import time
from absl import app, flags, logging
from absl.flags import FLAGS
import core.utils as utils
from core.yolov4 import YOLOv4, YOLOv3, YOLOv3_tiny, decode
from PIL import Image
from core.config import cfg
import cv2
import numpy as np
import tensorflow as tf

flags.DEFINE_string('framework', 'tf', '(tf, tflite')
flags.DEFINE_string('weights', './data/yolov4.weights',
                    'path to weights file')
flags.DEFINE_integer('size', 608, 'resize images to')
flags.DEFINE_boolean('tiny', False, 'yolo or yolo-tiny')
flags.DEFINE_string('model', 'yolov4', 'yolov3 or yolov4')
flags.DEFINE_string('video', './data/road.avi', 'path to input video')

def main(_argv):
    if FLAGS.tiny:
        STRIDES = np.array(cfg.YOLO.STRIDES_TINY)
        ANCHORS = utils.get_anchors(cfg.YOLO.ANCHORS_TINY, FLAGS.tiny)
    else:
        STRIDES = np.array(cfg.YOLO.STRIDES)
        if FLAGS.model == 'yolov4':
            ANCHORS = utils.get_anchors(cfg.YOLO.ANCHORS, FLAGS.tiny)
        else:
            ANCHORS = utils.get_anchors(cfg.YOLO.ANCHORS_V3, FLAGS.tiny)
    NUM_CLASS = len(utils.read_class_names(cfg.YOLO.CLASSES))
    XYSCALE = cfg.YOLO.XYSCALE
    input_size = FLAGS.size
    video_path = FLAGS.video

    print("Video from: ", video_path )
    vid = cv2.VideoCapture(video_path)

    if FLAGS.framework == 'tf':
        input_layer = tf.keras.layers.Input([input_size, input_size, 3])
        if FLAGS.tiny:
            feature_maps = YOLOv3_tiny(input_layer, NUM_CLASS)
            bbox_tensors = []
            for i, fm in enumerate(feature_maps):
                bbox_tensor = decode(fm, NUM_CLASS, i)
                bbox_tensors.append(bbox_tensor)
            model = tf.keras.Model(input_layer, bbox_tensors)
            utils.load_weights_tiny(model, FLAGS.weights)
        else:
            if FLAGS.model == 'yolov3':
                feature_maps = YOLOv3(input_layer, NUM_CLASS)
                bbox_tensors = []
                for i, fm in enumerate(feature_maps):
                    bbox_tensor = decode(fm, NUM_CLASS, i)
                    bbox_tensors.append(bbox_tensor)
                model = tf.keras.Model(input_layer, bbox_tensors)
                utils.load_weights_v3(model, FLAGS.weights)
            elif FLAGS.model == 'yolov4':
                feature_maps = YOLOv4(input_layer, NUM_CLASS)
                bbox_tensors = []
                for i, fm in enumerate(feature_maps):
                    bbox_tensor = decode(fm, NUM_CLASS, i)
                    bbox_tensors.append(bbox_tensor)
                model = tf.keras.Model(input_layer, bbox_tensors)
                utils.load_weights(model, FLAGS.weights)

        model.summary()
    else:
        # Load TFLite model and allocate tensors.
        interpreter = tf.lite.Interpreter(model_path=FLAGS.weights)
        interpreter.allocate_tensors()
        # Get input and output tensors.
        input_details = interpreter.get_input_details()
        output_details = interpreter.get_output_details()
        print(input_details)
        print(output_details)

    while True:
        return_value, frame = vid.read()
        if return_value:
            frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
            image = Image.fromarray(frame)
        else:
            raise ValueError("No image! Try with another video format")
        frame_size = frame.shape[:2]
        image_data = utils.image_preporcess(np.copy(frame), [input_size, input_size])
        image_data = image_data[np.newaxis, ...].astype(np.float32)
        prev_time = time.time()

        if FLAGS.framework == 'tf':
            pred_bbox = model.predict(image_data)
        else:
            interpreter.set_tensor(input_details[0]['index'], image_data)
            interpreter.invoke()
            pred_bbox = [interpreter.get_tensor(output_details[i]['index']) for i in range(len(output_details))]

        if FLAGS.model == 'yolov4':
            pred_bbox = utils.postprocess_bbbox(pred_bbox, ANCHORS, STRIDES, XYSCALE)
        else:
            pred_bbox = utils.postprocess_bbbox(pred_bbox, ANCHORS, STRIDES)

        bboxes = utils.postprocess_boxes(pred_bbox, frame_size, input_size, 0.25)
        bboxes = utils.nms(bboxes, 0.213, method='nms')

        image = utils.draw_bbox(frame, bboxes)
        curr_time = time.time()
        exec_time = curr_time - prev_time
        result = np.asarray(image)
        info = "time: %.2f ms" %(1000*exec_time)
        print(info)
        cv2.namedWindow("result", cv2.WINDOW_AUTOSIZE)
        result = cv2.cvtColor(image, cv2.COLOR_RGB2BGR)
        cv2.imshow("result", result)
        if cv2.waitKey(1) & 0xFF == ord('q'): break

if __name__ == '__main__':
    try:
        app.run(main)
    except SystemExit:
        pass