import os

import gradio as gr
import torch
from gradio.context import Context

from backend import memory_management, operations, stream
from backend.args import dynamic_args
from modules import infotext_utils, paths, processing, sd_models, shared, shared_items, ui_common

total_vram = int(memory_management.total_vram)

ui_forge_preset: gr.Radio = None

ui_checkpoint: gr.Dropdown = None
ui_vae: gr.Dropdown = None
ui_clip_skip: gr.Slider = None

ui_forge_unet_storage_dtype_options: gr.Radio = None
ui_forge_async_loading: gr.Radio = None
ui_forge_pin_shared_memory: gr.Radio = None
ui_forge_inference_memory: gr.Slider = None


forge_unet_storage_dtype_options = {
    "Automatic": (None, False),
    "Automatic (fp16 LoRA)": (None, True),
    "float8-e4m3fn": (torch.float8_e4m3fn, False),
    "float8-e4m3fn (fp16 LoRA)": (torch.float8_e4m3fn, True),
}

bnb_storage_dtype_options = {
    "bnb-nf4": ("nf4", False),
    "bnb-nf4 (fp16 LoRA)": ("nf4", True),
    "bnb-fp4": ("fp4", False),
    "bnb-fp4 (fp16 LoRA)": ("fp4", True),
}

if operations.bnb_available:
    forge_unet_storage_dtype_options.update(bnb_storage_dtype_options)

module_list = {}


def bind_to_opts(comp, k, save=False, callback=None):
    def on_change(v):
        shared.opts.set(k, v)
        if save:
            shared.opts.save(shared.config_filename)
        if callback is not None:
            callback()

    comp.change(on_change, inputs=[comp], queue=False, show_progress=False)


def make_checkpoint_manager_ui():
    global ui_checkpoint, ui_vae, ui_clip_skip, ui_forge_unet_storage_dtype_options, ui_forge_async_loading, ui_forge_pin_shared_memory, ui_forge_inference_memory, ui_forge_preset

    if shared.opts.sd_model_checkpoint in [None, "None", "none", ""]:
        if len(sd_models.checkpoints_list) == 0:
            sd_models.list_models()
        if len(sd_models.checkpoints_list) > 0:
            shared.opts.set("sd_model_checkpoint", next(iter(sd_models.checkpoints_list.values())).name)

    ui_forge_preset = gr.Radio(label="UI Preset", value=lambda: shared.opts.forge_preset, choices=("sd", "xl", "flux", "qwen", "lumina", "wan"), elem_id="forge_ui_preset")

    ui_checkpoint = gr.Dropdown(label="Checkpoint", value=None, choices=None, elem_id="setting_sd_model_checkpoint", elem_classes=["model_selection"])

    ui_vae = gr.Dropdown(label="VAE / Text Encoder", value=None, choices=None, multiselect=True)

    def gr_refresh_models():
        ckpt_list, vae_list = refresh_models()
        return gr.update(choices=ckpt_list), gr.update(choices=vae_list)

    refresh_button = ui_common.ToolButton(value=ui_common.refresh_symbol, elem_id="forge_refresh_checkpoint", tooltip="Refresh")
    refresh_button.click(fn=gr_refresh_models, outputs=[ui_checkpoint, ui_vae], queue=False)

    def gr_refresh_on_load():
        ckpt_list, vae_list = refresh_models()
        refresh_memory_management_settings()
        return [gr.update(value=shared.opts.sd_model_checkpoint, choices=ckpt_list), gr.update(value=[os.path.basename(x) for x in shared.opts.forge_additional_modules], choices=vae_list)]

    Context.root_block.load(fn=gr_refresh_on_load, outputs=[ui_checkpoint, ui_vae], show_progress=False, queue=False)

    ui_forge_unet_storage_dtype_options = gr.Dropdown(label="Diffusion in Low Bits", value=lambda: shared.opts.forge_unet_storage_dtype, choices=list(forge_unet_storage_dtype_options.keys()))
    bind_to_opts(ui_forge_unet_storage_dtype_options, "forge_unet_storage_dtype", save=True, callback=refresh_model_loading_parameters)

    ui_forge_async_loading = gr.Radio(label="Swap Method", value=lambda: shared.opts.forge_async_loading, choices=["Queue", "Async"])
    ui_forge_pin_shared_memory = gr.Radio(label="Swap Location", value=lambda: shared.opts.forge_pin_shared_memory, choices=["CPU", "Shared"])
    ui_forge_inference_memory = gr.Slider(label="GPU Weights (MB)", value=lambda: total_vram - shared.opts.forge_inference_memory, minimum=0, maximum=int(memory_management.total_vram), step=1)

    mem_comps = [ui_forge_inference_memory, ui_forge_async_loading, ui_forge_pin_shared_memory]

