = expectFetchAtt(ftmp, p)) != ACCEPT) {
        session.setLastError("Expected fetch_att");
        return res;
      }

      c_in.fatt.push_back(ftmp);

      if ((res = p.expectSPACE()) == REJECT)
        break;
      else if (res == ERROR)
        return ERROR;
    }

    if ((res = p.expectThisString(")")) != ACCEPT) {
      session.setLastError("Expected )");
      return res;
    }
  } else {
    session.setLastError("Expected ALL, FULL, FAST, fetch_att or (");
    return res;
  }

  if ((res = p.expectCRLF()) != ACCEPT) {
    session.setLastError("Expected CRLF");
    return res;
  }

  c_in.setName("FETCH");
  return ACCEPT;
}

Parser::ParseResult FetchOperator::expectSectionText(BincImapParserFetchAtt &f_in,
                                                     Parser &p) const
{
  Session &session = Session::getInstance();

  Parser::ParseResult res;
  if ((res = p.expectThisString("HEADER")) == ACCEPT) {
    f_in.sectiontext = "HEADER";

    if ((res = p.expectThisString(".FIELDS")) == ACCEPT) {
      f_in.sectiontext += ".FIELDS";

      if ((res = p.expectThisString(".NOT")) == ACCEPT) f_in.sectiontext += ".NOT";

      if ((res = p.expectSPACE()) != ACCEPT) {
        session.setLastError("expected SPACE");
        return res;
      }

      if ((res = expectHeaderList(f_in, p)) != ACCEPT) {
        session.setLastError("Expected header_list");
        return res;
      }
    }
  } else if ((res = p.expectThisString("TEXT")) == ACCEPT) {
    f_in.sectiontext = "TEXT";
  } else {
    return Parser::ParseResult::REJECT;
  }

  return ACCEPT;
}

Parser::ParseResult FetchOperator::expectSection(BincImapParserFetchAtt &f_in, Parser &p) const
{
  Session &session = Session::getInstance();

  Parser::ParseResult res;
  if ((res = p.expectThisString("[")) != ACCEPT) return REJECT;

  if ((res = expectSectionText(f_in, p)) != ACCEPT) {
    unsigned int n;
    if ((res = p.expectNZNumber(n)) == ACCEPT) {
      BincStream nstr;
      nstr << n;
      f_in.section = nstr.str();

      bool gotadotalready = false;
      while (1) {
        if ((res = p.expectThisString(".")) != ACCEPT) break;

        if ((res = p.expectNZNumber(n)) != ACCEPT) {
          gotadotalready = true;
          break;
        }

        f_in.section += ".";
        BincStream nstr;
        nstr << n;
        f_in.section += nstr.str();
      }

      if (gotadotalready || (res = p.expectThisString(".")) == ACCEPT) {
        if ((res = p.expectThisString("MIME")) == ACCEPT) {
          f_in.sectiontext = "MIME";
        } else if ((res = expectSectionText(f_in, p)) != ACCEPT) {
          session.setLastError("Expected MIME or section_text");
          return res;
        }
      }
    }
  }

  if ((res = p.expectThisString("]")) != ACCEPT) {
    session.setLastError("Expected ]");
    return res;
  }

  return ACCEPT;
}

Parser::ParseResult FetchOperator::expectHeaderList(BincImapParserFetchAtt &f_in,
                                                    Parser &p) const
{
  Session &session = Session::getInstance();

  Parser::ParseResult res;
  if ((res = p.expectThisString("(")) != ACCEPT) return REJECT;

  string header_fld_name;
  while (1) {
    if ((res = p.expectAstring(header_fld_name)) != ACCEPT) {
      session.setLastError("Expected header_fld_name");
      return res;
    }

    f_in.headerlist.push_back(header_fld_name);

    if ((res = p.expectSPACE()) == ACCEPT)
      continue;
    else
      break;
  }

  if ((res = p.expectThisString(")")) != ACCEPT) {
    session.setLastError("Expected )");
    return res;
  }

  return ACCEPT;
}

Parser::ParseResult FetchOperator::expectOffset(BincImapParserFetchAtt &f_in, Parser &p) const
{
  Session &session = Session::getInstance();
  Parser::ParseResult res;

  if ((res = p.expectThisString("<")) != ACCEPT) return REJECT;

  unsigned int i;
  if ((res = p.expectNumber(i)) != ACCEPT) {
    session.setLastError("Expected number");
    return res;
  }

  if ((res = p.expectThisString(".")) != ACCEPT) {
    session.setLastError("Expected .");
    return res;
  }

  unsigned int j;
  if ((res = p.expectNZNumber(j)) != ACCEPT) {
    session.setLastError("expected nz_number");
    return res;
  }

  if ((res = p.expectThisString(">")) != ACCEPT) {
    session.setLastError("Expected >");
    return res;
  }

  f_in.offsetstart = i;
  f_in.offsetlength = j;
  return ACCEPT;
}

Parser::ParseResult FetchOperator::expectFetchAtt(BincImapParserFetchAtt &f_in,
                                                  Parser &p) const
{
  Parser::ParseResult res;

  Session &session = Session::getInstance();

  if ((res = p.expectThisString("ENVELOPE")) == ACCEPT) {
    f_in.type = "ENVELOPE";
  } else if ((res = p.expectThisString("FLAGS")) == ACCEPT) {
    f_in.type = "FLAGS";
  } else if ((res = p.expectThisString("INTERNALDATE")) == ACCEPT) {
    f_in.type = "INTERNALDATE";
  } else if ((res = p.expectThisString("UID")) == ACCEPT) {
    f_in.type = "UID";
  } else if ((res = p.expectThisString("RFC822")) == ACCEPT) {
    f_in.type = "RFC822";
    if ((res = p.expectThisString(".HEADER")) == ACCEPT) {
      f_in.type += ".HEADER";
    } else if ((res = p.expectThisString(".SIZE")) == ACCEPT) {
      f_in.type += ".SIZE";
    } else if ((res = p.expectThisString(".TEXT")) == ACCEPT) {
      f_in.type += ".TEXT";
    } else if ((res = p.expectThisString(".")) == ACCEPT) {
      session.setLastError("Expected RFC822, RFC822.HEADER,"
                           " RFC822.SIZE or RFC822.TEXT");
      return ERROR;
    }

  } else if ((res = p.expectThisString("BODY")) == ACCEPT) {
    f_in.type = "BODY";

    if ((res = p.expectThisString("STRUCTURE")) == ACCEPT)
      f_in.type += "STRUCTURE";
    else if ((res = p.expectThisString(".PEEK")) == ACCEPT)
      f_in.type += ".PEEK";

    if ((res = expectSection(f_in, p)) != ACCEPT) {
      f_in.hassection = false;
    } else {
      f_in.hassection = true;
      if ((res = expectOffset(f_in, p)) == ERROR) return ERROR;
    }
  } else {
    return REJECT;
  }

  return ACCEPT;
}