#!/usr/bin/env python3

"""
#define  FT_FILENAME			 0x01	// <string>
#define  FT_FILESIZE			 0x02	// <uint32> (or <uint64> when supported)
#define  FT_FILESIZE_HI			 0x3A	// <uint32>
#define  FT_FILETYPE			 0x03	// <string>
#define  FT_FILEFORMAT			 0x04	// <string>
#define  FT_LASTSEENCOMPLETE	 0x05	// <uint32>
#define	TAG_PART_PATH			"\x06"	// <string>
#define	TAG_PART_HASH			"\x07"
#define  FT_TRANSFERRED			 0x08	// <uint32>
#define	TAG_TRANSFERRED			"\x08"	// <uint32>
#define  FT_GAPSTART			 0x09	// <uint32>
#define	TAG_GAPSTART			"\x09"	// <uint32>
#define  FT_GAPEND				 0x0A	// <uint32>
#define	TAG_GAPEND				"\x0A"	// <uint32>
#define  FT_DESCRIPTION			 0x0B	// <string>
#define	TAG_DESCRIPTION			"\x0B"	// <string>
#define	TAG_PING				"\x0C"
#define	TAG_FAIL				"\x0D"
#define	TAG_PREFERENCE			"\x0E"
#define  FT_PARTFILENAME		 0x12	// <string>
//#define FT_PRIORITY			 0x13	// Not used anymore
#define  FT_STATUS				 0x14	// <uint32>
#define  FT_SOURCES				 0x15	// <uint32>
#define  FT_PERMISSIONS			 0x16	// <uint32>
//#define FT_ULPRIORITY			 0x17	// Not used anymore
#define  FT_DLPRIORITY			 0x18	// Was 13
#define  FT_ULPRIORITY			 0x19	// Was 17
#define	 FT_COMPRESSION			 0x1A
#define	 FT_CORRUPTED			 0x1B
#define  FT_KADLASTPUBLISHKEY	 0x20	// <uint32>
#define  FT_KADLASTPUBLISHSRC	 0x21	// <uint32>
#define	 FT_FLAGS				 0x22	// <uint32>
#define	 FT_DL_ACTIVE_TIME		 0x23	// <uint32>
#define	 FT_CORRUPTEDPARTS		 0x24	// <string>
#define  FT_DL_PREVIEW			 0x25
#define  FT_KADLASTPUBLISHNOTES	 0x26	// <uint32>
#define  FT_AICH_HASH			 0x27
#define  FT_FILEHASH			 0x28
#define	 FT_COMPLETE_SOURCES	 0x30	// nr. of sources which share a complete version of the associated file (supported by eserver 16.46+)
#define  FT_COLLECTIONAUTHOR	 0x31
#define  FT_COLLECTIONAUTHORKEY  0x32
#define  FT_PUBLISHINFO			 0x33	// <uint32>
#define  FT_LASTSHARED			 0x34	// <uint32>
#define  FT_AICHHASHSET			 0x35	// <uint32>
#define	TAG_KADAICHHASHPUB		"\x36"	// <AICH Hash>

// statistic
#define  FT_ATTRANSFERRED		 0x50	// <uint32>
#define  FT_ATREQUESTED			 0x51	// <uint32>
#define  FT_ATACCEPTED			 0x52	// <uint32>
#define  FT_CATEGORY			 0x53	// <uint32>
#define	 FT_ATTRANSFERREDHI		 0x54	// <uint32>
#define	 FT_MAXSOURCES			 0x55	// <uint32>
#define	 FT_MEDIA_ARTIST		 0xD0	// <string>
#define	TAG_MEDIA_ARTIST		"\xD0"	// <string>
#define	 FT_MEDIA_ALBUM			 0xD1	// <string>
#define	TAG_MEDIA_ALBUM			"\xD1"	// <string>
#define	 FT_MEDIA_TITLE			 0xD2	// <string>
#define	TAG_MEDIA_TITLE			"\xD2"	// <string>
#define	 FT_MEDIA_LENGTH		 0xD3	// <uint32> !!!
#define	TAG_MEDIA_LENGTH		"\xD3"	// <uint32> !!!
#define	 FT_MEDIA_BITRATE		 0xD4	// <uint32>
#define	TAG_MEDIA_BITRATE		"\xD4"	// <uint32>
#define	 FT_MEDIA_CODEC			 0xD5	// <string>
#define	TAG_MEDIA_CODEC			"\xD5"	// <string>
#define  FT_FILECOMMENT			 0xF6	// <string>
#define  FT_FILERATING			 0xF7	// <uint8>
"""


