# Copyright (c) 2021 PaddlePaddle 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 argparse
import json
import multiprocessing
import os
import shutil
import sys
import time
from functools import partial


def get_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("--input_path", type=str, required=True, help="Path to you raw files. Folder or file path.")
    parser.add_argument("--output_path", type=str, required=True, help="Path to save the output json files.")
    parser.add_argument("--json_key", type=str, default="text", help="The content key of json file.")
    parser.add_argument(
        "--doc_spliter",
        type=str,
        default="",
        help="Spliter between documents. We will strip the line, if you use blank line to split doc, leave it blank.",
    )
    parser.add_argument("--min_doc_length", type=int, default=10, help="Minimal char of a document.")
    parser.add_argument("--workers", type=int, default=1, help="Number of worker processes to launch")
    parser.add_argument("--log_interval", type=int, default=1, help="Interval between progress updates.")
    parser.add_argument("--no-merge", action="store_true", help="Don't merge the file.")
    parser.add_argument("--no-shuffle", action="store_true", help="Don't shuffle the file.")
    args = parser.parse_args()
    return args


def raw_text_to_json(path, doc_spliter="", json_key="text", min_doc_length=10):
    path = os.path.abspath(path)
    if not os.path.exists(path):
        print("No found file %s" % path)
        return 0, None

    out_filepath = path + ".jsonl"
    fout = open(out_filepath, "w", encoding="utf-8")
    len_files = 0
    with open(path, "r") as f:
        doc = ""
        line = f.readline()
        while line:
            len_files += len(line)
            if line.strip() == doc_spliter:
                if len(doc) > min_doc_length:
                    fout.write(json.dumps({json_key: doc}, ensure_ascii=False) + "\n")
                doc = ""
            else:
                doc += line
            line = f.readline()

        if len(doc) > min_doc_length:
            fout.write(json.dumps({json_key: doc}, ensure_ascii=False) + "\n")
        doc = ""

    return len_files, out_filepath


def merge_file(file_paths, output_path):
    if not output_path.endswith(".jsonl"):
        output_path = output_path + ".jsonl"
    print("Merging files into %s" % output_path)
    with open(output_path, "wb") as wfd:
        for f in file_paths:
            if f is not None and os.path.exists(f):
                with open(f, "rb") as fd:
                    shutil.copyfileobj(fd, wfd)
                os.remove(f)
    print("File save in %s" % output_path)
    return output_path


def shuffle_file(output_path):
    print("Shuffling the jsonl file...")
    if os.path.exists(output_path):
        os.system("shuf %s -o %s" % (output_path, output_path))
        print("File shuffled!!!")
    else:
        raise ValueError("File not found: %s" % output_path)


def main():
    args = get_args()
    startup_start = time.time()

    file_paths = []
    if os.path.isfile(args.input_path):
        file_paths.append(args.input_path)
    else:
        for root, _, fs in os.walk(args.input_path):
            for f in fs:
                file_paths.append(os.path.join(root, f))

    pool = multiprocessing.Pool(args.workers)

    startup_end = time.time()
    proc_start = time.time()
    total_bytes_processed = 0
    print("Time to startup:", startup_end - startup_start)

    trans_json = partial(
        raw_text_to_json, doc_spliter=args.doc_spliter, json_key=args.json_key, min_doc_length=args.min_doc_length
    )
    encoded_files = pool.imap(trans_json, file_paths, 1)

    out_paths = []
    for i, (bytes_processed, out_path) in enumerate(encoded_files, start=1):
        total_bytes_processed += bytes_processed
        out_paths.append(out_path)

        if i % args.log_interval == 0:
            current = time.time()
            elapsed = current - proc_start
            mbs = total_bytes_processed / elapsed / 1024 / 1024
            print(f"Processed {i} files", f"({i/elapsed} files/s, {mbs} MB/s).", file=sys.stderr)

    if not args.no_merge:
        output_path = merge_file(out_paths, args.output_path)
        if not args.no_shuffle:
            shuffle_file(output_path)


if __name__ == "__main__":
    main()
    # profile.run("main()", "testprof")
