# fmt: off
# flake8: noqa

"""COCO Dataset."""
import copy
import itertools
import json
import os
from collections import defaultdict

import numpy as np
from scipy.optimize import linear_sum_assignment

from .. import _timing, utils
from ..config import get_default_dataset_config, init_config
from ..utils import TrackEvalException
from ._base_dataset import _BaseDataset


class COCO(_BaseDataset):
    """Tracking datasets in COCO format."""

    def __init__(self, config=None):
        """Initialize dataset, checking that all required files are present."""
        super().__init__()
        # Fill non-given config values with defaults
        self.config = init_config(config, get_default_dataset_config(), self.get_name())
        self.gt_fol = self.config["GT_FOLDER"]
        self.tracker_fol = self.config["TRACKERS_FOLDER"]
        self.should_classes_combine = True
        self.use_super_categories = False
        self.use_mask = self.config["USE_MASK"]

        self.tracker_sub_fol = self.config["TRACKER_SUB_FOLDER"]
        self.output_fol = self.config["OUTPUT_FOLDER"]
        if self.output_fol is None:
            self.output_fol = self.tracker_fol
        self.output_sub_fol = self.config["OUTPUT_SUB_FOLDER"]

        if self.gt_fol.endswith(".json"):
            self.gt_data = json.load(open(self.gt_fol, "r"))
        else:
            gt_dir_files = [
                file for file in os.listdir(self.gt_fol) if file.endswith(".json")
            ]
            if len(gt_dir_files) != 1:
                raise TrackEvalException(
                    f"{self.gt_fol} does not contain exactly one json file."
                )

            with open(os.path.join(self.gt_fol, gt_dir_files[0])) as f:
                self.gt_data = json.load(f)

        # fill missing video ids
        self._fill_video_ids_inplace(self.gt_data["annotations"])

        # get sequences to eval and sequence information
        self.seq_list = [
            vid["name"].replace("/", "-") for vid in self.gt_data["videos"]
        ]
        self.seq_name2seqid = {
            vid["name"].replace("/", "-"): vid["id"] for vid in self.gt_data["videos"]
        }
        # compute mappings from videos to annotation data
        self.video2gt_track, self.video2gt_image = self._compute_vid_mappings(
            self.gt_data["annotations"]
        )
        # compute sequence lengths
        self.seq_lengths = {vid["id"]: 0 for vid in self.gt_data["videos"]}
        for img in self.gt_data["images"]:
            self.seq_lengths[img["video_id"]] += 1
        self.seq2images2timestep = self._compute_image_to_timestep_mappings()
        self.seq2cls = {
            vid["id"]: {
                "pos_cat_ids": list(
                    {track["category_id"] for track in self.video2gt_track[vid["id"]]}
                ),
            }
            for vid in self.gt_data["videos"]
        }

        # Get classes to eval
        considered_vid_ids = [self.seq_name2seqid[vid] for vid in self.seq_list]
        seen_cats = set(
            [
                cat_id
                for vid_id in considered_vid_ids
                for cat_id in self.seq2cls[vid_id]["pos_cat_ids"]
            ]
        )
        # only classes with ground truth are evaluated in TAO
        self.valid_classes = [
            cls["name"] for cls in self.gt_data["categories"] if cls["id"] in seen_cats
        ]
        cls_name2clsid_map = {
            cls["name"]: cls["id"] for cls in self.gt_data["categories"]
        }

        if self.config["CLASSES_TO_EVAL"]:
            self.class_list = [
                cls.lower() if cls.lower() in self.valid_classes else None
                for cls in self.config["CLASSES_TO_EVAL"]
            ]
            if not all(self.class_list):
                valid_cls = ", ".join(self.valid_classes)
                raise TrackEvalException(
                    "Attempted to evaluate an invalid class. Only classes "
                    f"{valid_cls} are valid (classes present in ground truth"
                    " data)."
                )
        else:
            self.class_list = [cls for cls in self.valid_classes]
        self.cls_name2clsid = {
            k: v for k, v in cls_name2clsid_map.items() if k in self.class_list
        }
        self.clsid2cls_name = {
            v: k for k, v in cls_name2clsid_map.items() if k in self.class_list
        }
        # get trackers to eval
        if self.config["TRACKERS_TO_EVAL"] is None:
            self.tracker_list = os.listdir(self.tracker_fol)
        else:
            self.tracker_list = self.config["TRACKERS_TO_EVAL"]

