import gradio as gr
from transformers import AutoConfig  # Required for Hugging Face integration
from calc_params import calc_params  # Import calc_params from the new file
import math

# ---- Helper Functions ---- #
def get_hf_model_args(hf_model_name_or_path):
    try:
        config = AutoConfig.from_pretrained(hf_model_name_or_path, trust_remote_code=True).to_dict()
    except Exception as e:
        raise gr.Error(f"Error fetching Hugging Face model: {str(e)}")
    
    # Extract relevant values from the config
    num_layers = config.get("num_hidden_layers", None)
    hidden_size = config.get("hidden_size", None)
    num_attention_heads = config.get("num_attention_heads", None)
    vocab_size = config.get("vocab_size", None)
    sequence_length = config.get("max_position_embeddings", None)

    return {
        "num_layers": num_layers,
        "hidden_size": hidden_size,
        "num_attention_heads": num_attention_heads,
        "vocab_size": vocab_size,
        "sequence_length": sequence_length,
    }

# ---- Update Gradio inputs with Hugging Face model config ---- #
def update_from_hf_model(hf_model_name_or_path):
    model_params = get_hf_model_args(hf_model_name_or_path)
    
    return (gr.update(value=model_params["num_layers"]), 
            gr.update(value=model_params["hidden_size"]),
            gr.update(value=model_params["num_attention_heads"]),
            gr.update(value=model_params["vocab_size"]),
            gr.update(value=model_params["sequence_length"]),
            "")

# ---- Memory Calculation ---- #
def calc_mem(hf_model_name_or_path, num_gpus, tensor_parallel_size, pipeline_parallel_size, batch_size_per_gpu, sequence_length, vocab_size, hidden_size, num_attention_heads, num_layers, ffn_expansion_factor, is_mixed_precision, misc_mem_gib):
    model_params = get_hf_model_args(hf_model_name_or_path) if hf_model_name_or_path else None
    
    if model_params:
        num_layers = model_params["num_layers"] or num_layers
        hidden_size = model_params["hidden_size"] or hidden_size
        num_attention_heads = model_params["num_attention_heads"] or num_attention_heads
        vocab_size = model_params["vocab_size"] or vocab_size
        sequence_length = model_params["sequence_length"] or sequence_length
    
    dp_degree = num_gpus / (tensor_parallel_size * pipeline_parallel_size)
    embed_params = 2 * vocab_size * hidden_size
    positional_params = hidden_size * sequence_length
    ln_params = 8 * hidden_size * num_layers + (2 * hidden_size)
    attention_params = int(2 * (1 + ffn_expansion_factor) * num_layers * hidden_size * hidden_size)
    mlp_params = ffn_expansion_factor * num_layers * hidden_size * hidden_size
    total_params = embed_params + positional_params + ln_params + attention_params + mlp_params

    bytes_per_param = 2 if is_mixed_precision else 4
    model_mem = total_params * bytes_per_param
    per_gpu_mem_gib = (model_mem / (tensor_parallel_size * pipeline_parallel_size)) / 1024**3 + misc_mem_gib

    return f"Per-GPU Memory Required for Training: {per_gpu_mem_gib:.2f} GiB"

# ---- FLOP Calculation ---- #
def calc_flops(vocab_size, hidden_size, sequence_length, num_layers, kv_size_ratio, topk, moe, num_experts, expert_interval, batch_size, tokens, checkpoint_activations, ffn_expansion_factor, infer):
    # An A_(m x k) X B_(k x n) matrix multiplication requires 2m x k x n FLOPs (factor of 2 needed to account for multiplies and adds)
    tokens = 1e9 * tokens
    # determine the flops factor.
    iter_factor = 3
    if checkpoint_activations:
        iter_factor += 1
    if infer:
        iter_factor = 1

    qkv_flops = int(iter_factor * 2 * (1 + 2 * kv_size_ratio) * num_layers * tokens * hidden_size * hidden_size)
    attention_matrix_flops = iter_factor * 2 * num_layers * tokens * sequence_length * hidden_size
    attention_over_values_flops = iter_factor * 2 * num_layers * tokens * sequence_length * hidden_size
    linear_projection_flops = iter_factor * 2 * num_layers * tokens * hidden_size * hidden_size
    ffn_flops = int(iter_factor * 2 * ffn_expansion_factor) * num_layers * tokens * hidden_size * hidden_size
    embedding_flops = 6 * tokens * hidden_size * vocab_size

