#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
#
import re
import copy
import weakref
from io import BytesIO

from PIL import Image

from ppt_parser import RAGFlowPptParser
from nlp import rag_tokenizer, tokenize, is_english

from pptx import Presentation
from ordered_multimap import OrderedMultimap

def ppt_chunk(filename, binary=None, from_page=0, to_page=100000,
          lang="English", **kwargs):
    """
    The supported file formats are pptx.
    Every page will be treated as a chunk. And the thumbnail of every page will be stored.
    PPT file will be parsed by using this method automatically, setting-up for every PPT file is not necessary.
    """
    eng = lang.lower() == "english"
    doc = {
        "docnm_kwd": filename,
        "title_tks": rag_tokenizer.tokenize(re.sub(r"\.[a-zA-Z]+$", "", filename))
    }
    doc["title_sm_tks"] = rag_tokenizer.fine_grained_tokenize(doc["title_tks"])
    weakDict = weakref.WeakValueDictionary()

    ppt = Presentation(filename if not binary else BytesIO(binary))
    total_pages = len(ppt.slides)

    ppt_parser = RAGFlowPptParser()
    metadata_main_title = ''
    
    for pn, slide in enumerate(ppt.slides):
        if pn < from_page:
            continue
        if pn >= to_page:
            break

        try:
            _ = slide.shapes[0]
        except IndexError:
            continue

        text_shapes = [shape for shape in slide.shapes if shape.has_text_frame]

        if len(text_shapes) == 1:
            metadata_main_title = text_shapes[0].text_frame.text
            continue
            
        d = copy.deepcopy(doc)
        slide_text = ppt_parser(slide)
        d["page_num_int"] = [pn + 1]
        d["top_int"] = [0]
        tokenize(d, slide_text, eng)
        weakDict[d] = metadata_main_title
    return weakDict

    raise NotImplementedError(
        "file type not supported yet(pptx)")