"""
Copyright (c) Microsoft Corporation.
Licensed under the MIT license.

End-to-end inference codes for 
3D human body mesh reconstruction from an image
"""

from __future__ import absolute_import, division, print_function
import argparse
import os
import os.path as op
import code
import json
import time
import datetime
import torch
import torchvision.models as models
from torchvision.utils import make_grid
import gc
import numpy as np
import cv2
from mesh_graphormer.modeling.bert import BertConfig, Graphormer
from mesh_graphormer.modeling.bert import Graphormer_Body_Network as Graphormer_Network
from mesh_graphormer.modeling._smpl import SMPL, Mesh
from mesh_graphormer.modeling.hrnet.hrnet_cls_net_gridfeat import get_cls_net_gridfeat
from mesh_graphormer.modeling.hrnet.config import config as hrnet_config
from mesh_graphormer.modeling.hrnet.config import update_config as hrnet_update_config
import mesh_graphormer.modeling.data.config as cfg
from mesh_graphormer.datasets.build import make_data_loader

from mesh_graphormer.utils.logger import setup_logger
from mesh_graphormer.utils.comm import synchronize, is_main_process, get_rank, get_world_size, all_gather
from mesh_graphormer.utils.miscellaneous import mkdir, set_seed
from mesh_graphormer.utils.metric_logger import AverageMeter, EvalMetricsLogger
from mesh_graphormer.utils.renderer import Renderer, visualize_reconstruction_and_att_local, visualize_reconstruction_no_text
from mesh_graphormer.utils.metric_pampjpe import reconstruction_error
from mesh_graphormer.utils.geometric_layers import orthographic_projection

from PIL import Image
from torchvision import transforms


device = "cuda"

transform = transforms.Compose([           
                    transforms.Resize(224),
                    transforms.CenterCrop(224),
                    transforms.ToTensor(),
                    transforms.Normalize(
                        mean=[0.485, 0.456, 0.406],
                        std=[0.229, 0.224, 0.225])])

transform_visualize = transforms.Compose([           
                    transforms.Resize(224),
                    transforms.CenterCrop(224),
                    transforms.ToTensor()])

def run_inference(args, image_list, Graphormer_model, smpl, renderer, mesh_sampler):
    # switch to evaluate mode
    Graphormer_model.eval()
    smpl.eval()
    with torch.no_grad():
        for image_file in image_list:
            if 'pred' not in image_file:
                att_all = []
                img = Image.open(image_file)
                img_tensor = transform(img)
                img_visual = transform_visualize(img)

                batch_imgs = torch.unsqueeze(img_tensor, 0).to(device)
                batch_visual_imgs = torch.unsqueeze(img_visual, 0).to(device)
                # forward-pass
                pred_camera, pred_3d_joints, pred_vertices_sub2, pred_vertices_sub, pred_vertices, hidden_states, att = Graphormer_model(batch_imgs, smpl, mesh_sampler)
                    
                # obtain 3d joints from full mesh
                pred_3d_joints_from_smpl = smpl.get_h36m_joints(pred_vertices)

                pred_3d_pelvis = pred_3d_joints_from_smpl[:,cfg.H36M_J17_NAME.index('Pelvis'),:]
                pred_3d_joints_from_smpl = pred_3d_joints_from_smpl[:,cfg.H36M_J17_TO_J14,:]
                pred_3d_joints_from_smpl = pred_3d_joints_from_smpl - pred_3d_pelvis[:, None, :]
                pred_vertices = pred_vertices - pred_3d_pelvis[:, None, :]

                # save attantion
                att_max_value = att[-1]
                att_cpu = np.asarray(att_max_value.cpu().detach())
                att_all.append(att_cpu)

