#include "globals.h"
#include "fluxmap.h"
#include "decoders/fluxmapreader.h"
#include "protocol.h"
#include "decoders/decoders.h"
#include "sector.h"
#include "f85.h"
#include "crc.h"
#include "bytes.h"
#include "fmt/format.h"
#include <string.h>
#include <algorithm>

const FluxPattern SECTOR_RECORD_PATTERN(24, F85_SECTOR_RECORD);
const FluxPattern DATA_RECORD_PATTERN(24, F85_DATA_RECORD);
const FluxMatchers ANY_RECORD_PATTERN({ &SECTOR_RECORD_PATTERN, &DATA_RECORD_PATTERN });

static int decode_data_gcr(uint8_t gcr)
{
    switch (gcr)
    {
		#define GCR_ENTRY(gcr, data) \
			case gcr: return data;
		#include "data_gcr.h"
		#undef GCR_ENTRY
    }
    return -1;
}

static Bytes decode(const std::vector<bool>& bits)
{
    Bytes output;
    ByteWriter bw(output);
    BitWriter bitw(bw);

    auto ii = bits.begin();
    while (ii != bits.end())
    {
        uint8_t inputfifo = 0;
        for (size_t i=0; i<5; i++)
        {
            if (ii == bits.end())
                break;
            inputfifo = (inputfifo<<1) | *ii++;
        }

        bitw.push(decode_data_gcr(inputfifo), 4);
    }
    bitw.flush();

    return output;
}

class DurangoF85Decoder : public AbstractDecoder
{
public:
	DurangoF85Decoder(const DecoderProto& config):
		AbstractDecoder(config)
	{}

    RecordType advanceToNextRecord()
	{
		const FluxMatcher* matcher = nullptr;
		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
		if (matcher == &SECTOR_RECORD_PATTERN)
			return RecordType::SECTOR_RECORD;
		if (matcher == &DATA_RECORD_PATTERN)
			return RecordType::DATA_RECORD;
		return RecordType::UNKNOWN_RECORD;
	}

    void decodeSectorRecord()
	{
		/* Skip sync bits and ID byte. */

		readRawBits(24);

		/* Read header. */

		const auto& bytes = decode(readRawBits(6*10));

		_sector->logicalSector = bytes[2];
		_sector->logicalSide = 0;
		_sector->logicalTrack = bytes[0];

		uint16_t wantChecksum = bytes.reader().seek(4).read_be16();
		uint16_t gotChecksum = crc16(CCITT_POLY, 0xef21, bytes.slice(0, 4));
		if (wantChecksum == gotChecksum)
			_sector->status = Sector::DATA_MISSING; /* unintuitive but correct */
	}

    void decodeDataRecord()
	{
		/* Skip sync bits ID byte. */

		readRawBits(24);

		const auto& bytes = decode(readRawBits((F85_SECTOR_LENGTH+3)*10))
			.slice(0, F85_SECTOR_LENGTH+3);
		ByteReader br(bytes);

		_sector->data = br.read(F85_SECTOR_LENGTH);
		uint16_t wantChecksum = br.read_be16();
		uint16_t gotChecksum = crc16(CCITT_POLY, 0xbf84, _sector->data);
		_sector->status = (wantChecksum == gotChecksum) ? Sector::OK : Sector::BAD_CHECKSUM;
	}
};

std::unique_ptr<AbstractDecoder> createDurangoF85Decoder(const DecoderProto& config)
{
	return std::unique_ptr<AbstractDecoder>(new DurangoF85Decoder(config));
}