    ui_forge_inference_memory.change(ui_refresh_memory_management_settings, inputs=mem_comps, queue=False, show_progress=False)
    ui_forge_async_loading.change(ui_refresh_memory_management_settings, inputs=mem_comps, queue=False, show_progress=False)
    ui_forge_pin_shared_memory.change(ui_refresh_memory_management_settings, inputs=mem_comps, queue=False, show_progress=False)

    ui_clip_skip = gr.Slider(label="Clip Skip", value=lambda: shared.opts.CLIP_stop_at_last_layers, minimum=1, maximum=12, step=1)
    bind_to_opts(ui_clip_skip, "CLIP_stop_at_last_layers", save=True)

    ui_checkpoint.change(checkpoint_change, inputs=[ui_checkpoint, ui_forge_preset], show_progress=False)
    ui_vae.change(modules_change, inputs=[ui_vae, ui_forge_preset], queue=False, show_progress=False)


def find_files_with_extensions(base_path, extensions):
    found_files = {}
    for root, _, files in os.walk(base_path):
        for file in files:
            if any(file.endswith(ext) for ext in extensions):
                full_path = os.path.join(root, file)
                found_files[file] = full_path
    return found_files


def refresh_models():
    global module_list

    shared_items.refresh_checkpoints()
    ckpt_list = shared_items.list_checkpoint_tiles(shared.opts.sd_checkpoint_dropdown_use_short)

    file_extensions = ("ckpt", "pt", "pth", "bin", "safetensors", "sft", "gguf")

    module_list.clear()

    module_paths: set[str] = {
        os.path.abspath(os.path.join(paths.models_path, "VAE")),
        os.path.abspath(os.path.join(paths.models_path, "text_encoder")),
        *shared.cmd_opts.vae_dirs,
        *shared.cmd_opts.text_encoder_dirs,
    }

    for vae_path in module_paths:
        vae_files = find_files_with_extensions(vae_path, file_extensions)
        module_list.update(vae_files)

    return sorted(ckpt_list), sorted(module_list.keys())


def ui_refresh_memory_management_settings(model_memory, async_loading, pin_shared_memory):
    """Pass calculated `model_memory` from "GPU Weights" UI slider"""
    refresh_memory_management_settings(async_loading=async_loading, pin_shared_memory=pin_shared_memory, model_memory=model_memory)  # Use model_memory directly from UI slider value


def refresh_memory_management_settings(async_loading=None, inference_memory=None, pin_shared_memory=None, model_memory=None):
    # Fallback to defaults if values are not passed
    async_loading = async_loading if async_loading is not None else shared.opts.forge_async_loading
    inference_memory = inference_memory if inference_memory is not None else shared.opts.forge_inference_memory
    pin_shared_memory = pin_shared_memory if pin_shared_memory is not None else shared.opts.forge_pin_shared_memory

    # If model_memory is provided, calculate inference memory accordingly, otherwise use inference_memory directly
    if model_memory is None:
        model_memory = total_vram - inference_memory
    else:
        inference_memory = total_vram - model_memory

    shared.opts.set("forge_async_loading", async_loading)
    shared.opts.set("forge_inference_memory", inference_memory)
    shared.opts.set("forge_pin_shared_memory", pin_shared_memory)

    stream.stream_activated = async_loading == "Async"
    memory_management.current_inference_memory = inference_memory * 1024 * 1024  # Convert MB to bytes
    memory_management.PIN_SHARED_MEMORY = pin_shared_memory == "Shared"

    log_dict = dict(stream=stream.should_use_stream(), inference_memory=memory_management.minimum_inference_memory() / (1024 * 1024), pin_shared_memory=memory_management.PIN_SHARED_MEMORY)

    print(f"Environment vars changed: {log_dict}")

    if inference_memory < min(512, total_vram * 0.05):
        print("------------------")
        print(f"[Low VRAM Warning] You just set Forge to use 100% GPU memory ({model_memory:.2f} MB) to load model weights.")
        print("[Low VRAM Warning] This means you will have 0% GPU memory (0.00 MB) to do matrix computation. Computations may fallback to CPU or go Out of Memory.")
        print("[Low VRAM Warning] In many cases, image generation will be 10x slower.")
        print("[Low VRAM Warning] To solve the problem, you can set the 'GPU Weights' (on the top of page) to a lower value.")
        print("[Low VRAM Warning] If you cannot find 'GPU Weights', you can click the 'all' option in the 'UI' area on the left-top corner of the webpage.")
        print("[Low VRAM Warning] Make sure that you know what you are testing.")
        print("------------------")
    else:
        compute_percentage = (inference_memory / total_vram) * 100.0
        print(f"[GPU Setting] You will use {(100 - compute_percentage):.2f}% GPU memory ({model_memory:.2f} MB) to load weights, and use {compute_percentage:.2f}% GPU memory ({inference_memory:.2f} MB) to do matrix computation.")

