ragflow/deepdoc/parser/pdf_parser.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 os
import random

import xgboost as xgb
from io import BytesIO
import torch
import re
import pdfplumber
import logging
from PIL import Image, ImageDraw
import numpy as np
from timeit import default_timer as timer
from PyPDF2 import PdfReader as pdf2_read

from api.utils.file_utils import get_project_base_directory
from deepdoc.vision import OCR, Recognizer, LayoutRecognizer, TableStructureRecognizer
from rag.nlp import rag_tokenizer
from copy import deepcopy
from huggingface_hub import snapshot_download

logging.getLogger("pdfminer").setLevel(logging.WARNING)


class RAGFlowPdfParser:
    def __init__(self):
        self.ocr = OCR()
        if hasattr(self, "model_speciess"):
            self.layouter = LayoutRecognizer("layout." + self.model_speciess)
        else:
            self.layouter = LayoutRecognizer("layout")
        self.tbl_det = TableStructureRecognizer()

        self.updown_cnt_mdl = xgb.Booster()
        if torch.cuda.is_available():
            self.updown_cnt_mdl.set_param({"device": "cuda"})
        try:
            model_dir = os.path.join(
                get_project_base_directory(),
                "rag/res/deepdoc")
            self.updown_cnt_mdl.load_model(os.path.join(
                model_dir, "updown_concat_xgb.model"))
        except Exception as e:
            model_dir = snapshot_download(
                repo_id="InfiniFlow/text_concat_xgb_v1.0",
                local_dir=os.path.join(get_project_base_directory(), "rag/res/deepdoc"),
                local_dir_use_symlinks=False)
            self.updown_cnt_mdl.load_model(os.path.join(
                model_dir, "updown_concat_xgb.model"))

        self.page_from = 0
        """
        If you have trouble downloading HuggingFace models, -_^ this might help!!

        For Linux:
        export HF_ENDPOINT=https://hf-mirror.com

        For Windows:
        Good luck
        ^_-

        """

    def __char_width(self, c):
        return (c["x1"] - c["x0"]) // max(len(c["text"]), 1)

    def __height(self, c):
        return c["bottom"] - c["top"]

    def _x_dis(self, a, b):
        return min(abs(a["x1"] - b["x0"]), abs(a["x0"] - b["x1"]),
                   abs(a["x0"] + a["x1"] - b["x0"] - b["x1"]) / 2)

    def _y_dis(
            self, a, b):
        return (
                       b["top"] + b["bottom"] - a["top"] - a["bottom"]) / 2

    def _match_proj(self, b):
        proj_patt = [
            r"第[零一二三四五六七八九十百]+章",
            r"第[零一二三四五六七八九十百]+[条节]",
            r"[零一二三四五六七八九十百]+[、是 　]",
            r"[\(（][零一二三四五六七八九十百]+[）\)]",
            r"[\(（][0-9]+[）\)]",
            r"[0-9]+(、|\.[　 ]|）|\.[^0-9./a-zA-Z_%><-]{4,})",
            r"[0-9]+\.[0-9.]+(、|\.[ 　])",
            r"[⚫•➢①② ]",
        ]
        return any([re.match(p, b["text"]) for p in proj_patt])

    def _updown_concat_features(self, up, down):
        w = max(self.__char_width(up), self.__char_width(down))
        h = max(self.__height(up), self.__height(down))
        y_dis = self._y_dis(up, down)
        LEN = 6
        tks_down = rag_tokenizer.tokenize(down["text"][:LEN]).split(" ")
        tks_up = rag_tokenizer.tokenize(up["text"][-LEN:]).split(" ")
        tks_all = up["text"][-LEN:].strip() \
                  + (" " if re.match(r"[a-zA-Z0-9]+",
                                     up["text"][-1] + down["text"][0]) else "") \
                  + down["text"][:LEN].strip()
        tks_all = rag_tokenizer.tokenize(tks_all).split(" ")
        fea = [
            up.get("R", -1) == down.get("R", -1),
            y_dis / h,
            down["page_number"] - up["page_number"],
            up["layout_type"] == down["layout_type"],
            up["layout_type"] == "text",
            down["layout_type"] == "text",
            up["layout_type"] == "table",
            down["layout_type"] == "table",
            True if re.search(
                r"([。？！；!?;+)）]|[a-z]\.)$",
                up["text"]) else False,
            True if re.search(r"[，：‘“、0-9（+-]$", up["text"]) else False,
            True if re.search(
                r"(^.?[/,?;:\]，。；：’”？！》】）-])",
                down["text"]) else False,
            True if re.match(r"[\(（][^\(\)（）]+[）\)]$", up["text"]) else False,
            True if re.search(r"[，,][^。.]+$", up["text"]) else False,
            True if re.search(r"[，,][^。.]+$", up["text"]) else False,
            True if re.search(r"[\(（][^\)）]+$", up["text"])
                    and re.search(r"[\)）]", down["text"]) else False,
            self._match_proj(down),
            True if re.match(r"[A-Z]", down["text"]) else False,
            True if re.match(r"[A-Z]", up["text"][-1]) else False,
            True if re.match(r"[a-z0-9]", up["text"][-1]) else False,
            True if re.match(r"[0-9.%,-]+$", down["text"]) else False,
            up["text"].strip()[-2:] == down["text"].strip()[-2:] if len(up["text"].strip()
                                                                        ) > 1 and len(
                down["text"].strip()) > 1 else False,
            up["x0"] > down["x1"],
            abs(self.__height(up) - self.__height(down)) / min(self.__height(up),
                                                               self.__height(down)),
            self._x_dis(up, down) / max(w, 0.000001),
            (len(up["text"]) - len(down["text"])) /
            max(len(up["text"]), len(down["text"])),
            len(tks_all) - len(tks_up) - len(tks_down),
            len(tks_down) - len(tks_up),
            tks_down[-1] == tks_up[-1],
            max(down["in_row"], up["in_row"]),
            abs(down["in_row"] - up["in_row"]),
            len(tks_down) == 1 and rag_tokenizer.tag(tks_down[0]).find("n") >= 0,
            len(tks_up) == 1 and rag_tokenizer.tag(tks_up[0]).find("n") >= 0
        ]
        return fea

