#!/usr/bin/env python3
""" Holds the classes for the 3 main Faceswap 'media' objects for
    input (extract) and output (convert) tasks. Those being:
            Images
            Faces
            Alignments"""

import logging
import os
from pathlib import Path

import cv2
import imageio

from lib.alignments import Alignments as AlignmentsBase
from lib.face_filter import FaceFilter as FilterFunc
from lib.image import count_frames, read_image
from lib.utils import (camel_case_split, get_image_paths, set_system_verbosity, _video_extensions)

logger = logging.getLogger(__name__)  # pylint: disable=invalid-name


class Utils():
    """ Holds utility functions that are required by more than one media
        object """

    @staticmethod
    def set_verbosity(loglevel):
        """ Set the system output verbosity """
        set_system_verbosity(loglevel)

    @staticmethod
    def finalize(images_found, num_faces_detected, verify_output):
        """ Finalize the image processing """
        logger.info("-------------------------")
        logger.info("Images found:        %s", images_found)
        logger.info("Faces detected:      %s", num_faces_detected)
        logger.info("-------------------------")

        if verify_output:
            logger.info("Note:")
            logger.info("Multiple faces were detected in one or more pictures.")
            logger.info("Double check your results.")
            logger.info("-------------------------")

        logger.info("Process Succesfully Completed. Shutting Down...")


class Alignments(AlignmentsBase):
    """ Override main alignments class for extract """
    def __init__(self, arguments, is_extract, input_is_video=False):
        logger.debug("Initializing %s: (is_extract: %s, input_is_video: %s)",
                     self.__class__.__name__, is_extract, input_is_video)
        self.args = arguments
        self.is_extract = is_extract
        folder, filename = self.set_folder_filename(input_is_video)
        super().__init__(folder,
                         filename=filename)
        logger.debug("Initialized %s", self.__class__.__name__)

    def set_folder_filename(self, input_is_video):
        """ Return the folder for the alignments file"""
        if self.args.alignments_path:
            logger.debug("Alignments File provided: '%s'", self.args.alignments_path)
            folder, filename = os.path.split(str(self.args.alignments_path))
        elif input_is_video:
            logger.debug("Alignments from Video File: '%s'", self.args.input_dir)
            folder, filename = os.path.split(self.args.input_dir)
            filename = "{}_alignments".format(os.path.splitext(filename)[0])
        else:
            logger.debug("Alignments from Input Folder: '%s'", self.args.input_dir)
            folder = str(self.args.input_dir)
            filename = "alignments"
        logger.debug("Setting Alignments: (folder: '%s' filename: '%s')", folder, filename)
        return folder, filename

    def load(self):
        """ Override  parent loader to handle skip existing on extract """
        data = dict()
        if not self.is_extract:
            if not self.have_alignments_file:
                return data
            data = super().load()
            return data

        skip_existing = bool(hasattr(self.args, 'skip_existing')
                             and self.args.skip_existing)
        skip_faces = bool(hasattr(self.args, 'skip_faces')
                          and self.args.skip_faces)

        if not skip_existing and not skip_faces:
            logger.debug("No skipping selected. Returning empty dictionary")
            return data

        if not self.have_alignments_file and (skip_existing or skip_faces):
            logger.warning("Skip Existing/Skip Faces selected, but no alignments file found!")
            return data

        data = self.serializer.load(self.file)

        if skip_faces:
            # Remove items from algnments that have no faces so they will
            # be re-detected
            del_keys = [key for key, val in data.items() if not val]
            logger.debug("Frames with no faces selected for redetection: %s", len(del_keys))
            for key in del_keys:
                if key in data:
                    logger.trace("Selected for redetection: '%s'", key)
                    del data[key]
        return data


class Images():
    """ Holds the full frames/images """
    def __init__(self, arguments):
        logger.debug("Initializing %s", self.__class__.__name__)
        self.args = arguments
        self.is_video = self.check_input_folder()
        self.input_images = self.get_input_images()
        self.images_found = self.count_images()
        logger.debug("Initialized %s", self.__class__.__name__)

    def count_images(self):
        """ Number of images or frames """
        if self.is_video:
            retval = int(count_frames(self.args.input_dir, fast=True))
        else:
            retval = len(self.input_images)
        return retval

