/*
 * Copyright 2011-2016, Haiku, Inc. All rights reserved.
 * Copyright 2011, Clemens Zeidler <haiku@clemens-zeidler.de>
 * Distributed under the terms of the MIT License.
 */


#include "Commands.h"

#include <stdlib.h>

#include <AutoDeleter.h>


#define DEBUG_IMAP_HANDLER
#ifdef DEBUG_IMAP_HANDLER
#	include <stdio.h>
#	define TRACE(x...) printf(x)
#else
#	define TRACE(x...) ;
#endif


using namespace BPrivate;


/*!	Maximum size of commands to the server (soft limit) */
const size_t kMaxCommandLength = 2048;


static void
PutFlag(BString& string, const char* flag)
{
	if (!string.IsEmpty())
		string += " ";
	string += flag;
}


static BString
GenerateFlagString(uint32 flags)
{
	BString string;

	if ((flags & IMAP::kSeen) != 0)
		PutFlag(string, "\\Seen");
	if ((flags & IMAP::kAnswered) != 0)
		PutFlag(string, "\\Answered");
	if ((flags & IMAP::kFlagged) != 0)
		PutFlag(string, "\\Flagged");
	if ((flags & IMAP::kDeleted) != 0)
		PutFlag(string, "\\Deleted");
	if ((flags & IMAP::kDraft) != 0)
		PutFlag(string, "\\Draft");

	return string;
}


static uint32
ParseFlags(IMAP::ArgumentList& list)
{
	uint32 flags = 0;
	for (int32 i = 0; i < list.CountItems(); i++) {
		if (list.EqualsAt(i, "\\Seen"))
			flags |= IMAP::kSeen;
		else if (list.EqualsAt(i, "\\Answered"))
			flags |= IMAP::kAnswered;
		else if (list.EqualsAt(i, "\\Flagged"))
			flags |= IMAP::kFlagged;
		else if (list.EqualsAt(i, "\\Deleted"))
			flags |= IMAP::kDeleted;
		else if (list.EqualsAt(i, "\\Draft"))
			flags |= IMAP::kDraft;
	}
	return flags;
}


// #pragma mark -


namespace IMAP {


Handler::Handler()
{
}


Handler::~Handler()
{
}


// #pragma mark -


Command::~Command()
{
}


status_t
Command::HandleTagged(Response& response)
{
	if (response.StringAt(0) == "OK")
		return B_OK;
	if (response.StringAt(0) == "BAD")
		return B_BAD_VALUE;
	if (response.StringAt(0) == "NO")
		return B_NOT_ALLOWED;

	return B_ERROR;
}


// #pragma mark -

#if 0
HandlerListener::~HandlerListener()
{
}


void
HandlerListener::ExpungeReceived(int32 number)
{
}


void
HandlerListener::ExistsReceived(int32 number)
{
}
#endif

// #pragma mark -


RawCommand::RawCommand(const BString& command)
	:
	fCommand(command)
{
}


BString
RawCommand::CommandString()
{
	return fCommand;
}


// #pragma mark -


LoginCommand::LoginCommand(const char* user, const char* password)
	:
	fUser(user),
	fPassword(password)
{
}


BString
LoginCommand::CommandString()
{
	BString command = "LOGIN ";
	command << "\"" << fUser << "\" " << "\"" << fPassword << "\"";

	return command;
}


bool
LoginCommand::HandleUntagged(Response& response)
{
	if (!response.EqualsAt(0, "OK") || !response.IsListAt(1, '['))
		return false;

	// TODO: we only support capabilities at the moment
	ArgumentList& list = response.ListAt(1);
	if (!list.EqualsAt(0, "CAPABILITY"))
		return false;

	fCapabilities.MakeEmpty();
	while (list.CountItems() > 1)
		fCapabilities.AddItem(list.RemoveItemAt(1));

	TRACE("CAPABILITY: %s\n", fCapabilities.ToString().String());
	return true;
}


// #pragma mark -


SelectCommand::SelectCommand()
	:
	fNextUID(0),
	fUIDValidity(0)
{
}


SelectCommand::SelectCommand(const char* name)
	:
	fNextUID(0),
	fUIDValidity(0)
{
	SetTo(name);
}


BString
SelectCommand::CommandString()
{
	if (fMailboxName == "")
		return "";