    @staticmethod
    def sort_X_by_page(arr, threashold):
        # sort using y1 first and then x1
        arr = sorted(arr, key=lambda r: (r["page_number"], r["x0"], r["top"]))
        for i in range(len(arr) - 1):
            for j in range(i, -1, -1):
                # restore the order using th
                if abs(arr[j + 1]["x0"] - arr[j]["x0"]) < threashold \
                        and arr[j + 1]["top"] < arr[j]["top"] \
                        and arr[j + 1]["page_number"] == arr[j]["page_number"]:
                    tmp = arr[j]
                    arr[j] = arr[j + 1]
                    arr[j + 1] = tmp
        return arr

    def _has_color(self, o):
        if o.get("ncs", "") == "DeviceGray":
            if o["stroking_color"] and o["stroking_color"][0] == 1 and o["non_stroking_color"] and \
                    o["non_stroking_color"][0] == 1:
                if re.match(r"[a-zT_\[\]\(\)-]+", o.get("text", "")):
                    return False
        return True

    def _table_transformer_job(self, ZM):
        logging.info("Table processing...")
        imgs, pos = [], []
        tbcnt = [0]
        MARGIN = 10
        self.tb_cpns = []
        assert len(self.page_layout) == len(self.page_images)
        for p, tbls in enumerate(self.page_layout):  # for page
            tbls = [f for f in tbls if f["type"] == "table"]
            tbcnt.append(len(tbls))
            if not tbls:
                continue
            for tb in tbls:  # for table
                left, top, right, bott = tb["x0"] - MARGIN, tb["top"] - MARGIN, \
                                         tb["x1"] + MARGIN, tb["bottom"] + MARGIN
                left *= ZM
                top *= ZM
                right *= ZM
                bott *= ZM
                pos.append((left, top))
                imgs.append(self.page_images[p].crop((left, top, right, bott)))

        assert len(self.page_images) == len(tbcnt) - 1
        if not imgs:
            return
        recos = self.tbl_det(imgs)
        tbcnt = np.cumsum(tbcnt)
        for i in range(len(tbcnt) - 1):  # for page
            pg = []
            for j, tb_items in enumerate(
                    recos[tbcnt[i]: tbcnt[i + 1]]):  # for table
                poss = pos[tbcnt[i]: tbcnt[i + 1]]
                for it in tb_items:  # for table components
                    it["x0"] = (it["x0"] + poss[j][0])
                    it["x1"] = (it["x1"] + poss[j][0])
                    it["top"] = (it["top"] + poss[j][1])
                    it["bottom"] = (it["bottom"] + poss[j][1])
                    for n in ["x0", "x1", "top", "bottom"]:
                        it[n] /= ZM
                    it["top"] += self.page_cum_height[i]
                    it["bottom"] += self.page_cum_height[i]
                    it["pn"] = i
                    it["layoutno"] = j
                    pg.append(it)
            self.tb_cpns.extend(pg)

        def gather(kwd, fzy=10, ption=0.6):
            eles = Recognizer.sort_Y_firstly(
                [r for r in self.tb_cpns if re.match(kwd, r["label"])], fzy)
            eles = Recognizer.layouts_cleanup(self.boxes, eles, 5, ption)
            return Recognizer.sort_Y_firstly(eles, 0)

        # add R,H,C,SP tag to boxes within table layout
        headers = gather(r".*header$")
        rows = gather(r".* (row|header)")
        spans = gather(r".*spanning")
        clmns = sorted([r for r in self.tb_cpns if re.match(
            r"table column$", r["label"])], key=lambda x: (x["pn"], x["layoutno"], x["x0"]))
        clmns = Recognizer.layouts_cleanup(self.boxes, clmns, 5, 0.5)
        for b in self.boxes:
            if b.get("layout_type", "") != "table":
                continue
            ii = Recognizer.find_overlapped_with_threashold(b, rows, thr=0.3)
            if ii is not None:
                b["R"] = ii
                b["R_top"] = rows[ii]["top"]
                b["R_bott"] = rows[ii]["bottom"]

            ii = Recognizer.find_overlapped_with_threashold(
                b, headers, thr=0.3)
            if ii is not None:
                b["H_top"] = headers[ii]["top"]
                b["H_bott"] = headers[ii]["bottom"]
                b["H_left"] = headers[ii]["x0"]
                b["H_right"] = headers[ii]["x1"]
                b["H"] = ii

            ii = Recognizer.find_horizontally_tightest_fit(b, clmns)
            if ii is not None:
                b["C"] = ii
                b["C_left"] = clmns[ii]["x0"]
                b["C_right"] = clmns[ii]["x1"]

            ii = Recognizer.find_overlapped_with_threashold(b, spans, thr=0.3)
            if ii is not None:
                b["H_top"] = spans[ii]["top"]
                b["H_bott"] = spans[ii]["bottom"]
                b["H_left"] = spans[ii]["x0"]
                b["H_right"] = spans[ii]["x1"]
                b["SP"] = ii

    def __ocr(self, pagenum, img, chars, ZM=3):
        bxs = self.ocr.detect(np.array(img))
        if not bxs:
            self.boxes.append([])
            return
        bxs = [(line[0], line[1][0]) for line in bxs]
        bxs = Recognizer.sort_Y_firstly(
            [{"x0": b[0][0] / ZM, "x1": b[1][0] / ZM,
              "top": b[0][1] / ZM, "text": "", "txt": t,
              "bottom": b[-1][1] / ZM,
              "page_number": pagenum} for b, t in bxs if b[0][0] <= b[1][0] and b[0][1] <= b[-1][1]],
            self.mean_height[-1] / 3
        )