        if self.config["TRACKER_DISPLAY_NAMES"] is None:
            self.tracker_to_disp = dict(zip(self.tracker_list, self.tracker_list))
        elif (self.config["TRACKERS_TO_EVAL"] is not None) and (
            len(self.config["TK_DISPLAY_NAMES"]) == len(self.tracker_list)
        ):
            self.tracker_to_disp = dict(
                zip(self.tracker_list, self.config["TK_DISPLAY_NAMES"])
            )
        else:
            raise TrackEvalException(
                "List of tracker files and tracker display names do not match."
            )

        self.tracker_data = {tracker: dict() for tracker in self.tracker_list}

        for tracker in self.tracker_list:
            if self.tracker_sub_fol.endswith(".json"):
                with open(os.path.join(self.tracker_sub_fol)) as f:
                    curr_data = json.load(f)
            else:
                tr_dir = os.path.join(self.tracker_fol, tracker, self.tracker_sub_fol)
                tr_dir_files = [
                    file for file in os.listdir(tr_dir) if file.endswith(".json")
                ]
                if len(tr_dir_files) != 1:
                    raise TrackEvalException(
                        f"{tr_dir} does not contain exactly one json file."
                    )
                with open(os.path.join(tr_dir, tr_dir_files[0])) as f:
                    curr_data = json.load(f)

            # limit detections if MAX_DETECTIONS > 0
            if self.config["MAX_DETECTIONS"]:
                curr_data = self._limit_dets_per_image(curr_data)

            # fill missing video ids
            self._fill_video_ids_inplace(curr_data)

            # make track ids unique over whole evaluation set
            self._make_tk_ids_unique(curr_data)

            # get tracker sequence information
            curr_vids2tracks, curr_vids2images = self._compute_vid_mappings(curr_data)
            self.tracker_data[tracker]["vids_to_tracks"] = curr_vids2tracks
            self.tracker_data[tracker]["vids_to_images"] = curr_vids2images

    def get_display_name(self, tracker):
        return self.tracker_to_disp[tracker]

    def _load_raw_file(self, tracker, seq, is_gt):
        """Load a file (gt or tracker) in the TAO format

        If is_gt, this returns a dict which contains the fields:
        [gt_ids, gt_classes]:
            list (for each timestep) of 1D NDArrays (for each det).
        [gt_dets]: list (for each timestep) of lists of detections.

        if not is_gt, this returns a dict which contains the fields:
        [tk_ids, tk_classes]:
            list (for each timestep) of 1D NDArrays (for each det).
        [tk_dets]: list (for each timestep) of lists of detections.
        """
        seq_id = self.seq_name2seqid[seq]
        # file location
        if is_gt:
            imgs = self.video2gt_image[seq_id]
        else:
            imgs = self.tracker_data[tracker]["vids_to_images"][seq_id]

        # convert data to required format
        num_timesteps = self.seq_lengths[seq_id]
        img_to_timestep = self.seq2images2timestep[seq_id]
        data_keys = ["ids", "classes", "dets"]
        # if not is_gt:
        #     data_keys += ["tk_confidences"]
        raw_data = {key: [None] * num_timesteps for key in data_keys}
        for img in imgs:
            # some tracker data contains images without any ground truth info,
            # these are ignored
            if img["id"] not in img_to_timestep:
                continue
            t = img_to_timestep[img["id"]]
            anns = img["annotations"]
            tk_str = utils.get_track_id_str(anns[0])

            if self.use_mask:
                # When using mask, extract segmentation data
                raw_data["dets"][t] = [ann.get("segmentation") for ann in anns]
            else:
                # When using bbox, extract bbox data
                raw_data["dets"][t] = np.atleast_2d([ann["bbox"] for ann in anns]).astype(
                    float
                )
            raw_data["ids"][t] = np.atleast_1d([ann[tk_str] for ann in anns]).astype(
                int
            )
            raw_data["classes"][t] = np.atleast_1d(
                [ann["category_id"] for ann in anns]
            ).astype(int)
            # if not is_gt:
            #     raw_data["tk_confidences"][t] = np.atleast_1d(
            #         [ann["score"] for ann in anns]
            #     ).astype(float)

