rag/app/paper.py

#  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 copy
import re
from collections import Counter

from api.db import ParserType
from deepdoc.parser import tokenize
from rag.nlp import huqie
from deepdoc.parser import PdfParser
import numpy as np
from rag.utils import num_tokens_from_string


class Pdf(PdfParser):
    def __init__(self):
        self.model_speciess = ParserType.PAPER.value
        super().__init__()

    def __call__(self, filename, binary=None, from_page=0,
                 to_page=100000, zoomin=3, callback=None):
        self.__images__(
            filename if not binary else binary,
            zoomin,
            from_page,
            to_page)
        callback(0.2, "OCR finished.")

        from timeit import default_timer as timer
        start = timer()
        self._layouts_rec(zoomin)
        callback(0.47, "Layout analysis finished")
        print("paddle layouts:", timer() - start)
        self._table_transformer_job(zoomin)
        callback(0.68, "Table analysis finished")
        self._text_merge()
        column_width = np.median([b["x1"] - b["x0"] for b in self.boxes])
        self._concat_downward(concat_between_pages=False)
        self._filter_forpages()
        callback(0.75, "Text merging finished.")
        tbls = self._extract_table_figure(True, zoomin, False)

        # clean mess
        if column_width < self.page_images[0].size[0] / zoomin / 2:
            print("two_column...................", column_width,
                  self.page_images[0].size[0] / zoomin / 2)
            self.boxes = self.sort_X_by_page(self.boxes, column_width / 2)
        for b in self.boxes:
            b["text"] = re.sub(r"([\t 　]|\u3000){2,}", " ", b["text"].strip())
        freq = Counter([b["text"] for b in self.boxes])
        garbage = set([k for k, v in freq.items() if v > self.total_page * 0.6])
        i = 0
        while i < len(self.boxes):
            if self.boxes[i]["text"] in garbage \
                    or (re.match(r"[a-zA-Z0-9]+$", self.boxes[i]["text"]) and not self.boxes[i].get("layoutno")) \
                    or (i + 1 < len(self.boxes) and self.boxes[i]["text"] == self.boxes[i + 1]["text"]):
                self.boxes.pop(i)
            elif i + 1 < len(self.boxes) and self.boxes[i].get("layoutno", '0') == self.boxes[i + 1].get("layoutno",
                                                                                                         '1'):
                # merge within same layouts
                self.boxes[i + 1]["top"] = self.boxes[i]["top"]
                self.boxes[i + 1]["x0"] = min(self.boxes[i]["x0"], self.boxes[i + 1]["x0"])
                self.boxes[i + 1]["x1"] = max(self.boxes[i]["x1"], self.boxes[i + 1]["x1"])
                self.boxes[i + 1]["text"] = self.boxes[i]["text"] + " " + self.boxes[i + 1]["text"]
                self.boxes.pop(i)
            else:
                i += 1

        def _begin(txt):
            return re.match(
                "[0-9. 一、i]*(introduction|abstract|摘要|引言|keywords|key words|关键词|background|背景|目录|前言|contents)",
                txt.lower().strip())

        if from_page > 0:
            return {
                "title":"",
                "authors": "",
                "abstract": "",
                "lines": [(b["text"] + self._line_tag(b, zoomin), b.get("layoutno", "")) for b in self.boxes[i:] if
                          re.match(r"(text|title)", b.get("layoutno", "text"))],
                "tables": tbls
            }
        # get title and authors
        title = ""
        authors = []
        i = 0
        while i < min(32, len(self.boxes)):
            b = self.boxes[i]
            i += 1
            if b.get("layoutno", "").find("title") >= 0:
                title = b["text"]
                if _begin(title):
                    title = ""
                    break
                for j in range(3):
                    if _begin(self.boxes[i + j]["text"]): break
                    authors.append(self.boxes[i + j]["text"])
                    break
                break
        # get abstract
        abstr = ""
        i = 0
        while i + 1 < min(32, len(self.boxes)):
            b = self.boxes[i]
            i += 1
            txt = b["text"].lower().strip()
            if re.match("(abstract|摘要)", txt):
                if len(txt.split(" ")) > 32 or len(txt) > 64:
                    abstr = txt + self._line_tag(b, zoomin)
                    i += 1
                    break
                txt = self.boxes[i + 1]["text"].lower().strip()
                if len(txt.split(" ")) > 32 or len(txt) > 64:
                    abstr = txt + self._line_tag(self.boxes[i + 1], zoomin)
                i += 1
                break
        if not abstr: i = 0

        callback(0.8, "Page {}~{}: Text merging finished".format(from_page, min(to_page, self.total_page)))
        for b in self.boxes: print(b["text"], b.get("layoutno"))
        print(tbls)

