/* Container - message part container class
**
** Copyright 2001 Dr. Zoidberg Enterprises. All rights reserved.
*/


#include <String.h>
#include <List.h>
#include <Mime.h>

#include <stdlib.h>
#include <strings.h>
#include <unistd.h>

class _EXPORT BMIMEMultipartMailContainer;

#include <MailContainer.h>
#include <MailAttachment.h>

typedef struct message_part {
        message_part(off_t start, off_t end) { this->start = start; this->end = end; }

        // Offset where the part starts (includes MIME sub-headers but not the
        // boundary line) in the message file.
        int32 start;

        // Offset just past the last byte of data, so total length == end - start.
        // Note that the CRLF that starts the next boundary isn't included in the
        // data, the end points at the start of the next CRLF+Boundary.  This can
        // lead to weird things like the blank line ending the subheader being the
        // same as the boundary starting CRLF.  So if you have something malformed
        // like this:
        // ------=_NextPart_005_0040_ENBYSXVW.VACTSCVC
    // Content-Type: text/plain; charset="ISO-8859-1"
    //
    // ------=_NextPart_005_0040_ENBYSXVW.VACTSCVC
    // If you subtract the header length (which includes the blank line) from
    // the MIME part total length (which doesn't include the blank line - it's
    // part of the next boundary), you get -2.
        int32 end;
} message_part;


BMIMEMultipartMailContainer::BMIMEMultipartMailContainer(
        const char *boundary,
        const char *this_is_an_MIME_message_text,
        uint32 defaultCharSet)
        :
        BMailContainer (defaultCharSet),
        _boundary(NULL),
        _MIME_message_warning(this_is_an_MIME_message_text),
        _io_data(NULL)
{
        // Definition of the MIME version in the mail header should be enough
        SetHeaderField("MIME-Version","1.0");
        SetHeaderField("Content-Type","multipart/mixed");
        SetBoundary(boundary);
}

/*BMIMEMultipartMailContainer::BMIMEMultipartMailContainer(BMIMEMultipartMailContainer &copy) :
        BMailComponent(copy),
        _boundary(copy._boundary),
        _MIME_message_warning(copy._MIME_message_warning),
        _io_data(copy._io_data) {
                AddHeaderField("MIME-Version","1.0");
                AddHeaderField("Content-Type","multipart/mixed");
                SetBoundary(boundary);
        }*/


BMIMEMultipartMailContainer::~BMIMEMultipartMailContainer() {
        for (int32 i = 0; i < _components_in_raw.CountItems(); i++)
                delete (message_part *)_components_in_raw.ItemAt(i);

        for (int32 i = 0; i < _components_in_code.CountItems(); i++)
                delete (BMailComponent *)_components_in_code.ItemAt(i);

        free((void *)_boundary);
}


void BMIMEMultipartMailContainer::SetBoundary(const char *boundary) {
        free ((void *) _boundary);
        _boundary = NULL;
        if (boundary != NULL)
                _boundary = strdup(boundary);

        BMessage structured;
        HeaderField("Content-Type",&structured);

        if (_boundary == NULL)
                structured.RemoveName("boundary");
        else if (structured.ReplaceString("boundary",_boundary) != B_OK)
                structured.AddString("boundary",_boundary);

        SetHeaderField("Content-Type",&structured);
}


void BMIMEMultipartMailContainer::SetThisIsAnMIMEMessageText(const char *text) {
        _MIME_message_warning = text;
}


status_t BMIMEMultipartMailContainer::AddComponent(BMailComponent *component) {
        if (!_components_in_code.AddItem(component))
                return B_ERROR;
        if (_components_in_raw.AddItem(NULL))
                return B_OK;

        _components_in_code.RemoveItem(component);
        return B_ERROR;
}


BMailComponent *BMIMEMultipartMailContainer::GetComponent(int32 index, bool parse_now) {
        if (index >= CountComponents())
                return NULL;
        
        if (BMailComponent *component = (BMailComponent *)_components_in_code.ItemAt(index))
                return component;       //--- Handle easy case

        message_part *part = (message_part *)(_components_in_raw.ItemAt(index));
        if (part == NULL)
                return NULL;

