import os
import sys

import numpy as np
import torch
from diffusers import FlowMatchEulerDiscreteScheduler
from omegaconf import OmegaConf
from PIL import Image

current_file_path = os.path.abspath(__file__)
project_roots = [os.path.dirname(current_file_path), os.path.dirname(os.path.dirname(current_file_path)), os.path.dirname(os.path.dirname(os.path.dirname(current_file_path)))]
for project_root in project_roots:
    sys.path.insert(0, project_root) if project_root not in sys.path else None

from videox_fun.dist import set_multi_gpus_devices, shard_model
from videox_fun.models import (AutoencoderKLFlux2,
                               Mistral3ForConditionalGeneration,
                               PixtralProcessor, Flux2ControlTransformer2DModel)
from videox_fun.models.cache_utils import get_teacache_coefficients
from videox_fun.pipeline import Flux2ControlPipeline
from videox_fun.utils.fm_solvers import FlowDPMSolverMultistepScheduler
from videox_fun.utils.fm_solvers_unipc import FlowUniPCMultistepScheduler
from videox_fun.utils.fp8_optimization import (convert_model_weight_to_float8,
                                               convert_weight_dtype_wrapper)
from videox_fun.utils.lora_utils import merge_lora, unmerge_lora
from videox_fun.utils.utils import (filter_kwargs, get_image, get_image_latent,
                                    get_image_to_video_latent,
                                    get_video_to_video_latent,
                                    save_videos_grid)

# GPU memory mode, which can be chosen in [model_full_load, model_full_load_and_qfloat8, model_cpu_offload, model_cpu_offload_and_qfloat8, sequential_cpu_offload].
# model_full_load means that the entire model will be moved to the GPU.
# 
# model_full_load_and_qfloat8 means that the entire model will be moved to the GPU,
# and the transformer model has been quantized to float8, which can save more GPU memory. 
# 
# model_cpu_offload means that the entire model will be moved to the CPU after use, which can save some GPU memory.
# 
# model_cpu_offload_and_qfloat8 indicates that the entire model will be moved to the CPU after use, 
# and the transformer model has been quantized to float8, which can save more GPU memory. 
# 
# sequential_cpu_offload means that each layer of the model will be moved to the CPU after use, 
# resulting in slower speeds but saving a large amount of GPU memory.
GPU_memory_mode     = "model_cpu_offload"
# Multi GPUs config
# Please ensure that the product of ulysses_degree and ring_degree equals the number of GPUs used. 
# For example, if you are using 8 GPUs, you can set ulysses_degree = 2 and ring_degree = 4.
# If you are using 1 GPU, you can set ulysses_degree = 1 and ring_degree = 1.
ulysses_degree      = 1
ring_degree         = 1
# Use FSDP to save more GPU memory in multi gpus.
fsdp_dit            = False
fsdp_text_encoder   = False
# Compile will give a speedup in fixed resolution and need a little GPU memory. 
# The compile_dit is not compatible with the fsdp_dit and sequential_cpu_offload.
compile_dit         = False

# Config and model path
config_path         = "config/flux2/flux2_control.yaml"
# model path
model_name          = "models/Diffusion_Transformer/FLUX.2-dev"

# Choose the sampler in "Flow", "Flow_Unipc", "Flow_DPM++"
sampler_name        = "Flow"

# Load pretrained model if need
transformer_path    = "models/Personalized_Model/FLUX.2-dev-Fun-Controlnet-Union.safetensors" 
vae_path            = None
lora_path           = None

# Other params
sample_size         = [1728, 992]

# Use torch.float16 if GPU does not support torch.bfloat16
# ome graphics cards, such as v100, 2080ti, do not support torch.bfloat16
weight_dtype        = torch.bfloat16
image               = "asset/8.png"
control_image       = "asset/pose.jpg"
inpaint_image       = None
mask_image          = None
control_context_scale  = 0.75

# 使用更长的neg prompt如"模糊，突变，变形，失真，画面暗，文本字幕，画面固定，连环画，漫画，线稿，没有主体。"，可以增加稳定性
# 在neg prompt中添加"安静，固定"等词语可以增加动态性。
prompt              = "This is a panoramic portrait photo of a young woman. She has flowing long hair and a soft lavender like color. She is wearing a white sleeveless dress with a blue ribbon bow tied around the collar. She has a confident posture, with her left hand naturally hanging down and her right hand in her pocket, and her legs slightly apart. Look straight at the camera. The sea breeze gently brushed her long hair, and they stood on the sunny seaside path, surrounded by blooming purple seaside flowers and smooth pebbles, with the sparkling sea and blue sky behind them. The screen presents a bright summer atmosphere, with soft and natural lighting, realistic details, and 8K ultra high definition image quality, clearly presenting fine textures such as clothing and hair. "
negative_prompt     = " "
guidance_scale      = 4.00
seed                = 43
num_inference_steps = 50
lora_weight         = 0.55
save_path           = "samples/flux2-t2i-control"

device = set_multi_gpus_devices(ulysses_degree, ring_degree)
config = OmegaConf.load(config_path)

transformer = Flux2ControlTransformer2DModel.from_pretrained(
    model_name, 
    subfolder="transformer",
    low_cpu_mem_usage=True,
    torch_dtype=weight_dtype,
    transformer_additional_kwargs=OmegaConf.to_container(config['transformer_additional_kwargs']),
).to(weight_dtype)

if transformer_path is not None:
    print(f"From checkpoint: {transformer_path}")
    if transformer_path.endswith("safetensors"):
        from safetensors.torch import load_file, safe_open
        state_dict = load_file(transformer_path)
    else:
        state_dict = torch.load(transformer_path, map_location="cpu")
    state_dict = state_dict["state_dict"] if "state_dict" in state_dict else state_dict

    m, u = transformer.load_state_dict(state_dict, strict=False)
    print(f"missing keys: {len(m)}, unexpected keys: {len(u)}")