        # solve char content confusion
        record_error_length, ct = 0, 1
        for c in chars[0:128]:
            ii = Recognizer.find_overlapped(c, bxs)
            if ii is None:
                continue
            record_error_length += abs((bxs[ii]["bottom"] + bxs[ii]["top"] - c["bottom"] - c["top"]) / 2)
            ct += 1

        record_error_length = record_error_length / ct
        for char in chars:
            char["top"] -= record_error_length
            char["bottom"] -= record_error_length
        
        # merge chars in the same rect
        for c in Recognizer.sort_X_firstly(
                chars, self.mean_width[pagenum - 1] // 4):
            ii = Recognizer.find_overlapped(c, bxs)
            if ii is None:
                self.lefted_chars.append(c)
                continue
            ch = c["bottom"] - c["top"]
            bh = bxs[ii]["bottom"] - bxs[ii]["top"]
            if abs(ch - bh) / max(ch, bh) >= 0.7 and c["text"] != ' ':
                self.lefted_chars.append(c)
                continue
            if c["text"] == " " and bxs[ii]["text"]:
                if re.match(r"[0-9a-zA-Z,.?;:!%%]", bxs[ii]["text"][-1]):
                    bxs[ii]["text"] += " "
            else:
                bxs[ii]["text"] += c["text"]

        for b in bxs:
            if not b["text"]:
                left, right, top, bott = b["x0"] * ZM, b["x1"] * \
                                         ZM, b["top"] * ZM, b["bottom"] * ZM
                b["text"] = self.ocr.recognize(np.array(img),
                                               np.array([[left, top], [right, top], [right, bott], [left, bott]],
                                                        dtype=np.float32))
            del b["txt"]
        bxs = [b for b in bxs if b["text"]]
        if self.mean_height[-1] == 0:
            self.mean_height[-1] = np.median([b["bottom"] - b["top"]
                                              for b in bxs])
        self.boxes.append(bxs)

    def _layouts_rec(self, ZM, drop=True):
        assert len(self.page_images) == len(self.boxes)
        self.boxes, self.page_layout = self.layouter(
            self.page_images, self.boxes, ZM, drop=drop)
        # cumlative Y
        for i in range(len(self.boxes)):
            self.boxes[i]["top"] += \
                self.page_cum_height[self.boxes[i]["page_number"] - 1]
            self.boxes[i]["bottom"] += \
                self.page_cum_height[self.boxes[i]["page_number"] - 1]

    def _text_merge(self):
        # merge adjusted boxes
        bxs = self.boxes

        def end_with(b, txt):
            txt = txt.strip()
            tt = b.get("text", "").strip()
            return tt and tt.find(txt) == len(tt) - len(txt)

        def start_with(b, txts):
            tt = b.get("text", "").strip()
            return tt and any([tt.find(t.strip()) == 0 for t in txts])

        # horizontally merge adjacent box with the same layout
        i = 0
        while i < len(bxs) - 1:
            b = bxs[i]
            b_ = bxs[i + 1]
            if b.get("layoutno", "0") != b_.get("layoutno", "1") or b.get("layout_type", "") in ["table", "figure",
                                                                                                 "equation"]:
                i += 1
                continue
            if abs(self._y_dis(b, b_)
                   ) < self.mean_height[bxs[i]["page_number"] - 1] / 3:
                # merge
                bxs[i]["x1"] = b_["x1"]
                bxs[i]["top"] = (b["top"] + b_["top"]) / 2
                bxs[i]["bottom"] = (b["bottom"] + b_["bottom"]) / 2
                bxs[i]["text"] += b_["text"]
                bxs.pop(i + 1)
                continue
            i += 1
            continue

            dis_thr = 1
            dis = b["x1"] - b_["x0"]
            if b.get("layout_type", "") != "text" or b_.get(
                    "layout_type", "") != "text":
                if end_with(b, "，") or start_with(b_, "（，"):
                    dis_thr = -8
                else:
                    i += 1
                    continue

            if abs(self._y_dis(b, b_)) < self.mean_height[bxs[i]["page_number"] - 1] / 5 \
                    and dis >= dis_thr and b["x1"] < b_["x1"]:
                # merge
                bxs[i]["x1"] = b_["x1"]
                bxs[i]["top"] = (b["top"] + b_["top"]) / 2
                bxs[i]["bottom"] = (b["bottom"] + b_["bottom"]) / 2
                bxs[i]["text"] += b_["text"]
                bxs.pop(i + 1)
                continue
            i += 1
        self.boxes = bxs