                # obtain 3d joints, which are regressed from the full mesh
                pred_3d_joints_from_smpl = smpl.get_h36m_joints(pred_vertices)
                pred_3d_joints_from_smpl = pred_3d_joints_from_smpl[:,cfg.H36M_J17_TO_J14,:]
                # obtain 2d joints, which are projected from 3d joints of smpl mesh
                pred_2d_joints_from_smpl = orthographic_projection(pred_3d_joints_from_smpl, pred_camera)
                pred_2d_431_vertices_from_smpl = orthographic_projection(pred_vertices_sub2, pred_camera)
                visual_imgs_output = visualize_mesh( renderer, batch_visual_imgs[0],
                                                                pred_vertices[0].detach(), 
                                                                pred_camera.detach())
                # visual_imgs_output = visualize_mesh_and_attention( renderer, batch_visual_imgs[0],
                #                                             pred_vertices[0].detach(), 
                #                                             pred_vertices_sub2[0].detach(), 
                #                                             pred_2d_431_vertices_from_smpl[0].detach(),
                #                                             pred_2d_joints_from_smpl[0].detach(),
                #                                             pred_camera.detach(),
                #                                             att[-1][0].detach())

                visual_imgs = visual_imgs_output.transpose(1,2,0)
                visual_imgs = np.asarray(visual_imgs)
                        
                temp_fname = image_file[:-4] + '_graphormer_pred.jpg'
                print('save to ', temp_fname)
                cv2.imwrite(temp_fname, np.asarray(visual_imgs[:,:,::-1]*255))

    return 

def visualize_mesh( renderer, images,
                    pred_vertices_full,
                    pred_camera):
    img = images.cpu().numpy().transpose(1,2,0)
    # Get predict vertices for the particular example
    vertices_full = pred_vertices_full.cpu().numpy() 
    cam = pred_camera.cpu().numpy()
    # Visualize only mesh reconstruction 
    rend_img = visualize_reconstruction_no_text(img, 224, vertices_full, cam, renderer, color='light_blue')
    rend_img = rend_img.transpose(2,0,1)
    return rend_img

def visualize_mesh_and_attention( renderer, images,
                    pred_vertices_full,
                    pred_vertices, 
                    pred_2d_vertices,
                    pred_2d_joints,
                    pred_camera,
                    attention):
    img = images.cpu().numpy().transpose(1,2,0)
    # Get predict vertices for the particular example
    vertices_full = pred_vertices_full.cpu().numpy() 
    vertices = pred_vertices.cpu().numpy()
    vertices_2d = pred_2d_vertices.cpu().numpy()
    joints_2d = pred_2d_joints.cpu().numpy()
    cam = pred_camera.cpu().numpy()
    att = attention.cpu().numpy()
    # Visualize reconstruction and attention
    rend_img = visualize_reconstruction_and_att_local(img, 224, vertices_full, vertices, vertices_2d, cam, renderer, joints_2d, att, color='light_blue')
    rend_img = rend_img.transpose(2,0,1)
    return rend_img


def parse_args():
    parser = argparse.ArgumentParser()
    #########################################################
    # Data related arguments
    #########################################################
    parser.add_argument("--num_workers", default=4, type=int, 
                        help="Workers in dataloader.")
    parser.add_argument("--img_scale_factor", default=1, type=int, 
                        help="adjust image resolution.")
    parser.add_argument("--image_file_or_path", default='./samples/human-body', type=str, 
                        help="test data") 
    #########################################################
    # Loading/saving checkpoints
    #########################################################
    parser.add_argument("--model_name_or_path", default='src/modeling/bert/bert-base-uncased/', type=str, required=False,
                        help="Path to pre-trained transformer model or model type.")
    parser.add_argument("--resume_checkpoint", default=None, type=str, required=False,
                        help="Path to specific checkpoint for resume training.")
    parser.add_argument("--output_dir", default='output/', type=str, required=False,
                        help="The output directory to save checkpoint and test results.")
    parser.add_argument("--config_name", default="", type=str, 
                        help="Pretrained config name or path if not the same as model_name.")
    #########################################################
    # Model architectures
    #########################################################
    parser.add_argument('-a', '--arch', default='hrnet-w64',
                    help='CNN backbone architecture: hrnet-w64, hrnet, resnet50')
    parser.add_argument("--num_hidden_layers", default=4, type=int, required=False, 
                        help="Update model config if given")
    parser.add_argument("--hidden_size", default=-1, type=int, required=False, 
                        help="Update model config if given")
    parser.add_argument("--num_attention_heads", default=4, type=int, required=False, 
                        help="Update model config if given. Note that the division of "
                        "hidden_size / num_attention_heads should be in integer.")
    parser.add_argument("--intermediate_size", default=-1, type=int, required=False, 
                        help="Update model config if given.")
    parser.add_argument("--input_feat_dim", default='2051,512,128', type=str, 
                        help="The Image Feature Dimension.")          
    parser.add_argument("--hidden_feat_dim", default='1024,256,64', type=str, 
                        help="The Image Feature Dimension.")   
    parser.add_argument("--which_gcn", default='0,0,1', type=str, 
                        help="which encoder block to have graph conv. Encoder1, Encoder2, Encoder3. Default: only Encoder3 has graph conv") 
    parser.add_argument("--mesh_type", default='body', type=str, help="body or hand") 
    parser.add_argument("--interm_size_scale", default=2, type=int)
    #########################################################
    # Others
    #########################################################
    parser.add_argument("--run_eval_only", default=True, action='store_true',) 
    parser.add_argument("--device", type=str, default='cuda', 
                        help="cuda or cpu")
    parser.add_argument('--seed', type=int, default=88, 
                        help="random seed for initialization.")