	BString command = "SELECT \"";
	command += fMailboxName;
	command += "\"";
	return command;
}


bool
SelectCommand::HandleUntagged(Response& response)
{
	if (response.EqualsAt(0, "OK") && response.IsListAt(1, '[')) {
		const ArgumentList& arguments = response.ListAt(1);
		if (arguments.EqualsAt(0, "UIDVALIDITY")
			&& arguments.IsNumberAt(1)) {
			fUIDValidity = arguments.NumberAt(1);
			return true;
		} else if (arguments.EqualsAt(0, "UIDNEXT")
			&& arguments.IsNumberAt(1)) {
			fNextUID = arguments.NumberAt(1);
			return true;
		}
	}

	return false;
}


void
SelectCommand::SetTo(const char* mailboxName)
{
	RFC3501Encoding encoding;
	fMailboxName = encoding.Encode(mailboxName);
}


// #pragma mark -


BString
CapabilityHandler::CommandString()
{
	return "CAPABILITY";
}


bool
CapabilityHandler::HandleUntagged(Response& response)
{
	if (!response.IsCommand("CAPABILITY"))
		return false;

	fCapabilities.MakeEmpty();
	while (response.CountItems() > 1)
		fCapabilities.AddItem(response.RemoveItemAt(1));

	TRACE("CAPABILITY: %s\n", fCapabilities.ToString().String());
	return true;
}


// #pragma mark -


FetchMessageEntriesCommand::FetchMessageEntriesCommand(
	MessageEntryList& entries, uint32 from, uint32 to, bool uids)
	:
	fEntries(entries),
	fFrom(from),
	fTo(to),
	fUIDs(uids)
{
}


BString
FetchMessageEntriesCommand::CommandString()
{
	BString command = fUIDs ? "UID FETCH " : "FETCH ";
	command << fFrom;
	if (fFrom != fTo)
		command << ":" << fTo;

	command << " (FLAGS RFC822.SIZE";
	if (!fUIDs)
		command << " UID";
	command << ")";

	return command;
}


bool
FetchMessageEntriesCommand::HandleUntagged(Response& response)
{
	if (!response.EqualsAt(1, "FETCH") || !response.IsListAt(2))
		return false;

	MessageEntry entry;

	ArgumentList& list = response.ListAt(2);
	for (int32 i = 0; i < list.CountItems(); i += 2) {
		if (list.EqualsAt(i, "UID") && list.IsNumberAt(i + 1))
			entry.uid = list.NumberAt(i + 1);
		else if (list.EqualsAt(i, "RFC822.SIZE") && list.IsNumberAt(i + 1))
			entry.size = list.NumberAt(i + 1);
		else if (list.EqualsAt(i, "FLAGS") && list.IsListAt(i + 1)) {
			// Parse flags
			ArgumentList& flags = list.ListAt(i + 1);
			entry.flags = ParseFlags(flags);
		}
	}

	if (entry.uid == 0)
		return false;

	fEntries.push_back(entry);
	return true;
}


// #pragma mark -


FetchCommand::FetchCommand(uint32 from, uint32 to, uint32 flags)
	:
	fFlags(flags)
{
	fSequence << from;
	if (from != to)
		fSequence << ":" << to;
}


/*!	Builds the sequence from the passed in UID list, and takes \a max entries
	at maximum. If the sequence gets too large, it might fetch less entries
	than specified. The fetched UIDs will be removed from the \uids list.
*/
FetchCommand::FetchCommand(MessageUIDList& uids, size_t max, uint32 flags)
	:
	fFlags(flags)
{
	// Build sequence string
	max = std::min(max, uids.size());

	size_t index = 0;
	while (index < max && (size_t)fSequence.Length() < kMaxCommandLength) {
		// Get start of range
		uint32 first = uids[index++];
		uint32 last = first;
		if (!fSequence.IsEmpty())
			fSequence += ",";
		fSequence << first;

		for (; index < max; index++) {
			uint32 uid = uids[index];
			if (uid != last + 1)
				break;

			last = uid;
		}

		if (last != first)
			fSequence << ":" << last;
	}

	uids.erase(uids.begin(), uids.begin() + index);
}


void
FetchCommand::SetListener(FetchListener* listener)
{
	fListener = listener;
}


