/*
 * Copyright 2008-2016, Haiku, Inc. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Bruno Albuquerque, bga@bug-br.org.br
 */


#include "cddb_server.h"

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>


static const char* kDefaultLocalHostName = "unknown";
static const uint32 kDefaultPortNumber = 80;

static const uint32 kFramesPerSecond = 75;
static const uint32 kFramesPerMinute = kFramesPerSecond * 60;


CDDBServer::CDDBServer(const BString& cddbServer)
        :
        fInitialized(false),
        fConnected(false)
{
        // Set up local host name.
        char localHostName[MAXHOSTNAMELEN + 1];
        if (gethostname(localHostName,  MAXHOSTNAMELEN + 1) == 0) {
                fLocalHostName = localHostName;
        } else {
                fLocalHostName = kDefaultLocalHostName;
        }

        // Set up local user name.
        char* user = getenv("USER");
        if (user == NULL)
                fLocalUserName = "unknown";
        else
                fLocalUserName = user;

        // Set up server address;
        if (_ParseAddress(cddbServer) == B_OK)
                fInitialized = true;
}


status_t
CDDBServer::Query(uint32 cddbID, const scsi_toc_toc* toc,
        QueryResponseList& queryResponses)
{
        if (_OpenConnection() != B_OK)
                return B_ERROR;

        // Convert CDDB id to hexadecimal format.
        char hexCddbId[9];
        sprintf(hexCddbId, "%08" B_PRIx32, cddbID);

        // Assemble the Query command.
        int32 numTracks = toc->last_track + 1 - toc->first_track;

        BString cddbCommand("cddb query ");
        cddbCommand << hexCddbId << " " << numTracks << " ";

        // Add track offsets in frames.
        for (int32 i = 0; i < numTracks; ++i) {
                const scsi_cd_msf& start = toc->tracks[i].start.time;

                uint32 startFrameOffset = start.minute * kFramesPerMinute +
                        start.second * kFramesPerSecond + start.frame;

                cddbCommand << startFrameOffset << " ";
        }

        // Add total disc time in seconds. Last track is lead-out.
        const scsi_cd_msf& lastTrack = toc->tracks[numTracks].start.time;
        uint32 totalTimeInSeconds = lastTrack.minute * 60 + lastTrack.second;
        cddbCommand << totalTimeInSeconds;

        BString output;
        status_t result = _SendCommand(cddbCommand, output);
        if (result == B_OK) {
                // Remove the header from the reply.
                output.Remove(0, output.FindFirst("\r\n\r\n") + 4);

                // Check status code.
                BString statusCode;
                output.MoveInto(statusCode, 0, 3);
                if (statusCode == "210" || statusCode == "211") {
                        // TODO(bga): We can get around with returning the first result
                        // in case of multiple matches, but we most definitely need a
                        // better handling of inexact matches.
                        if (statusCode == "211")
                                printf("Warning : Inexact match found.\n");

                        // Multiple results, remove the first line and parse the others.
                        output.Remove(0, output.FindFirst("\r\n") + 2);
                } else if (statusCode == "200") {
                        // Remove the first char which is a left over space.
                        output.Remove(0, 1);
                } else if (statusCode == "202") {
                        // No match found.
                        printf("Error : CDDB entry for id %s not found.\n", hexCddbId);

                        return B_ENTRY_NOT_FOUND;
                } else {
                        // Something bad happened.
                        if (statusCode.Trim() != "") {
                                printf("Error : CDDB server status code is %s.\n",
                                        statusCode.String());
                        } else {
                                printf("Error : Could not find any status code.\n");
                        }

                        return B_ERROR;
                }

                // Process all entries.
                bool done = false;
                while (!done) {
                        QueryResponseData* responseData = new QueryResponseData;

                        output.MoveInto(responseData->category, 0, output.FindFirst(" "));
                        output.Remove(0, 1);

                        output.MoveInto(responseData->cddbID, 0, output.FindFirst(" "));
                        output.Remove(0, 1);

                        output.MoveInto(responseData->artist, 0, output.FindFirst(" / "));
                        output.Remove(0, 3);

