ragflow/deepdoc/parser/pdf_parser.py

#
#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
#
#  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 logging
import os
import random
from timeit import default_timer as timer

import xgboost as xgb
from io import BytesIO
import re
import pdfplumber
from PIL import Image
import numpy as np
from pypdf import PdfReader as pdf2_read

from api import settings
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

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 not settings.LIGHTEN:
            try:
                import torch
                if torch.cuda.is_available():
                    self.updown_cnt_mdl.set_param({"device": "cuda"})
            except Exception:
                logging.exception("RAGFlowPdfParser __init__")
        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:
            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] if tks_down and tks_up else False,
            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.debug("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):
        start = timer()
        bxs = self.ocr.detect(np.array(img))
        logging.info(f"__ocr detecting boxes of a image cost ({timer() - start}s)")

        start = timer()
        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
        )
        
        # merge chars in the same rect
        for c in Recognizer.sort_Y_firstly(
                chars, self.mean_height[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-Zа-яА-Я,.?;:!%%]", bxs[ii]["text"][-1]):
                    bxs[ii]["text"] += " "
            else:
                bxs[ii]["text"] += c["text"]

        logging.info(f"__ocr sorting {len(chars)} chars cost {timer() - start}s")
        start = timer()
        boxes_to_reg = []
        img_np = np.array(img)
        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["box_image"] = self.ocr.get_rotate_crop_image(img_np, np.array([[left, top], [right, top], [right, bott], [left, bott]], dtype=np.float32))
                boxes_to_reg.append(b)
            del b["txt"]
        texts = self.ocr.recognize_batch([b["box_image"] for b in boxes_to_reg])
        for i in range(len(boxes_to_reg)):
            boxes_to_reg[i]["text"] = texts[i]
            del boxes_to_reg[i]["box_image"]
        logging.info(f"__ocr recognize {len(bxs)} boxes cost {timer() - start}s")
        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):
                logging.debug("{} {} {} {}".format(
                    b["text"],
                    b_["text"],
                    any(feats),
                    any(concatting_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() or not up["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 = [layout for layout in self.page_layout[pn] if layout["type"] == ltype]
                ii = Recognizer.find_overlapped(b, louts, naive=True)
                if ii is not None:
                    b = louts[ii]
                else:
                    logging.warning(
                        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))
                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:
                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:
            logging.exception("total_page_number")

    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
        start = 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])]
            try:
                self.page_chars = [[c for c in page.dedupe_chars().chars if self._has_color(c)] for page in self.pdf.pages[page_from:page_to]]
            except Exception as e:
                logging.warning(f"Failed to extract characters for pages {page_from}-{page_to}: {str(e)}")
                self.page_chars = [[] for _ in range(page_to - page_from)]  # If failed to extract, using empty list instead.
                
            self.total_page = len(self.pdf.pages)
        except Exception:
            logging.exception("RAGFlowPdfParser __images__")
        logging.info(f"__images__ dedupe_chars cost {timer() - start}s")

        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("Miss outlines")

        logging.debug("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

        start = 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="")
        logging.info(f"__images__ {len(self.page_images)} pages cost {timer() - start}s")

        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.debug("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:
            logging.exception("Outlines exception")
        if not self.outlines:
            logging.warning("Miss outlines")

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

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

    @staticmethod
    def remove_tag(txt):
        raise NotImplementedError


if __name__ == "__main__":
    pass