#
# SPDX-FileCopyrightText: Copyright (c) 1993-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# 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 os

import tensorrt as trt
from loguru import logger

from .common_runtime import *

try:
    # Sometimes python does not understand FileNotFoundError
    FileNotFoundError
except NameError:
    FileNotFoundError = IOError


def GiB(val):
    return val * 1 << 30


def add_help(description):
    parser = argparse.ArgumentParser(description=description, formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    args, _ = parser.parse_known_args()


def find_sample_data(description="Runs a TensorRT Python sample", subfolder="", find_files=[], err_msg=""):
    """
    Parses sample arguments.

    Args:
        description (str): Description of the sample.
        subfolder (str): The subfolder containing data relevant to this sample
        find_files (str): A list of filenames to find. Each filename will be replaced with an absolute path.

    Returns:
        str: Path of data directory.
    """

    # Standard command-line arguments for all samples.
    kDEFAULT_DATA_ROOT = os.path.join(os.sep, "usr", "src", "tensorrt", "data")
    parser = argparse.ArgumentParser(description=description, formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument(
        "-d",
        "--datadir",
        help="Location of the TensorRT sample data directory, and any additional data directories.",
        action="append",
        default=[kDEFAULT_DATA_ROOT],
    )
    args, _ = parser.parse_known_args()

    def get_data_path(data_dir):
        # If the subfolder exists, append it to the path, otherwise use the provided path as-is.
        data_path = os.path.join(data_dir, subfolder)
        if not os.path.exists(data_path):
            if data_dir != kDEFAULT_DATA_ROOT:
                logger.info("WARNING: " + data_path + " does not exist. Trying " + data_dir + " instead.")
            data_path = data_dir
        # Make sure data directory exists.
        if not (os.path.exists(data_path)) and data_dir != kDEFAULT_DATA_ROOT:
            logger.info("WARNING: {:} does not exist. Please provide the correct data path with the -d option.".format(data_path))
        return data_path

    data_paths = [get_data_path(data_dir) for data_dir in args.datadir]
    return data_paths, locate_files(data_paths, find_files, err_msg)


def locate_files(data_paths, filenames, err_msg=""):
    """
    Locates the specified files in the specified data directories.
    If a file exists in multiple data directories, the first directory is used.

    Args:
        data_paths (List[str]): The data directories.
        filename (List[str]): The names of the files to find.

    Returns:
        List[str]: The absolute paths of the files.

    Raises:
        FileNotFoundError if a file could not be located.
    """
    found_files = [None] * len(filenames)
    for data_path in data_paths:
        # Find all requested files.
        for index, (found, filename) in enumerate(zip(found_files, filenames)):
            if not found:
                file_path = os.path.abspath(os.path.join(data_path, filename))
                if os.path.exists(file_path):
                    found_files[index] = file_path

    # Check that all files were found
    for f, filename in zip(found_files, filenames):
        if not f or not os.path.exists(f):
            raise FileNotFoundError("Could not find {:}. Searched in data paths: {:}\n{:}".format(filename, data_paths, err_msg))
    return found_files


# Sets up the builder to use the timing cache file, and creates it if it does not already exist
def setup_timing_cache(config: trt.IBuilderConfig, timing_cache_path: os.PathLike):
    buffer = b""
    if os.path.exists(timing_cache_path):
        with open(timing_cache_path, mode="rb") as timing_cache_file:
            buffer = timing_cache_file.read()
    timing_cache: trt.ITimingCache = config.create_timing_cache(buffer)
    config.set_timing_cache(timing_cache, True)


# Saves the config's timing cache to file
def save_timing_cache(config: trt.IBuilderConfig, timing_cache_path: os.PathLike):
    timing_cache: trt.ITimingCache = config.get_timing_cache()
    with open(timing_cache_path, "wb") as timing_cache_file:
        timing_cache_file.write(memoryview(timing_cache.serialize()))
