import glob
import os, io
from itertools import repeat
from multiprocessing.pool import Pool, ThreadPool
from pathlib import Path
from threading import Thread
from urllib.parse import urlparse
import cv2
import numpy as np
from tqdm import tqdm
import tarfile
from datetime import datetime, timezone
from torchvision.datasets import ImageFolder

IMG_FORMATS = 'bmp', 'dng', 'jpeg', 'jpg', 'mpo', 'png', 'tif', 'tiff', 'webp', 'pfm'  # include image suffixes
VID_FORMATS = 'asf', 'avi', 'gif', 'm4v', 'mkv', 'mov', 'mp4', 'mpeg', 'mpg', 'ts', 'wmv'  # include video suffixes

def _letterbox(im, new_shape=(640, 640), color=(114, 114, 114), auto=True, scaleFill=False, scaleup=True, stride=32):
    # Resize and pad image while meeting stride-multiple constraints
    shape = im.shape[:2]  # current shape [height, width]
    if isinstance(new_shape, int):
        new_shape = (new_shape, new_shape)

    # Scale ratio (new / old)
    r = min(new_shape[0] / shape[0], new_shape[1] / shape[1])
    if not scaleup:  # only scale down, do not scale up (for better val mAP)
        r = min(r, 1.0)

    # Compute padding
    ratio = r, r  # width, height ratios
    new_unpad = int(round(shape[1] * r)), int(round(shape[0] * r))
    dw, dh = new_shape[1] - new_unpad[0], new_shape[0] - new_unpad[1]  # wh padding
    if auto:  # minimum rectangle
        dw, dh = np.mod(dw, stride), np.mod(dh, stride)  # wh padding
    elif scaleFill:  # stretch
        dw, dh = 0.0, 0.0
        new_unpad = (new_shape[1], new_shape[0])
        ratio = new_shape[1] / shape[1], new_shape[0] / shape[0]  # width, height ratios

    dw /= 2  # divide padding into 2 sides
    dh /= 2

    if shape[::-1] != new_unpad:  # resize
        im = cv2.resize(im, new_unpad, interpolation=cv2.INTER_LINEAR)
    top, bottom = int(round(dh - 0.1)), int(round(dh + 0.1))
    left, right = int(round(dw - 0.1)), int(round(dw + 0.1))
    im = cv2.copyMakeBorder(im, top, bottom, left, right, cv2.BORDER_CONSTANT, value=color)  # add border
    return im, ratio, (dw, dh)


class LoadImages:
    # YOLOv5 image/video dataloader, i.e. `python detect.py --source image.jpg/vid.mp4`
    def __init__(self, path, img_size=640, stride=32, auto=True, transforms=None, vid_stride=1):
        if isinstance(path, str) and Path(path).suffix == '.txt':  # *.txt file with img/vid/dir on each line
            path = Path(path).read_text().rsplit()
        files = []
        for p in sorted(path) if isinstance(path, (list, tuple)) else [path]:
            p = str(Path(p).resolve())
            if '*' in p:
                files.extend(sorted(glob.glob(p, recursive=True)))  # glob
            elif os.path.isdir(p):
                files.extend(sorted(glob.glob(os.path.join(p, '*.*'))))  # dir
            elif os.path.isfile(p):
                files.append(p)  # files
            else:
                raise FileNotFoundError(f'{p} does not exist')

        images = [x for x in files if x.split('.')[-1].lower() in IMG_FORMATS]
        videos = [x for x in files if x.split('.')[-1].lower() in VID_FORMATS]
        ni, nv = len(images), len(videos)

        self.img_size = img_size
        self.stride = stride
        self.files = images + videos
        self.nf = ni + nv  # number of files
        self.video_flag = [False] * ni + [True] * nv
        self.mode = 'image'
        self.auto = auto
        self.transforms = transforms  # optional
        self.vid_stride = vid_stride  # video frame-rate stride
        if any(videos):
            self._new_video(videos[0])  # new video
        else:
            self.cap = None
        assert self.nf > 0, f'No images or videos found in {p}. ' \
                            f'Supported formats are:\nimages: {IMG_FORMATS}\nvideos: {VID_FORMATS}'

