__license__   = 'GPL v3'
__docformat__ = 'restructuredtext en'

import io
import os
from struct import unpack


class Bookmark:  # {{{
    '''
    A simple class fetching bookmark data
    Kindle-specific
    '''

    def __init__(self, path, id, book_format, bookmark_extension):
        self.book_format = book_format
        self.bookmark_extension = bookmark_extension
        self.book_length = 0
        self.id = id
        self.last_read = 0
        self.last_read_location = 0
        self.path = path
        self.timestamp = 0
        self.user_notes = None

        self.get_bookmark_data()
        self.get_book_length()
        try:
            self.percent_read = min(float(100*self.last_read / self.book_length),100)
        except Exception:
            self.percent_read = 0

    def record(self, n):
        from calibre.ebooks.metadata.mobi import StreamSlicer
        if n >= self.nrecs:
            raise ValueError(f'non-existent record {n!r}')
        offoff = 78 + (8 * n)
        start, = unpack('>I', self.data[offoff + 0:offoff + 4])
        stop = None
        if n < (self.nrecs - 1):
            stop, = unpack('>I', self.data[offoff + 8:offoff + 12])
        return StreamSlicer(self.stream, start, stop)

    def get_bookmark_data(self):
        ''' Return the timestamp and last_read_location '''
        from calibre.ebooks.metadata.mobi import StreamSlicer
        user_notes = {}
        if self.bookmark_extension == 'mbp':
            MAGIC_MOBI_CONSTANT = 150
            with open(self.path,'rb') as f:
                stream = io.BytesIO(f.read())
                data = StreamSlicer(stream)
                self.timestamp, = unpack('>I', data[0x24:0x28])
                bpar_offset, = unpack('>I', data[0x4e:0x52])
                lrlo = bpar_offset + 0x0c
                self.last_read = int(unpack('>I', data[lrlo:lrlo+4])[0])
                self.last_read_location = self.last_read // MAGIC_MOBI_CONSTANT + 1
                entries, = unpack('>I', data[0x4a:0x4e])

                # Store the annotations/locations
                bpl = bpar_offset + 4
                bpar_len, = unpack('>I', data[bpl:bpl+4])
                bpar_len += 8
                # print('bpar_len: 0x%x' % bpar_len)
                eo = bpar_offset + bpar_len

                # Walk bookmark entries
                # print(' --- %s --- ' % self.path)
                current_entry = 1
                sig = data[eo:eo+4]
                previous_block = None

                while sig == b'DATA':
                    text = None
                    entry_type = None
                    rec_len, = unpack('>I', data[eo+4:eo+8])
                    if rec_len == 0:
                        current_block = 'empty_data'
                    elif data[eo+8:eo+12] == b'EBAR':
                        current_block = 'data_header'
                        # entry_type = "data_header"
                        location, = unpack('>I', data[eo+0x34:eo+0x38])
                        # print('data_header location: %d' % location)
                    else:
                        current_block = 'text_block'
                        if previous_block == 'empty_data':
                            entry_type = 'Note'
                        elif previous_block == 'data_header':
                            entry_type = 'Highlight'
                        text = data[eo+8:eo+8+rec_len].decode('utf-16-be')

                    if entry_type:
                        displayed_location = location // MAGIC_MOBI_CONSTANT + 1
                        user_notes[location] = {'id': self.id,
                                                'displayed_location': displayed_location,
                                                'type': entry_type,
                                                'text': text}

                    eo += rec_len + 8
                    current_entry += 1
                    previous_block = current_block
                    sig = data[eo:eo+4]

                while sig == b'BKMK':
                    # Fix start location for Highlights using BKMK data
                    end_loc, = unpack('>I', data[eo+0x10:eo+0x14])