        for t, d in enumerate(raw_data["dets"]):
            if d is None:
                raw_data["dets"][t] = np.empty((0, 4)).astype(float)
                raw_data["ids"][t] = np.empty(0).astype(int)
                raw_data["classes"][t] = np.empty(0).astype(int)
                # if not is_gt:
                #     raw_data["tk_confidences"][t] = np.empty(0)

        if is_gt:
            key_map = {"ids": "gt_ids", "classes": "gt_classes", "dets": "gt_dets"}
        else:
            key_map = {"ids": "tk_ids", "classes": "tk_classes", "dets": "tk_dets"}
        for k, v in key_map.items():
            raw_data[v] = raw_data.pop(k)

        raw_data["num_timesteps"] = num_timesteps
        raw_data["seq"] = seq
        return raw_data

    def get_preprocessed_seq_data_thr(self, raw_data, cls, assignment=None):
        """Preprocess data for a single sequence for a single class.

        Inputs:
            raw_data: dict containing the data for the sequence already
                read in by get_raw_seq_data().
            cls: class to be evaluated.
        Outputs:
            gt_ids:
                list (for each timestep) of ids of GT tracks
            tk_ids:
                list (for each timestep) of ids of predicted tracks (all for TP
                matching (Det + AssocA))
            tk_overlap_ids:
                list (for each timestep) of ids of predicted tracks that overlap
                with GTs
            tk_dets:
                list (for each timestep) of lists of detections that
                corresponding to the tk_ids
            tk_classes:
                list (for each timestep) of lists of classes that corresponding
                to the tk_ids
            tk_confidences:
                list (for each timestep) of lists of classes that corresponding
                to the tk_ids
            sim_scores:
                similarity score between gt_ids and tk_ids.
        """
        if cls != "all":
            cls_id = self.cls_name2clsid[cls]

        data_keys = [
            "gt_ids",
            "tk_ids",
            "gt_id_map",
            "tk_id_map",
            "gt_dets",
            "gt_classes",
            "gt_class_name",
            "tk_overlap_classes",
            "tk_overlap_ids",
            "tk_class_eval_tk_ids",
            "tk_dets",
            "tk_classes",
            # "tk_confidences",
            "tk_exh_ids",
            "sim_scores",
        ]
        data = {key: [None] * raw_data["num_timesteps"] for key in data_keys}
        unique_gt_ids = []
        unique_tk_ids = []
        num_gt_dets = 0
        num_tk_cls_dets = 0
        num_tk_overlap_dets = 0
        overlap_ious_thr = 0.5
        loc_and_asso_tk_ids = []
        exh_class_tk_ids = []

        for t in range(raw_data["num_timesteps"]):
            # only extract relevant dets for this class for preproc and eval
            if cls == "all":
                gt_class_mask = np.ones_like(raw_data["gt_classes"][t]).astype(bool)
            else:
                gt_class_mask = np.atleast_1d(
                    raw_data["gt_classes"][t] == cls_id
                ).astype(bool)

            # select GT that is not in the evaluating classes
            if assignment is not None and assignment:
                all_gt_ids = list(assignment[t].keys())
                gt_ids_in = raw_data["gt_ids"][t][gt_class_mask]
                gt_ids_out = set(all_gt_ids) - set(gt_ids_in)
                tk_ids_out = set([assignment[t][key] for key in list(gt_ids_out)])