    def _naive_vertical_merge(self):
        bxs = Recognizer.sort_Y_firstly(
            self.boxes, np.median(
                self.mean_height) / 3)
        i = 0
        while i + 1 < len(bxs):
            b = bxs[i]
            b_ = bxs[i + 1]
            if b["page_number"] < b_["page_number"] and re.match(
                    r"[0-9  •一—-]+$", b["text"]):
                bxs.pop(i)
                continue
            if not b["text"].strip():
                bxs.pop(i)
                continue
            concatting_feats = [
                b["text"].strip()[-1] in ",;:'\"，、‘“；：-",
                len(b["text"].strip()) > 1 and b["text"].strip(
                )[-2] in ",;:'\"，‘“、；：",
                b_["text"].strip() and b_["text"].strip()[0] in "。；？！?”）),，、：",
            ]
            # features for not concating
            feats = [
                b.get("layoutno", 0) != b_.get("layoutno", 0),
                b["text"].strip()[-1] in "。？！?",
                self.is_english and b["text"].strip()[-1] in ".!?",
                b["page_number"] == b_["page_number"] and b_["top"] -
                b["bottom"] > self.mean_height[b["page_number"] - 1] * 1.5,
                b["page_number"] < b_["page_number"] and abs(
                    b["x0"] - b_["x0"]) > self.mean_width[b["page_number"] - 1] * 4,
            ]
            # split features
            detach_feats = [b["x1"] < b_["x0"],
                            b["x0"] > b_["x1"]]
            if (any(feats) and not any(concatting_feats)) or any(detach_feats):
                print(
                    b["text"],
                    b_["text"],
                    any(feats),
                    any(concatting_feats),
                    any(detach_feats))
                i += 1
                continue
            # merge up and down
            b["bottom"] = b_["bottom"]
            b["text"] += b_["text"]
            b["x0"] = min(b["x0"], b_["x0"])
            b["x1"] = max(b["x1"], b_["x1"])
            bxs.pop(i + 1)
        self.boxes = bxs

    def _concat_downward(self, concat_between_pages=True):
        # count boxes in the same row as a feature
        for i in range(len(self.boxes)):
            mh = self.mean_height[self.boxes[i]["page_number"] - 1]
            self.boxes[i]["in_row"] = 0
            j = max(0, i - 12)
            while j < min(i + 12, len(self.boxes)):
                if j == i:
                    j += 1
                    continue
                ydis = self._y_dis(self.boxes[i], self.boxes[j]) / mh
                if abs(ydis) < 1:
                    self.boxes[i]["in_row"] += 1
                elif ydis > 0:
                    break
                j += 1

        # concat between rows
        boxes = deepcopy(self.boxes)
        blocks = []
        while boxes:
            chunks = []

            def dfs(up, dp):
                chunks.append(up)
                i = dp
                while i < min(dp + 12, len(boxes)):
                    ydis = self._y_dis(up, boxes[i])
                    smpg = up["page_number"] == boxes[i]["page_number"]
                    mh = self.mean_height[up["page_number"] - 1]
                    mw = self.mean_width[up["page_number"] - 1]
                    if smpg and ydis > mh * 4:
                        break
                    if not smpg and ydis > mh * 16:
                        break
                    down = boxes[i]
                    if not concat_between_pages and down["page_number"] > up["page_number"]:
                        break

                    if up.get("R", "") != down.get(
                            "R", "") and up["text"][-1] != "，":
                        i += 1
                        continue

                    if re.match(r"[0-9]{2,3}/[0-9]{3}$", up["text"]) \
                            or re.match(r"[0-9]{2,3}/[0-9]{3}$", down["text"]) \
                            or not down["text"].strip():
                        i += 1
                        continue

                    if not down["text"].strip():
                        i += 1
                        continue

                    if up["x1"] < down["x0"] - 10 * \
                            mw or up["x0"] > down["x1"] + 10 * mw:
                        i += 1
                        continue

                    if i - dp < 5 and up.get("layout_type") == "text":
                        if up.get("layoutno", "1") == down.get(
                                "layoutno", "2"):
                            dfs(down, i + 1)
                            boxes.pop(i)
                            return
                        i += 1
                        continue

                    fea = self._updown_concat_features(up, down)
                    if self.updown_cnt_mdl.predict(
                            xgb.DMatrix([fea]))[0] <= 0.5:
                        i += 1
                        continue
                    dfs(down, i + 1)
                    boxes.pop(i)
                    return

            dfs(boxes[0], 1)
            boxes.pop(0)
            if chunks:
                blocks.append(chunks)

        # concat within each block
        boxes = []
        for b in blocks:
            if len(b) == 1:
                boxes.append(b[0])
                continue
            t = b[0]
            for c in b[1:]:
                t["text"] = t["text"].strip()
                c["text"] = c["text"].strip()
                if not c["text"]:
                    continue
                if t["text"] and re.match(
                        r"[0-9\.a-zA-Z]+$", t["text"][-1] + c["text"][-1]):
                    t["text"] += " "
                t["text"] += c["text"]
                t["x0"] = min(t["x0"], c["x0"])
                t["x1"] = max(t["x1"], c["x1"])
                t["page_number"] = min(t["page_number"], c["page_number"])
                t["bottom"] = c["bottom"]
                if not t["layout_type"] \
                        and c["layout_type"]:
                    t["layout_type"] = c["layout_type"]
            boxes.append(t)

        self.boxes = Recognizer.sort_Y_firstly(boxes, 0)

