# coding=utf-8
# Copyright 2020 The HuggingFace Datasets Authors and the current dataset script contributor.
#
# 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.
"""DUDE dataset loader"""

import os
from pathlib import Path
import time
import copy
import json
import numpy as np
import pandas as pd
from tqdm import tqdm
from io import BytesIO

tqdm.pandas()
from joblib import Parallel, delayed

import pdf2image
import PyPDF2

from PIL import Image as PIL_Image
from datasets import load_dataset_builder, load_dataset, logging


logger = logging.get_logger(__name__)

PIL_Image.MAX_IMAGE_PIXELS = None  # 933120000

MAX_PAGES = 50
MAX_PDF_SIZE = 100000000  # almost 100MB
MIN_WIDTH, MIN_HEIGHT = 150, 150


def load_json(json_path):
    return json.load(open(json_path, "r"))


def save_json(json_path, data):
    with open(json_path, "w") as f:
        json.dump(data, f)


def get_images_pdf2image(document_filepath, chunksize=10):
    info = pdf2image.pdfinfo_from_path(document_filepath, userpw=None, poppler_path=None)
    maxPages = info["Pages"]
    maxPages = min(MAX_PAGES, maxPages)

    # logger.info(f"{document_filepath} has {str(maxPages)} pages")
    images = []
    for page in range(1, maxPages + 1, chunksize):
        try:
            images.extend(
                pdf2image.convert_from_path(
                    document_filepath,
                    first_page=page,
                    last_page=min(page + chunksize - 1, maxPages),
                )
            )
        except Exception as e:
            logger.warning(f"page: {page} get_images {e}")
    return images


def pdf_to_images(document_filepath, converter="PyPDF2"):
    def images_to_pagenames(images, document_filepath, page_image_dir):
        page_image_names = []
        for page_idx, page_image in enumerate(images):
            page_image_name = document_filepath.replace("PDF", "images").replace(".pdf", f"_{page_idx}.jpg")
            page_image_names.append(
                page_image_name.replace(page_image_dir, page_image_dir.split("/")[-1])
            )  # without dir
            if not os.path.exists(page_image_name):
                page_image.convert("RGB").save(page_image_name)
        return page_image_names

    example = {}
    example["num_pages"] = 0
    example["page_image_names"] = []
    images = []

    page_image_dir = "/".join(document_filepath.split("/")[:-1]).replace("PDF", "images")
    if not os.path.exists(page_image_dir):
        os.makedirs(page_image_dir)

    # if len(document_filepath) > MAX_PDF_SIZE:
    #     logger.warning(f"too large document {len(example['document'])}")
    #     return example
    reached_page_limit = False

    if converter == "PyPDF2":
        try:
            reader = PyPDF2.PdfReader(document_filepath)
        except Exception as e:
            logger.warning(f"read_pdf {e}")
            return example

        for p, page in enumerate(reader.pages):
            if reached_page_limit:
                break
            try:
                for image in page.images:
                    if len(images) == MAX_PAGES:
                        reached_page_limit = True
                        break
                    im = PIL_Image.open(BytesIO(image.data))
                    if im.width < MIN_WIDTH and im.height < MIN_HEIGHT:
                        continue
                    images.append(im)
            except Exception as e:
                logger.warning(f"get_images {e}")

    elif converter == "pdf2image":
        images = get_images_pdf2image(document_filepath)

    example["num_pages"] = len(images)
    if len(images) == 0:
        return example

    example["page_image_names"] = images_to_pagenames(images, document_filepath, page_image_dir)

    return example


def pdf_to_images_block(document_paths_blocks, converter):
    new_doc_metadata = {}
    for document_filepath in document_paths_blocks:
        docId = document_filepath.split("/")[-1].replace(".pdf", "")
        new_doc_metadata[docId] = pdf_to_images(document_filepath, converter=converter)
    return new_doc_metadata


def parse_textract_bbox(box):
    # 0.47840896, 0.12897822, 0.5341576 , 0.14347914 # x,w,y,h
    return np.array([box["Left"], box["Width"], box["Top"], box["Height"]])


def parse_azure_box(box, page_width, page_height):
    # Box in Azure are in format X top left, Y top left, X top right, Y top right, X bottom right, Y bottom right, X bottom left, Y bottom left
    # [14.1592, 3.8494, 28.668, 3.8494, 28.668, 8.0487, 13.9844, 7.8738]
    left = min(box[0], box[6])
    right = max(box[2], box[4])
    top = min(box[1], box[3])
    bottom = max(box[5], box[7])
    width = right - left
    height = bottom - top

