# -*- coding: utf-8 -*-
# File: logger.py

# Copyright (c) Tensorpack Contributors
# Licensed under the Apache License, Version 2.0 (the "License")
"""
This file is modified from
https://github.com/tensorpack/tensorpack/blob/master/tensorpack/utils/logger.py

The logger module itself has the common logging functions of Python's
`logging.Logger`.

**Example:**

    ..code-block::python

        from deepdoctection.utils.logger import logger

        logger.set_logger_dir("path/to/dir")
        logger.info("Something has happened")
        logger.warning("Attention!")
        logger.error("Error happened!")

Log levels can be set via the environment variable `LOG_LEVEL` (default: INFO).
`STD_OUT_VERBOSE` will print a verbose message to the terminal (default: False).
"""

import errno
import functools
import json
import logging
import logging.config
import os
import shutil
import sys
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path
from typing import Any, Optional, Union, no_type_check

from termcolor import colored

from .types import PathLikeOrStr

__all__ = ["logger", "set_logger_dir", "auto_set_dir", "get_logger_dir"]

ENV_VARS_TRUE: set[str] = {"1", "True", "TRUE", "true", "yes"}


@dataclass
class LoggingRecord:
    """LoggingRecord to pass to the logger in order to distinguish from third party libraries."""

    msg: str
    log_dict: Optional[dict[Union[int, str], Any]] = field(default=None)

    def __post_init__(self) -> None:
        """log_dict will be added to the log record as a dict."""
        if self.log_dict is not None:
            self.log_dict["msg"] = self.msg

    def __str__(self) -> str:
        """Return the message."""
        return self.msg


class CustomFilter(logging.Filter):
    """A custom filter"""

    filter_third_party_lib = os.environ.get("FILTER_THIRD_PARTY_LIB", "False") in ENV_VARS_TRUE

    def filter(self, record: logging.LogRecord) -> bool:
        if self.filter_third_party_lib:
            if not isinstance(record.msg, LoggingRecord):
                return False

        return True


class StreamFormatter(logging.Formatter):
    """A custom formatter to produce unified LogRecords"""

    std_out_verbose = os.environ.get("STD_OUT_VERBOSE", "False") in ENV_VARS_TRUE

    @no_type_check
    def format(self, record: logging.LogRecord) -> str:
        date = colored("[%(asctime)s @%(filename)s:%(lineno)d]", "green")
        msg = colored("%(message)s", "white")

        if self.std_out_verbose:
            if isinstance(record.msg, LoggingRecord):
                verbose_info = f" Additional verbose infos: {repr(record.msg.log_dict)}"
                msg += verbose_info

        if record.levelno == logging.WARNING:
            fmt = f"{date}  {colored('WRN', 'magenta', attrs=['blink'])}  {msg}"
        elif record.levelno == logging.ERROR or record.levelno == logging.CRITICAL:  # pylint: disable=R1714
            fmt = f"{date}  {colored('ERR', 'red', attrs=['blink', 'underline'])}  {msg}"
        elif record.levelno == logging.DEBUG:
            fmt = f"{date}  {colored('DBG', 'green', attrs=['blink'])}  {msg}"
        elif record.levelno == logging.INFO:
            fmt = f"{date}  {colored('INF', 'green')}  {msg}"
        else:
            fmt = f"{date} {msg}"
        self._style._fmt = fmt  # pylint: disable=W0212
        self._fmt = fmt
        return super().format(record)


class FileFormatter(logging.Formatter):
    """A custom formatter to produce a loggings in json format"""

    filter_third_party_lib = os.environ.get("FILTER_THIRD_PARTY_LIB", "False") in ENV_VARS_TRUE

    @no_type_check
    def format(self, record: logging.LogRecord) -> str:
        message = super().format(record)
        log_dict = {
            "level_no": record.levelno,
            "level_name": record.levelname,
            "module_name": record.filename,
            "line_number": record.lineno,
            "time": datetime.now().strftime("%m%d-%H%M%S"),
            "message": message,
        }
        if isinstance(record.msg, LoggingRecord):
            if record.msg.log_dict:
                log_dict.update(record.msg.log_dict)
                log_dict.pop("msg")
        elif not self.filter_third_party_lib:
            log_dict = {"message": record.msg}
        return json.dumps(log_dict)


_LOG_DIR = None
_CONFIG_DICT: dict[str, Any] = {
    "version": 1,
    "disable_existing_loggers": False,
    "filters": {"customfilter": {"()": lambda: CustomFilter()}},  # pylint: disable=W0108
    "formatters": {
        "streamformatter": {"()": lambda: StreamFormatter(datefmt="%m%d %H:%M.%S")},
    },
    "handlers": {
        "streamhandler": {"filters": ["customfilter"], "formatter": "streamformatter", "class": "logging.StreamHandler"}
    },
    "root": {
        "handlers": ["streamhandler"],
        "level": os.environ.get("LOG_LEVEL", "INFO"),
        "propagate": os.environ.get("LOG_PROPAGATE", "False") in ENV_VARS_TRUE,
    },
}


def _get_logger() -> logging.Logger:
    logging.config.dictConfig(_CONFIG_DICT)
    _logger = logging.getLogger(__name__)
    return _logger


logger = _get_logger()

