import gradio as gr
import pandas as pd
from datasets import Dataset
from transformers import GPT2Tokenizer, GPT2LMHeadModel, Trainer, TrainingArguments
import torch
import os
import matplotlib.pyplot as plt
import json
import io
from datetime import datetime

# Variables globales pour stocker les colonnes détectées
columns = []


# Fonction pour lire le fichier et détecter les colonnes
def read_file(data_file):
    global columns
    try:
        # Charger les données
        file_extension = os.path.splitext(data_file.name)[1]
        if file_extension == '.csv':
            df = pd.read_csv(data_file.name)
        elif file_extension == '.json':
            df = pd.read_json(data_file.name)
        elif file_extension == '.xlsx':
            df = pd.read_excel(data_file.name)
        else:
            return "Invalid file format. Please upload a CSV, JSON, or Excel file."

        # Détecter les colonnes
        columns = df.columns.tolist()
        return columns
    except Exception as e:
        return f"An error occurred: {str(e)}"


# Fonction pour valider les colonnes sélectionnées
def validate_columns(prompt_col, description_col):
    if prompt_col not in columns or description_col not in columns:
        return False
    return True


# Fonction pour entraîner le modèle
def train_model(data_file, model_name, epochs, batch_size, learning_rate, output_dir, prompt_col, description_col):
    try:
        # Valider les colonnes sélectionnées
        if not validate_columns(prompt_col, description_col):
            return "Invalid column selection. Please ensure the columns exist in the dataset."

        # Charger les données
        file_extension = os.path.splitext(data_file.name)[1]
        if file_extension == '.csv':
            df = pd.read_csv(data_file.name)
        elif file_extension == '.json':
            df = pd.read_json(data_file.name)
        elif file_extension == '.xlsx':
            df = pd.read_excel(data_file.name)

        # Prévisualisation des données
        preview = df.head().to_string(index=False)

        # Préparer le texte d'entraînement
        df['text'] = df[prompt_col] + ': ' + df[description_col]
        dataset = Dataset.from_pandas(df[['text']])

        # Initialiser le tokenizer et le modèle GPT-2
        tokenizer = GPT2Tokenizer.from_pretrained(model_name)
        model = GPT2LMHeadModel.from_pretrained(model_name)

        # Ajouter un token de padding si nécessaire
        if tokenizer.pad_token is None:
            tokenizer.add_special_tokens({'pad_token': '[PAD]'})
            model.resize_token_embeddings(len(tokenizer))

        # Tokenizer les données
        def tokenize_function(examples):
            tokens = tokenizer(examples['text'], padding="max_length", truncation=True, max_length=128)
            tokens['labels'] = tokens['input_ids'].copy()
            return tokens

        tokenized_datasets = dataset.map(tokenize_function, batched=True)

        # Ajustement des hyperparamètres
        training_args = TrainingArguments(
            output_dir=output_dir,
            overwrite_output_dir=True,
            num_train_epochs=int(epochs),
            per_device_train_batch_size=int(batch_size),
            per_device_eval_batch_size=int(batch_size),
            warmup_steps=1000,
            weight_decay=0.01,
            learning_rate=float(learning_rate),
            logging_dir="./logs",
            logging_steps=10,
            save_steps=500,
            save_total_limit=2,
            evaluation_strategy="steps",
            eval_steps=500,
            load_best_model_at_end=True,
            metric_for_best_model="eval_loss"
        )

        # Configuration du Trainer
        trainer = Trainer(
            model=model,
            args=training_args,
            train_dataset=tokenized_datasets,
            eval_dataset=tokenized_datasets,
        )

        # Entraînement et évaluation
        trainer.train()
        eval_results = trainer.evaluate()

        # Sauvegarder le modèle fine-tuné
        model.save_pretrained(output_dir)
        tokenizer.save_pretrained(output_dir)

        # Générer un graphique des pertes d'entraînement et de validation
        train_loss = [x['loss'] for x in trainer.state.log_history if 'loss' in x]
        eval_loss = [x['eval_loss'] for x in trainer.state.log_history if 'eval_loss' in x]
        plt.plot(train_loss, label='Training Loss')
        plt.plot(eval_loss, label='Validation Loss')
        plt.xlabel('Steps')
        plt.ylabel('Loss')
        plt.title('Training and Validation Loss')
        plt.legend()
        plt.savefig(os.path.join(output_dir, 'training_eval_loss.png'))

        return f"Training completed successfully.\nPreview of data:\n{preview}", eval_results
    except Exception as e:
        return f"An error occurred: {str(e)}"


