#!/usr/bin/env python3

# Copyright (C) 2011-2017 Damon Lynch <damonlynch@gmail.com>

# This file is part of Rapid Photo Downloader.
#
# Rapid Photo Downloader is free software: you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Rapid Photo Downloader is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Rapid Photo Downloader.  If not,
# see <http://www.gnu.org/licenses/>.

__author__ = 'Damon Lynch'
__copyright__ = "Copyright 2011-2017, Damon Lynch"

import datetime
import logging
from typing import Optional, Union, Any

import arrow.arrow
from arrow.arrow import Arrow

import raphodo.exiftool as exiftool
from raphodo.utilities import datetime_roughly_equal

try:
    import pymediainfo
    have_pymediainfo = True
    pymedia_library_file = 'libmediainfo.so.0'
except ImportError:
    have_pymediainfo = False
    libmediainfo_missing = None

if have_pymediainfo:
    libmediainfo_missing = False
    try:
        if not pymediainfo.MediaInfo.can_parse(library_file=pymedia_library_file):
            # attempt to work around MediaInfoLib issue #695:
            # 'SONAME is different when compiling with CMake and autotools'
            pymedia_library_file = 'libmediainfo.so.17'
            if not pymediainfo.MediaInfo.can_parse(library_file=pymedia_library_file):
                have_pymediainfo = False
                libmediainfo_missing = True
    except TypeError:
        # older versions of pymediainfo do not have the library_file option
        pymedia_library_file = None
        if not pymediainfo.MediaInfo.can_parse():
            have_pymediainfo = False
            libmediainfo_missing = True
    except AttributeError:
        try:
            # Attempt to parse null... it will fail if libmediainfo is not present, which is
            # what we want to check
            pymediainfo.MediaInfo.parse('/dev/null')
        except OSError:
            have_pymediainfo = False
            libmediainfo_missing = True
            pymedia_library_file = None


def pymedia_version_info() -> Optional[str]:
    if have_pymediainfo:
        if pymedia_library_file == 'libmediainfo.so.0':
            return pymediainfo.__version__
        else:
            return '{} (using {})'.format(pymediainfo.__version__, pymedia_library_file)
    else:
        return None

EXIFTOOL_VERSION = exiftool.version_info()


class MetaData:
    def __init__(self, full_file_name: str, et_process: exiftool.ExifTool):
        """
        Get video metadata using Exiftool

        :param filename: the file from which to get metadata
        :param et_process: instance of ExifTool class, which allows
        calling EXifTool without it exiting with each call
        """

        self.filename = full_file_name
        self.metadata = dict()
        self.metadata_string_format = dict()
        self.et_process = et_process
        if have_pymediainfo:
            if pymedia_library_file is not None:
                self.media_info = pymediainfo.MediaInfo.parse(
                    filename=full_file_name, library_file=pymedia_library_file
                )  # type: pymediainfo.MediaInfo
            else:
                self.media_info = pymediainfo.MediaInfo.parse(
                    filename=full_file_name
                )  # type: pymediainfo.MediaInfo
        else:
            self.media_info = None

    def _get(self, key, missing):

        if key in ("VideoStreamType", "FileNumber"):
            # special case: want ExifTool's string formatting
            # i.e. no -n tag
            if not self.metadata_string_format:
                try:
                    self.metadata_string_format = \
                        self.et_process.execute_json_no_formatting(self.filename)
                except ValueError:
                    return missing
            try:
                return self.metadata_string_format[0][key]
            except:
                return missing

        elif not self.metadata:
            try:
                self.metadata = self.et_process.get_metadata(self.filename)
            except ValueError:
                return missing

        return self.metadata.get(key, missing)

    def _exiftool_date_time(self, missing: Optional[str]='',
                            ignore_file_modify_date: bool = False) -> Union[datetime.datetime, Any]:
        """
        Tries to get value from key "DateTimeOriginal"
        If that fails, tries "CreateDate", and then finally
        FileModifyDate