    processing.need_global_unload = True


def refresh_model_loading_parameters():
    from modules.sd_models import model_data, select_checkpoint

    checkpoint_info = select_checkpoint()

    unet_storage_dtype, lora_fp16 = forge_unet_storage_dtype_options.get(shared.opts.forge_unet_storage_dtype, (None, False))

    dynamic_args["online_lora"] = lora_fp16

    model_data.forge_loading_parameters = dict(checkpoint_info=checkpoint_info, additional_modules=shared.opts.forge_additional_modules, unet_storage_dtype=unet_storage_dtype)

    print(f"Model selected: {model_data.forge_loading_parameters}")
    print(f"Using online LoRAs in FP16: {lora_fp16}")
    processing.need_global_unload = True


def checkpoint_change(ckpt_name: str, preset: str, save=True, refresh=True) -> bool:
    """`ckpt_name` accepts valid aliases; returns `True` if checkpoint changed"""
    new_ckpt_info = sd_models.get_closet_checkpoint_match(ckpt_name)
    current_ckpt_info = sd_models.get_closet_checkpoint_match(shared.opts.data.get("sd_model_checkpoint", ""))
    if new_ckpt_info == current_ckpt_info:
        return False

    shared.opts.set("sd_model_checkpoint", ckpt_name)
    if preset is not None:
        shared.opts.set(f"forge_checkpoint_{preset}", ckpt_name)

    if save:
        shared.opts.save(shared.config_filename)
    if refresh:
        refresh_model_loading_parameters()
    return True


def modules_change(module_values: list, preset: str, save=True, refresh=True) -> bool:
    """`module_values` accepts file paths or just the module names; returns `True` if modules changed"""
    modules = []
    for v in module_values:
        module_name = os.path.basename(v)  # If the input is a filepath, extract the file name
        if module_name in module_list:
            modules.append(module_list[module_name])

    # skip further processing if value unchanged
    if sorted(modules) == sorted(shared.opts.data.get("forge_additional_modules", [])):
        return False

    shared.opts.set("forge_additional_modules", modules)
    if preset is not None:
        shared.opts.set(f"forge_additional_modules_{preset}", modules)

    if save:
        shared.opts.save(shared.config_filename)
    if refresh:
        refresh_model_loading_parameters()
    return True


def get_a1111_ui_component(tab, label):
    fields = infotext_utils.paste_fields[tab]["fields"]
    for f in fields:
        if f.label == label or f.api == label:
            return f.component


def forge_main_entry():
    ui_txt2img_width = get_a1111_ui_component("txt2img", "Size-1")
    ui_txt2img_height = get_a1111_ui_component("txt2img", "Size-2")
    ui_txt2img_cfg = get_a1111_ui_component("txt2img", "CFG scale")
    ui_txt2img_distilled_cfg = get_a1111_ui_component("txt2img", "Distilled CFG Scale")
    ui_txt2img_sampler = get_a1111_ui_component("txt2img", "sampler_name")
    ui_txt2img_scheduler = get_a1111_ui_component("txt2img", "scheduler")

    ui_img2img_width = get_a1111_ui_component("img2img", "Size-1")
    ui_img2img_height = get_a1111_ui_component("img2img", "Size-2")
    ui_img2img_cfg = get_a1111_ui_component("img2img", "CFG scale")
    ui_img2img_distilled_cfg = get_a1111_ui_component("img2img", "Distilled CFG Scale")
    ui_img2img_sampler = get_a1111_ui_component("img2img", "sampler_name")
    ui_img2img_scheduler = get_a1111_ui_component("img2img", "scheduler")

    ui_txt2img_hr_cfg = get_a1111_ui_component("txt2img", "Hires CFG Scale")
    ui_txt2img_hr_distilled_cfg = get_a1111_ui_component("txt2img", "Hires Distilled CFG Scale")

    ui_txt2img_batch_size = get_a1111_ui_component("txt2img", "Batch size")
    ui_img2img_batch_size = get_a1111_ui_component("img2img", "Batch size")

    output_targets = [
        ui_checkpoint,
        ui_vae,
        ui_clip_skip,
        ui_forge_unet_storage_dtype_options,
        ui_forge_async_loading,
        ui_forge_pin_shared_memory,
        ui_forge_inference_memory,
        ui_txt2img_width,
        ui_img2img_width,
        ui_txt2img_height,
        ui_img2img_height,
        ui_txt2img_cfg,
        ui_img2img_cfg,
        ui_txt2img_distilled_cfg,
        ui_img2img_distilled_cfg,
        ui_txt2img_sampler,
        ui_img2img_sampler,
        ui_txt2img_scheduler,
        ui_img2img_scheduler,
        ui_txt2img_hr_cfg,
        ui_txt2img_hr_distilled_cfg,
        ui_txt2img_batch_size,
        ui_img2img_batch_size,
    ]