    args = parser.parse_args()
    return args


def main(args):
    global logger
    # Setup CUDA, GPU & distributed training
    args.num_gpus = int(os.environ['WORLD_SIZE']) if 'WORLD_SIZE' in os.environ else 1
    os.environ['OMP_NUM_THREADS'] = str(args.num_workers)
    print('set os.environ[OMP_NUM_THREADS] to {}'.format(os.environ['OMP_NUM_THREADS']))

    args.distributed = args.num_gpus > 1
    args.device = torch.device(args.device)
    
    mkdir(args.output_dir)
    logger = setup_logger("Graphormer", args.output_dir, get_rank())
    set_seed(args.seed, args.num_gpus)
    logger.info("Using {} GPUs".format(args.num_gpus))

    # Mesh and SMPL utils
    smpl = SMPL().to(args.device)
    mesh_sampler = Mesh()

    # Renderer for visualization
    renderer = Renderer(faces=smpl.faces.cpu().numpy())

    # Load model
    trans_encoder = []

    input_feat_dim = [int(item) for item in args.input_feat_dim.split(',')]
    hidden_feat_dim = [int(item) for item in args.hidden_feat_dim.split(',')]
    output_feat_dim = input_feat_dim[1:] + [3]

    # which encoder block to have graph convs
    which_blk_graph = [int(item) for item in args.which_gcn.split(',')]
    
    if args.run_eval_only==True and args.resume_checkpoint!=None and args.resume_checkpoint!='None' and 'state_dict' not in args.resume_checkpoint:
        # if only run eval, load checkpoint
        logger.info("Evaluation: Loading from checkpoint {}".format(args.resume_checkpoint))
        _model = torch.load(args.resume_checkpoint)
    else:
        # init three transformer-encoder blocks in a loop
        for i in range(len(output_feat_dim)):
            config_class, model_class = BertConfig, Graphormer
            config = config_class.from_pretrained(args.config_name if args.config_name \
                    else args.model_name_or_path)

            config.output_attentions = False
            config.img_feature_dim = input_feat_dim[i] 
            config.output_feature_dim = output_feat_dim[i]
            args.hidden_size = hidden_feat_dim[i]
            args.intermediate_size = int(args.hidden_size*args.interm_size_scale)

            if which_blk_graph[i]==1:
                config.graph_conv = True
                logger.info("Add Graph Conv")
            else:
                config.graph_conv = False

            config.mesh_type = args.mesh_type

            # update model structure if specified in arguments
            update_params = ['num_hidden_layers', 'hidden_size', 'num_attention_heads', 'intermediate_size']

            for idx, param in enumerate(update_params):
                arg_param = getattr(args, param)
                config_param = getattr(config, param)
                if arg_param > 0 and arg_param != config_param:
                    logger.info("Update config parameter {}: {} -> {}".format(param, config_param, arg_param))
                    setattr(config, param, arg_param)