        :param ignore_file_modify_date: if True, don't return the file
        modification date
        :return  python datetime format the date and time the video was
        recorded, else missing
        """
        d = self._get('DateTimeOriginal', None)
        if d is None:
            d = self._get('CreateDate', None)
        if d is None and not ignore_file_modify_date:
            d = self._get('FileModifyDate', None)
        if d is not None:
            d = d.strip()
            try:
                # returned value may or may not have a time offset
                if len(d) > 19:
                    # remove the : from the timezone component, if it's present
                    if d[-3] == ':' and (d[-6] in ('+', '-')):
                        d = d[:-3] + d[-2:]
                    dt = datetime.datetime.strptime(d, "%Y:%m:%d %H:%M:%S%z")
                else:
                    dt = datetime.datetime.strptime(d, "%Y:%m:%d %H:%M:%S")

            except ValueError:
                logging.warning(
                    "Error parsing date time metadata %s for video %s", d, self.filename
                )
                return missing
            except Exception:
                logging.error(
                    "Unknown error parsing date time metadata %s for video %s", d, self.filename
                )
                return missing

            return dt
        else:
            return missing

    def date_time(self, missing: Optional[str]='',
                  ignore_file_modify_date: bool=False) -> datetime.datetime:
        """
        Use pymediainfo (if present) to extract file encoding date.

        Also use ExifTool if appropriate.

        :param ignore_file_modify_date: if True, don't return the file
        modification date
        :return  python datetime format the date and time the video was
        recorded, else missing
        """

        if have_pymediainfo:
            try:
                d = self.media_info.to_data()['tracks'][0]['encoded_date']  # type: str
            except KeyError:
                logging.debug(
                    'Failed to extract date time from %s using pymediainfo: trying ExifTool',
                    self.filename
                )
                return self._exiftool_date_time(
                    missing=missing, ignore_file_modify_date=ignore_file_modify_date
                )
            else:
                # format of date string is something like:
                # UTC 2016-05-09 03:28:03
                try:
                    if d.startswith('UTC'):
                        u = d[4:]
                        a = arrow.get(u, "YYYY-MM-DD HH:mm:ss")  # type: Arrow
                        dt_mi = a.to('local')
                        dt = dt_mi.datetime  # type: datetime.datetime

                        # Compare the value returned by mediainfo against that
                        # returned by ExifTool, if and only if there is a time zone
                        # setting in the video file that ExifTool can extract
                        tz = self._get('TimeZone', None)
                        if tz is None:
                            logging.debug(
                                "Using pymediainfo datetime (%s), because ExifTool did "
                                "not detect a time zone in %s", dt_mi, self.filename
                            )
                        if tz is not None:
                            dt_et = self._exiftool_date_time(
                                missing=None, ignore_file_modify_date=True
                            )
                            if dt_et is not None:
                                hour = tz // 60 * -1
                                minute = tz % 60 * -1
                                adjusted_dt_mi = dt_mi.replace(hours=hour, minutes=minute).naive
                                if datetime_roughly_equal(adjusted_dt_mi, dt_et):
                                    logging.debug(
                                        "Favoring ExifTool datetime metadata (%s) "
                                        "over mediainfo (%s) for %s, because it includes "
                                        "a timezone", dt_et, adjusted_dt_mi, self.filename
                                    )
                                    dt = dt_et
                                else:
                                    logging.debug(
                                        "Although ExifTool located a time zone"
                                        "in %s's metadata, using the mediainfo result, "
                                        "because the two results are different. Mediainfo: %s / "
                                        "%s  (before / after). ExifTool: %s. Time zone: %s",
                                        self.filename, dt, adjusted_dt_mi, dt_et, tz
                                    )