import sys
import os
import binascii
from collections import namedtuple


METENTRY_FIELDS = ('FT_FILENAME', 'ED2KHASH', 'NUMPARTS', 'LASTCHANGED', 'PARTHASHES', 'FT_FILESIZE',
                   'FT_ATTRANSFERRED', 'FT_ATREQUESTED', 'FT_ATACCEPTED', 'FT_ATTRANSFERREDHI', 'FT_PARTFILENAME',
                   'FT_AICHHASHSET', 'FT_AICH_HASH', 'FT_ULPRIORITY', 'FT_KADLASTPUBLISHSRC')
MetEntry = namedtuple('met_entry', METENTRY_FIELDS)

HEADER_KNOWN_MET_FILE = b'\x0e'
HEADER_PART_MET_FILE = b'\xe0'

FT_FILENAME = 0x01
FT_FILESIZE = 0x02
FT_PARTFILENAME = 0x12
FT_PERMISSIONS = 0x16
FT_ULPRIORITY = 0x19

FT_KADLASTPUBLISHKEY = 0x20
FT_KADLASTPUBLISHSRC = 0x21
FT_FLAGS = 0x22
FT_KADLASTPUBLISHNOTES = 0x26
FT_AICH_HASH = 0x27

FT_LASTSHARED = 0x34
FT_AICHHASHSET = 0x35

FT_ATTRANSFERRED = 0x50
FT_ATREQUESTED = 0x51
FT_ATACCEPTED = 0x52
FT_ATTRANSFERREDHI = 0x54

FT_MEDIA_ARTIST = 0xd0
FT_MEDIA_ALBUM = 0xd1
FT_MEDIA_TITLE = 0xd2
FT_MEDIA_LENGTH = 0xd3
FT_MEDIA_BITRATE = 0xd4
FT_MEDIA_CODEC = 0xd5

FT_STRING = (
    0x03, 0x04, 0x06, 0x0b, 0x11, 0x24, 0x28, 0xf6
)

FT_INT = (
    0x05, 0x08, 0x09, 0x0a, 0x14, 0x15, 0x18, 0x1a, 0x1b, 0x23, 0x25, 0x30, 0x33, 0x53, 0x55, 0xf7
)

def met_readstring(fd):
    string_len = int.from_bytes(fd.read(2), byteorder='little')
    return fd.read(string_len).decode('utf-8', errors='replace')


def met_readinteger(fd, size=4):
    return int.from_bytes(fd.read(size), byteorder='little')


def record_last_changed(fd):
    return met_readinteger(fd)


def record_read_hash16(fd):
    aichash = fd.read(16)
    return binascii.hexlify(aichash).decode('utf-8')