BString
FetchCommand::CommandString()
{
	BString command = "UID FETCH ";
	command += fSequence;

	command += " (UID ";
	if ((fFlags & kFetchFlags) != 0)
		command += "FLAGS ";
	switch (fFlags & kFetchAll) {
		case kFetchHeader:
			command += "RFC822.HEADER";
			break;
		case kFetchBody:
			command += "BODY.PEEK[TEXT]";
			break;
		case kFetchAll:
			command += "BODY.PEEK[]";
			break;
	}
	command += ")";

	return command;
}


bool
FetchCommand::HandleUntagged(Response& response)
{
	if (!response.EqualsAt(1, "FETCH") || !response.IsListAt(2))
		return false;

	ArgumentList& list = response.ListAt(2);
	uint32 uid = 0;
	uint32 flags = 0;

	for (int32 i = 0; i < list.CountItems(); i += 2) {
		if (list.EqualsAt(i, "UID") && list.IsNumberAt(i + 1))
			uid = list.NumberAt(i + 1);
		else if (list.EqualsAt(i, "FLAGS") && list.IsListAt(i + 1)) {
			// Parse flags
			ArgumentList& flagList = list.ListAt(i + 1);
			flags = ParseFlags(flagList);
		}
	}

	if (fListener != NULL)
		fListener->FetchedData(fFlags, uid, flags);
	return true;
}


bool
FetchCommand::HandleLiteral(Response& response, ArgumentList& arguments,
	BDataIO& stream, size_t& length)
{
	if (fListener == NULL || !response.EqualsAt(1, "FETCH")
		|| !response.IsListAt(2))
		return false;

	return fListener->FetchData(fFlags, stream, length);
}


// #pragma mark -


SetFlagsCommand::SetFlagsCommand(uint32 uid, uint32 flags)
	:
	fUID(uid),
	fFlags(flags)
{
}


BString
SetFlagsCommand::CommandString()
{
	BString command = "UID STORE ";
	command << fUID << " FLAGS (" << GenerateFlagString(fFlags) << ")";

	return command;
}


bool
SetFlagsCommand::HandleUntagged(Response& response)
{
	// We're not that interested in the outcome, apparently
	return response.EqualsAt(1, "FETCH");
}


// #pragma mark -


#if 0
AppendCommand::AppendCommand(IMAPMailbox& mailbox, BPositionIO& message,
	off_t size, int32 flags, time_t time)
	:
	IMAPMailboxCommand(mailbox),

	fMessageData(message),
	fDataSize(size),
	fFlags(flags),
	fTime(time)
{
}


BString
AppendCommand::CommandString()
{
	BString command = "APPEND ";
	command << fIMAPMailbox.Mailbox();
	command += " (";
	command += SetFlagsCommand::GenerateFlagList(fFlags);
	command += ")";
	command += " {";
	command << fDataSize;
	command += "}";
	return command;
}


bool
AppendCommand::HandleUntagged(const BString& response)
{
	if (response.FindFirst("+") != 0)
		return false;
	fMessageData.Seek(0, SEEK_SET);

	const int32 kBunchSize = 1024; // 1Kb
	char buffer[kBunchSize];

	int32 writeSize = fDataSize;
	while (writeSize > 0) {
		int32 bunchSize = writeSize < kBunchSize ? writeSize : kBunchSize;
		fMessageData.Read(buffer, bunchSize);
		int nWritten = fIMAPMailbox.SendRawData(buffer, bunchSize);
		if (nWritten < 0)
			return false;
		writeSize -= nWritten;
		TRACE("%i\n", (int)writeSize);
	}

	fIMAPMailbox.SendRawData(CRLF, strlen(CRLF));
	return true;
}
#endif


// #pragma mark -


ExistsHandler::ExistsHandler()
{
}


void
ExistsHandler::SetListener(ExistsListener* listener)
{
	fListener = listener;
}


bool
ExistsHandler::HandleUntagged(Response& response)
{
	if (!response.EqualsAt(1, "EXISTS") || !response.IsNumberAt(0))
		return false;

	uint32 count = response.NumberAt(0);

	if (fListener != NULL)
		fListener->MessageExistsReceived(count);

	return true;
}


// #pragma mark -


ExpungeCommand::ExpungeCommand()
{
}


BString
ExpungeCommand::CommandString()
{
	return "EXPUNGE";
}


// #pragma mark -


ExpungeHandler::ExpungeHandler()
{
}


void
ExpungeHandler::SetListener(ExpungeListener* listener)
{
	fListener = listener;
}


bool
ExpungeHandler::HandleUntagged(Response& response)
{
	if (!response.EqualsAt(1, "EXPUNGE") || !response.IsNumberAt(0))
		return false;