                    else:
                        dt = datetime.datetime.strptime(d, "%Y-%m-%d %H:%M:%S")
                except ValueError:
                    logging.warning(
                        "Error parsing date time metadata %s for video %s. Will try ExifTool.",
                        d, self.filename
                    )
                    return self._exiftool_date_time(missing)
                except arrow.parser.ParserError:
                    logging.warning(
                        "Error parsing date time metadata using Arrow %s for video %s. Will try "
                        "ExifTool.", d, self.filename
                    )
                    return self._exiftool_date_time(missing)
                except Exception as e:
                    logging.error(
                        "Unknown error parsing date time metadata %s for video %s. %s. "
                        "Will try ExifTool.", d, self.filename, e
                    )
                    return self._exiftool_date_time(missing)
                except:
                    logging.error(
                        "Unknown error parsing date time metadata %s for video %s. "
                        "Will try ExifTool.", d, self.filename
                    )
                    return self._exiftool_date_time(missing)
                else:
                    return dt

        else:
            return self._exiftool_date_time(missing)


    def timestamp(self, missing='') -> Union[float, Any]:
        """
        :return: a float value representing the time stamp, if it exists
        """

        dt = self.date_time(missing=None)
        if dt is not None:
            try:
                ts = dt.timestamp()
                ts = float(ts)
            except:
                ts = missing
        else:
            ts = missing
        return ts

    def file_number(self, missing='') -> Union[str, Any]:
        v = self._get("FileNumber", None)
        if v is not None:
            return str(v)
        else:
            return missing

    def width(self, missing='') -> Union[str, Any]:
        v = self._get('ImageWidth', None)
        if v is not None:
            return str(v)
        else:
            return missing

    def height(self, missing='') -> Union[str, Any]:
        v = self._get('ImageHeight', None)
        if v is not None:
            return str(v)
        else:
            return missing

    def length(self, missing='') -> Union[str, Any]:
        """
        return the duration (length) of the video, rounded to the nearest second, in string format
        """
        v = self._get("Duration", None)
        if v is not None:
            try:
                v = float(v)
                v = "%0.f" % v
            except:
                return missing
            return v
        else:
            return missing

    def frames_per_second(self, missing='') -> Union[str, Any]:
        v = self._get("FrameRate", None)
        if v is None:
            v = self._get("VideoFrameRate", None)

        if v is None:
            return missing
        try:
            v = '%.0f' % v
        except:
            return missing
        return v

    def codec(self, missing='') -> Union[str, Any]:
        v = self._get("VideoStreamType", None)
        if v is None:
            v = self._get("VideoCodec", None)
        if v is not None:
            return v
        return missing

    def fourcc(self, missing='') -> Union[str, Any]:
        return self._get("CompressorID", missing)

    def rotation(self, missing=0) -> Union[int, Any]:
        v = self._get("Rotation", None)
        if v is not None:
            return v
        return missing


class DummyMetaData():
    """
    Class which gives metadata values for an imaginary video.

    Useful for displaying in preference examples etc. when no video is ready to
    be downloaded.
    """
    def __init__(self, filename, et_process):
        pass

    def date_time(self, missing=''):
        return datetime.datetime.now()

    def codec(self, stream=0, missing=''):
        return 'H.264 AVC'

    def length(self, missing=''):
        return '57'

    def width(self, stream=0, missing=''):
        return '1920'

    def height(self, stream=0, missing=''):
        return '1080'

    def frames_per_second(self, stream=0, missing=''):
        return '24'

    def fourcc(self, stream=0, missing=''):
        return 'AVC1'

if __name__ == '__main__':
    import sys

    with exiftool.ExifTool() as et_process:
        if (len(sys.argv) != 2):
            print('Usage: ' + sys.argv[0] + ' path/to/video/containing/metadata')
        else:
            file = sys.argv[1]

            print("ExifTool", EXIFTOOL_VERSION)
            m = MetaData(file, et_process)
            dt = m.date_time()
            print(dt)
            print("%sx%s" % (m.width(), m.height()))
            print("Length:", m.length())
            print("FPS: ", m.frames_per_second())
            print("Codec:", m.codec())