    if moe and topk > 1:
        ffn_flops += ffn_flops * topk / expert_interval

    if moe:
        gating_flops = 2 * num_experts * hidden_size / expert_interval

    total_flops = qkv_flops + attention_matrix_flops + attention_over_values_flops + linear_projection_flops + ffn_flops + embedding_flops

    if moe:
        total_flops += gating_flops

    def convert_flops(params):
        if params == 0:
            return "0"
        size_name = ("", "KFLOPs", "MFLOPs", "GFLOPs", "TFLOPs", "PFLOPs", "EFLOPs", "ZFLOPs", "YFLOPs")
        i = int(math.floor(math.log(params, 1000)))
        p = math.pow(1000, i)
        s = round(params / p, 2)
        return f"{s} {size_name[i]}"

    return {
        'qkv_flops': convert_flops(qkv_flops),
        'attention_matrix_flops': convert_flops(attention_matrix_flops),
        'attention_over_values_flops': convert_flops(attention_over_values_flops),
        'linear_projection_flops': convert_flops(linear_projection_flops),
        'ffn_flops': convert_flops(ffn_flops),
        'embedding_flops': convert_flops(embedding_flops),
        'total_flops': convert_flops(total_flops)
    }


# ---- Gradio Interface ---- #
with gr.Blocks(theme=gr.themes.Soft()) as demo:
    with gr.Accordion("Credits and General Idea", open=False):
        gr.Markdown("""
        This app is a re-creation of [this calculator](https://github.com/EleutherAI/cookbook/tree/main/calc) from EleutherAI.
        
        Before training or inference even begins, common practical questions about potential models must be answered such as:

        1. How many parameters are we targeting? How should those parameters be allocated within the model?
        1. How many FLOPs does the model from step 1 take to train on t tokens? How about inference?
        1. How much memory does the model from step 1 take to train/infer on d devices? What memory-saving strategies (e.g. parallelism, quantization, etc) are necessary to fit the model on device memory?
        """)
    with gr.Tab("Memory Calculation"):
        #with gr.TabItem("Memory Calculation"):
        with gr.Accordion("About Memory Calculation", open=False):
            gr.Markdown("""
            ## Memory Calculation
        
            Memory Calculation calculates the amount of device memory required to train or infer a model. See [Transformers Math 101](https://blog.eleuther.ai/transformer-math/) for more details on how memory overhead is calculated. 
            Take this estimation with a grain of salt, because every implementation is different and these calculations were written to match the GPT-NeoX library as close as possible. 
            Even for other training and inference libraries, however, we expect our script to give approximate memory estimations within acceptable error. 
            (Please see [LLM finetuning memory requirements](https://blog.scottlogic.com/2023/11/24/llm-mem.html) for a treatment of how specific memory costs may vary framework-to-framework). Other good resources that we consulted are the [ZeRO Paper](https://arxiv.org/abs/1910.02054) and [Reducing Activation Recomputation in Large Transformer Models](https://arxiv.org/pdf/2205.05198.pdf).
            """)
        with gr.Accordion("How to use it?", open=False):
            gr.Markdown("""
            ## To Use
            Fill in the required details below and click 'Calculate Memory' to get a result.
            """)
        with gr.Row():
            with gr.Column("Generatable"):
                gr.Markdown("## Generatable")
                with gr.Group():
                    hf_model_name_or_path = gr.Textbox(
                        label="HuggingFace Model Name or Path",
                        info="Name of the HuggingFace Hub repository or the local file path for it"
                    )
                    sequence_length = gr.Number(
                        label="Sequence Length", 
                        value=2048, 
                        info="Sequence length used for training"
                    )
                    vocab_size = gr.Number(
                        label="Vocab Size", 
                        value=51200, 
                        info="How many tokens are in the embedding layer"
                    )
                    hidden_size = gr.Number(
                        label="Hidden Size", 
                        value=6144, 
                        info="Dimension of the model's hidden size"
                    )
                    num_attention_heads = gr.Number(
                        label="Number of Attention Heads", 
                        value=64, 
                        info="Number of attention heads used in the model"
                    )
                    num_layers = gr.Number(
                        label="Number of Layers", 
                        value=44, 
                        info="Number of transformer layers used in the model"
                    )          
            with gr.Column("User Defined"):  
                gr.Markdown("## User Defined")
                num_gpus = gr.Number(
                    label="Number of GPUs", 
                    value=1, 
                    info="Number of GPUs used for training"
                )
                tensor_parallel_size = gr.Number(
                    label="Tensor Parallel Size", 
                    value=1, 
                    info="Tensor parallel degree (1 if not used)"
                )
                pipeline_parallel_size = gr.Number(
                    label="Pipeline Parallel Size", 
                    value=1, 
                    info="Pipeline parallel degree (1 if not used)"
                )
                batch_size_per_gpu = gr.Number(
                    label="Batch Size per GPU", 
                    value=8, 
                    info="Batch size per GPU"
                )
                ffn_expansion_factor = gr.Number(
                    label="FFN Expansion Factor", 
                    value=4, 
                    info="How much the MLP hidden size expands"
                )
                is_mixed_precision = gr.Checkbox(
                    label="Mixed Precision", 
                    value=True, 
                    info="Whether mixed precision is enabled"
                )
                misc_mem_gib = gr.Number(
                    label="Miscellaneous Memory Overhead (GiB)", 
                    value=5, 
                    info="Miscellaneous memory overhead per GPU by DL frameworks, communication libraries, etc."
                )