                        output.MoveInto(responseData->title, 0, output.FindFirst("\r\n"));
                        output.Remove(0, 2);

                        queryResponses.AddItem(responseData);

                        if (output == "" || output == ".\r\n") {
                                // All returned data was processed exit the loop.
                                done = true;
                        }
                }
        } else {
                printf("Error sending CDDB command : \"%s\".\n", cddbCommand.String());
        }

        _CloseConnection();
        return result;
}


status_t
CDDBServer::Read(const QueryResponseData& diskData,
        ReadResponseData& readResponse, bool verbose)
{
        return Read(diskData.category, diskData.cddbID, diskData.artist,
                readResponse, verbose);
}


status_t
CDDBServer::Read(const BString& category, const BString& cddbID,
        const BString& artist, ReadResponseData& readResponse, bool verbose)
{
        if (_OpenConnection() != B_OK)
                return B_ERROR;

        // Assemble the Read command.
        BString cddbCommand("cddb read ");
        cddbCommand << category << " " << cddbID;

        BString output;
        status_t result = _SendCommand(cddbCommand, output);
        if (result == B_OK) {
                if (verbose)
                        puts(output);

                // Remove the header from the reply.
                output.Remove(0, output.FindFirst("\r\n\r\n") + 4);

                // Check status code.
                BString statusCode;
                output.MoveInto(statusCode, 0, 3);
                if (statusCode == "210") {
                        // Remove first line and parse the others.
                        output.Remove(0, output.FindFirst("\r\n") + 2);
                } else {
                        // Something bad happened.
                        return B_ERROR;
                }

                // Process all entries.
                bool done = false;
                while (!done) {
                        if (output[0] == '#') {
                                // Comment. Remove it.
                                output.Remove(0, output.FindFirst("\r\n") + 2);
                                continue;
                        }

                        // Extract one line to reduce the scope of processing to it.
                        BString line;
                        output.MoveInto(line, 0, output.FindFirst("\r\n"));
                        output.Remove(0, 2);

                        // Obtain prefix.
                        BString prefix;
                        line.MoveInto(prefix, 0, line.FindFirst("="));
                        line.Remove(0, 1);

                        if (prefix == "DTITLE") {
                                // Disk title.
                                BString artist;
                                line.MoveInto(artist, 0, line.FindFirst(" / "));
                                line.Remove(0, 3);
                                readResponse.title = line;
                                readResponse.artist = artist;
                        } else if (prefix == "DYEAR") {
                                // Disk year.
                                char* firstInvalid;
                                errno = 0;
                                uint32 year = strtoul(line.String(), &firstInvalid, 10);
                                if ((errno == ERANGE &&
                                        (year == (uint32)LONG_MAX || year == (uint32)LONG_MIN))
                                        || (errno != 0 && year == 0)) {
                                        // Year out of range.
                                        printf("Year out of range: %s\n", line.String());
                                        year = 0;
                                }

                                if (firstInvalid == line.String()) {
                                        printf("Invalid year: %s\n", line.String());
                                        year = 0;
                                }

                                readResponse.year = year;
                        } else if (prefix == "DGENRE") {
                                // Disk genre.
                                readResponse.genre = line;
                        } else if (prefix.FindFirst("TTITLE") == 0) {
                                // Track title.
                                BString index;
                                prefix.MoveInto(index, 6, prefix.Length() - 6);

                                char* firstInvalid;
                                errno = 0;
                                uint32 track = strtoul(index.String(), &firstInvalid, 10);
                                if (errno != 0 || track > 99) {
                                        // Track out of range.
                                        printf("Track out of range: %s\n", index.String());
                                        return B_ERROR;
                                }

                                if (firstInvalid == index.String()) {
                                        printf("Invalid track: %s\n", index.String());
                                        return B_ERROR;
                                }

                                BString trackArtist;
                                int32 pos = line.FindFirst(" / ");
                                if (pos >= 0 && artist.ICompare("Various") == 0) {
                                        // Disk is set to have a compilation artist and
                                        // we have track specific artist information.
                                        line.MoveInto(trackArtist, 0, pos);
                                                // Move artist information from line to artist.
                                        line.Remove(0, 3);
                                                // Remove " / " from line.
                                } else {
                                        trackArtist = artist;
                                }