# Fonction de génération de texte
def generate_text(prompt, temperature, top_k, top_p, max_length, repetition_penalty, use_comma, batch_size):
    try:
        model_name = "./fine-tuned-gpt2"
        tokenizer = GPT2Tokenizer.from_pretrained(model_name)
        model = GPT2LMHeadModel.from_pretrained(model_name)

        if use_comma:
            prompt = prompt.replace('.', ',')

        inputs = tokenizer(prompt, return_tensors="pt", padding=True)
        attention_mask = inputs.attention_mask
        outputs = model.generate(
            inputs.input_ids,
            attention_mask=attention_mask,
            max_length=int(max_length),
            temperature=float(temperature),
            top_k=int(top_k),
            top_p=float(top_p),
            repetition_penalty=float(repetition_penalty),
            num_return_sequences=int(batch_size),
            pad_token_id=tokenizer.eos_token_id
        )

        return [tokenizer.decode(output, skip_special_tokens=True) for output in outputs]
    except Exception as e:
        return f"An error occurred: {str(e)}"


# Fonction pour configurer les presets
def set_preset(preset):
    if preset == "Default":
        return 5, 8, 3e-5
    elif preset == "Fast Training":
        return 3, 16, 5e-5
    elif preset == "High Accuracy":
        return 10, 4, 1e-5


# Interface Gradio
with gr.Blocks() as ui:
    gr.Markdown("# Fine-Tune GPT-2 UI Design Model")

    with gr.Tab("Train Model"):
        with gr.Row():
            data_file = gr.File(label="Upload Data File (CSV, JSON, Excel)")
            model_name = gr.Textbox(label="Model Name", value="gpt2")
            output_dir = gr.Textbox(label="Output Directory", value="./fine-tuned-gpt2")

        with gr.Row():
            preset = gr.Radio(["Default", "Fast Training", "High Accuracy"], label="Preset")
            epochs = gr.Number(label="Epochs", value=5)
            batch_size = gr.Number(label="Batch Size", value=8)
            learning_rate = gr.Number(label="Learning Rate", value=3e-5)

        preset.change(set_preset, preset, [epochs, batch_size, learning_rate])

        # Champs pour sélectionner les colonnes
        with gr.Row():
            prompt_col = gr.Dropdown(label="Prompt Column")
            description_col = gr.Dropdown(label="Description Column")

        # Détection des colonnes lors du téléchargement du fichier
        data_file.upload(read_file, inputs=data_file, outputs=[prompt_col, description_col])

        train_button = gr.Button("Train Model")
        train_output = gr.Textbox(label="Training Output")
        train_graph = gr.Image(label="Training and Validation Loss Graph")

        train_button.click(train_model,
                           inputs=[data_file, model_name, epochs, batch_size, learning_rate, output_dir, prompt_col,
                                   description_col], outputs=[train_output, train_graph])

    with gr.Tab("Generate Text"):
        with gr.Row():
            with gr.Column():
                temperature = gr.Slider(label="Temperature", minimum=0.1, maximum=1.0, value=0.7)
                top_k = gr.Slider(label="Top K", minimum=1, maximum=100, value=50)
                top_p = gr.Slider(label="Top P", minimum=0.0, maximum=1.0, value=0.9)
                max_length = gr.Slider(label="Max Length", minimum=10, maximum=1024, value=128)
                repetition_penalty = gr.Slider(label="Repetition Penalty", minimum=1.0, maximum=2.0, value=1.2)
                use_comma = gr.Checkbox(label="Use Comma", value=True)
                batch_size = gr.Number(label="Batch Size", value=1, minimum=1)

            with gr.Column():
                prompt = gr.Textbox(label="Prompt")
                generate_button = gr.Button("Generate Text")
                generated_text = gr.Textbox(label="Generated Text", lines=20)

        generate_button.click(generate_text,
                              inputs=[prompt, temperature, top_k, top_p, max_length, repetition_penalty, use_comma,
                                      batch_size], outputs=generated_text)

ui.launch()