        calc_memory_button = gr.Button("Calculate Memory")
        memory_result = gr.Textbox(label="Memory Calculation Result", interactive=False)
        calc_memory_button.click(
                calc_mem, 
                inputs=[
                    hf_model_name_or_path, num_gpus, tensor_parallel_size, pipeline_parallel_size, batch_size_per_gpu, sequence_length, vocab_size, hidden_size, num_attention_heads, num_layers, ffn_expansion_factor, is_mixed_precision, misc_mem_gib
                ], 
                outputs=memory_result
        )

        hf_model_name_or_path.change(
                fn=update_from_hf_model, 
                inputs=[hf_model_name_or_path], 
                outputs=[num_layers, hidden_size, num_attention_heads, vocab_size, sequence_length, memory_result]
        )

        # Parameter Calculation Tab
    with gr.TabItem("Parameter Calculation"):
        gr.Markdown("""
        ## Parameter Calculation
        
        Parameter Calculation calculates the number of parameters present in a given model based on its hyperparams. 
        Such calculations are important to determine memory overheads, FLOPs, or to determine the size of an unknown transformer model. 
        We also found the following resources helpful: 
        [How does GPT-3 spend its 175B parameters?](https://www.lesswrong.com/posts/3duR8CrvcHywrnhLo/how-does-gpt-3-spend-its-175b-parameters) 
        and [LLM Parameter Counting](https://kipp.ly/transformer-param-count/).

        ## How To Use
        Simply input the model details, such as the hidden size, number of layers, and attention heads, and press 'Calculate Parameters' to get a result.

        """)
        with gr.Row():
            with gr.Column("Generatable"):
                with gr.Group():
                    hf_model_name_or_path = gr.Textbox(
                        label="HuggingFace Model Name or Path",
                        info="Name of the HuggingFace Hub repository or the local file path for it"
                    )
                    vocab_size = gr.Number(
                        label="Vocab Size", 
                        value=51200, 
                        info="How many tokens are in the embedding layer"
                    )
                    hidden_size = gr.Number(
                        label="Hidden Size", 
                        value=6144, 
                        info="Dimension of the model's hidden size"
                    )
                    sequence_length = gr.Number(
                        label="Sequence Length", 
                        value=2048, 
                        info="Sequence length used for training"
                    )
                    num_layers = gr.Number(
                        label="Number of Layers", 
                        value=44, 
                        info="Number of transformer layers used in the model"
                    )
            with gr.Column("User Defined"):
                tied_embeddings = gr.Checkbox(
                    label="Tied Embeddings", 
                    value=False, 
                    info="Whether embeddings are tied (shared between input and output)"
                )
                ffn_expansion_factor = gr.Number(
                    label="FFN Expansion Factor", 
                    value=4, 
                    info="How much the MLP hidden size expands"
                )
                num_mlp_linears = gr.Number(
                    label="Number of Linear Layers per MLP Block", 
                    value=2, 
                    info="How many linear layers per MLP block"
                )
                kv_size_ratio = gr.Number(
                    label="KV Size Ratio", 
                    value=1.0, 
                    info="Ratio of total query heads to key/value heads. 1.0 for MHA, 1/num_attention_heads for MQA"
                )
    
                with gr.Accordion("MoE Parameters", open=False):
                    moe = gr.Checkbox(
                        label="MoE", 
                        value=False, 
                        info="Whether the model is MoE"
                    )
                    num_experts = gr.Number(
                        label="Number of Experts", 
                        value=8, 
                        info="Number of experts for MoE"
                    )
                    expert_interval = gr.Number(
                        label="Expert Interval", 
                        value=1, 
                        info="Expert interval for MoE"
                    )
                    topk = gr.Number(
                        label="Top k Routing", 
                        value=1, 
                        info="Top k routing for MoE"
                    )

        calc_param_button = gr.Button("Calculate Parameters")
        param_result = gr.Textbox(label="Parameter Calculation Result", interactive=False)
        calc_param_button.click(calc_params, 
            inputs=[vocab_size, tied_embeddings, hidden_size, sequence_length, num_layers, moe, num_experts, expert_interval, topk, ffn_expansion_factor, num_mlp_linears, kv_size_ratio], 
            outputs=param_result)

        hf_model_name_or_path.change(fn=update_from_hf_model, 
            inputs=[hf_model_name_or_path], 
            outputs=[num_layers, hidden_size, num_attention_heads, vocab_size, sequence_length])