    def _filter_forpages(self):
        if not self.boxes:
            return
        findit = False
        i = 0
        while i < len(self.boxes):
            if not re.match(r"(contents|目录|目次|table of contents|致谢|acknowledge)$",
                            re.sub(r"( | |\u3000)+", "", self.boxes[i]["text"].lower())):
                i += 1
                continue
            findit = True
            eng = re.match(
                r"[0-9a-zA-Z :'.-]{5,}",
                self.boxes[i]["text"].strip())
            self.boxes.pop(i)
            if i >= len(self.boxes):
                break
            prefix = self.boxes[i]["text"].strip()[:3] if not eng else " ".join(
                self.boxes[i]["text"].strip().split(" ")[:2])
            while not prefix:
                self.boxes.pop(i)
                if i >= len(self.boxes):
                    break
                prefix = self.boxes[i]["text"].strip()[:3] if not eng else " ".join(
                    self.boxes[i]["text"].strip().split(" ")[:2])
            self.boxes.pop(i)
            if i >= len(self.boxes) or not prefix:
                break
            for j in range(i, min(i + 128, len(self.boxes))):
                if not re.match(prefix, self.boxes[j]["text"]):
                    continue
                for k in range(i, j):
                    self.boxes.pop(i)
                break
        if findit:
            return

        page_dirty = [0] * len(self.page_images)
        for b in self.boxes:
            if re.search(r"(··|··|··)", b["text"]):
                page_dirty[b["page_number"] - 1] += 1
        page_dirty = set([i + 1 for i, t in enumerate(page_dirty) if t > 3])
        if not page_dirty:
            return
        i = 0
        while i < len(self.boxes):
            if self.boxes[i]["page_number"] in page_dirty:
                self.boxes.pop(i)
                continue
            i += 1

    def _merge_with_same_bullet(self):
        i = 0
        while i + 1 < len(self.boxes):
            b = self.boxes[i]
            b_ = self.boxes[i + 1]
            if not b["text"].strip():
                self.boxes.pop(i)
                continue
            if not b_["text"].strip():
                self.boxes.pop(i + 1)
                continue

            if b["text"].strip()[0] != b_["text"].strip()[0] \
                    or b["text"].strip()[0].lower() in set("qwertyuopasdfghjklzxcvbnm") \
                    or rag_tokenizer.is_chinese(b["text"].strip()[0]) \
                    or b["top"] > b_["bottom"]:
                i += 1
                continue
            b_["text"] = b["text"] + "\n" + b_["text"]
            b_["x0"] = min(b["x0"], b_["x0"])
            b_["x1"] = max(b["x1"], b_["x1"])
            b_["top"] = b["top"]
            self.boxes.pop(i)

    def _extract_table_figure(self, need_image, ZM,
                              return_html, need_position):
        tables = {}
        figures = {}
        # extract figure and table boxes
        i = 0
        lst_lout_no = ""
        nomerge_lout_no = []
        while i < len(self.boxes):
            if "layoutno" not in self.boxes[i]:
                i += 1
                continue
            lout_no = str(self.boxes[i]["page_number"]) + \
                      "-" + str(self.boxes[i]["layoutno"])
            if TableStructureRecognizer.is_caption(self.boxes[i]) or self.boxes[i]["layout_type"] in ["table caption",
                                                                                                      "title",
                                                                                                      "figure caption",
                                                                                                      "reference"]:
                nomerge_lout_no.append(lst_lout_no)
            if self.boxes[i]["layout_type"] == "table":
                if re.match(r"(数据|资料|图表)*来源[:： ]", self.boxes[i]["text"]):
                    self.boxes.pop(i)
                    continue
                if lout_no not in tables:
                    tables[lout_no] = []
                tables[lout_no].append(self.boxes[i])
                self.boxes.pop(i)
                lst_lout_no = lout_no
                continue
            if need_image and self.boxes[i]["layout_type"] == "figure":
                if re.match(r"(数据|资料|图表)*来源[:： ]", self.boxes[i]["text"]):
                    self.boxes.pop(i)
                    continue
                if lout_no not in figures:
                    figures[lout_no] = []
                figures[lout_no].append(self.boxes[i])
                self.boxes.pop(i)
                lst_lout_no = lout_no
                continue
            i += 1

        # merge table on different pages
        nomerge_lout_no = set(nomerge_lout_no)
        tbls = sorted([(k, bxs) for k, bxs in tables.items()],
                      key=lambda x: (x[1][0]["top"], x[1][0]["x0"]))

        i = len(tbls) - 1
        while i - 1 >= 0:
            k0, bxs0 = tbls[i - 1]
            k, bxs = tbls[i]
            i -= 1
            if k0 in nomerge_lout_no:
                continue
            if bxs[0]["page_number"] == bxs0[0]["page_number"]:
                continue
            if bxs[0]["page_number"] - bxs0[0]["page_number"] > 1:
                continue
            mh = self.mean_height[bxs[0]["page_number"] - 1]
            if self._y_dis(bxs0[-1], bxs[0]) > mh * 23:
                continue
            tables[k0].extend(tables[k])
            del tables[k]

        def x_overlapped(a, b):
            return not any([a["x1"] < b["x0"], a["x0"] > b["x1"]])

        # find captions and pop out
        i = 0
        while i < len(self.boxes):
            c = self.boxes[i]
            # mh = self.mean_height[c["page_number"]-1]
            if not TableStructureRecognizer.is_caption(c):
                i += 1
                continue