        _io_data->Seek(part->start,SEEK_SET);

        BMailComponent component (_charSetForTextDecoding);
        if (component.SetToRFC822(_io_data,part->end - part->start) < B_OK)
                return NULL;

        BMailComponent *piece = component.WhatIsThis();

        /* Debug code
        _io_data->Seek(part->start,SEEK_SET);
        char *data = new char[part->end - part->start + 1];
        _io_data->Read(data,part->end - part->start);
        data[part->end - part->start] = 0;
        puts((char *)(data));
        printf("Instantiating from %d to %d (%d octets)\n",part->start, part->end, part->end - part->start);
        */
        _io_data->Seek(part->start,SEEK_SET);
        if (piece->SetToRFC822(_io_data,part->end - part->start, parse_now) < B_OK)
        {
                delete piece;
                return NULL;
        }
        _components_in_code.ReplaceItem(index,piece);

        return piece;
}


int32
BMIMEMultipartMailContainer::CountComponents() const
{
        return _components_in_code.CountItems();
}


status_t
BMIMEMultipartMailContainer::RemoveComponent(BMailComponent *component)
{
        if (component == NULL)
                return B_BAD_VALUE;

        int32 index = _components_in_code.IndexOf(component);
        if (component == NULL)
                return B_ENTRY_NOT_FOUND;

        delete (BMailComponent *)_components_in_code.RemoveItem(index);
        delete (message_part *)_components_in_raw.RemoveItem(index);

        return B_OK;
}


status_t
BMIMEMultipartMailContainer::RemoveComponent(int32 index)
{
        if (index >= CountComponents())
                return B_BAD_INDEX;

        delete (BMailComponent *)_components_in_code.RemoveItem(index);
        delete (message_part *)_components_in_raw.RemoveItem(index);

        return B_OK;
}


status_t BMIMEMultipartMailContainer::GetDecodedData(BPositionIO *)
{
        return B_BAD_TYPE; //------We don't play dat
}


status_t BMIMEMultipartMailContainer::SetDecodedData(BPositionIO *) {
        return B_BAD_TYPE; //------We don't play dat
}


status_t BMIMEMultipartMailContainer::SetToRFC822(BPositionIO *data, size_t length, bool copy_data)
{
        typedef enum LookingForEnum {
                FIRST_NEWLINE,
                INITIAL_DASHES,
                BOUNDARY_BODY,
                LAST_NEWLINE,
                MAX_LOOKING_STATES
        } LookingFor;

        ssize_t     amountRead;
        ssize_t     amountToRead;
        ssize_t     boundaryLength;
        char        buffer [4096];
        ssize_t     bufferIndex;
        off_t       bufferOffset;
        ssize_t     bufferSize;
        BMessage    content_type;
        const char *content_type_string;
        bool        finalBoundary = false;
        bool        finalComponentCompleted = false;
        int         i;
        off_t       lastBoundaryOffset;
        LookingFor  state;
        off_t       startOfBoundaryOffset;
        off_t       topLevelEnd;
        off_t       topLevelStart;

        // Clear out old components.  Maybe make a MakeEmpty method?

        for (i = _components_in_code.CountItems(); i-- > 0;)
                delete (BMailComponent *)_components_in_code.RemoveItem(i);

        for (i = _components_in_raw.CountItems(); i-- > 0;)
                delete (message_part *)_components_in_raw.RemoveItem(i);

        // Start by reading the headers and getting the boundary string.

        _io_data = data;
        topLevelStart = data->Position();
        topLevelEnd = topLevelStart + length;

        BMailComponent::SetToRFC822(data,length);

        HeaderField("Content-Type",&content_type);
        content_type_string = content_type.FindString("unlabeled");
        if (content_type_string == NULL ||
                strncasecmp(content_type_string,"multipart",9) != 0)
                return B_BAD_TYPE;

        if (!content_type.HasString("boundary"))
                return B_BAD_TYPE;
        free ((void *) _boundary);
        _boundary = strdup(content_type.FindString("boundary"));
        boundaryLength = strlen(_boundary);
        if (boundaryLength > (ssize_t) sizeof (buffer) / 2)
                return B_BAD_TYPE; // Boundary is way too long, should be max 70 chars.