            # compute overlapped tracks and add their ids to overlap_tk_ids
            sim_scores = raw_data["similarity_scores"]
            overlap_ids_masks = (sim_scores[t][gt_class_mask] >= overlap_ious_thr).any(
                axis=0
            )
            overlap_tk_ids_t = raw_data["tk_ids"][t][overlap_ids_masks]
            if assignment is not None and assignment:
                data["tk_overlap_ids"][t] = list(set(overlap_tk_ids_t) - tk_ids_out)
            else:
                data["tk_overlap_ids"][t] = list(set(overlap_tk_ids_t))

            loc_and_asso_tk_ids += data["tk_overlap_ids"][t]

            data["tk_exh_ids"][t] = []
            if cls == "all":
                continue

            # add the track ids of exclusive annotated class to exh_class_tk_ids
            tk_exh_mask = np.atleast_1d(raw_data["tk_classes"][t] == cls_id)
            tk_exh_mask = tk_exh_mask.astype(bool)
            exh_class_tk_ids_t = raw_data["tk_ids"][t][tk_exh_mask]
            exh_class_tk_ids.append(exh_class_tk_ids_t)
            data["tk_exh_ids"][t] = exh_class_tk_ids_t

        # remove tk_ids that has been assigned to GT belongs to other classes.
        loc_and_asso_tk_ids = list(set(loc_and_asso_tk_ids))

        # remove all unwanted unmatched tracker detections
        for t in range(raw_data["num_timesteps"]):
            # add gt to the data
            if cls == "all":
                gt_class_mask = np.ones_like(raw_data["gt_classes"][t]).astype(bool)
            else:
                gt_class_mask = np.atleast_1d(
                    raw_data["gt_classes"][t] == cls_id
                ).astype(bool)
                data["gt_classes"][t] = cls_id
                data["gt_class_name"][t] = cls

            gt_ids = raw_data["gt_ids"][t][gt_class_mask]
            if self.use_mask:
                gt_dets = [raw_data['gt_dets'][t][ind] for ind in range(len(gt_class_mask)) if gt_class_mask[ind]]
            else:
                gt_dets = raw_data["gt_dets"][t][gt_class_mask]
            data["gt_ids"][t] = gt_ids
            data["gt_dets"][t] = gt_dets

            # filter pred and only keep those that highly overlap with GTs
            tk_mask = np.isin(
                raw_data["tk_ids"][t], np.array(loc_and_asso_tk_ids), assume_unique=True
            )
            tk_overlap_mask = np.isin(
                raw_data["tk_ids"][t],
                np.array(data["tk_overlap_ids"][t]),
                assume_unique=True,
            )

            tk_ids = raw_data["tk_ids"][t][tk_mask]
            if self.use_mask:
                tk_dets = [raw_data['tk_dets'][t][ind] for ind in range(len(tk_mask)) if
                            tk_mask[ind]]
            else:
                tk_dets = raw_data["tk_dets"][t][tk_mask]

            tracker_classes = raw_data["tk_classes"][t][tk_mask]

            # add overlap classes for computing the FP for Cls term
            tracker_overlap_classes = raw_data["tk_classes"][t][tk_overlap_mask]
            # tracker_confidences = raw_data["tk_confidences"][t][tk_mask]
            sim_scores_masked = sim_scores[t][gt_class_mask, :][:, tk_mask]

            # add filtered prediction to the data
            data["tk_classes"][t] = tracker_classes
            data["tk_overlap_classes"][t] = tracker_overlap_classes
            data["tk_ids"][t] = tk_ids
            data["tk_dets"][t] = tk_dets
            # data["tk_confidences"][t] = tracker_confidences
            data["sim_scores"][t] = sim_scores_masked
            data["tk_class_eval_tk_ids"][t] = set(
                list(data["tk_overlap_ids"][t]) + list(data["tk_exh_ids"][t])
            )

            # count total number of detections
            unique_gt_ids += list(np.unique(data["gt_ids"][t]))
            # the unique track ids are for association.
            unique_tk_ids += list(np.unique(data["tk_ids"][t]))

            num_tk_overlap_dets += len(data["tk_overlap_ids"][t])
            num_tk_cls_dets += len(data["tk_class_eval_tk_ids"][t])
            num_gt_dets += len(data["gt_ids"][t])