            # init a transformer encoder and append it to a list
            assert config.hidden_size % config.num_attention_heads == 0
            model = model_class(config=config) 
            logger.info("Init model from scratch.")
            trans_encoder.append(model)

        # init ImageNet pre-trained backbone model
        if args.arch=='hrnet':
            hrnet_yaml = 'models/hrnet/cls_hrnet_w40_sgd_lr5e-2_wd1e-4_bs32_x100.yaml'
            hrnet_checkpoint = 'models/hrnet/hrnetv2_w40_imagenet_pretrained.pth'
            hrnet_update_config(hrnet_config, hrnet_yaml)
            backbone = get_cls_net_gridfeat(hrnet_config, pretrained=hrnet_checkpoint)
            logger.info('=> loading hrnet-v2-w40 model')
        elif args.arch=='hrnet-w64':
            hrnet_yaml = 'models/hrnet/cls_hrnet_w64_sgd_lr5e-2_wd1e-4_bs32_x100.yaml'
            hrnet_checkpoint = 'models/hrnet/hrnetv2_w64_imagenet_pretrained.pth'
            hrnet_update_config(hrnet_config, hrnet_yaml)
            backbone = get_cls_net_gridfeat(hrnet_config, pretrained=hrnet_checkpoint)
            logger.info('=> loading hrnet-v2-w64 model')
        else:
            print("=> using pre-trained model '{}'".format(args.arch))
            backbone = models.__dict__[args.arch](pretrained=True)
            # remove the last fc layer
            backbone = torch.nn.Sequential(*list(backbone.children())[:-2])


        trans_encoder = torch.nn.Sequential(*trans_encoder)
        total_params = sum(p.numel() for p in trans_encoder.parameters())
        logger.info('Graphormer encoders total parameters: {}'.format(total_params))
        backbone_total_params = sum(p.numel() for p in backbone.parameters())
        logger.info('Backbone total parameters: {}'.format(backbone_total_params))

        # build end-to-end Graphormer network (CNN backbone + multi-layer graphormer encoder)
        _model = Graphormer_Network(args, config, backbone, trans_encoder, mesh_sampler)

        if args.resume_checkpoint!=None and args.resume_checkpoint!='None':
            # for fine-tuning or resume training or inference, load weights from checkpoint
            logger.info("Loading state dict from checkpoint {}".format(args.resume_checkpoint))
            # workaround approach to load sparse tensor in graph conv.
            states = torch.load(args.resume_checkpoint)
            # states = checkpoint_loaded.state_dict()
            for k, v in states.items():
                states[k] = v.cpu()
            # del checkpoint_loaded
            _model.load_state_dict(states, strict=False)
            del states
            gc.collect()
            torch.cuda.empty_cache()

    # update configs to enable attention outputs
    setattr(_model.trans_encoder[-1].config,'output_attentions', True)
    setattr(_model.trans_encoder[-1].config,'output_hidden_states', True)
    _model.trans_encoder[-1].bert.encoder.output_attentions = True
    _model.trans_encoder[-1].bert.encoder.output_hidden_states =  True
    for iter_layer in range(4):
        _model.trans_encoder[-1].bert.encoder.layer[iter_layer].attention.self.output_attentions = True
    for inter_block in range(3):
        setattr(_model.trans_encoder[-1].config,'device', args.device)

    _model.to(args.device)
    logger.info("Run inference")

    image_list = []
    if not args.image_file_or_path:
        raise ValueError("image_file_or_path not specified")
    if op.isfile(args.image_file_or_path):
        image_list = [args.image_file_or_path]
    elif op.isdir(args.image_file_or_path):
        # should be a path with images only
        for filename in os.listdir(args.image_file_or_path):
            if filename.endswith(".png") or filename.endswith(".jpg") and 'pred' not in filename:
                image_list.append(args.image_file_or_path+'/'+filename) 
    else:
        raise ValueError("Cannot find images at {}".format(args.image_file_or_path))

    run_inference(args, image_list, _model, smpl, renderer, mesh_sampler)   

if __name__ == "__main__":
    args = parse_args()
    main(args)