        //      Find container parts by scanning through the given portion of the file
        //      for the boundary marker lines.  The stuff between the header and the
        //      first boundary is ignored, the same as the stuff after the last
        //      boundary.  The rest get stored away as our sub-components.  See RFC2046
        //      section 5.1 for details.

        bufferOffset = data->Position(); // File offset of the start of the buffer.
        bufferIndex = 0; // Current position we are examining in the buffer.
        bufferSize = 0; // Amount of data actually in the buffer, not including NUL.
        startOfBoundaryOffset = -1;
        lastBoundaryOffset = -1;
        state = INITIAL_DASHES; // Starting just after a new line so don't search for it.
        while (((bufferOffset + bufferIndex < topLevelEnd)
                || (state == LAST_NEWLINE /* No EOF test in LAST_NEWLINE state */))
                && !finalComponentCompleted)
        {
                // Refill the buffer if the remaining amount of data is less than a
                // boundary's worth, plus four dashes and two CRLFs.
                if (bufferSize - bufferIndex < boundaryLength + 8)
                {
                        // Shuffle the remaining bit of data in the buffer over to the front.
                        if (bufferSize - bufferIndex > 0)
                                memmove (buffer, buffer + bufferIndex, bufferSize - bufferIndex);
                        bufferOffset += bufferIndex;
                        bufferSize = bufferSize - bufferIndex;
                        bufferIndex = 0;

                        // Fill up the rest of the buffer with more data.  Also leave space
                        // for a NUL byte just past the last data in the buffer so that
                        // simple string searches won't go off past the end of the data.
                        amountToRead = topLevelEnd - (bufferOffset + bufferSize);
                        if (amountToRead > (ssize_t) sizeof (buffer) - 1 - bufferSize)
                                amountToRead = sizeof (buffer) - 1 - bufferSize;
                        if (amountToRead > 0) {
                                amountRead = data->Read (buffer + bufferSize, amountToRead);
                                if (amountRead < 0)
                                        return amountRead;
                                bufferSize += amountRead;
                        }
                        buffer [bufferSize] = 0; // Add an end of string NUL byte.
                }

                // Search for whatever parts of the boundary we are currently looking
                // for in the buffer.  It starts with a newline (officially CRLF but we
                // also accept just LF for off-line e-mail files), followed by two
                // hyphens or dashes "--", followed by the unique boundary string
                // specified earlier in the header, followed by two dashes "--" for the
                // final boundary (or zero dashes for intermediate boundaries),
                // followed by white space (possibly including header style comments in
                // brackets), and then a newline.

                switch (state) {
                        case FIRST_NEWLINE:
                                // The newline before the boundary is considered to be owned by
                                // the boundary, not part of the previous MIME component.
                                startOfBoundaryOffset = bufferOffset + bufferIndex;
                                if (buffer[bufferIndex] == '\r' && buffer[bufferIndex + 1] == '\n') {
                                        bufferIndex += 2;
                                        state = INITIAL_DASHES;
                                } else if (buffer[bufferIndex] == '\n') {
                                        bufferIndex += 1;
                                        state = INITIAL_DASHES;
                                } else
                                        bufferIndex++;
                                break;

                        case INITIAL_DASHES:
                                if (buffer[bufferIndex] == '-' && buffer[bufferIndex + 1] == '-') {
                                        bufferIndex += 2;
                                        state = BOUNDARY_BODY;
                                } else
                                        state = FIRST_NEWLINE;
                                break;

                        case BOUNDARY_BODY:
                                if (strncmp (buffer + bufferIndex, _boundary, boundaryLength) != 0) {
                                        state = FIRST_NEWLINE;
                                        break;
                                }
                                bufferIndex += boundaryLength;
                                finalBoundary = false;
                                if (buffer[bufferIndex] == '-' && buffer[bufferIndex + 1] == '-') {
                                        bufferIndex += 2;
                                        finalBoundary = true;
                                }
                                state = LAST_NEWLINE;
                                break;

