import sys
sys.path.append('./extern/dust3r')
from dust3r.inference import inference, load_model
from dust3r.utils.image import load_images
from dust3r.image_pairs import make_pairs
from dust3r.cloud_opt import global_aligner, GlobalAlignerMode
from dust3r.utils.device import to_numpy
import trimesh
import torch
import numpy as np
import torchvision
import os
import copy
import cv2  
from PIL import Image
import pytorch3d
from pytorch3d.structures import Pointclouds
from torchvision.utils import save_image
import torch.nn.functional as F
import torchvision.transforms as transforms
from PIL import Image
from utils.pvd_utils import *
from omegaconf import OmegaConf
from pytorch_lightning import seed_everything
from utils.diffusion_utils import instantiate_from_config,load_model_checkpoint,image_guided_synthesis
from pathlib import Path
from torchvision.utils import save_image

class ViewCrafter:
    def __init__(self, opts, gradio = False):
        self.opts = opts
        self.device = opts.device
        self.setup_dust3r()
        # self.setup_diffusion()
        # initialize ref images, pcd
        if not gradio:
            self.images, self.img_ori = self.load_initial_images(image_dir=self.opts.image_dir)
            self.run_dust3r(input_images=self.images)
        
    def run_dust3r(self, input_images,clean_pc = False):
        pairs = make_pairs(input_images, scene_graph='complete', prefilter=None, symmetrize=True)
        output = inference(pairs, self.dust3r, self.device, batch_size=self.opts.batch_size)

        mode = GlobalAlignerMode.PointCloudOptimizer #if len(self.images) > 2 else GlobalAlignerMode.PairViewer
        scene = global_aligner(output, device=self.device, mode=mode)
        if mode == GlobalAlignerMode.PointCloudOptimizer:
            loss = scene.compute_global_alignment(init='mst', niter=self.opts.niter, schedule=self.opts.schedule, lr=self.opts.lr)

        if clean_pc:
            self.scene = scene.clean_pointcloud()
        else:
            self.scene = scene

    def render_pcd(self,pts3d,imgs,masks,views,renderer,device):
        
        imgs = to_numpy(imgs)
        pts3d = to_numpy(pts3d)

        if masks == None:
            pts = torch.from_numpy(np.concatenate([p for p in pts3d])).view(-1, 3).to(device)
            col = torch.from_numpy(np.concatenate([p for p in imgs])).view(-1, 3).to(device)
        else:
            # masks = to_numpy(masks)
            pts = torch.from_numpy(np.concatenate([p[m] for p, m in zip(pts3d, masks)])).to(device)
            col = torch.from_numpy(np.concatenate([p[m] for p, m in zip(imgs, masks)])).to(device)
        
        color_mask = torch.ones(col.shape).to(device)

        point_cloud_mask = Pointclouds(points=[pts],features=[color_mask]).extend(views)
        point_cloud = Pointclouds(points=[pts], features=[col]).extend(views)
        images = renderer(point_cloud)
        view_masks = renderer(point_cloud_mask)
        return images, view_masks
    
    def run_render(self, pcd, imgs,masks, H, W, camera_traj,num_views,use_cpu=False):
        if use_cpu:
            device = torch.device("cpu")
        else:
            device = self.device
        render_setup = setup_renderer(camera_traj, image_size=(H,W))
        renderer = render_setup['renderer']
        render_results, viewmask = self.render_pcd(pcd, imgs, masks, num_views,renderer,device)
        return render_results, viewmask

    
    def run_diffusion(self, renderings):

        prompts = [self.opts.prompt]
        videos = (renderings * 2. - 1.).permute(3,0,1,2).unsqueeze(0).to(self.device)
        condition_index = [0]
        with torch.no_grad(), torch.cuda.amp.autocast():
            # [1,1,c,t,h,w]
            batch_samples = image_guided_synthesis(self.diffusion, prompts, videos, self.noise_shape, self.opts.n_samples, self.opts.ddim_steps, self.opts.ddim_eta, \
                               self.opts.unconditional_guidance_scale, self.opts.cfg_img, self.opts.frame_stride, self.opts.text_input, self.opts.multiple_cond_cfg, self.opts.timestep_spacing, self.opts.guidance_rescale, condition_index)

            # save_results_seperate(batch_samples[0], self.opts.save_dir, fps=8)
            # torch.Size([1, 3, 25, 576, 1024]) [-1,1]

        return torch.clamp(batch_samples[0][0].permute(1,2,3,0), -1., 1.) 

