# Copyright (c) 2020 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 os
import sys
import subprocess
import multiprocessing
from datetime import datetime

import re
import copy
import errno
import time
import logging
import six
import abc
import paddle.fluid as fluid
from paddle.fluid import core
import functools

from pathlib import PurePosixPath, Path
import shutil

__all__ = [
    'FS', 'LocalFS', 'HDFSClient', 'ExecuteError', 'FSTimeOut',
    'FSFileExistsError', 'FSFileNotExistsError', 'FSShellCmdAborted'
]


class ExecuteError(Exception):
    pass


class FSFileExistsError(Exception):
    pass


class FSFileNotExistsError(Exception):
    pass


class FSTimeOut(Exception):
    pass


class FSShellCmdAborted(ExecuteError):
    pass


class FS(object):
    @abc.abstractmethod
    def ls_dir(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def is_file(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def is_dir(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def is_exist(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def upload(self, local_path, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def download(self, fs_path, local_path):
        raise NotImplementedError

    @abc.abstractmethod
    def mkdirs(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def delete(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def need_upload_download(self):
        raise NotImplementedError

    @abc.abstractmethod
    def rename(self, fs_src_path, fs_dst_path):
        raise NotImplementedError

    @abc.abstractmethod
    def mv(self, fs_src_path, fs_dst_path, overwrite=False, test_exists=False):
        raise NotImplementedError

    @abc.abstractmethod
    def upload_dir(self, local_dir, dest_dir):
        raise NotImplementedError

    @abc.abstractmethod
    def list_dirs(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def touch(self, fs_path, exist_ok=True):
        raise NotImplementedError


class LocalFS(FS):
    def ls_dir(self, fs_path):
        if not self.is_exist(fs_path):
            return [], []

        dirs = []
        files = []
        for f in os.listdir(fs_path):
            if os.path.isdir(fs_path + "/" + f):
                dirs.append(f)
            else:
                files.append(f)

        return dirs, files

    def mkdirs(self, fs_path):
        assert not os.path.isfile(fs_path), "{} is already a file".format(
            fs_path)
        os.system("mkdir -p {}".format(fs_path))

    def rename(self, fs_src_path, fs_dst_path):
        os.rename(fs_src_path, fs_dst_path)

    def _rmr(self, fs_path):
        shutil.rmtree(fs_path)

    def _rm(self, fs_path):
        os.remove(fs_path)

    def delete(self, fs_path):
        if not self.is_exist(fs_path):
            return

        if os.path.isfile(fs_path):
            return self._rm(fs_path)

        return self._rmr(fs_path)

    def need_upload_download(self):
        return False

    def is_file(self, fs_path):
        return os.path.isfile(fs_path)

    def is_dir(self, fs_path):
        return os.path.isdir(fs_path)

    def is_exist(self, fs_path):
        return os.path.exists(fs_path)

    def touch(self, fs_path, exist_ok=True):
        if self.is_exist(fs_path):
            if exist_ok:
                return
            raise FSFileExistsError

        return Path(fs_path).touch(exist_ok=True)

    def mv(self, src_path, dst_path, overwrite=False, test_exists=False):
        if not self.is_exist(src_path):
            raise FSFileNotExistsError

        if overwrite and self.is_exist(dst_path):
            self.delete(dst_path)

        if self.is_exist(dst_path):
            raise FSFileExistsError

        return self.rename(src_path, dst_path)

    def list_dirs(self, fs_path):
        """	
        list directory under fs_path, and only give the pure name, not include the fs_path	
        """
        if not self.is_exist(fs_path):
            return []

        dirs = [
            f for f in os.listdir(fs_path) if os.path.isdir(fs_path + "/" + f)
        ]

        return dirs


"""HDFS Utils."""


