import os
import sys
import cv2
import argparse
from pathlib import Path
import torch
import numpy as np
from data_loader import load_dir
from facemodel import Face_3DMM
from util import *
from render_3dmm import Render_3DMM


# torch.autograd.set_detect_anomaly(True)

dir_path = os.path.dirname(os.path.realpath(__file__))


def set_requires_grad(tensor_list):
    for tensor in tensor_list:
        tensor.requires_grad = True


parser = argparse.ArgumentParser()
parser.add_argument(
    "--path", type=str, default="obama/ori_imgs", help="idname of target person"
)
parser.add_argument("--img_h", type=int, default=512, help="image height")
parser.add_argument("--img_w", type=int, default=512, help="image width")
parser.add_argument("--frame_num", type=int, default=11000, help="image number")
args = parser.parse_args()

start_id = 0
end_id = args.frame_num

lms, img_paths = load_dir(args.path, start_id, end_id)
num_frames = lms.shape[0]
h, w = args.img_h, args.img_w
cxy = torch.tensor((w / 2.0, h / 2.0), dtype=torch.float).cuda()
id_dim, exp_dim, tex_dim, point_num = 100, 79, 100, 34650
model_3dmm = Face_3DMM(
    os.path.join(dir_path, "3DMM"), id_dim, exp_dim, tex_dim, point_num
)

# only use one image per 40 to do fit the focal length
sel_ids = np.arange(0, num_frames, 40)
sel_num = sel_ids.shape[0]
arg_focal = 1600
arg_landis = 1e5

print(f'[INFO] fitting focal length...')

# fit the focal length
for focal in range(600, 1500, 100):
    id_para = lms.new_zeros((1, id_dim), requires_grad=True)
    exp_para = lms.new_zeros((sel_num, exp_dim), requires_grad=True)
    euler_angle = lms.new_zeros((sel_num, 3), requires_grad=True)
    trans = lms.new_zeros((sel_num, 3), requires_grad=True)
    trans.data[:, 2] -= 7
    focal_length = lms.new_zeros(1, requires_grad=False)
    focal_length.data += focal
    set_requires_grad([id_para, exp_para, euler_angle, trans])

    optimizer_idexp = torch.optim.Adam([id_para, exp_para], lr=0.1)
    optimizer_frame = torch.optim.Adam([euler_angle, trans], lr=0.1)

    for iter in range(2000):
        id_para_batch = id_para.expand(sel_num, -1)
        geometry = model_3dmm.get_3dlandmarks(
            id_para_batch, exp_para, euler_angle, trans, focal_length, cxy
        )
        proj_geo = forward_transform(geometry, euler_angle, trans, focal_length, cxy)
        loss_lan = cal_lan_loss(proj_geo[:, :, :2], lms[sel_ids].detach())
        loss = loss_lan
        optimizer_frame.zero_grad()
        loss.backward()
        optimizer_frame.step()
        # if iter % 100 == 0:
        #     print(focal, 'pose', iter, loss.item())

    for iter in range(2500):
        id_para_batch = id_para.expand(sel_num, -1)
        geometry = model_3dmm.get_3dlandmarks(
            id_para_batch, exp_para, euler_angle, trans, focal_length, cxy
        )
        proj_geo = forward_transform(geometry, euler_angle, trans, focal_length, cxy)
        loss_lan = cal_lan_loss(proj_geo[:, :, :2], lms[sel_ids].detach())
        loss_regid = torch.mean(id_para * id_para)
        loss_regexp = torch.mean(exp_para * exp_para)
        loss = loss_lan + loss_regid * 0.5 + loss_regexp * 0.4
        optimizer_idexp.zero_grad()
        optimizer_frame.zero_grad()
        loss.backward()
        optimizer_idexp.step()
        optimizer_frame.step()
        # if iter % 100 == 0:
        #     print(focal, 'poseidexp', iter, loss_lan.item(), loss_regid.item(), loss_regexp.item())

        if iter % 1500 == 0 and iter >= 1500:
            for param_group in optimizer_idexp.param_groups:
                param_group["lr"] *= 0.2
            for param_group in optimizer_frame.param_groups:
                param_group["lr"] *= 0.2

    print(focal, loss_lan.item(), torch.mean(trans[:, 2]).item())

    if loss_lan.item() < arg_landis:
        arg_landis = loss_lan.item()
        arg_focal = focal

print("[INFO] find best focal:", arg_focal)

print(f'[INFO] coarse fitting...')