    def nvs_single_view(self, gradio=False):
        # 最后一个view为 0 pose
        c2ws = self.scene.get_im_poses().detach()[1:] 
        principal_points = self.scene.get_principal_points().detach()[1:] #cx cy
        focals = self.scene.get_focals().detach()[1:] 
        shape = self.images[0]['true_shape']
        H, W = int(shape[0][0]), int(shape[0][1])
        pcd = [i.detach() for i in self.scene.get_pts3d(clip_thred=self.opts.dpt_trd)] # a list of points of size whc
        depth = [i.detach() for i in self.scene.get_depthmaps()]
        depth_avg = depth[-1][H//2,W//2] #以图像中心处的depth(z)为球心旋转
        radius = depth_avg*self.opts.center_scale #缩放调整

        ## change coordinate
        c2ws,pcd =  world_point_to_obj(poses=c2ws, points=torch.stack(pcd), k=-1, r=radius, elevation=self.opts.elevation, device=self.device)

        imgs = np.array(self.scene.imgs)
        
        masks = None

        if self.opts.mode == 'single_view_nbv':
            ## 输入candidate->渲染mask->最大mask对应的pose作为nbv
            ## nbv模式下self.opts.d_theta[0], self.opts.d_phi[0]代表search space中的网格theta, phi之间的间距; self.opts.d_phi[0]的符号代表方向,分为左右两个方向
            ## FIXME hard coded candidate view数量, 以left为例,第一次迭代从[左,左上]中选取, 从第二次开始可以从[左,左上,左下]中选取
            num_candidates = 2
            candidate_poses,thetas,phis = generate_candidate_poses(c2ws, H, W, focals, principal_points, self.opts.d_theta[0], self.opts.d_phi[0],num_candidates, self.device)
            _, viewmask = self.run_render([pcd[-1]], [imgs[-1]],masks, H, W, candidate_poses,num_candidates,use_cpu=True)
            nbv_id = torch.argmin(viewmask.sum(dim=[1,2,3])).item()
            save_image( viewmask.permute(0,3,1,2), os.path.join(self.opts.save_dir,f"candidate_mask0_nbv{nbv_id}.png"), normalize=True, value_range=(0, 1))
            theta_nbv = thetas[nbv_id]
            phi_nbv = phis[nbv_id]
            # generate camera trajectory from T_curr to T_nbv
            camera_traj,num_views = generate_traj_specified(c2ws, H, W, focals, principal_points, theta_nbv, phi_nbv, self.opts.d_r[0],self.opts.video_length, self.device)
            # 重置elevation
            self.opts.elevation -= theta_nbv
        elif self.opts.mode == 'single_view_target':
            camera_traj,num_views = generate_traj_specified(c2ws, H, W, focals, principal_points, self.opts.d_theta[0], self.opts.d_phi[0], self.opts.d_r[0],self.opts.video_length, self.device)
        elif self.opts.mode == 'single_view_txt':
            if not gradio:
                with open(self.opts.traj_txt, 'r') as file:
                    lines = file.readlines()
                    phi = [float(i) for i in lines[0].split()]
                    theta = [float(i) for i in lines[1].split()]
                    r = [float(i) for i in lines[2].split()]
            else: 
                phi, theta, r = self.gradio_traj
            device = torch.device("cpu")
            camera_traj,num_views = generate_traj_txt(c2ws, H, W, focals, principal_points, phi, theta, r,self.opts.video_length, device,viz_traj=True, save_dir = self.opts.save_dir)
            # camera_traj,num_views = generate_traj_txt(c2ws, H, W, focals, principal_points, phi, theta, r,self.opts.video_length, self.device,viz_traj=True, save_dir = self.opts.save_dir)
        else:
            raise KeyError(f"Invalid Mode: {self.opts.mode}")

        render_results, viewmask = self.run_render([pcd[-1]], [imgs[-1]],masks, H, W, camera_traj,num_views,use_cpu=True)
        render_results = render_results.to(self.device)
        render_results = F.interpolate(render_results.permute(0,3,1,2), size=(576, 1024), mode='bilinear', align_corners=False).permute(0,2,3,1)
        render_results[0] = self.img_ori
        if self.opts.mode == 'single_view_txt':
            if phi[-1]==0. and theta[-1]==0. and r[-1]==0.:
                render_results[-1] = self.img_ori
                
        save_video(render_results, os.path.join(self.opts.save_dir, 'render0.mp4'))
        save_pointcloud_with_normals([imgs[-1]], [pcd[-1]], msk=None, save_path=os.path.join(self.opts.save_dir,'pcd0.ply') , mask_pc=False, reduce_pc=False)
        diffusion_results = self.run_diffusion(render_results)
        save_video((diffusion_results + 1.0) / 2.0, os.path.join(self.opts.save_dir, 'diffusion0.mp4'))