                    if end_loc in user_notes and \
                       (user_notes[end_loc]['type'] == 'Highlight' or
                        user_notes[end_loc]['type'] == 'Note'):
                        # Switch location to start (0x08:0x0c)
                        start, = unpack('>I', data[eo+8:eo+12])
                        user_notes[start] = user_notes[end_loc]
                        # print(" %s: swapping 0x%x (%d) to 0x%x (%d)" % (user_notes[end_loc]['type'],
                        #                                             end_loc,
                        #                                             end_loc/MAGIC_MOBI_CONSTANT + 1,
                        #                                             start,
                        #                                             start//MAGIC_MOBI_CONSTANT + 1))
                        user_notes[start]['displayed_location'] = start // MAGIC_MOBI_CONSTANT + 1
                        user_notes.pop(end_loc)
                    # If a bookmark coincides with a user annotation, the locs could
                    # be the same - cheat by nudging -1
                    # Skip bookmark for last_read_location
                    elif end_loc != self.last_read:
                        # print(' adding Bookmark at 0x%x (%d)' % (end_loc, end_loc/MAGIC_MOBI_CONSTANT + 1))
                        displayed_location = end_loc // MAGIC_MOBI_CONSTANT + 1
                        user_notes[end_loc - 1] = {'id': self.id,
                                                   'displayed_location': displayed_location,
                                                   'type': 'Bookmark',
                                                   'text': None}
                    rec_len, = unpack('>I', data[eo+4:eo+8])
                    eo += rec_len + 8
                    sig = data[eo:eo+4]

        elif self.bookmark_extension == 'tan':
            from calibre.ebooks.metadata.topaz import get_metadata as get_topaz_metadata

            def get_topaz_highlight(displayed_location):
                # Parse My Clippings.txt for a matching highlight
                # Search looks for book title match, highlight match, and location match
                # Author is not matched
                # This will find the first instance of a clipping only
                book_fs = self.path.replace(f'.{self.bookmark_extension}',f'.{self.book_format}')
                with open(book_fs,'rb') as f2:
                    stream = io.BytesIO(f2.read())
                    mi = get_topaz_metadata(stream)
                my_clippings = self.path
                split = my_clippings.find('documents') + len('documents/')
                my_clippings = my_clippings[:split] + 'My Clippings.txt'
                try:
                    with open(my_clippings, encoding='utf-8', errors='replace') as f2:
                        marker_found = 0
                        text = ''
                        search_str1 = f'{mi.title}'
                        search_str2 = f'- Highlight Loc. {displayed_location}'
                        for line in f2:
                            if marker_found == 0:
                                if line.startswith(search_str1):
                                    marker_found = 1
                            elif marker_found == 1:
                                if line.startswith(search_str2):
                                    marker_found = 2
                            elif marker_found == 2:
                                if line.startswith('=========='):
                                    break
                                text += line.strip()
                        else:
                            raise Exception('error')
                except Exception:
                    text = '(Unable to extract highlight text from My Clippings.txt)'
                return text

            MAGIC_TOPAZ_CONSTANT = 33.33
            self.timestamp = os.path.getmtime(self.path)
            with open(self.path,'rb') as f:
                stream = io.BytesIO(f.read())
                data = StreamSlicer(stream)
                self.last_read = int(unpack('>I', data[5:9])[0])
                self.last_read_location = self.last_read/MAGIC_TOPAZ_CONSTANT + 1
                entries, = unpack('>I', data[9:13])
                current_entry = 0
                e_base = 0x0d
                while current_entry < entries:
                    location, = unpack('>I', data[e_base+2:e_base+6])
                    text = None
                    text_len, = unpack('>I', data[e_base+0xA:e_base+0xE])
                    e_type, = unpack('>B', data[e_base+1])
                    if e_type == 0:
                        e_type = 'Bookmark'
                    elif e_type == 1:
                        e_type = 'Highlight'
                        text = get_topaz_highlight(location/MAGIC_TOPAZ_CONSTANT + 1)
                    elif e_type == 2:
                        e_type = 'Note'
                        text = data[e_base+0x10:e_base+0x10+text_len]
                    else:
                        e_type = 'Unknown annotation type'