def record_tags(fd):
    tags = {}
    tags['TAGCOUNT'] = met_readinteger(fd)
    # print('Tags:                {}'.format(tags['TAGCOUNT']))
    for index in range(tags['TAGCOUNT']):
        filetag = fd.read(4)
        if filetag[:3] not in [b'\x02\x01\x00', b'\x03\x01\x00']:
            print('<<< Premature end of record at offset 0x{:08X}'.format(fd.tell()))
            return tags
        tagid = filetag[-1]
        if tagid == FT_FILENAME:
            tags['FT_FILENAME'] = met_readstring(fd)
        elif tagid == FT_FILESIZE:
            tags['FT_FILESIZE'] = met_readinteger(fd)
        elif tagid == FT_ATTRANSFERRED:
            tags['FT_ATTRANSFERRED'] = met_readinteger(fd)
        elif tagid == FT_ATREQUESTED:
            tags['FT_ATREQUESTED'] = met_readinteger(fd)
        elif tagid == FT_ATACCEPTED:
            tags['FT_ATACCEPTED'] = met_readinteger(fd)
        elif tagid == FT_ATTRANSFERREDHI:
            tags['FT_ATTRANSFERREDHI'] = met_readinteger(fd)
        elif tagid == FT_ULPRIORITY:
            tags['FT_ULPRIORITY'] = met_readinteger(fd)
        elif tagid == FT_KADLASTPUBLISHSRC:
            tags['FT_KADLASTPUBLISHSRC'] = met_readinteger(fd)
        elif tagid == FT_KADLASTPUBLISHNOTES:
            print('FT_KADLASTPUBLISHNOTES')
            met_readinteger(fd)
        elif tagid == FT_FLAGS:
            print('FT_FLAGS')
            met_readinteger(fd)
        elif tagid == FT_PERMISSIONS:
            print('FT_PERMISSIONS')
            met_readinteger(fd)
        elif tagid == FT_KADLASTPUBLISHKEY:
            print('FT_KADLASTPUBLISHKEY')
            met_readinteger(fd)
        elif tagid == FT_AICH_HASH:
            tags['FT_AICH_HASH'] = met_readstring(fd)
        elif tagid == FT_LASTSHARED:
            tags['FT_LASTSHARED'] =  met_readinteger(fd)
        elif tagid == FT_AICHHASHSET:
            tags['FT_AICHHASHSET'] = met_readinteger(fd, 1)
        elif tagid == FT_PARTFILENAME:
            tags['FT_PARTFILENAME'] = met_readstring(fd)
        elif tagid == FT_MEDIA_LENGTH:
            print('Media Length:        {}'.format(met_readinteger(fd)))
        elif tagid == FT_MEDIA_CODEC:
            print('Media Codec:         {}'.format(met_readstring(fd)))
        elif tagid == FT_MEDIA_BITRATE:
            print('Media Bitrate:       {}'.format(met_readinteger(fd)))
        elif tagid == FT_MEDIA_TITLE:
            print('Media Title:         {}'.format(met_readstring(fd)))
        elif tagid == FT_MEDIA_ARTIST:
            print('Media Artist:        {}'.format(met_readstring(fd)))
        elif tagid == FT_MEDIA_ALBUM:
            print('Media Album:         {}'.format(met_readstring(fd)))
        elif tagid in FT_STRING:
            print('... Reading data with tag: {}'.format(tagid))
            met_readstring(fd)
        elif tagid in FT_INT:
            print('... Reading data with tag: {}'.format(tagid))
            met_readstring(fd)
    return tags


def record_num_parts(fd):
    return met_readinteger(fd, 2)


def load_record(fd):
    met_tags = {}

    met_tags['LASTCHANGED'] = record_last_changed(fd)
    met_tags['ED2KHASH'] = record_read_hash16(fd)
    met_tags['NUMPARTS'] = record_num_parts(fd)
    partshashes = []
    for i in range(met_tags['NUMPARTS']):
        partshashes.append(record_read_hash16(fd))
    met_tags['PARTHASHES'] = partshashes
    met_tags.update(record_tags(fd))

    for field in METENTRY_FIELDS:
        if field not in met_tags:
            met_tags[field] = None
    # print(met_tags)
    metentry = MetEntry(met_tags['FT_FILENAME'],
                        met_tags['ED2KHASH'],
                        met_tags['NUMPARTS'],
                        met_tags['LASTCHANGED'],
                        met_tags['PARTHASHES'],
                        met_tags['FT_FILESIZE'],
                        met_tags['FT_ATTRANSFERRED'],
                        met_tags['FT_ATREQUESTED'],
                        met_tags['FT_ATACCEPTED'],
                        met_tags['FT_ATTRANSFERREDHI'],
                        met_tags['FT_PARTFILENAME'],
                        met_tags['FT_AICHHASHSET'],
                        met_tags['FT_AICH_HASH'],
                        met_tags['FT_ULPRIORITY'],
                        met_tags['FT_KADLASTPUBLISHSRC']
                       )
    # print(metentry)
    return metentry


def load_knownfiles(filename):
    with open(filename, 'rb') as fd:
        magic = fd.read(1)
        if os.path.basename(filename) == 'known.met':
            count = int.from_bytes(fd.read(4), byteorder='little')
            # print('Number of records:   {}'.format(count))
        if magic == HEADER_KNOWN_MET_FILE:
            for index in range(count):
                # print('>>> [{}] NEW RECORD ***'.format(index+1))
                yield load_record(fd)
        elif magic == HEADER_PART_MET_FILE:
            # print('>>> [{}] NEW RECORD ***'.format(0))
            yield load_record(fd)