# Get Vae
vae = AutoencoderKLFlux2.from_pretrained(
    model_name, 
    subfolder="vae"
).to(weight_dtype)

if vae_path is not None:
    print(f"From checkpoint: {vae_path}")
    if vae_path.endswith("safetensors"):
        from safetensors.torch import load_file, safe_open
        state_dict = load_file(vae_path)
    else:
        state_dict = torch.load(vae_path, map_location="cpu")
    state_dict = state_dict["state_dict"] if "state_dict" in state_dict else state_dict

    m, u = vae.load_state_dict(state_dict, strict=False)
    print(f"missing keys: {len(m)}, unexpected keys: {len(u)}")

# Get tokenizer and text_encoder
tokenizer = PixtralProcessor.from_pretrained(
    model_name, subfolder="tokenizer"
)
text_encoder = Mistral3ForConditionalGeneration.from_pretrained(
    model_name, subfolder="text_encoder", torch_dtype=weight_dtype,
    low_cpu_mem_usage=True,
)

# Get Scheduler
Chosen_Scheduler = scheduler_dict = {
    "Flow": FlowMatchEulerDiscreteScheduler,
    "Flow_Unipc": FlowUniPCMultistepScheduler,
    "Flow_DPM++": FlowDPMSolverMultistepScheduler,
}[sampler_name]
scheduler = Chosen_Scheduler.from_pretrained(
    model_name, 
    subfolder="scheduler"
)

pipeline = Flux2ControlPipeline(
    vae=vae,
    tokenizer=tokenizer,
    text_encoder=text_encoder,
    transformer=transformer,
    scheduler=scheduler,
)

if ulysses_degree > 1 or ring_degree > 1:
    from functools import partial
    transformer.enable_multi_gpus_inference()
    if fsdp_dit:
        shard_fn = partial(shard_model, device_id=device, param_dtype=weight_dtype, module_to_wrapper=list(transformer.transformer_blocks) + list(transformer.single_transformer_blocks))
        pipeline.transformer = shard_fn(pipeline.transformer)
        print("Add FSDP DIT")
    if fsdp_text_encoder:
        shard_fn = partial(shard_model, device_id=device, param_dtype=weight_dtype, module_to_wrapper=text_encoder.language_model.layers, ignored_modules=[text_encoder.language_model.embed_tokens], transformer_layer_cls_to_wrap=["MistralDecoderLayer", "PixtralTransformer"])
        text_encoder = shard_fn(text_encoder)
        print("Add FSDP TEXT ENCODER")

if compile_dit:
    for i in range(len(pipeline.transformer.transformer_blocks)):
        pipeline.transformer.transformer_blocks[i] = torch.compile(pipeline.transformer.transformer_blocks[i])
    print("Add Compile")

if GPU_memory_mode == "sequential_cpu_offload":
    pipeline.enable_sequential_cpu_offload(device=device)
elif GPU_memory_mode == "model_cpu_offload_and_qfloat8":
    convert_model_weight_to_float8(transformer, exclude_module_name=["img_in", "txt_in", "timestep"], device=device)
    convert_weight_dtype_wrapper(transformer, weight_dtype)
    pipeline.enable_model_cpu_offload(device=device)
elif GPU_memory_mode == "model_cpu_offload":
    pipeline.enable_model_cpu_offload(device=device)
elif GPU_memory_mode == "model_full_load_and_qfloat8":
    convert_model_weight_to_float8(transformer, exclude_module_name=["img_in", "txt_in", "timestep"], device=device)
    convert_weight_dtype_wrapper(transformer, weight_dtype)
    pipeline.to(device=device)
else:
    pipeline.to(device=device)

generator = torch.Generator(device=device).manual_seed(seed)

if lora_path is not None:
    pipeline = merge_lora(pipeline, lora_path, lora_weight, device=device, dtype=weight_dtype)

with torch.no_grad():
    if image is not None:
        if not isinstance(image, list):
            image = get_image(image)
        else:
            image = [get_image(_image) for _image in image]

    if inpaint_image is not None:
        inpaint_image = get_image_latent(inpaint_image, sample_size=sample_size)[:, :, 0]
    else:
        inpaint_image = torch.zeros([1, 3, sample_size[0], sample_size[1]])

    if mask_image is not None:
        mask_image = get_image_latent(mask_image, sample_size=sample_size)[:, :1, 0]
    else:
        mask_image = torch.ones([1, 1, sample_size[0], sample_size[1]]) * 255

    if control_image is not None:
        control_image = get_image_latent(control_image, sample_size=sample_size)[:, :, 0]

    sample = pipeline(
        prompt              = prompt, 
        height              = sample_size[0],
        width               = sample_size[1],
        generator           = generator,
        guidance_scale      = guidance_scale,
        image               = image,
        inpaint_image       = inpaint_image,
        mask_image          = mask_image,
        control_image       = control_image,
        num_inference_steps = num_inference_steps,
        control_context_scale  = control_context_scale,
    ).images

if lora_path is not None:
    pipeline = unmerge_lora(pipeline, lora_path, lora_weight, device=device, dtype=weight_dtype)

def save_results():
    if not os.path.exists(save_path):
        os.makedirs(save_path, exist_ok=True)

    index = len([path for path in os.listdir(save_path)]) + 1
    prefix = str(index).zfill(8)
    video_path = os.path.join(save_path, prefix + ".png")
    image = sample[0]
    image.save(video_path)

if ulysses_degree * ring_degree > 1:
    import torch.distributed as dist
    if dist.get_rank() == 0:
        save_results()
else:
    save_results()