    ui_forge_preset.change(on_preset_change, inputs=[ui_forge_preset], outputs=output_targets, queue=False, show_progress=False).then(js="clickLoraRefresh", fn=None, queue=False, show_progress=False)
    Context.root_block.load(on_preset_change, inputs=[ui_forge_preset], outputs=output_targets, queue=False, show_progress=False)

    refresh_model_loading_parameters()


def on_preset_change(preset: str):
    assert preset is not None
    shared.opts.set("forge_preset", preset)
    shared.opts.save(shared.config_filename)

    model_mem = getattr(shared.opts, f"{preset}_gpu_mb", total_vram - 1024)
    if model_mem < 0 or model_mem > total_vram:
        model_mem = total_vram - 1024

    show_clip_skip = preset not in ("qwen", "lumina", "wan")
    show_basic_mem = preset != "sd"
    show_adv_mem = preset in ("flux", "qwen", "wan")
    distilled = preset in ("flux", "lumina", "wan")
    d_label = "Distilled CFG Scale" if preset == "flux" else "Shift"
    batch_args = {"minimum": 1, "maximum": 97, "step": 16, "label": "Frames", "value": 1} if preset == "wan" else {"minimum": 1, "maximum": 8, "step": 1, "label": "Batch size", "value": 1}

    additional_modules = [os.path.basename(x) for x in getattr(shared.opts, f"forge_additional_modules_{preset}", [])]

    return [
        gr.update(value=getattr(shared.opts, f"forge_checkpoint_{preset}", shared.opts.sd_model_checkpoint)),  # ui_checkpoint
        gr.update(value=additional_modules),  # ui_vae
        gr.update(visible=show_clip_skip, value=getattr(shared.opts, "CLIP_stop_at_last_layers", 2)),  # ui_clip_skip
        gr.update(visible=show_basic_mem, value=getattr(shared.opts, "forge_unet_storage_dtype", "Automatic")),  # ui_forge_unet_storage_dtype_options
        gr.update(visible=show_adv_mem, value=getattr(shared.opts, "forge_async_loading", "Queue")),  # ui_forge_async_loading
        gr.update(visible=show_adv_mem, value=getattr(shared.opts, "forge_pin_shared_memory", "CPU")),  # ui_forge_pin_shared_memory
        gr.update(visible=show_basic_mem, value=model_mem),  # ui_forge_inference_memory
        gr.update(value=getattr(shared.opts, f"{preset}_t2i_width", 768)),  # ui_txt2img_width
        gr.update(value=getattr(shared.opts, f"{preset}_i2i_width", 768)),  # ui_img2img_width
        gr.update(value=getattr(shared.opts, f"{preset}_t2i_height", 768)),  # ui_txt2img_height
        gr.update(value=getattr(shared.opts, f"{preset}_i2i_height", 768)),  # ui_img2img_height
        gr.update(value=getattr(shared.opts, f"{preset}_t2i_cfg", 1.0)),  # ui_txt2img_cfg
        gr.update(value=getattr(shared.opts, f"{preset}_i2i_cfg", 1.0)),  # ui_img2img_cfg
        gr.update(visible=distilled, label=d_label, value=getattr(shared.opts, f"{preset}_t2i_d_cfg", 3.0)),  # ui_txt2img_distilled_cfg
        gr.update(visible=distilled, label=d_label, value=getattr(shared.opts, f"{preset}_i2i_d_cfg", 3.0)),  # ui_img2img_distilled_cfg
        gr.update(value=getattr(shared.opts, f"{preset}_t2i_sampler", "Euler")),  # ui_txt2img_sampler
        gr.update(value=getattr(shared.opts, f"{preset}_i2i_sampler", "Euler")),  # ui_img2img_sampler
        gr.update(value=getattr(shared.opts, f"{preset}_t2i_scheduler", "Simple")),  # ui_txt2img_scheduler
        gr.update(value=getattr(shared.opts, f"{preset}_i2i_scheduler", "Simple")),  # ui_img2img_scheduler
        gr.update(value=getattr(shared.opts, f"{preset}_t2i_hr_cfg", 1.0)),  # ui_txt2img_hr_cfg
        gr.update(visible=distilled, label=d_label, value=getattr(shared.opts, f"{preset}_t2i_hr_d_cfg", 3.0)),  # ui_txt2img_hr_distilled_cfg
        gr.update(**batch_args),  # ui_txt2img_batch_size
        gr.update(**batch_args),  # ui_img2img_batch_size
    ]