    def __iter__(self):
        self.count = 0
        return self

    def __next__(self):
        if self.count == self.nf:
            raise StopIteration
        path = self.files[self.count]

        if self.video_flag[self.count]:
            # Read video
            self.mode = 'video'
            for _ in range(self.vid_stride):
                self.cap.grab()
            ret_val, im0 = self.cap.retrieve()
            while not ret_val:
                self.count += 1
                self.cap.release()
                if self.count == self.nf:  # last video
                    raise StopIteration
                path = self.files[self.count]
                self._new_video(path)
                ret_val, im0 = self.cap.read()

            self.frame += 1
            # im0 = self._cv2_rotate(im0)  # for use if cv2 autorotation is False
            s = f'video {self.count + 1}/{self.nf} ({self.frame}/{self.frames}) {path}: '

        else:
            # Read image
            self.count += 1
            im0 = cv2.imread(path)  # BGR
            assert im0 is not None, f'Image Not Found {path}'
            s = f'image {self.count}/{self.nf} {path}: '

        if self.transforms:
            im = self.transforms(im0)  # transforms
        else:
            im = _letterbox(im0, self.img_size, stride=self.stride, auto=self.auto)[0]  # padded resize
            im = im.transpose((2, 0, 1))[::-1]  # HWC to CHW, BGR to RGB
            im = np.ascontiguousarray(im)  # contiguous

        return path, im, im0, self.cap, s

    def _new_video(self, path):
        # Create a new video capture object
        self.frame = 0
        self.cap = cv2.VideoCapture(path)
        self.frames = int(self.cap.get(cv2.CAP_PROP_FRAME_COUNT) / self.vid_stride)
        self.orientation = int(self.cap.get(cv2.CAP_PROP_ORIENTATION_META))  # rotation degrees
        # self.cap.set(cv2.CAP_PROP_ORIENTATION_AUTO, 0)  # disable https://github.com/ultralytics/yolov5/issues/8493

    def _cv2_rotate(self, im):
        # Rotate a cv2 video manually
        if self.orientation == 0:
            return cv2.rotate(im, cv2.ROTATE_90_CLOCKWISE)
        elif self.orientation == 180:
            return cv2.rotate(im, cv2.ROTATE_90_COUNTERCLOCKWISE)
        elif self.orientation == 90:
            return cv2.rotate(im, cv2.ROTATE_180)
        return im

    def __len__(self):
        return self.nf  # number of files

def db_load_dataset(cnx, id, img_size=None, stride=None, load_img=True, transform=None):#数据集读取函数
    cursor = cnx.cursor()
    cursor.execute(
        "SELECT content, length FROM archive_content WHERE id_archive=%s ORDER BY sequence",
        (id,)
    )
    with open(f"dataset/{id}.tar", "wb") as fi:
        for (content, length) in tqdm(cursor):
            fi.write(content[:length])
    cursor.close()

    with tarfile.open(f"dataset/{id}.tar", "r") as tar:
        tar.extractall(f"dataset/{id}")
    os.remove(f"dataset/{id}.tar")

    if load_img:
        return LoadImages(f"dataset/{id}", img_size=img_size, stride=stride)
    else:
        return ImageFolder(f"dataset/{id}", transform=transform)

def db_save_predictions(cnx, job_id, buf):  # 存放预测结果的函数
    cursor = cnx.cursor()
    cur_dt = datetime.now(tz=timezone.utc)
    cursor.execute(
        "INSERT INTO archive (archive_type, id_job, name, create_time, update_time) VALUES (%s, %s, %s, %s, %s)",
        ("prediction", job_id, f"prediction#{job_id}", cur_dt, cur_dt)
    )
    test_id = cursor.lastrowid

    exc_state = "INSERT INTO archive_content (id_archive, content, length, sequence, create_time, update_time) VALUES (%s, %s, %s, %s, %s, %s)"

    for seq, beg in enumerate(range(0, len(buf), 128)):
        cur_dt = datetime.now(tz=timezone.utc)
        block = buf[beg:(beg + 128)]
        exc_val = (test_id, block, len(block), seq, cur_dt, cur_dt)

        cursor.execute(exc_state, exc_val)

    cnx.commit()
    cursor.close()
    return test_id