        # re-label IDs such that there are no empty IDs
        if len(unique_gt_ids) > 0:
            unique_gt_ids = np.unique(unique_gt_ids)
            gt_id_map = np.nan * np.ones((np.max(unique_gt_ids) + 1))
            gt_id_map[unique_gt_ids] = np.arange(len(unique_gt_ids))
            data["gt_id_map"] = {}
            for gt_id in unique_gt_ids:
                new_gt_id = gt_id_map[gt_id].astype(int)
                data["gt_id_map"][new_gt_id] = gt_id

            for t in range(raw_data["num_timesteps"]):
                if len(data["gt_ids"][t]) > 0:
                    data["gt_ids"][t] = gt_id_map[data["gt_ids"][t]].astype(int)

        if len(unique_tk_ids) > 0:
            unique_tk_ids = np.unique(unique_tk_ids)
            tk_id_map = np.nan * np.ones((np.max(unique_tk_ids) + 1))
            tk_id_map[unique_tk_ids] = np.arange(len(unique_tk_ids))

            data["tk_id_map"] = {}
            for track_id in unique_tk_ids:
                new_track_id = tk_id_map[track_id].astype(int)
                data["tk_id_map"][new_track_id] = track_id

            for t in range(raw_data["num_timesteps"]):
                if len(data["tk_ids"][t]) > 0:
                    data["tk_ids"][t] = tk_id_map[data["tk_ids"][t]].astype(int)
                if len(data["tk_overlap_ids"][t]) > 0:
                    data["tk_overlap_ids"][t] = tk_id_map[
                        data["tk_overlap_ids"][t]
                    ].astype(int)

        # record overview statistics.
        data["num_tk_cls_dets"] = num_tk_cls_dets
        data["num_tk_overlap_dets"] = num_tk_overlap_dets
        data["num_gt_dets"] = num_gt_dets
        data["num_tk_ids"] = len(unique_tk_ids)
        data["num_gt_ids"] = len(unique_gt_ids)
        data["num_timesteps"] = raw_data["num_timesteps"]
        data["seq"] = raw_data["seq"]

        self._check_unique_ids(data)

        return data

    @_timing.time
    def get_preprocessed_seq_data(
        self, raw_data, cls, assignment=None, thresholds=[50, 75]
    ):
        """Preprocess data for a single sequence for a single class."""
        data = {}
        if thresholds is None:
            thresholds = [50, 75]
        elif isinstance(thresholds, int):
            thresholds = [thresholds]

        for thr in thresholds:
            assignment_thr = None
            if assignment is not None:
                assignment_thr = assignment[thr]
            data[thr] = self.get_preprocessed_seq_data_thr(
                raw_data, cls, assignment_thr
            )

        return data

    def _calculate_similarities(self, gt_dets_t, tk_dets_t):
        """Compute similarity scores."""
        if self.use_mask:
            similarity_scores = self._calculate_mask_ious(gt_dets_t, tk_dets_t, is_encoded=True, do_ioa=False)
        else:
            similarity_scores = self._calculate_box_ious(gt_dets_t, tk_dets_t)
        return similarity_scores

    def _compute_vid_mappings(self, annotations):
        """Computes mappings from videos to corresponding tracks and images."""
        vids_to_tracks = {}
        vids_to_imgs = {}
        vid_ids = [vid["id"] for vid in self.gt_data["videos"]]

        # compute an mapping from image IDs to images
        images = {}
        for image in self.gt_data["images"]:
            images[image["id"]] = image

        tk_str = utils.get_track_id_str(annotations[0])
        for ann in annotations:
            ann["area"] = ann["bbox"][2] * ann["bbox"][3]

            vid = ann["video_id"]
            if ann["video_id"] not in vids_to_tracks.keys():
                vids_to_tracks[ann["video_id"]] = list()
            if ann["video_id"] not in vids_to_imgs.keys():
                vids_to_imgs[ann["video_id"]] = list()

            # fill in vids_to_tracks
            tid = ann[tk_str]
            exist_tids = [track["id"] for track in vids_to_tracks[vid]]
            try:
                index1 = exist_tids.index(tid)
            except ValueError:
                index1 = -1
            if tid not in exist_tids:
                curr_track = {
                    "id": tid,
                    "category_id": ann["category_id"],
                    "video_id": vid,
                    "annotations": [ann],
                }
                vids_to_tracks[vid].append(curr_track)
            else:
                vids_to_tracks[vid][index1]["annotations"].append(ann)