    def check_input_folder(self):
        """ Check whether the input is a folder or video """
        if not os.path.exists(self.args.input_dir):
            logger.error("Input location %s not found.", self.args.input_dir)
            exit(1)
        if (os.path.isfile(self.args.input_dir) and
                os.path.splitext(self.args.input_dir)[1].lower() in _video_extensions):
            logger.info("Input Video: %s", self.args.input_dir)
            retval = True
        else:
            logger.info("Input Directory: %s", self.args.input_dir)
            retval = False
        return retval

    def get_input_images(self):
        """ Return the list of images or video file that is to be processed """
        if self.is_video:
            input_images = self.args.input_dir
        else:
            input_images = get_image_paths(self.args.input_dir)

        return input_images

    def load(self):
        """ Load an image and yield it with it's filename """
        iterator = self.load_video_frames if self.is_video else self.load_disk_frames
        for filename, image in iterator():
            yield filename, image

    def load_disk_frames(self):
        """ Load frames from disk """
        logger.debug("Input is separate Frames. Loading images")
        for filename in self.input_images:
            image = read_image(filename, raise_error=False)
            if image is None:
                continue
            yield filename, image

    def load_video_frames(self):
        """ Return frames from a video file """
        logger.debug("Input is video. Capturing frames")
        vidname = os.path.splitext(os.path.basename(self.args.input_dir))[0]
        reader = imageio.get_reader(self.args.input_dir, "ffmpeg")
        for i, frame in enumerate(reader):
            # Convert to BGR for cv2 compatibility
            frame = frame[:, :, ::-1]
            filename = "{}_{:06d}.png".format(vidname, i + 1)
            logger.trace("Loading video frame: '%s'", filename)
            yield filename, frame
        reader.close()

    def load_one_image(self, filename):
        """ load requested image """
        logger.trace("Loading image: '%s'", filename)
        if self.is_video:
            if filename.isdigit():
                frame_no = filename
            else:
                frame_no = os.path.splitext(filename)[0][filename.rfind("_") + 1:]
                logger.trace("Extracted frame_no %s from filename '%s'", frame_no, filename)
            retval = self.load_one_video_frame(int(frame_no))
        else:
            retval = read_image(filename, raise_error=True)
        return retval

    def load_one_video_frame(self, frame_no):
        """ Load a single frame from a video file """
        logger.trace("Loading video frame: %s", frame_no)
        reader = imageio.get_reader(self.args.input_dir, "ffmpeg")
        reader.set_image_index(frame_no - 1)
        frame = reader.get_next_data()[:, :, ::-1]
        reader.close()
        return frame


class PostProcess():
    """ Optional post processing tasks """
    def __init__(self, arguments):
        logger.debug("Initializing %s", self.__class__.__name__)
        self.args = arguments
        self.actions = self.set_actions()
        logger.debug("Initialized %s", self.__class__.__name__)

    def set_actions(self):
        """ Compile the actions to be performed into a list """
        postprocess_items = self.get_items()
        actions = list()
        for action, options in postprocess_items.items():
            options = dict() if options is None else options
            args = options.get("args", tuple())
            kwargs = options.get("kwargs", dict())
            args = args if isinstance(args, tuple) else tuple()
            kwargs = kwargs if isinstance(kwargs, dict) else dict()
            task = globals()[action](*args, **kwargs)
            if task.valid:
                logger.debug("Adding Postprocess action: '%s'", task)
                actions.append(task)

        for action in actions:
            action_name = camel_case_split(action.__class__.__name__)
            logger.info("Adding post processing item: %s", " ".join(action_name))

        return actions

    def get_items(self):
        """ Set the post processing actions """
        postprocess_items = dict()
        # Debug Landmarks
        if (hasattr(self.args, 'debug_landmarks')
                and self.args.debug_landmarks):
            postprocess_items["DebugLandmarks"] = None