def _handle_errors(f):
    def handler(*args, **kwargs):
        start = time.time()
        while True:
            try:
                return f(*args, **kwargs)
            except ExecuteError as e:
                o = args[0]
                time_out = float(o._time_out) / 1000.0
                inter = float(o._sleep_inter) / 1000.0
                if time.time() - start >= time_out:
                    raise FSTimeOut
                time.sleep(inter)

    return functools.wraps(f)(handler)


def _handle_errors(max_time_out=None):
    def decorator(f):
        @functools.wraps(f)
        def handler(*args, **kwargs):
            o = args[0]
            time_out = max_time_out
            if time_out is None:
                time_out = float(o._time_out) / 1000.0
            else:
                time_out /= 1000.0
            inter = float(o._sleep_inter) / 1000.0

            start = time.time()
            last_print_time = start
            while True:
                try:
                    return f(*args, **kwargs)
                #important: only ExecuteError need to retry
                except ExecuteError as e:
                    if time.time() - start >= time_out:
                        raise FSTimeOut("args:{} timeout:{}".format(
                            args, time.time() - start))

                    time.sleep(inter)

                if time.time() - last_print_time > 30:
                    print("hadoop operator timeout:args:{} timeout:{}".format(
                        args, time.time() - start))
                    last_print_time = time.time()

        return handler

    return decorator


class HDFSClient(FS):
    def __init__(
            self,
            hadoop_home,
            configs,
            time_out=5 * 60 * 1000,  #ms
            sleep_inter=1000):  #ms
        # Raise exception if JAVA_HOME not exists.
        java_home = os.environ["JAVA_HOME"]

        self.pre_commands = []
        hadoop_bin = '%s/bin/hadoop' % hadoop_home
        self.pre_commands.append(hadoop_bin)
        dfs = 'fs'
        self.pre_commands.append(dfs)

        if configs:
            for k, v in six.iteritems(configs):
                config_command = '-D%s=%s' % (k, v)
                self.pre_commands.append(config_command)

        self._time_out = time_out
        self._sleep_inter = sleep_inter
        self._base_cmd = " ".join(self.pre_commands)
        self._bd_err_re = re.compile(
            r'\s?responseErrorMsg\s?\:.*, errorCode\:\s?[0-9]+, path\:')

    def _run_cmd(self, cmd, redirect_stderr=False):
        exe_cmd = "{} -{}".format(self._base_cmd, cmd)
        ret, output = core.shell_execute_cmd(exe_cmd, 0, 0, redirect_stderr)
        ret = int(ret)
        if ret == 134:
            raise FSShellCmdAborted(cmd)
        return ret, output.splitlines()

    @_handle_errors()
    def list_dirs(self, fs_path):
        if not self.is_exist(fs_path):
            return []

        dirs, files = self._ls_dir(fs_path)
        return dirs

    @_handle_errors()
    def ls_dir(self, fs_path):
        """	
        list directory under fs_path, and only give the pure name, not include the fs_path	
        """
        if not self.is_exist(fs_path):
            return [], []

        return self._ls_dir(fs_path)

    def _ls_dir(self, fs_path):
        cmd = "ls {}".format(fs_path)
        ret, lines = self._run_cmd(cmd)

        if ret != 0:
            raise ExecuteError(cmd)

        dirs = []
        files = []
        for line in lines:
            arr = line.split()
            if len(arr) != 8:
                continue

            p = PurePosixPath(arr[7])
            if arr[0][0] == 'd':
                dirs.append(p.name)
            else:
                files.append(p.name)

        return dirs, files

    def _test_match(self, lines):
        for l in lines:
            m = self._bd_err_re.match(l)
            if m != None:
                return m

        return None

    @_handle_errors()
    def is_dir(self, fs_path):
        if not self.is_exist(fs_path):
            return False

        return self._is_dir(fs_path)

    def _is_dir(self, fs_path):
        cmd = "test -d {}".format(fs_path, redirect_stderr=True)
        ret, lines = self._run_cmd(cmd)
        if ret:
            # other error
            if self._test_match(lines):
                raise ExecuteError(cmd)

            return False

        return True

    def is_file(self, fs_path):
        if not self.is_exist(fs_path):
            return False

        return not self._is_dir(fs_path)