# for all frames, do a coarse fitting ???
id_para = lms.new_zeros((1, id_dim), requires_grad=True)
exp_para = lms.new_zeros((num_frames, exp_dim), requires_grad=True)
tex_para = lms.new_zeros(
    (1, tex_dim), requires_grad=True
)  # not optimized in this block ???
euler_angle = lms.new_zeros((num_frames, 3), requires_grad=True)
trans = lms.new_zeros((num_frames, 3), requires_grad=True)
light_para = lms.new_zeros((num_frames, 27), requires_grad=True)
trans.data[:, 2] -= 7 # ???
focal_length = lms.new_zeros(1, requires_grad=True)
focal_length.data += arg_focal

set_requires_grad([id_para, exp_para, tex_para, euler_angle, trans, light_para])

optimizer_idexp = torch.optim.Adam([id_para, exp_para], lr=0.1)
optimizer_frame = torch.optim.Adam([euler_angle, trans], lr=1)

for iter in range(1500):
    id_para_batch = id_para.expand(num_frames, -1)
    geometry = model_3dmm.get_3dlandmarks(
        id_para_batch, exp_para, euler_angle, trans, focal_length, cxy
    )
    proj_geo = forward_transform(geometry, euler_angle, trans, focal_length, cxy)
    loss_lan = cal_lan_loss(proj_geo[:, :, :2], lms.detach())
    loss = loss_lan
    optimizer_frame.zero_grad()
    loss.backward()
    optimizer_frame.step()
    if iter == 1000:
        for param_group in optimizer_frame.param_groups:
            param_group["lr"] = 0.1
    # if iter % 100 == 0:
    #     print('pose', iter, loss.item())

for param_group in optimizer_frame.param_groups:
    param_group["lr"] = 0.1

for iter in range(2000):
    id_para_batch = id_para.expand(num_frames, -1)
    geometry = model_3dmm.get_3dlandmarks(
        id_para_batch, exp_para, euler_angle, trans, focal_length, cxy
    )
    proj_geo = forward_transform(geometry, euler_angle, trans, focal_length, cxy)
    loss_lan = cal_lan_loss(proj_geo[:, :, :2], lms.detach())
    loss_regid = torch.mean(id_para * id_para)
    loss_regexp = torch.mean(exp_para * exp_para)
    loss = loss_lan + loss_regid * 0.5 + loss_regexp * 0.4
    optimizer_idexp.zero_grad()
    optimizer_frame.zero_grad()
    loss.backward()
    optimizer_idexp.step()
    optimizer_frame.step()
    # if iter % 100 == 0:
    #     print('poseidexp', iter, loss_lan.item(), loss_regid.item(), loss_regexp.item())
    if iter % 1000 == 0 and iter >= 1000:
        for param_group in optimizer_idexp.param_groups:
            param_group["lr"] *= 0.2
        for param_group in optimizer_frame.param_groups:
            param_group["lr"] *= 0.2

print(loss_lan.item(), torch.mean(trans[:, 2]).item())

print(f'[INFO] fitting light...')

batch_size = 32

device_default = torch.device("cuda:0" if torch.cuda.is_available() else (
    "mps" if (hasattr(torch.backends, "mps") and torch.backends.mps.is_available()) else "cpu"))
device_render = torch.device("cuda:0" if torch.cuda.is_available() else (
    "mps" if (hasattr(torch.backends, "mps") and torch.backends.mps.is_available()) else "cpu"))

renderer = Render_3DMM(arg_focal, h, w, batch_size, device_render)

sel_ids = np.arange(0, num_frames, int(num_frames / batch_size))[:batch_size]
imgs = []
for sel_id in sel_ids:
    imgs.append(cv2.imread(img_paths[sel_id])[:, :, ::-1])
imgs = np.stack(imgs)
sel_imgs = torch.as_tensor(imgs).cuda()
sel_lms = lms[sel_ids]
sel_light = light_para.new_zeros((batch_size, 27), requires_grad=True)
set_requires_grad([sel_light])