        return diffusion_results

    def nvs_sparse_view(self,iter):

        c2ws = self.scene.get_im_poses().detach()
        principal_points = self.scene.get_principal_points().detach()
        focals = self.scene.get_focals().detach()
        shape = self.images[0]['true_shape']
        H, W = int(shape[0][0]), int(shape[0][1])
        pcd = [i.detach() for i in self.scene.get_pts3d(clip_thred=self.opts.dpt_trd)] # a list of points of size whc
        depth = [i.detach() for i in self.scene.get_depthmaps()]
        depth_avg = depth[0][H//2,W//2] #以ref图像中心处的depth(z)为球心旋转
        radius = depth_avg*self.opts.center_scale #缩放调整

        ## masks for cleaner point cloud
        self.scene.min_conf_thr = float(self.scene.conf_trf(torch.tensor(self.opts.min_conf_thr)))
        masks = self.scene.get_masks()
        depth = self.scene.get_depthmaps()
        bgs_mask = [dpt > self.opts.bg_trd*(torch.max(dpt[40:-40,:])+torch.min(dpt[40:-40,:])) for dpt in depth]
        masks_new = [m+mb for m, mb in zip(masks,bgs_mask)] 
        masks = to_numpy(masks_new)

        ## render, 从c2ws[0]即ref image对应的相机开始
        imgs = np.array(self.scene.imgs)

        if self.opts.mode == 'single_view_ref_iterative':
            c2ws,pcd =  world_point_to_obj(poses=c2ws, points=torch.stack(pcd), k=0, r=radius, elevation=self.opts.elevation, device=self.device)
            camera_traj,num_views = generate_traj_specified(c2ws[0:1], H, W, focals[0:1], principal_points[0:1], self.opts.d_theta[iter], self.opts.d_phi[iter], self.opts.d_r[iter],self.opts.video_length, self.device)
            render_results, viewmask = self.run_render(pcd, imgs,masks, H, W, camera_traj,num_views)
            render_results = F.interpolate(render_results.permute(0,3,1,2), size=(576, 1024), mode='bilinear', align_corners=False).permute(0,2,3,1)
            render_results[0] = self.img_ori
        elif self.opts.mode == 'single_view_1drc_iterative':
            self.opts.elevation -= self.opts.d_theta[iter-1]
            c2ws,pcd =  world_point_to_obj(poses=c2ws, points=torch.stack(pcd), k=-1, r=radius, elevation=self.opts.elevation, device=self.device)
            camera_traj,num_views = generate_traj_specified(c2ws[-1:], H, W, focals[-1:], principal_points[-1:], self.opts.d_theta[iter], self.opts.d_phi[iter], self.opts.d_r[iter],self.opts.video_length, self.device)
            render_results, viewmask = self.run_render(pcd, imgs,masks, H, W, camera_traj,num_views)
            render_results = F.interpolate(render_results.permute(0,3,1,2), size=(576, 1024), mode='bilinear', align_corners=False).permute(0,2,3,1)
            render_results[0] = (self.images[-1]['img_ori'].squeeze(0).permute(1,2,0)+1.)/2.
        elif self.opts.mode == 'single_view_nbv':
            c2ws,pcd =  world_point_to_obj(poses=c2ws, points=torch.stack(pcd), k=-1, r=radius, elevation=self.opts.elevation, device=self.device)
            ## 输入candidate->渲染mask->最大mask对应的pose作为nbv
            ## nbv模式下self.opts.d_theta[0], self.opts.d_phi[0]代表search space中的网格theta, phi之间的间距; self.opts.d_phi[0]的符号代表方向,分为左右两个方向
            ## FIXME hard coded candidate view数量, 以left为例,第一次迭代从[左,左上]中选取, 从第二次开始可以从[左,左上,左下]中选取
            num_candidates = 3
            candidate_poses,thetas,phis = generate_candidate_poses(c2ws[-1:], H, W, focals[-1:], principal_points[-1:], self.opts.d_theta[0], self.opts.d_phi[0], num_candidates, self.device)
            _, viewmask = self.run_render(pcd, imgs,masks, H, W, candidate_poses,num_candidates)
            nbv_id = torch.argmin(viewmask.sum(dim=[1,2,3])).item()
            save_image(viewmask.permute(0,3,1,2), os.path.join(self.opts.save_dir,f"candidate_mask{iter}_nbv{nbv_id}.png"), normalize=True, value_range=(0, 1))
            theta_nbv = thetas[nbv_id]
            phi_nbv = phis[nbv_id]   
            # generate camera trajectory from T_curr to T_nbv
            camera_traj,num_views = generate_traj_specified(c2ws[-1:], H, W, focals[-1:], principal_points[-1:], theta_nbv, phi_nbv, self.opts.d_r[0],self.opts.video_length, self.device)
            # 重置elevation
            self.opts.elevation -= theta_nbv    
            render_results, viewmask = self.run_render(pcd, imgs,masks, H, W, camera_traj,num_views)
            render_results = F.interpolate(render_results.permute(0,3,1,2), size=(576, 1024), mode='bilinear', align_corners=False).permute(0,2,3,1)
            render_results[0] = (self.images[-1]['img_ori'].squeeze(0).permute(1,2,0)+1.)/2. 
        else:
            raise KeyError(f"Invalid Mode: {self.opts.mode}")