            # find the nearest layouts
            def nearest(tbls):
                nonlocal c
                mink = ""
                minv = 1000000000
                for k, bxs in tbls.items():
                    for b in bxs:
                        if b.get("layout_type", "").find("caption") >= 0:
                            continue
                        y_dis = self._y_dis(c, b)
                        x_dis = self._x_dis(
                            c, b) if not x_overlapped(
                            c, b) else 0
                        dis = y_dis * y_dis + x_dis * x_dis
                        if dis < minv:
                            mink = k
                            minv = dis
                return mink, minv

            tk, tv = nearest(tables)
            fk, fv = nearest(figures)
            # if min(tv, fv) > 2000:
            #    i += 1
            #    continue
            if tv < fv and tk:
                tables[tk].insert(0, c)
                logging.debug(
                    "TABLE:" +
                    self.boxes[i]["text"] +
                    "; Cap: " +
                    tk)
            elif fk:
                figures[fk].insert(0, c)
                logging.debug(
                    "FIGURE:" +
                    self.boxes[i]["text"] +
                    "; Cap: " +
                    tk)
            self.boxes.pop(i)

        res = []
        positions = []

        def cropout(bxs, ltype, poss):
            nonlocal ZM
            pn = set([b["page_number"] - 1 for b in bxs])
            if len(pn) < 2:
                pn = list(pn)[0]
                ht = self.page_cum_height[pn]
                b = {
                    "x0": np.min([b["x0"] for b in bxs]),
                    "top": np.min([b["top"] for b in bxs]) - ht,
                    "x1": np.max([b["x1"] for b in bxs]),
                    "bottom": np.max([b["bottom"] for b in bxs]) - ht
                }
                louts = [l for l in self.page_layout[pn] if l["type"] == ltype]
                ii = Recognizer.find_overlapped(b, louts, naive=True)
                if ii is not None:
                    b = louts[ii]
                else:
                    logging.warn(
                        f"Missing layout match: {pn + 1},%s" %
                        (bxs[0].get(
                            "layoutno", "")))

                left, top, right, bott = b["x0"], b["top"], b["x1"], b["bottom"]
                if right < left: right = left + 1
                poss.append((pn + self.page_from, left, right, top, bott))
                return self.page_images[pn] \
                    .crop((left * ZM, top * ZM,
                           right * ZM, bott * ZM))
            pn = {}
            for b in bxs:
                p = b["page_number"] - 1
                if p not in pn:
                    pn[p] = []
                pn[p].append(b)
            pn = sorted(pn.items(), key=lambda x: x[0])
            imgs = [cropout(arr, ltype, poss) for p, arr in pn]
            pic = Image.new("RGB",
                            (int(np.max([i.size[0] for i in imgs])),
                             int(np.sum([m.size[1] for m in imgs]))),
                            (245, 245, 245))
            height = 0
            for img in imgs:
                pic.paste(img, (0, int(height)))
                height += img.size[1]
            return pic

        # crop figure out and add caption
        for k, bxs in figures.items():
            txt = "\n".join([b["text"] for b in bxs])
            if not txt:
                continue

            poss = []
            res.append(
                (cropout(
                    bxs,
                    "figure", poss),
                 [txt]))
            positions.append(poss)

        for k, bxs in tables.items():
            if not bxs:
                continue
            bxs = Recognizer.sort_Y_firstly(bxs, np.mean(
                [(b["bottom"] - b["top"]) / 2 for b in bxs]))
            poss = []
            res.append((cropout(bxs, "table", poss),
                        self.tbl_det.construct_table(bxs, html=return_html, is_english=self.is_english)))
            positions.append(poss)

        assert len(positions) == len(res)

        if need_position:
            return list(zip(res, positions))
        return res

    def proj_match(self, line):
        if len(line) <= 2:
            return
        if re.match(r"[0-9 ().,%%+/-]+$", line):
            return False
        for p, j in [
            (r"第[零一二三四五六七八九十百]+章", 1),
            (r"第[零一二三四五六七八九十百]+[条节]", 2),
            (r"[零一二三四五六七八九十百]+[、 　]", 3),
            (r"[\(（][零一二三四五六七八九十百]+[）\)]", 4),
            (r"[0-9]+(、|\.[　 ]|\.[^0-9])", 5),
            (r"[0-9]+\.[0-9]+(、|[. 　]|[^0-9])", 6),
            (r"[0-9]+\.[0-9]+\.[0-9]+(、|[ 　]|[^0-9])", 7),
            (r"[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+(、|[ 　]|[^0-9])", 8),
            (r".{,48}[：:?？]$", 9),
            (r"[0-9]+）", 10),
            (r"[\(（][0-9]+[）\)]", 11),
            (r"[零一二三四五六七八九十百]+是", 12),
            (r"[⚫•➢✓]", 12)
        ]:
            if re.match(p, line):
                return j
        return

    def _line_tag(self, bx, ZM):
        pn = [bx["page_number"]]
        top = bx["top"] - self.page_cum_height[pn[0] - 1]
        bott = bx["bottom"] - self.page_cum_height[pn[0] - 1]
        page_images_cnt = len(self.page_images)
        if pn[-1] - 1 >= page_images_cnt: return ""
        while bott * ZM > self.page_images[pn[-1] - 1].size[1]:
            bott -= self.page_images[pn[-1] - 1].size[1] / ZM
            pn.append(pn[-1] + 1)
            if pn[-1] - 1 >= page_images_cnt:
                return ""

        return "@@{}\t{:.1f}\t{:.1f}\t{:.1f}\t{:.1f}##" \
            .format("-".join([str(p) for p in pn]),
                    bx["x0"], bx["x1"], top, bott)

    def __filterout_scraps(self, boxes, ZM):

        def width(b):
            return b["x1"] - b["x0"]

        def height(b):
            return b["bottom"] - b["top"]

        def usefull(b):
            if b.get("layout_type"):
                return True
            if width(
                    b) > self.page_images[b["page_number"] - 1].size[0] / ZM / 3:
                return True
            if b["bottom"] - b["top"] > self.mean_height[b["page_number"] - 1]:
                return True
            return False