optimizer_tl = torch.optim.Adam([tex_para, sel_light], lr=0.1)
optimizer_id_frame = torch.optim.Adam([euler_angle, trans, exp_para, id_para], lr=0.01)

for iter in range(71):
    sel_exp_para, sel_euler, sel_trans = (
        exp_para[sel_ids],
        euler_angle[sel_ids],
        trans[sel_ids],
    )
    sel_id_para = id_para.expand(batch_size, -1)
    geometry = model_3dmm.get_3dlandmarks(
        sel_id_para, sel_exp_para, sel_euler, sel_trans, focal_length, cxy
    )
    proj_geo = forward_transform(geometry, sel_euler, sel_trans, focal_length, cxy)

    loss_lan = cal_lan_loss(proj_geo[:, :, :2], sel_lms.detach())
    loss_regid = torch.mean(id_para * id_para)
    loss_regexp = torch.mean(sel_exp_para * sel_exp_para)

    sel_tex_para = tex_para.expand(batch_size, -1)
    sel_texture = model_3dmm.forward_tex(sel_tex_para)
    geometry = model_3dmm.forward_geo(sel_id_para, sel_exp_para)
    rott_geo = forward_rott(geometry, sel_euler, sel_trans)
    render_imgs = renderer(
        rott_geo.to(device_render),
        sel_texture.to(device_render),
        sel_light.to(device_render),
    )
    render_imgs = render_imgs.to(device_default)

    mask = (render_imgs[:, :, :, 3]).detach() > 0.0
    render_proj = sel_imgs.clone()
    render_proj[mask] = render_imgs[mask][..., :3].byte()
    loss_col = cal_col_loss(render_imgs[:, :, :, :3], sel_imgs.float(), mask)

    if iter > 50:
        loss = loss_col + loss_lan * 0.05 + loss_regid * 1.0 + loss_regexp * 0.8
    else:
        loss = loss_col + loss_lan * 3 + loss_regid * 2.0 + loss_regexp * 1.0

    optimizer_tl.zero_grad()
    optimizer_id_frame.zero_grad()
    loss.backward()

    optimizer_tl.step()
    optimizer_id_frame.step()

    if iter % 50 == 0 and iter > 0:
        for param_group in optimizer_id_frame.param_groups:
            param_group["lr"] *= 0.2
        for param_group in optimizer_tl.param_groups:
            param_group["lr"] *= 0.2
    # print(iter, loss_col.item(), loss_lan.item(), loss_regid.item(), loss_regexp.item())


light_mean = torch.mean(sel_light, 0).unsqueeze(0).repeat(num_frames, 1)
light_para.data = light_mean

exp_para = exp_para.detach()
euler_angle = euler_angle.detach()
trans = trans.detach()
light_para = light_para.detach()

print(f'[INFO] fine frame-wise fitting...')

for i in range(int((num_frames - 1) / batch_size + 1)):

    if (i + 1) * batch_size > num_frames:
        start_n = num_frames - batch_size
        sel_ids = np.arange(num_frames - batch_size, num_frames)
    else:
        start_n = i * batch_size
        sel_ids = np.arange(i * batch_size, i * batch_size + batch_size)

    imgs = []
    for sel_id in sel_ids:
        imgs.append(cv2.imread(img_paths[sel_id])[:, :, ::-1])
    imgs = np.stack(imgs)
    sel_imgs = torch.as_tensor(imgs).cuda()
    sel_lms = lms[sel_ids]

    sel_exp_para = exp_para.new_zeros((batch_size, exp_dim), requires_grad=True)
    sel_exp_para.data = exp_para[sel_ids].clone()
    sel_euler = euler_angle.new_zeros((batch_size, 3), requires_grad=True)
    sel_euler.data = euler_angle[sel_ids].clone()
    sel_trans = trans.new_zeros((batch_size, 3), requires_grad=True)
    sel_trans.data = trans[sel_ids].clone()
    sel_light = light_para.new_zeros((batch_size, 27), requires_grad=True)
    sel_light.data = light_para[sel_ids].clone()