        save_video(render_results, os.path.join(self.opts.save_dir, f'render{iter}.mp4'))
        save_pointcloud_with_normals(imgs, pcd, msk=masks, save_path=os.path.join(self.opts.save_dir, f'pcd{iter}.ply') , mask_pc=True, reduce_pc=False)
        diffusion_results = self.run_diffusion(render_results)
        save_video((diffusion_results + 1.0) / 2.0, os.path.join(self.opts.save_dir, f'diffusion{iter}.mp4'))
        # torch.Size([25, 576, 1024, 3])
        return diffusion_results
    
    def nvs_single_view_ref_iterative(self):

        all_results = []
        sample_rate = 6
        idx = 1 #初始包含1张ref image
        for itr in range(0, len(self.opts.d_phi)):
            if itr == 0:
                self.images = [self.images[0]] #去掉后一份copy
                diffusion_results_itr = self.nvs_single_view()
                # diffusion_results_itr = torch.randn([25, 576, 1024, 3]).to(self.device)
                diffusion_results_itr = diffusion_results_itr.permute(0,3,1,2)
                all_results.append(diffusion_results_itr)
            else:
                for i in range(0+sample_rate, diffusion_results_itr.shape[0], sample_rate):
                    self.images.append(get_input_dict(diffusion_results_itr[i:i+1,...],idx,dtype = torch.float32))
                    idx += 1
                self.run_dust3r(input_images=self.images, clean_pc=True)
                diffusion_results_itr = self.nvs_sparse_view(itr)
                # diffusion_results_itr = torch.randn([25, 576, 1024, 3]).to(self.device)
                diffusion_results_itr = diffusion_results_itr.permute(0,3,1,2)
                all_results.append(diffusion_results_itr)
        return all_results

    def nvs_single_view_1drc_iterative(self):

        all_results = []
        sample_rate = 6
        idx = 1 #初始包含1张ref image
        for itr in range(0, len(self.opts.d_phi)):
            if itr == 0:
                self.images = [self.images[0]] #去掉后一份copy
                diffusion_results_itr = self.nvs_single_view()
                # diffusion_results_itr = torch.randn([25, 576, 1024, 3]).to(self.device)
                diffusion_results_itr = diffusion_results_itr.permute(0,3,1,2)
                all_results.append(diffusion_results_itr)
            else:
                for i in range(0+sample_rate, diffusion_results_itr.shape[0], sample_rate):
                    self.images.append(get_input_dict(diffusion_results_itr[i:i+1,...],idx,dtype = torch.float32))
                    idx += 1
                self.run_dust3r(input_images=self.images, clean_pc=True)
                diffusion_results_itr = self.nvs_sparse_view(itr)
                # diffusion_results_itr = torch.randn([25, 576, 1024, 3]).to(self.device)
                diffusion_results_itr = diffusion_results_itr.permute(0,3,1,2)
                all_results.append(diffusion_results_itr)
        return all_results

    def nvs_single_view_nbv(self):
        # lef and right
        # d_theta and a_phi 是搜索空间的顶点间隔
        all_results = []
        ## FIXME: hard coded
        sample_rate = 6
        max_itr = 3