        res = []
        while boxes:
            lines = []
            widths = []
            pw = self.page_images[boxes[0]["page_number"] - 1].size[0] / ZM
            mh = self.mean_height[boxes[0]["page_number"] - 1]
            mj = self.proj_match(
                boxes[0]["text"]) or boxes[0].get(
                "layout_type",
                "") == "title"

            def dfs(line, st):
                nonlocal mh, pw, lines, widths
                lines.append(line)
                widths.append(width(line))
                width_mean = np.mean(widths)
                mmj = self.proj_match(
                    line["text"]) or line.get(
                    "layout_type",
                    "") == "title"
                for i in range(st + 1, min(st + 20, len(boxes))):
                    if (boxes[i]["page_number"] - line["page_number"]) > 0:
                        break
                    if not mmj and self._y_dis(
                            line, boxes[i]) >= 3 * mh and height(line) < 1.5 * mh:
                        break

                    if not usefull(boxes[i]):
                        continue
                    if mmj or \
                            (self._x_dis(boxes[i], line) < pw / 10): \
                            # and abs(width(boxes[i])-width_mean)/max(width(boxes[i]),width_mean)<0.5):
                        # concat following
                        dfs(boxes[i], i)
                        boxes.pop(i)
                        break

            try:
                if usefull(boxes[0]):
                    dfs(boxes[0], 0)
                else:
                    logging.debug("WASTE: " + boxes[0]["text"])
            except Exception as e:
                pass
            boxes.pop(0)
            mw = np.mean(widths)
            if mj or mw / pw >= 0.35 or mw > 200:
                res.append(
                    "\n".join([c["text"] + self._line_tag(c, ZM) for c in lines]))
            else:
                logging.debug("REMOVED: " +
                              "<<".join([c["text"] for c in lines]))

        return "\n\n".join(res)

    @staticmethod
    def total_page_number(fnm, binary=None):
        try:
            pdf = pdfplumber.open(
                fnm) if not binary else pdfplumber.open(BytesIO(binary))
            return len(pdf.pages)
        except Exception as e:
            logging.error(str(e))

    def __images__(self, fnm, zoomin=3, page_from=0,
                   page_to=299, callback=None):
        self.lefted_chars = []
        self.mean_height = []
        self.mean_width = []
        self.boxes = []
        self.garbages = {}
        self.page_cum_height = [0]
        self.page_layout = []
        self.page_from = page_from
        st = timer()
        try:
            self.pdf = pdfplumber.open(fnm) if isinstance(
                fnm, str) else pdfplumber.open(BytesIO(fnm))
            self.page_images = [p.to_image(resolution=72 * zoomin).annotated for i, p in
                                enumerate(self.pdf.pages[page_from:page_to])]
            self.page_chars = [[{**c, 'top': max(0, c['top'] - 10), 'bottom': max(0, c['bottom'] - 10)} for c in page.chars if self._has_color(c)] for page in
                               self.pdf.pages[page_from:page_to]]
            self.total_page = len(self.pdf.pages)
        except Exception as e:
            logging.error(str(e))

        self.outlines = []
        try:
            self.pdf = pdf2_read(fnm if isinstance(fnm, str) else BytesIO(fnm))
            outlines = self.pdf.outline

            def dfs(arr, depth):
                for a in arr:
                    if isinstance(a, dict):
                        self.outlines.append((a["/Title"], depth))
                        continue
                    dfs(a, depth + 1)

            dfs(outlines, 0)
        except Exception as e:
            logging.warning(f"Outlines exception: {e}")
        if not self.outlines:
            logging.warning(f"Miss outlines")

        logging.info("Images converted.")
        self.is_english = [re.search(r"[a-zA-Z0-9,/¸;:'\[\]\(\)!@#$%^&*\"?<>._-]{30,}", "".join(
            random.choices([c["text"] for c in self.page_chars[i]], k=min(100, len(self.page_chars[i]))))) for i in
                           range(len(self.page_chars))]
        if sum([1 if e else 0 for e in self.is_english]) > len(
                self.page_images) / 2:
            self.is_english = True
        else:
            self.is_english = False
        self.is_english = False

        st = timer()
        for i, img in enumerate(self.page_images):
            chars = self.page_chars[i] if not self.is_english else []
            self.mean_height.append(
                np.median(sorted([c["height"] for c in chars])) if chars else 0
            )
            self.mean_width.append(
                np.median(sorted([c["width"] for c in chars])) if chars else 8
            )
            self.page_cum_height.append(img.size[1] / zoomin)
            j = 0
            while j + 1 < len(chars):
                if chars[j]["text"] and chars[j + 1]["text"] \
                        and re.match(r"[0-9a-zA-Z,.:;!%]+", chars[j]["text"] + chars[j + 1]["text"]) \
                        and chars[j + 1]["x0"] - chars[j]["x1"] >= min(chars[j + 1]["width"],
                                                                       chars[j]["width"]) / 2:
                    chars[j]["text"] += " "
                j += 1

            self.__ocr(i + 1, img, chars, zoomin)
            if callback and i % 6 == 5:
                callback(prog=(i + 1) * 0.6 / len(self.page_images), msg="")
        # print("OCR:", timer()-st)

        if not self.is_english and not any(
                [c for c in self.page_chars]) and self.boxes:
            bxes = [b for bxs in self.boxes for b in bxs]
            self.is_english = re.search(r"[\na-zA-Z0-9,/¸;:'\[\]\(\)!@#$%^&*\"?<>._-]{30,}",
                                        "".join([b["text"] for b in random.choices(bxes, k=min(30, len(bxes)))]))