            # fill in vids_to_imgs
            img_id = ann["image_id"]
            exist_img_ids = [img["id"] for img in vids_to_imgs[vid]]
            try:
                index2 = exist_img_ids.index(img_id)
            except ValueError:
                index2 = -1
            if index2 == -1:
                curr_img = {"id": img_id, "annotations": [ann]}
                vids_to_imgs[vid].append(curr_img)
            else:
                vids_to_imgs[vid][index2]["annotations"].append(ann)

        # sort annotations by frame index and compute track area
        for vid, tracks in vids_to_tracks.items():
            for track in tracks:
                track["annotations"] = sorted(
                    track["annotations"],
                    key=lambda x: images[x["image_id"]]["frame_id"],
                )
                # compute average area
                track["area"] = sum(x["area"] for x in track["annotations"]) / len(
                    track["annotations"]
                )

        # ensure all videos are present
        for vid_id in vid_ids:
            if vid_id not in vids_to_tracks.keys():
                vids_to_tracks[vid_id] = []
            if vid_id not in vids_to_imgs.keys():
                vids_to_imgs[vid_id] = []

        return vids_to_tracks, vids_to_imgs

    def _compute_image_to_timestep_mappings(self):
        """Computes a mapping from images to timestep in sequence."""
        images = {}
        for image in self.gt_data["images"]:
            images[image["id"]] = image

        seq_to_imgs_to_timestep = {vid["id"]: dict() for vid in self.gt_data["videos"]}
        for vid in seq_to_imgs_to_timestep:
            curr_imgs = [img["id"] for img in self.video2gt_image[vid]]
            curr_imgs = sorted(curr_imgs, key=lambda x: images[x]["frame_id"])
            seq_to_imgs_to_timestep[vid] = {
                curr_imgs[i]: i for i in range(len(curr_imgs))
            }

        return seq_to_imgs_to_timestep

    def _limit_dets_per_image(self, annotations):
        """Limits the number of detections for each image.

        Adapted from https://github.com/TAO-Dataset/.
        """
        max_dets = self.config["MAX_DETECTIONS"]
        img_ann = defaultdict(list)
        for ann in annotations:
            img_ann[ann["image_id"]].append(ann)

        for img_id, _anns in img_ann.items():
            if len(_anns) <= max_dets:
                continue
            _anns = sorted(_anns, key=lambda x: x["score"], reverse=True)
            img_ann[img_id] = _anns[:max_dets]

        return [ann for anns in img_ann.values() for ann in anns]

    def _fill_video_ids_inplace(self, annotations):
        """Fills in missing video IDs inplace.

        Adapted from https://github.com/TAO-Dataset/.
        """
        missing_video_id = [x for x in annotations if "video_id" not in x]
        if missing_video_id:
            image_id_to_video_id = {
                x["id"]: x["video_id"] for x in self.gt_data["images"]
            }
            for x in missing_video_id:
                x["video_id"] = image_id_to_video_id[x["image_id"]]

    @staticmethod
    def _make_tk_ids_unique(annotations):
        """Makes track IDs unqiue over the whole annotation set.

        Adapted from https://github.com/TAO-Dataset/.
        """
        track_id_videos = {}
        track_ids_to_update = set()
        max_track_id = 0

        tk_str = utils.get_track_id_str(annotations[0])
        for ann in annotations:
            t = int(ann[tk_str])
            if t not in track_id_videos:
                track_id_videos[t] = ann["video_id"]

            if ann["video_id"] != track_id_videos[t]:
                # track id is assigned to multiple videos
                track_ids_to_update.add(t)
            max_track_id = max(max_track_id, t)

        if track_ids_to_update:
            print("true")
            next_id = itertools.count(max_track_id + 1)
            new_tk_ids = defaultdict(lambda: next(next_id))
            for ann in annotations:
                t = ann[tk_str]
                v = ann["video_id"]
                if t in track_ids_to_update:
                    ann[tk_str] = new_tk_ids[t, v]
        return len(track_ids_to_update)