    # Normalize
    left = left / page_width
    top = top / page_height
    width = width / page_width
    height = height / page_height

    return [left, width, top, height]


def get_ocr_information(ocr_path, num_pages):
    ocr_info = load_json(ocr_path)

    ocr_pages = ocr_info[0]["DocumentMetadata"]["Pages"]

    if num_pages != ocr_pages and num_pages != MAX_PAGES:  # MAX_PAGES is the limit for conversion
        raise AssertionError("Pages from images and OCR not matching, should go for pdf2image")

    page_ocr_tokens = [[] for page_ix in range(num_pages)]
    page_ocr_boxes = [[] for page_ix in range(num_pages)]
    for ocr_block in ocr_info:
        for ocr_extraction in ocr_block["Blocks"]:
            if ocr_extraction["BlockType"] == "WORD":
                text = ocr_extraction["Text"].lower()
                bounding_box = parse_textract_bbox(ocr_extraction["Geometry"]["BoundingBox"]).tolist()
                page = ocr_extraction["Page"] - 1

                if page >= num_pages:  # additional condition when MAX_PAGES vs. OCR pages
                    break

                page_ocr_tokens[page].append(text)
                page_ocr_boxes[page].append(bounding_box)

    """
    for page in range(num_pages):
        page_ocr_boxes[page] = np.array(page_ocr_boxes[page])
    """
    return page_ocr_tokens, page_ocr_boxes


def create_header(split, version, has_answer):
    header = {
        "creation_time": time.time(),
        "version": version,
        "dataset_type": split,
        "has_answer": has_answer,
    }

    return header


def get_document_info(documents_metadata, docId):
    doc_metadata = documents_metadata[docId]
    num_pages = doc_metadata["num_pages"]
    page_image_names = doc_metadata["page_image_names"]
    return num_pages, page_image_names


def format_answers(answers_list):
    answers_list = list(set([answer for answer in answers_list]))  # standardization is done
    return answers_list


def create_imdb_record_from_json(
    record, documents_metadata, documents_ocr_info, split, include_answers, include_variants=False
):
    docId = record["docId"].split("_")[0]
    try:
        num_pages, page_image_names = get_document_info(documents_metadata, docId)
        document_ocr_info = documents_ocr_info[docId]
    except Exception as e:
        from pdb import set_trace

        set_trace()
        print(
            "Missing: ",
            e,
            docId,
        )
        return {}

    if include_answers:
        answers = format_answers(record["answers"])
    else:
        answers = None

    if include_variants and record["answers_variants"] and not "list" in record["answer_type"]:
        answers += record["answers_variants"]

    page_image_dir = "/".join(record["document"].split("/")[:-2]).replace("PDF", "images")
    if not page_image_names or any([not os.path.exists(os.path.join(page_image_dir, p)) for p in page_image_names]):
        print(
            "Missing images: ",
            docId,
            # [p for p in page_image_names if not os.path.exists(os.path.join(page_image_dir, p))],
        )
        return {}

    # fix if wrongly saved pagenames
    # page_image_names = [
    #     split + image_name for image_name in page_image_names if image_name.startswith("/")
    # ]

    imdb_record = {
        "question_id": record["questionId"],
        "question": record["question"],
        "docId": docId,
        "image_name": page_image_names,
        "num_pages": num_pages,
        "ocr_tokens": document_ocr_info["ocr_tokens"],
        "ocr_normalized_boxes": document_ocr_info["ocr_boxes"],
        "set_name": split,
        "answers": answers,  # list
        "answer_page": None,
        "extra": {
            #'question_type': record['qtype'],
            #'industry': record['industry'],
            #'category': record['category'],
            "answer_type": record["answer_type"],
        },
    }

    return imdb_record


def create_imdb_from_json(
    data,
    documents_metadata,
    documents_ocr_info,
    split,
    version,
    include_answers=True,
    include_variants=False,
):
    imdb_header = create_header(split, version, include_answers)

    imdb_records = []
    for record in tqdm(data):
        imdb_record = create_imdb_record_from_json(
            record, documents_metadata, documents_ocr_info, split, include_answers, include_variants
        )
        if imdb_record:
            imdb_records.append(imdb_record)

    imdb = [imdb_header] + imdb_records

    return imdb


def parse_arguments():
    import argparse

    parser = argparse.ArgumentParser(description="Instantiate HuggingFace dataloader and convert to ImDB format")

    parser.add_argument(
        "--redo-imdb-build",
        action="store_true",
        default=False,
        help="Whether to rebuild the imdb record and overwrite",
    )