        # Face Filter post processing
        if ((hasattr(self.args, "filter") and self.args.filter is not None) or
                (hasattr(self.args, "nfilter") and
                 self.args.nfilter is not None)):

            if hasattr(self.args, "detector"):
                detector = self.args.detector.replace("-", "_").lower()
            else:
                detector = "cv2_dnn"
            if hasattr(self.args, "aligner"):
                aligner = self.args.aligner.replace("-", "_").lower()
            else:
                aligner = "cv2_dnn"

            face_filter = dict(detector=detector,
                               aligner=aligner,
                               multiprocess=not self.args.singleprocess)
            filter_lists = dict()
            if hasattr(self.args, "ref_threshold"):
                face_filter["ref_threshold"] = self.args.ref_threshold
            for filter_type in ('filter', 'nfilter'):
                filter_args = getattr(self.args, filter_type, None)
                filter_args = None if not filter_args else filter_args
                filter_lists[filter_type] = filter_args
            face_filter["filter_lists"] = filter_lists
            postprocess_items["FaceFilter"] = {"kwargs": face_filter}

        logger.debug("Postprocess Items: %s", postprocess_items)
        return postprocess_items

    def do_actions(self, output_item):
        """ Perform the requested post-processing actions """
        for action in self.actions:
            logger.debug("Performing postprocess action: '%s'", action.__class__.__name__)
            action.process(output_item)


class PostProcessAction():  # pylint: disable=too-few-public-methods
    """ Parent class for Post Processing Actions
        Usuable in Extract or Convert or both
        depending on context """
    def __init__(self, *args, **kwargs):
        logger.debug("Initializing %s: (args: %s, kwargs: %s)",
                     self.__class__.__name__, args, kwargs)
        self.valid = True  # Set to False if invalid params passed in to disable
        logger.debug("Initialized base class %s", self.__class__.__name__)

    def process(self, output_item):
        """ Override for specific post processing action """
        raise NotImplementedError


class DebugLandmarks(PostProcessAction):  # pylint: disable=too-few-public-methods
    """ Draw debug landmarks on face
        Extract Only """

    def process(self, output_item):
        """ Draw landmarks on image """
        frame = os.path.splitext(os.path.basename(output_item["filename"]))[0]
        for idx, face in enumerate(output_item["detected_faces"]):
            logger.trace("Drawing Landmarks. Frame: '%s'. Face: %s", frame, idx)
            aligned_landmarks = face.aligned_landmarks
            for (pos_x, pos_y) in aligned_landmarks:
                cv2.circle(face.aligned_face, (pos_x, pos_y), 2, (0, 0, 255), -1)


class FaceFilter(PostProcessAction):
    """ Filter in or out faces based on input image(s)
        Extract or Convert """

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        logger.info("Extracting and aligning face for Face Filter...")
        self.filter = self.load_face_filter(**kwargs)
        logger.debug("Initialized %s", self.__class__.__name__)

    def load_face_filter(self, filter_lists, ref_threshold, aligner, detector,
                         multiprocess):
        """ Load faces to filter out of images """
        if not any(val for val in filter_lists.values()):
            return None

        facefilter = None
        filter_files = [self.set_face_filter(f_type, filter_lists[f_type])
                        for f_type in ("filter", "nfilter")]

        if any(filters for filters in filter_files):
            facefilter = FilterFunc(filter_files[0],
                                    filter_files[1],
                                    detector,
                                    aligner,
                                    multiprocess,
                                    ref_threshold)
            logger.debug("Face filter: %s", facefilter)
        else:
            self.valid = False
        return facefilter

    @staticmethod
    def set_face_filter(f_type, f_args):
        """ Set the required filters """
        if not f_args:
            return list()

        logger.info("%s: %s", f_type.title(), f_args)
        filter_files = f_args if isinstance(f_args, list) else [f_args]
        filter_files = list(filter(lambda fpath: Path(fpath).exists(), filter_files))
        if not filter_files:
            logger.warning("Face %s files were requested, but no files could be found. This "
                           "filter will not be applied.", f_type)
        logger.debug("Face Filter files: %s", filter_files)
        return filter_files

    def process(self, output_item):
        """ Filter in/out wanted/unwanted faces """
        if not self.filter:
            return
        ret_faces = list()
        for idx, detect_face in enumerate(output_item["detected_faces"]):
            check_item = detect_face["face"] if isinstance(detect_face, dict) else detect_face
            check_item.load_aligned(output_item["image"])
            if not self.filter.check(check_item):
                logger.verbose("Skipping not recognized face: (Frame: %s Face %s)",
                               output_item["filename"], idx)
                continue
            logger.trace("Accepting recognised face. Frame: %s. Face: %s",
                         output_item["filename"], idx)
            ret_faces.append(detect_face)
        output_item["detected_faces"] = ret_faces