        idx = 1 #初始包含1张ref image
        for itr in range(0, max_itr):
            if itr == 0:
                self.images = [self.images[0]] #去掉后一份copy
                diffusion_results_itr = self.nvs_single_view()
                # diffusion_results_itr = torch.randn([25, 576, 1024, 3]).to(self.device)
                diffusion_results_itr = diffusion_results_itr.permute(0,3,1,2)
                all_results.append(diffusion_results_itr)
            else:
                for i in range(0+sample_rate, diffusion_results_itr.shape[0], sample_rate):
                    self.images.append(get_input_dict(diffusion_results_itr[i:i+1,...],idx,dtype = torch.float32))
                    idx += 1
                self.run_dust3r(input_images=self.images, clean_pc=True)
                diffusion_results_itr = self.nvs_sparse_view(itr)
                # diffusion_results_itr = torch.randn([25, 576, 1024, 3]).to(self.device)
                diffusion_results_itr = diffusion_results_itr.permute(0,3,1,2)
                all_results.append(diffusion_results_itr)
        return all_results

    def setup_diffusion(self):
        seed_everything(self.opts.seed)

        config = OmegaConf.load(self.opts.config)
        model_config = config.pop("model", OmegaConf.create())

        ## set use_checkpoint as False as when using deepspeed, it encounters an error "deepspeed backend not set"
        model_config['params']['unet_config']['params']['use_checkpoint'] = False
        model = instantiate_from_config(model_config)
        model = model.to(self.device)
        model.cond_stage_model.device = self.device
        model.perframe_ae = self.opts.perframe_ae
        assert os.path.exists(self.opts.ckpt_path), "Error: checkpoint Not Found!"
        model = load_model_checkpoint(model, self.opts.ckpt_path)
        model.eval()
        self.diffusion = model

        h, w = self.opts.height // 8, self.opts.width // 8
        channels = model.model.diffusion_model.out_channels
        n_frames = self.opts.video_length
        self.noise_shape = [self.opts.bs, channels, n_frames, h, w]

    def setup_dust3r(self):
        self.dust3r = load_model(self.opts.model_path, self.device)
    
    def load_initial_images(self, image_dir):
        ## load images
        ## dict_keys(['img', 'true_shape', 'idx', 'instance', 'img_ori']),张量形式
        images = load_images([image_dir], size=512,force_1024 = True)
        img_ori = (images[0]['img_ori'].squeeze(0).permute(1,2,0)+1.)/2. # [576,1024,3] [0,1]

        # img_ori = Image.open(image_dir).convert('RGB')

        # transform = transforms.Compose([
        #     transforms.Resize((576, 1024)),  
        #     transforms.ToTensor(), 
        #     transforms.Normalize((0., 0., 0.), (1., 1., 1.))  # 归一化到[-1,1]，如果要归一化到[0,1]，请使用transforms.Normalize((0., 0., 0.), (1., 1., 1.))
        # ])

        # img_ori = transform(img_ori).permute(1,2,0).to(self.device)
        if len(images) == 1:
            images = [images[0], copy.deepcopy(images[0])]
            images[1]['idx'] = 1

        return images, img_ori
    
    def run_gradio(self,i2v_input_image, i2v_elevation, i2v_center_scale, i2v_d_phi, i2v_d_theta, i2v_d_r, i2v_steps, i2v_seed):
        self.opts.elevation = float(i2v_elevation)
        self.opts.center_scale = float(i2v_center_scale)
        self.opts.ddim_steps = i2v_steps
        self.gradio_traj = [float(i) for i in i2v_d_phi.split()],[float(i) for i in i2v_d_theta.split()],[float(i) for i in i2v_d_r.split()]
        seed_everything(i2v_seed)
        transform = transforms.Compose([
            transforms.Resize(576),
            transforms.CenterCrop((576,1024)),
            ])
        torch.cuda.empty_cache()
        img_tensor = torch.from_numpy(i2v_input_image).permute(2, 0, 1).unsqueeze(0).float().to(self.device)
        img_tensor = (img_tensor / 255. - 0.5) * 2
        image_tensor_resized = transform(img_tensor) #1,3,h,w
        images = get_input_dict(image_tensor_resized,idx = 0,dtype = torch.float32)
        images = [images, copy.deepcopy(images)]
        images[1]['idx'] = 1
        self.images = images
        self.img_ori = (image_tensor_resized.squeeze(0).permute(1,2,0) + 1.)/2.

        # self.images: torch.Size([1, 3, 288, 512]), [-1,1]
        # self.img_ori:  torch.Size([576, 1024, 3]), [0,1]
        # self.images, self.img_ori = self.load_initial_images(image_dir=i2v_input_image)
        self.run_dust3r(input_images=self.images)
        self.nvs_single_view(gradio=True)

        traj_dir = os.path.join(self.opts.save_dir, "viz_traj.mp4")
        gen_dir = os.path.join(self.opts.save_dir, "diffusion0.mp4")
        
        return traj_dir, gen_dir