        logging.info("Is it English:", self.is_english)

        self.page_cum_height = np.cumsum(self.page_cum_height)
        assert len(self.page_cum_height) == len(self.page_images) + 1
        if len(self.boxes) == 0 and zoomin < 9: self.__images__(fnm, zoomin * 3, page_from,
                                                                page_to, callback)

    def __call__(self, fnm, need_image=True, zoomin=3, return_html=False):
        self.__images__(fnm, zoomin)
        self._layouts_rec(zoomin)
        self._table_transformer_job(zoomin)
        self._text_merge()
        self._concat_downward()
        self._filter_forpages()
        tbls = self._extract_table_figure(
            need_image, zoomin, return_html, False)
        return self.__filterout_scraps(deepcopy(self.boxes), zoomin), tbls

    def remove_tag(self, txt):
        return re.sub(r"@@[\t0-9.-]+?##", "", txt)

    def crop(self, text, ZM=3, need_position=False):
        imgs = []
        poss = []
        for tag in re.findall(r"@@[0-9-]+\t[0-9.\t]+##", text):
            pn, left, right, top, bottom = tag.strip(
                "#").strip("@").split("\t")
            left, right, top, bottom = float(left), float(
                right), float(top), float(bottom)
            poss.append(([int(p) - 1 for p in pn.split("-")],
                         left, right, top, bottom))
        if not poss:
            if need_position:
                return None, None
            return

        max_width = max(
            np.max([right - left for (_, left, right, _, _) in poss]), 6)
        GAP = 6
        pos = poss[0]
        poss.insert(0, ([pos[0][0]], pos[1], pos[2], max(
            0, pos[3] - 120), max(pos[3] - GAP, 0)))
        pos = poss[-1]
        poss.append(([pos[0][-1]], pos[1], pos[2], min(self.page_images[pos[0][-1]].size[1] / ZM, pos[4] + GAP),
                     min(self.page_images[pos[0][-1]].size[1] / ZM, pos[4] + 120)))

        positions = []
        for ii, (pns, left, right, top, bottom) in enumerate(poss):
            right = left + max_width
            bottom *= ZM
            for pn in pns[1:]:
                bottom += self.page_images[pn - 1].size[1]
            imgs.append(
                self.page_images[pns[0]].crop((left * ZM, top * ZM,
                                               right *
                                               ZM, min(
                    bottom, self.page_images[pns[0]].size[1])
                                               ))
            )
            if 0 < ii < len(poss) - 1:
                positions.append((pns[0] + self.page_from, left, right, top, min(
                    bottom, self.page_images[pns[0]].size[1]) / ZM))
            bottom -= self.page_images[pns[0]].size[1]
            for pn in pns[1:]:
                imgs.append(
                    self.page_images[pn].crop((left * ZM, 0,
                                               right * ZM,
                                               min(bottom,
                                                   self.page_images[pn].size[1])
                                               ))
                )
                if 0 < ii < len(poss) - 1:
                    positions.append((pn + self.page_from, left, right, 0, min(
                        bottom, self.page_images[pn].size[1]) / ZM))
                bottom -= self.page_images[pn].size[1]

        if not imgs:
            if need_position:
                return None, None
            return
        height = 0
        for img in imgs:
            height += img.size[1] + GAP
        height = int(height)
        width = int(np.max([i.size[0] for i in imgs]))
        pic = Image.new("RGB",
                        (width, height),
                        (245, 245, 245))
        height = 0
        for ii, img in enumerate(imgs):
            if ii == 0 or ii + 1 == len(imgs):
                img = img.convert('RGBA')
                overlay = Image.new('RGBA', img.size, (0, 0, 0, 0))
                overlay.putalpha(128)
                img = Image.alpha_composite(img, overlay).convert("RGB")
            pic.paste(img, (0, int(height)))
            height += img.size[1] + GAP

        if need_position:
            return pic, positions
        return pic

    def get_position(self, bx, ZM):
        poss = []
        pn = bx["page_number"]
        top = bx["top"] - self.page_cum_height[pn - 1]
        bott = bx["bottom"] - self.page_cum_height[pn - 1]
        poss.append((pn, bx["x0"], bx["x1"], top, min(
            bott, self.page_images[pn - 1].size[1] / ZM)))
        while bott * ZM > self.page_images[pn - 1].size[1]:
            bott -= self.page_images[pn - 1].size[1] / ZM
            top = 0
            pn += 1
            poss.append((pn, bx["x0"], bx["x1"], top, min(
                bott, self.page_images[pn - 1].size[1] / ZM)))
        return poss


class PlainParser(object):
    def __call__(self, filename, from_page=0, to_page=100000, **kwargs):
        self.outlines = []
        lines = []
        try:
            self.pdf = pdf2_read(
                filename if isinstance(
                    filename, str) else BytesIO(filename))
            for page in self.pdf.pages[from_page:to_page]:
                lines.extend([t for t in page.extract_text().split("\n")])

            outlines = self.pdf.outline

            def dfs(arr, depth):
                for a in arr:
                    if isinstance(a, dict):
                        self.outlines.append((a["/Title"], depth))
                        continue
                    dfs(a, depth + 1)

            dfs(outlines, 0)
        except Exception as e:
            logging.warning(f"Outlines exception: {e}")
        if not self.outlines:
            logging.warning(f"Miss outlines")

        return [(l, "") for l in lines], []

    def crop(self, ck, need_position):
        raise NotImplementedError

    @staticmethod
    def remove_tag(txt):
        raise NotImplementedError


if __name__ == "__main__":
    pass