    # New FLOP Calculation Tab
    with gr.TabItem("FLOP Calculation"):
        gr.Markdown("""
        ## FLOP Calculation
        
        FLOP Calculation calculates the number of theoretical FLOPs required to train a model on t tokens. 
        See [Transformers Math 101](https://blog.eleuther.ai/transformer-math/) for more details on how FLOPs are calculated. 
        Other good resources that we consulted are the [Chinchilla Paper](https://arxiv.org/abs/2203.15556) and 
        [Efficient Large-Scale Language Model Training on GPU Clusters Using Megatron-LM](https://people.eecs.berkeley.edu/~matei/papers/2021/sc_megatron_lm.pdf).
        """)
        with gr.Row():
            with gr.Column("Generatable"):
                with gr.Group():
                    hf_model_name_or_path = gr.Textbox(
                        label="HuggingFace Model Name or Path",
                        info="Name of the HuggingFace Hub repository or the local file path for it"
                    )
                    vocab_size = gr.Number(
                        label="Vocab Size", 
                        value=51200, 
                        info="How many tokens are in the embedding layer"
                    )
                    hidden_size = gr.Number(
                        label="Hidden Size", 
                        value=6144, 
                        info="Dimension of the model's hidden size"
                    )
                    sequence_length = gr.Number(
                        label="Sequence Length", 
                        value=2048, 
                        info="Sequence length used for training"
                    )
                    num_layers = gr.Number(
                        label="Number of Layers", 
                        value=44, 
                        info="Number of transformer layers used in the model"
                    )
            with gr.Column("Generatable"):
                kv_size_ratio = gr.Number(
                    label="KV Size Ratio", 
                    value=1.0, 
                    info="Ratio of kv heads to query heads used in model. 1.0 for MHA"
                )
                ffn_expansion_factor = gr.Number(
                    label="FFN Expansion Factor", 
                    value=4, 
                    info="How much the MLP hidden size expands"
                )
                batch_size = gr.Number(
                    label="Batch Size", 
                    value=1, 
                    info="Global batch size in units of samples"
                )
                tokens = gr.Number(
                    label="Number of GigaTokens", 
                    value=300, 
                    info="Total number of GigaTokens for training"
                )
                checkpoint_activations = gr.Checkbox(
                    label="Checkpoint Activations", 
                    value=True, 
                    info="Whether Megatron-style activation checkpointing is being used"
                )
                infer = gr.Checkbox(
                    label="Inference-Only", 
                    value=False, 
                    info="Whether the model is being used for inference-only"
                )

                # MoE parameters hidden in accordion
                with gr.Accordion("Mixture of Experts (MoE)", open=False):
                    moe = gr.Checkbox(
                        label="Mixture of Experts (MoE)", 
                        value=False, 
                        info="Whether the model uses Mixture of Experts"
                    )
                    num_experts = gr.Number(
                        label="Number of Experts", 
                        value=128, 
                        info="Number of experts for Mixture of Experts (MoE)"
                    )
                    expert_interval = gr.Number(
                        label="Expert Interval", 
                        value=2, 
                        info="Expert interval for Mixture of Experts (MoE)"
                    )
                    topk = gr.Number(
                        label="Top K Routing for MoE", 
                        value=1, 
                        info="Top k routing for Mixture of Experts (MoE)"
                    )

        calc_flops_button = gr.Button("Calculate FLOPs")
        flops_result = gr.JSON(label="FLOP Calculation Result")
        calc_flops_button.click(
            calc_flops, 
            inputs=[vocab_size, hidden_size, sequence_length, num_layers, kv_size_ratio, topk, moe, num_experts, expert_interval, batch_size, tokens, checkpoint_activations, ffn_expansion_factor, infer], 
            outputs=flops_result
        )

        hf_model_name_or_path.change(fn=update_from_hf_model, 
            inputs=[hf_model_name_or_path], 
            outputs=[num_layers, hidden_size, vocab_size, sequence_length])

demo.launch()