    set_requires_grad([sel_exp_para, sel_euler, sel_trans, sel_light])

    optimizer_cur_batch = torch.optim.Adam(
        [sel_exp_para, sel_euler, sel_trans, sel_light], lr=0.005
    )

    sel_id_para = id_para.expand(batch_size, -1).detach()
    sel_tex_para = tex_para.expand(batch_size, -1).detach()

    pre_num = 5

    if i > 0:
        pre_ids = np.arange(start_n - pre_num, start_n)

    for iter in range(50):
        
        geometry = model_3dmm.get_3dlandmarks(
            sel_id_para, sel_exp_para, sel_euler, sel_trans, focal_length, cxy
        )
        proj_geo = forward_transform(geometry, sel_euler, sel_trans, focal_length, cxy)
        loss_lan = cal_lan_loss(proj_geo[:, :, :2], sel_lms.detach())
        loss_regexp = torch.mean(sel_exp_para * sel_exp_para)

        sel_geometry = model_3dmm.forward_geo(sel_id_para, sel_exp_para)
        sel_texture = model_3dmm.forward_tex(sel_tex_para)
        geometry = model_3dmm.forward_geo(sel_id_para, sel_exp_para)
        rott_geo = forward_rott(geometry, sel_euler, sel_trans)
        render_imgs = renderer(
            rott_geo.to(device_render),
            sel_texture.to(device_render),
            sel_light.to(device_render),
        )
        render_imgs = render_imgs.to(device_default)

        mask = (render_imgs[:, :, :, 3]).detach() > 0.0

        loss_col = cal_col_loss(render_imgs[:, :, :, :3], sel_imgs.float(), mask)

        if i > 0:
            geometry_lap = model_3dmm.forward_geo_sub(
                id_para.expand(batch_size + pre_num, -1).detach(),
                torch.cat((exp_para[pre_ids].detach(), sel_exp_para)),
                model_3dmm.rigid_ids,
            )
            rott_geo_lap = forward_rott(
                geometry_lap,
                torch.cat((euler_angle[pre_ids].detach(), sel_euler)),
                torch.cat((trans[pre_ids].detach(), sel_trans)),
            )
            loss_lap = cal_lap_loss(
                [rott_geo_lap.reshape(rott_geo_lap.shape[0], -1).permute(1, 0)], [1.0]
            )
        else:
            geometry_lap = model_3dmm.forward_geo_sub(
                id_para.expand(batch_size, -1).detach(),
                sel_exp_para,
                model_3dmm.rigid_ids,
            )
            rott_geo_lap = forward_rott(geometry_lap, sel_euler, sel_trans)
            loss_lap = cal_lap_loss(
                [rott_geo_lap.reshape(rott_geo_lap.shape[0], -1).permute(1, 0)], [1.0]
            )


        if iter > 30:
            loss = loss_col * 0.5 + loss_lan * 1.5 + loss_lap * 100000 + loss_regexp * 1.0
        else:
            loss = loss_col * 0.5 + loss_lan * 8 + loss_lap * 100000 + loss_regexp * 1.0

        optimizer_cur_batch.zero_grad()
        loss.backward()
        optimizer_cur_batch.step()

        # if iter % 10 == 0:
        #     print(
        #         i,
        #         iter,
        #         loss_col.item(),
        #         loss_lan.item(),
        #         loss_lap.item(),
        #         loss_regexp.item(),
        #     )

    print(str(i) + " of " + str(int((num_frames - 1) / batch_size + 1)) + " done")

    render_proj = sel_imgs.clone()
    render_proj[mask] = render_imgs[mask][..., :3].byte()

    exp_para[sel_ids] = sel_exp_para.clone()
    euler_angle[sel_ids] = sel_euler.clone()
    trans[sel_ids] = sel_trans.clone()
    light_para[sel_ids] = sel_light.clone()

torch.save(
    {
        "id": id_para.detach().cpu(),
        "exp": exp_para.detach().cpu(),
        "euler": euler_angle.detach().cpu(),
        "trans": trans.detach().cpu(),
        "focal": focal_length.detach().cpu(),
    },
    os.path.join(os.path.dirname(args.path), "track_params.pt"),
)

print("params saved")