_LOGGING_METHOD = ["info", "warning", "error", "critical", "debug"]
for func in _LOGGING_METHOD:
    locals()[func] = getattr(logger, func)
    __all__.append(func)


_FILE_HANDLER = None


def _get_time_str() -> str:
    return datetime.now().strftime("%m%d-%H%M%S")


def _set_file(path: PathLikeOrStr) -> None:
    path = os.fspath(path)
    global _FILE_HANDLER  # pylint: disable=W0603
    if os.path.isfile(path):
        backup_name = path + "." + _get_time_str()
        shutil.move(path, backup_name)
        logger.info("Existing log file %s backuped to %s", path, backup_name)
    hdl = logging.FileHandler(filename=path, encoding="utf-8", mode="w")
    hdl.setFormatter(FileFormatter(datefmt="%m%d %H:%M:%S"))
    hdl.addFilter(CustomFilter())

    _FILE_HANDLER = hdl
    logger.addHandler(hdl)
    logger.info("Argv: %s ", sys.argv)


def set_logger_dir(dir_name: PathLikeOrStr, action: Optional[str] = None) -> None:
    """
    Set the directory for global logging.

    :param dir_name: log directory
    :param action: an action of ["k","d","q"] to be performed
                   when the directory exists. Will ask user by default.

                   "d": delete the directory. Note that the deletion may fail when
                   the directory is used by tensorboard.
                   "k": keep the directory. This is useful when you resume from a
                   previous training and want the directory to look as if the
                   training was not interrupted.
                   Note that this option does not load old models or any other
                   old states for you. It simply does nothing.
    """
    if isinstance(dir_name, Path):
        dir_name = dir_name.as_posix()
    dir_name = os.path.normpath(dir_name)
    global _LOG_DIR, _FILE_HANDLER  # pylint: disable=W0603
    if _FILE_HANDLER:
        # unload and close the old file handler, so that we may safely delete the logger directory
        logger.removeHandler(_FILE_HANDLER)
        del _FILE_HANDLER

    def dir_nonempty(directory: PathLikeOrStr) -> int:
        return os.path.isdir(directory) and len([x for x in os.listdir(directory) if x[0] != "."])

    if dir_nonempty(dir_name):
        if not action:
            logger.warning("Log directory %s exists! Use 'd' to delete it. ", dir_name)
            logger.warning(
                "If you're resuming from a previous run, you can choose to keep it. Press any other key to exit. "
            )
        while not action:
            action = input("Select Action: k (keep) / d (delete) / q (quit):").lower().strip()
        act = action
        if act == "b":
            backup_name = dir_name + _get_time_str()
            shutil.move(dir_name, backup_name)
            logger.info("Directory %s backuped to %s", dir_name, backup_name)
        elif act == "d":
            shutil.rmtree(dir_name, ignore_errors=True)
            if dir_nonempty(dir_name):
                shutil.rmtree(dir_name, ignore_errors=False)
        elif act == "n":
            dir_name = dir_name + _get_time_str()
            logger.info("Use a new log directory %s ", dir_name)
        elif act == "k":
            pass
        else:
            raise OSError(f"Directory {dir_name} exits!")
    _LOG_DIR = os.path.join(dir_name, "log.jsonl")
    try:
        os.makedirs(dir_name)
    except OSError as err:
        if err.errno != errno.EEXIST:
            raise err

    _set_file(_LOG_DIR)


def auto_set_dir(action: Optional[str] = None, name: Optional[str] = None) -> None:
    """
    Will set the log directory to './train_log/{script_name}:{name}'.
    'script_name' is the name of the main python file currently running.

    :param action: an action of ["k","d","q"] to be performed (see also func: set_logger_dir)
    :param name: Optional suffix of file name.
    """

    mod = sys.modules["__main__"]
    basename = str(os.path.basename(mod.__file__))  # type: ignore  # pylint: disable=E1101
    auto_dir_name = os.path.join("train_log", basename[: basename.rfind(".")])
    if name:
        auto_dir_name += "_%s" % name if os.name == "nt" else ":%s" % name  # pylint: disable=C0209
    set_logger_dir(auto_dir_name, action=action)


def get_logger_dir() -> Optional[PathLikeOrStr]:
    """
    The logger directory, or None if not set.
    The directory is used for general logging, tensorboard events, checkpoints, etc.
    """
    return _LOG_DIR


@functools.lru_cache(maxsize=None)
def log_once(message: str, function: str = "info") -> None:
    """
    Log certain message only once. Call this function more than one times with
    the same message will result in no-op.

    :param message:  message to log
    :param function: the name of the logger method. e.g. "info", "warn", "error".
    :return:
    """
    getattr(logger, function)(message)