    @_handle_errors()
    def is_exist(self, fs_path):
        cmd = "ls {} ".format(fs_path)
        ret, out = self._run_cmd(cmd, redirect_stderr=True)
        if ret != 0:
            for l in out:
                if "No such file or directory" in l:
                    return False
            raise ExecuteError(cmd)

        return True

    # can't retry
    def upload(self, local_path, fs_path):
        if self.is_exist(fs_path):
            raise FSFileExistsError("{} exists".format(fs_path))

        local = LocalFS()
        if not local.is_exist(local_path):
            raise FSFileNotExistsError("{} not exists".format(local_path))

        return self._try_upload(local_path, fs_path)

    @_handle_errors()
    def _try_upload(self, local_path, fs_path):
        cmd = "put {} {}".format(local_path, fs_path)
        ret = 0
        try:
            ret, lines = self._run_cmd(cmd)
            if ret != 0:
                raise ExecuteError(cmd)
        except Exception as e:
            self.delete(fs_path)
            raise e

    # can't retry
    def download(self, fs_path, local_path):
        if self.is_exist(local_path):
            raise FSFileExistsError("{} exists".format(local_path))

        if not self.is_exist(fs_path):
            raise FSFileNotExistsError("{} not exits".format(fs_path))

        return self._try_download(fs_path, local_path)

    @_handle_errors()
    def _try_download(self, fs_path, local_path):
        cmd = "get {} {}".format(fs_path, local_path)
        ret = 0
        try:
            ret, lines = self._run_cmd(cmd)
            if ret != 0:
                raise ExecuteError(cmd)
        except Exception as e:
            local_fs = LocalFS()
            local_fs.delete(local_path)
            raise e

    @_handle_errors()
    def mkdirs(self, fs_path):
        if self.is_exist(fs_path):
            return

        out_hdfs = False

        cmd = "mkdir {} ".format(fs_path)
        ret, out = self._run_cmd(cmd, redirect_stderr=True)
        if ret != 0:
            for l in out:
                if "No such file or directory" in l:
                    out_hdfs = True
                    break
            if not out_hdfs:
                raise ExecuteError(cmd)

        if out_hdfs and not self.is_exist(fs_path):
            cmd = "mkdir -p {}".format(fs_path)
            ret, lines = self._run_cmd(cmd)
            if ret != 0:
                raise ExecuteError(cmd)

    def mv(self, fs_src_path, fs_dst_path, overwrite=False, test_exists=True):
        if overwrite and self.is_exist(fs_dst_path):
            self.delete(fs_dst_path)

        if test_exists:
            if not self.is_exist(fs_src_path):
                raise FSFileNotExistsError("{} is not exists".format(
                    fs_src_path))

            if self.is_exist(fs_dst_path):
                raise FSFileExistsError("{} exists already".format(
                    fs_src_path, fs_dst_path, fs_dst_path))

        return self._try_mv(fs_src_path, fs_dst_path)

    @_handle_errors()
    def _try_mv(self, fs_src_path, fs_dst_path):
        cmd = "mv {} {}".format(fs_src_path, fs_dst_path)
        ret = 0
        try:
            ret, _ = self._run_cmd(cmd)
            if ret != 0:
                raise ExecuteError(cmd)
        except Exception as e:
            if not self.is_exist(fs_src_path) and \
                    self.is_exist(fs_dst_path):
                return
            raise e

    def _rmr(self, fs_path):
        cmd = "rmr {}".format(fs_path)
        ret, _ = self._run_cmd(cmd)
        if ret != 0:
            raise ExecuteError(cmd)

    def _rm(self, fs_path):
        cmd = "rm {}".format(fs_path)
        ret, _ = self._run_cmd(cmd)
        if ret != 0:
            raise ExecuteError(cmd)

    @_handle_errors()
    def delete(self, fs_path):
        if not self.is_exist(fs_path):
            return

        is_dir = self._is_dir(fs_path)
        if is_dir:
            return self._rmr(fs_path)

        return self._rm(fs_path)

    def touch(self, fs_path, exist_ok=True):
        if self.is_exist(fs_path):
            if exist_ok:
                return
            raise FSFileExistsError

        return self._touchz(fs_path)

    @_handle_errors()
    def _touchz(self, fs_path):
        cmd = "touchz {}".format(fs_path)
        ret, _ = self._run_cmd(cmd)
        if ret != 0:
            raise ExecuteError

    def need_upload_download(self):
        return True