    # Optional
    parser.add_argument(
        "--no-include-variants",
        action="store_false",
        default=True,
        help="Whether to include variants as full ground truths",
    )

    # Overwrite/Pass HF parameters
    parser.add_argument(
        "--DUDE_config",
        type=str,
        default="Amazon_original",
        help="HF Config to load to control OCR version",
    )
    parser.add_argument(
        "--data_dir",
        type=str,
        default="/home/jordy/Downloads/DUDE_train-val-test_binaries",
        help="Load PDFs and store images",
    )

    return parser.parse_args()


if __name__ == "__main__":
    """
    Parse and redo
    """
    args = parse_arguments()

    dataset = load_dataset("jordyvl/DUDE_loader", args.DUDE_config, data_dir=args.data_dir)

    splits = dataset.keys()

    for split in splits:
        split_indices = []
        OCR_paths = []
        document_paths = []
        for i, x in enumerate(dataset[split]):
            if x["data_split"] != split:  # redundant check
                continue
            if x["document"] not in document_paths:
                document_paths.append(x["document"])
                OCR_paths.append(x["OCR"])
                split_indices.append(i)

        # document_paths = document_paths[:30]
        # OCR_paths = OCR_paths[:30]

        # 1. PDF to image dir and collect document metadata (num_pages, page_image_names)
        documents_metadata_filename = f"{split}-documents_metadata.json"
        if os.path.exists(documents_metadata_filename):
            print(f"Loading from disk: {documents_metadata_filename}")
            documents_metadata = load_json(documents_metadata_filename)
        else:
            documents_metadata = {}
            num_jobs = 6
            block_size = int(len(document_paths) / num_jobs) + 1
            print(f"{block_size} * {num_jobs} = {block_size*num_jobs} ({len(document_paths)})")
            document_blocks = [document_paths[block_size * i : block_size * i + block_size] for i in range(num_jobs)]
            print(
                "chunksize",
                len(set([docId for doc_block in document_blocks for docId in doc_block])),
            )
            parallel_results = Parallel(n_jobs=num_jobs)(
                delayed(pdf_to_images_block)(document_blocks[i], "pdf2image") for i in range(num_jobs)
            )

            for block_result in parallel_results:
                for docId, metadata in tqdm(block_result.items()):
                    if docId not in documents_metadata:
                        documents_metadata[docId] = metadata

            save_json(documents_metadata_filename, documents_metadata)

        # 2. Process OCR to obtain doc_ocr_info
        documents_ocr_filename = f"{split}-documents_ocr.json"

        if os.path.exists(documents_ocr_filename):
            print(f"Loading from disk: {documents_ocr_filename}")
            documents_ocr_info = load_json(documents_ocr_filename)
        else:
            documents_ocr_info = {}
            no_ocr = []
            error_ocr = []

            for i, document_filepath in enumerate(document_paths):
                docId = document_filepath.split("/")[-1].replace(".pdf", "")
                try:
                    ocr_tokens, ocr_boxes = get_ocr_information(OCR_paths[i], documents_metadata[docId]["num_pages"])
                    documents_ocr_info[docId] = {"ocr_tokens": ocr_tokens, "ocr_boxes": ocr_boxes}
                except AssertionError as e:
                    print(f"image2pages issue: {e}")
                    error_ocr.append(docId)
                except IndexError as e:
                    print(f"pages issue: {e}")
                    error_ocr.append(docId)
                except FileNotFoundError as e:
                    print(f"FileNotFoundError issue: {e}")
                    no_ocr.append(docId)
                except KeyError as e:
                    print(f"Keyerror issue: {e}")
                    error_ocr.append(docId)

            save_json(documents_ocr_filename, documents_ocr_info)

        imdb_filename = f"imdb_{split}.npy"
        if os.path.exists(imdb_filename) and not args.redo_imdb_build:
            print(f"Loading from disk: {imdb_filename}")
            imdb = np.load(imdb_filename, allow_pickle=True)

        else:
            imdb = create_imdb_from_json(
                dataset[split],  # .select(split_indices),
                documents_metadata=documents_metadata,
                documents_ocr_info=documents_ocr_info,
                split=split,
                version="0.1",
                include_answers=(not split == "test"),
                include_variants=(not args.no_include_variants),
            )
            np.save(imdb_filename, imdb)