	uint32 index = response.NumberAt(0);

	if (fListener != NULL)
		fListener->MessageExpungeReceived(index);

	return true;
}


// #pragma mark -


#if 0
FlagsHandler::FlagsHandler(IMAPMailbox& mailbox)
	:
	IMAPMailboxCommand(mailbox)
{
}


bool
FlagsHandler::HandleUntagged(const BString& response)
{
	if (response.FindFirst("FETCH") < 0)
		return false;

	int32 fetch = 0;
	if (!IMAPParser::ExtractUntagedFromLeft(response, "FETCH", fetch))
		return false;

	int32 flags = FetchMinMessageCommand::ExtractFlags(response);
	int32 uid = fIMAPMailbox.MessageNumberToUID(fetch);
	fStorage.SetFlags(uid, flags);
	TRACE("FlagsHandler id %i flags %i\n", (int)fetch, (int)flags);
	fIMAPMailbox.SendRawCommand("DONE");

	return true;
}
#endif


// #pragma mark -


ListCommand::ListCommand(const char* prefix, bool subscribedOnly)
	:
	fPrefix(prefix),
	fSubscribedOnly(subscribedOnly)
{
}


BString
ListCommand::CommandString()
{
	BString command = _Command();
	command += " \"\" \"";
	if (fPrefix != NULL)
		command << fEncoding.Encode(fPrefix) << "%";
	else
		command += "*";
	command += "\"";

	return command;
}


bool
ListCommand::HandleUntagged(Response& response)
{
	if (response.IsCommand(_Command()) && response.IsStringAt(2)
		&& response.IsStringAt(3)) {
		fSeparator = response.StringAt(2);

		if (response.IsListAt(1)) {
			// We're not supposed to select \Noselect mailboxes,
			// so we'll just hide them
			ArgumentList& attributes = response.ListAt(1);
			if (attributes.Contains("\\Noselect"))
				return true;
		}

		BString folder = response.StringAt(3);
		if (folder == "")
			return true;

		try {
			folder = fEncoding.Decode(folder);
			// The folder INBOX is always case insensitive
			if (folder.ICompare("INBOX") == 0)
				folder = "Inbox";
			fFolders.Add(folder);
		} catch (ParseException& exception) {
			// Decoding failed, just add the plain text
			fprintf(stderr, "Decoding \"%s\" failed: %s\n", folder.String(),
				exception.Message());
			fFolders.Add(folder);
		}
		return true;
	}

	return false;
}


const BStringList&
ListCommand::FolderList()
{
	return fFolders;
}


const char*
ListCommand::_Command() const
{
	return fSubscribedOnly ? "LSUB" : "LIST";
}


// #pragma mark -


SubscribeCommand::SubscribeCommand(const char* mailboxName)
	:
	fMailboxName(mailboxName)
{
}


BString
SubscribeCommand::CommandString()
{
	BString command = "SUBSCRIBE \"";
	command += fMailboxName;
	command += "\"";
	return command;
}


// #pragma mark -


UnsubscribeCommand::UnsubscribeCommand(const char* mailboxName)
	:
	fMailboxName(mailboxName)
{
}


BString
UnsubscribeCommand::CommandString()
{
	BString command = "UNSUBSCRIBE \"";
	command += fMailboxName;
	command += "\"";
	return command;
}


// #pragma mark -


GetQuotaCommand::GetQuotaCommand(const char* mailboxName)
	:
	fMailboxName(mailboxName),
	fUsedStorage(0),
	fTotalStorage(0)
{
}


BString
GetQuotaCommand::CommandString()
{
	BString command = "GETQUOTAROOT \"";
	command += fMailboxName;
	command += "\"";
	return command;
}


bool
GetQuotaCommand::HandleUntagged(Response& response)
{
	if (!response.IsCommand("QUOTA") || !response.IsListAt(2))
		return false;

	const ArgumentList& arguments = response.ListAt(2);
	if (!arguments.EqualsAt(0, "STORAGE"))
		return false;

	fUsedStorage = (uint64)arguments.NumberAt(1) * 1024;
	fTotalStorage = (uint64)arguments.NumberAt(2) * 1024;

	return true;
}


uint64
GetQuotaCommand::UsedStorage()
{
	return fUsedStorage;
}


uint64
GetQuotaCommand::TotalStorage()
{
	return fTotalStorage;
}


}	// namespace