                        case LAST_NEWLINE:
                                // Just keep on scanning until the next new line or end of file.
                                if (buffer[bufferIndex] == '\r' && buffer[bufferIndex + 1] == '\n')
                                        bufferIndex += 2;
                                else if (buffer[bufferIndex] == '\n')
                                        bufferIndex += 1;
                                else if (buffer[bufferIndex] != 0 /* End of file is like a newline */) {
                                        // Not a new line or end of file, just skip over
                                        // everything.  White space or not, we don't really care.
                                        bufferIndex += 1;
                                        break;
                                }
                                // Got to the end of the boundary line and maybe now have
                                // another component to add.
                                if (lastBoundaryOffset >= 0) {
                                        _components_in_raw.AddItem (new message_part (lastBoundaryOffset, startOfBoundaryOffset));
                                        _components_in_code.AddItem (NULL);
                                }
                                // Next component's header starts just after the boundary line.
                                lastBoundaryOffset = bufferOffset + bufferIndex;
                                if (finalBoundary)
                                        finalComponentCompleted = true;
                                state = FIRST_NEWLINE;
                                break;

                        default: // Should not happen.
                                state = FIRST_NEWLINE;
                }
        }

        // Some bad MIME encodings (usually spam, or damaged files) don't put on
        // the trailing boundary.  Dump whatever is remaining into a final
        // component if there wasn't a trailing boundary and there is some data
        // remaining.

        if (!finalComponentCompleted
                && lastBoundaryOffset >= 0 && lastBoundaryOffset < topLevelEnd) {
                _components_in_raw.AddItem (new message_part (lastBoundaryOffset, topLevelEnd));
                _components_in_code.AddItem (NULL);
        }

        // If requested, actually read the data inside each component, otherwise
        // only the positions in the BPositionIO are recorded.

        if (copy_data) {
                for (i = 0; GetComponent(i, true /* parse_now */) != NULL; i++) {}
        }
        
        data->Seek (topLevelEnd, SEEK_SET);
        return B_OK;
}


status_t BMIMEMultipartMailContainer::RenderToRFC822(BPositionIO *render_to) {
        BMailComponent::RenderToRFC822(render_to);

        BString delimiter;
        delimiter << "\r\n--" << _boundary << "\r\n";

        if (_MIME_message_warning != NULL) {
                render_to->Write(_MIME_message_warning,strlen(_MIME_message_warning));
                render_to->Write("\r\n",2);
        }

        for (int32 i = 0; i < _components_in_code.CountItems() /* both have equal length, so pick one at random */; i++) {
                render_to->Write(delimiter.String(),delimiter.Length());
                if (_components_in_code.ItemAt(i) != NULL) { //---- _components_in_code has precedence

                        BMailComponent *code = (BMailComponent *)_components_in_code.ItemAt(i);
                        status_t status = code->RenderToRFC822(render_to); //----Easy enough
                        if (status < B_OK)
                                return status;
                } else {
                        // copy message contents

                        uint8 buffer[1024];
                        ssize_t amountWritten, length;
                        message_part *part = (message_part *)_components_in_raw.ItemAt(i);

                        for (off_t begin = part->start; begin < part->end;
                                begin += sizeof(buffer)) {
                                length = (((off_t)part->end - begin) >= (off_t)sizeof(buffer))
                                        ? sizeof(buffer) : (part->end - begin);

                                _io_data->ReadAt(begin,buffer,length);
                                amountWritten = render_to->Write(buffer,length);
                                if (amountWritten < 0)
                                        return amountWritten; // IO error of some sort.
                        }
                }
        }

        render_to->Write(delimiter.String(),delimiter.Length() - 2);    // strip CRLF
        render_to->Write("--\r\n",4);

        return B_OK;
}

void BMIMEMultipartMailContainer::_ReservedMultipart1() {}
void BMIMEMultipartMailContainer::_ReservedMultipart2() {}
void BMIMEMultipartMailContainer::_ReservedMultipart3() {}

void BMailContainer::_ReservedContainer1() {}
void BMailContainer::_ReservedContainer2() {}
void BMailContainer::_ReservedContainer3() {}
void BMailContainer::_ReservedContainer4() {}