                                TrackData* trackData = _Track(readResponse, track);
                                trackData->artist += trackArtist;
                                trackData->title += line;
                        }

                        if (output == "" || output == ".\r\n") {
                                // All returned data was processed exit the loop.
                                done = true;
                        }
                }
        } else {
                printf("Error sending CDDB command : \"%s\".\n", cddbCommand.String());
        }

        _CloseConnection();
        return B_OK;
}


status_t
CDDBServer::_ParseAddress(const BString& cddbServer)
{
        // Set up server address.
        int32 pos = cddbServer.FindFirst(":");
        if (pos == B_ERROR) {
                // It seems we do not have the address:port format. Use hostname as-is.
                fServerHostname.SetTo(cddbServer);
                fServerPort = kDefaultPortNumber;
                return B_OK;
        } else {
                // Parse address:port format.
                int32 port;
                BString newCddbServer(cddbServer);
                BString portString;
                newCddbServer.MoveInto(portString, pos + 1,
                        newCddbServer.CountChars() - pos + 1);
                if (portString.CountChars() > 0) {
                        char* firstInvalid;
                        errno = 0;
                        port = strtol(portString.String(), &firstInvalid, 10);
                        if ((errno == ERANGE && (port == INT32_MAX || port == INT32_MIN))
                                || (errno != 0 && port == 0)) {
                                return B_ERROR;
                        }
                        if (firstInvalid == portString.String()) {
                                return B_ERROR;
                        }

                        newCddbServer.RemoveAll(":");
                        fServerHostname.SetTo(newCddbServer);
                        fServerPort = port;
                        return B_OK;
                }
        }

        return B_ERROR;
}


status_t
CDDBServer::_OpenConnection()
{
        if (!fInitialized)
                return B_ERROR;

        if (fConnected)
                return B_OK;

        if (fServerAddress.InitCheck() != B_OK) {
                // This performs a DNS lookup, hence why we don't do it earlier.
                if (fServerAddress.SetTo(fServerHostname, fServerPort) != B_OK)
                        return B_ERROR;
        }

        if (fConnection.Connect(fServerAddress) == B_OK) {
                fConnected = true;
                return B_OK;
        }

        return B_ERROR;
}


void
CDDBServer::_CloseConnection()
{
        if (!fConnected)
                return;

        fConnection.Close();
        fConnected = false;
}


status_t
CDDBServer::_SendCommand(const BString& command, BString& output)
{
        if (!fConnected)
                return B_ERROR;

        // Assemble full command string.
        BString fullCommand;
        fullCommand << command << "&hello=" << fLocalUserName << " " <<
                fLocalHostName << " cddb_lookup 1.0&proto=6";

        // Replace spaces by + signs.
        fullCommand.ReplaceAll(" ", "+");

        // And now add command header and footer.
        fullCommand.Prepend("GET /~cddb/cddb.cgi?cmd=");
        fullCommand << " HTTP/1.0\n\n";

        int32 result = fConnection.Send((void*)fullCommand.String(),
                fullCommand.Length());
        if (result == fullCommand.Length()) {
                BNetBuffer netBuffer;
                while (fConnection.Receive(netBuffer, 1024) != 0) {
                        // Do nothing. Data is automatically appended to the NetBuffer.
                }

                // AppendString automatically adds the terminating \0.
                netBuffer.AppendString("");

                output.SetTo((char*)netBuffer.Data(), netBuffer.Size());
                return B_OK;
        }

        return B_ERROR;
}


TrackData*
CDDBServer::_Track(ReadResponseData& response, uint32 track) const
{
        for (int32 i = 0; i < response.tracks.CountItems(); i++) {
                TrackData* trackData = response.tracks.ItemAt(i);
                if (trackData->trackNumber == track)
                        return trackData;
        }

        TrackData* trackData = new TrackData();
        trackData->trackNumber = track;
        response.tracks.AddItem(trackData);

        return trackData;
}