                    displayed_location = location/MAGIC_TOPAZ_CONSTANT + 1
                    user_notes[location] = {'id': self.id,
                                            'displayed_location': displayed_location,
                                            'type': e_type,
                                            'text': text}
                    if text_len == 0xFFFFFFFF:
                        e_base = e_base + 14
                    else:
                        e_base = e_base + 14 + 2 + text_len
                    current_entry += 1
                for location in user_notes:
                    if location == self.last_read:
                        user_notes.pop(location)
                        break

        elif self.bookmark_extension == 'pdr':
            self.timestamp = os.path.getmtime(self.path)
            with open(self.path,'rb') as f:
                stream = io.BytesIO(f.read())
                data = StreamSlicer(stream)
                self.last_read = int(unpack('>I', data[5:9])[0])
                entries, = unpack('>I', data[9:13])
                current_entry = 0
                e_base = 0x0d
                self.pdf_page_offset = 0
                while current_entry < entries:
                    # location, = unpack('>I', data[e_base+2:e_base+6])
                    # text = None
                    # text_len, = unpack('>I', data[e_base+0xA:e_base+0xE])
                    # e_type, = unpack('>B', data[e_base+1])
                    # if e_type == 0:
                    #     e_type = 'Bookmark'
                    # elif e_type == 1:
                    #     e_type = 'Highlight'
                    #     text = get_topaz_highlight(location/MAGIC_TOPAZ_CONSTANT + 1)
                    # elif e_type == 2:
                    #     e_type = 'Note'
                    #     text = data[e_base+0x10:e_base+0x10+text_len]
                    # else:
                    #     e_type = 'Unknown annotation type'
                    #
                    # if self.book_format in ['tpz','azw1']:
                    #     displayed_location = location/MAGIC_TOPAZ_CONSTANT + 1
                    # elif self.book_format == 'pdf':
                    #     # *** This needs implementation
                    #     displayed_location = location
                    # user_notes[location] = dict(id=self.id,
                    #                             displayed_location=displayed_location,
                    #                             type=e_type,
                    #                             text=text)
                    # if text_len == 0xFFFFFFFF:
                    #     e_base = e_base + 14
                    # else:
                    #     e_base = e_base + 14 + 2 + text_len
                    # current_entry += 1

                    # Use label as page number
                    pdf_location, = unpack('>I', data[e_base+1:e_base+5])
                    label_len, = unpack('>H', data[e_base+5:e_base+7])
                    location = int(data[e_base+7:e_base+7+label_len])
                    displayed_location = location
                    e_type = 'Bookmark'
                    text = None
                    user_notes[location] = {'id': self.id,
                                            'displayed_location': displayed_location,
                                            'type': e_type,
                                            'text': text}
                    self.pdf_page_offset = pdf_location - location
                    e_base += (7 + label_len)
                    current_entry += 1

                self.last_read_location = self.last_read - self.pdf_page_offset

        else:
            print(f'unsupported bookmark_extension: {self.bookmark_extension}')
        self.user_notes = user_notes

    def get_book_length(self):
        from calibre.ebooks.metadata.mobi import StreamSlicer
        book_fs = self.path.replace(f'.{self.bookmark_extension}',f'.{self.book_format}')

        self.book_length = 0
        if self.bookmark_extension == 'mbp':
            # Read the book len from the header
            try:
                with open(book_fs,'rb') as f:
                    self.stream = io.BytesIO(f.read())
                    self.data = StreamSlicer(self.stream)
                    self.nrecs, = unpack('>H', self.data[76:78])
                    record0 = self.record(0)
                    self.book_length = int(unpack('>I', record0[0x04:0x08])[0])
            except Exception:
                pass
        elif self.bookmark_extension == 'tan':
            # Read bookLength from metadata
            from calibre.ebooks.metadata.topaz import MetadataUpdater
            try:
                with open(book_fs,'rb') as f:
                    mu = MetadataUpdater(f)
                    self.book_length = mu.book_length
            except Exception:
                pass
        else:
            print(f'unsupported bookmark_extension: {self.bookmark_extension}')

# }}}
