# -*- coding: utf-8 -*-
"""
Created on Wed Sep 20 14:28:20 2023

@author: ym
"""
import numpy as np
from scipy.spatial.distance import cdist


def boxes_add_fid(tboxes):
    '''
        将 bboxes 对应的帧索引添加到 boxes 最后一列
    Return：
        bboxes: [x1, y1, x2, y2, track_id, score, cls, frame_index]
    '''
    
    bboxes = np.empty((0, 8), dtype = np.float32)  
    for tbox, f in tboxes:
        data = tbox.numpy()
        
        frame = f * np.ones([data.shape[0], 1])
        bbox = np.concatenate([data, frame], axis=1)
        bboxes = np.concatenate([bboxes, bbox], axis=0)
    
    return bboxes


    
def array2list(bboxes):
    '''
        将 bboxes 变换为 track 列表
        bboxes: [x1, y1, x2, y2, track_id, score, cls, frame_index]
    Return：
        lboxes：列表，列表中元素具有同一 track_id，xywh 格式
                [x, y, w, h, track_id, score, cls, frame_index]        
    '''
    track_ids = set(bboxes[:, 4])
    lboxes = []
    for t_id in track_ids:
        idx = np.where(bboxes[:, 4] == t_id)[0]
        box = bboxes[idx, :]
        
        x = (box[:, 0] + box[:, 2]) / 2
        y = (box[:, 1] + box[:, 3]) / 2
        
        # box: [x, y, w, h, track_id, score, cls, frame_index]
        box[:, 2] = box[:, 2] - box[:, 0]    
        box[:, 3] = box[:, 3] - box[:, 1]
        box[:, 0] = x
        box[:, 1] = y
  
        lboxes.append(box)
    
    return lboxes


def max_dist_track(tboxes):
    
    '''
        计算 tboxes 中最大dist的 track
    Return：     
    '''
    
    max_track_dist, max_dist = 0, 0
    for track in tboxes:
        box = track[:, :4].astype(int)
        
        dist = cdist(box[:, :2], box[:, :2])
        
        dm = np.max(dist)
        if dm > max_dist:
            max_dist = dm 
            max_track = track.copy()
            max_track_dist = dist.copy()
            
            
            # 同一 track_id 中目标中心移动最大距离的索引（ix1, ix2）
            indx, indy = np.where(dist == dm)
            ix1,  ix2 = indx[0], indy[0]
            # 确保 ix1 < ix2，索引 ix1 是开始时的视频
            if ix1 > ix2: ix1, ix2 = ix2, ix1
            
# =============================================================================
# # =============================================================================
# # 逻辑分析
# # =============================================================================
#     Scanzone = ((0, int(Height/4)), (int(2*Weight/3), Weight))
#     if max_track.shape[0] > 10:    
#     
#         # max_track 视频序列的第一帧索引 idx1
#         frame_1 = int(min(max_track[:, 7]))
#         idx1 = np.where(max_track[:, 7] == frame_1)[0][0]
#         
#         # max_track 视频序列的最后一帧索引 idx2
#         frame_2 = int(max(max_track[:, 7]))
#         idx2 = np.where(max_track[:, 7] == frame_2)[0][0]
#         
#         # max_track 视频序列的第一帧目标位置中心 (x1, y1)
#         x1, y1 = max_track[idx1, :2]
#         
#         # max_track 视频序列的第最后一帧目标位置中心 (x2, y2)
#         x2, y2 = max_track[idx2, :2]
#             
#         
#         # track序列第一帧和最后一帧的距离，该距离和 mx_dist 不是一个概念
#         dist_1_2 = max_track_dist[idx1, idx2]
#         
#         if max_dist < 3 * Height/10:
#             State = Uncertain
#         
#         elif y1 > y2:
#             State = TakeOut
#             
#         elif y1 < y2:
#             State = PutIn
# =============================================================================
    return max_track, max_dist