        return {
            "title": title if title else filename,
            "authors": " ".join(authors),
            "abstract": abstr,
            "lines": [(b["text"] + self._line_tag(b, zoomin), b.get("layoutno", "")) for b in self.boxes[i:] if
                      re.match(r"(text|title)", b.get("layoutno", "text"))],
            "tables": tbls
        }


def chunk(filename, binary=None, from_page=0, to_page=100000, callback=None, **kwargs):
    """
        Only pdf is supported.
        The abstract of the paper will be sliced as an entire chunk, and will not be sliced partly.
    """
    pdf_parser = None
    if re.search(r"\.pdf$", filename, re.IGNORECASE):
        pdf_parser = Pdf()
        paper = pdf_parser(filename if not binary else binary,
                           from_page=from_page, to_page=to_page, callback=callback)
    else: raise NotImplementedError("file type not supported yet(pdf supported)")
    doc = {"docnm_kwd": filename, "authors_tks": paper["authors"],
           "title_tks": huqie.qie(paper["title"] if paper["title"] else filename)}
    doc["title_sm_tks"] = huqie.qieqie(doc["title_tks"])
    doc["authors_sm_tks"] = huqie.qieqie(doc["authors_tks"])
    # is it English
    eng = pdf_parser.is_english
    print("It's English.....", eng)

    res = []
    # add tables
    for img, rows in paper["tables"]:
        bs = 10
        de = ";" if eng else "；"
        for i in range(0, len(rows), bs):
            d = copy.deepcopy(doc)
            r = de.join(rows[i:i + bs])
            r = re.sub(r"\t——(来自| in ).*”%s" % de, "", r)
            tokenize(d, r)
            d["image"] = img
            res.append(d)

    if paper["abstract"]:
        d = copy.deepcopy(doc)
        txt = pdf_parser.remove_tag(paper["abstract"])
        d["important_kwd"] = ["abstract", "总结", "概括", "summary", "summarize"]
        d["important_tks"] = " ".join(d["important_kwd"])
        d["image"] = pdf_parser.crop(paper["abstract"])
        tokenize(d, txt, eng)
        res.append(d)

    readed = [0] * len(paper["lines"])
    # find colon firstly
    i = 0
    while i + 1 < len(paper["lines"]):
        txt = pdf_parser.remove_tag(paper["lines"][i][0])
        j = i
        if txt.strip("\n").strip()[-1] not in ":：":
            i += 1
            continue
        i += 1
        while i < len(paper["lines"]) and not paper["lines"][i][0]:
            i += 1
        if i >= len(paper["lines"]): break
        proj = [paper["lines"][i][0].strip()]
        i += 1
        while i < len(paper["lines"]) and paper["lines"][i][0].strip()[0] == proj[-1][0]:
            proj.append(paper["lines"][i])
            i += 1
        for k in range(j, i): readed[k] = True
        txt = txt[::-1]
        if eng:
            r = re.search(r"(.*?) ([\.;?!]|$)", txt)
            txt = r.group(1)[::-1] if r else txt[::-1]
        else:
            r = re.search(r"(.*?) ([。？；！]|$)", txt)
            txt = r.group(1)[::-1] if r else txt[::-1]
        for p in proj:
            d = copy.deepcopy(doc)
            txt += "\n" + pdf_parser.remove_tag(p)
            d["image"] = pdf_parser.crop(p)
            tokenize(d, txt)
            res.append(d)

    i = 0
    chunk = []
    tk_cnt = 0
    def add_chunk():
        nonlocal chunk, res, doc, pdf_parser, tk_cnt
        d = copy.deepcopy(doc)
        ck = "\n".join(chunk)
        tokenize(d, pdf_parser.remove_tag(ck), pdf_parser.is_english)
        d["image"] = pdf_parser.crop(ck)
        res.append(d)
        chunk = []
        tk_cnt = 0

    while i < len(paper["lines"]):
        if tk_cnt > 128:
            add_chunk()
        if readed[i]:
            i += 1
            continue
        readed[i] = True
        txt, layouts = paper["lines"][i]
        txt_ = pdf_parser.remove_tag(txt)
        i += 1
        cnt = num_tokens_from_string(txt_)
        if any([
            layouts.find("title") >= 0 and chunk,
            cnt + tk_cnt > 128 and tk_cnt > 32,
        ]):
            add_chunk()
            chunk = [txt]
            tk_cnt = cnt
        else:
            chunk.append(txt)
            tk_cnt += cnt

    if chunk: add_chunk()
    for i, d in enumerate(res):
        print(d)
        # d["image"].save(f"./logs/{i}.jpg")
    return res


if __name__ == "__main__":
    import sys
    def dummy(a, b):
        pass
    chunk(sys.argv[1], callback=dummy)