import gradio as gr
import torch
from transformers import AutoTokenizer, AutoModelForCausalLM
import evaluate
import re
import matplotlib
matplotlib.use('Agg')  # for non-interactive envs
import matplotlib.pyplot as plt
import io
import base64
import os
from huggingface_hub import login

# Read token and login
hf_token = os.getenv("HF_TOKEN_READ_WRITE")
if hf_token:
    login(hf_token)
else:
    print("⚠️ No HF_TOKEN_READ_WRITE found in environment")

# Check GPU availability
if torch.cuda.is_available():
    print("✅ GPU is available")
    print("GPU Name:", torch.cuda.get_device_name(0))
else:
    print("❌ No GPU available")

# ---------------------------------------------------------------------------
# 1. Define model name and load model/tokenizer
# ---------------------------------------------------------------------------
model_name = "mistralai/Mistral-7B-Instruct-v0.3"

tokenizer = AutoTokenizer.from_pretrained(model_name, token=hf_token)
device = "cuda" if torch.cuda.is_available() else "cpu"
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    token=hf_token,
    torch_dtype=torch.float16,
    device_map="auto"
)

print(f"✅ Model loaded on {device}")

# ---------------------------------------------------------------------------
# 2. Test dataset
# ---------------------------------------------------------------------------
test_data = [
    {"question": "What is 2+2?", "answer": "4"},
    {"question": "What is 3*3?", "answer": "9"},
    {"question": "What is 10/2?", "answer": "5"},
]

# ---------------------------------------------------------------------------
# 3. Load metric
# ---------------------------------------------------------------------------
accuracy_metric = evaluate.load("accuracy")

# ---------------------------------------------------------------------------
# 4. Inference helper functions
# ---------------------------------------------------------------------------
def generate_answer(question):
    """
    Generates an answer using Mistral's instruction format.
    """
    # Mistral instruction format
    prompt = f"""<s>[INST] {question} [/INST]"""
    
    inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
    with torch.no_grad():
        outputs = model.generate(
            **inputs,
            max_new_tokens=50,
            temperature=0.0,  # deterministic
            pad_token_id=tokenizer.pad_token_id,
            eos_token_id=tokenizer.eos_token_id
        )
    text_output = tokenizer.decode(outputs[0], skip_special_tokens=True)
    # Remove the original question from the output
    return text_output.replace(question, "").strip()

def parse_answer(model_output):
    """
    Extract numeric answer from model's text output.
    """
    # Look for numbers (including decimals)
    match = re.search(r"(-?\d*\.?\d+)", model_output)
    if match:
        return match.group(1)
    return model_output.strip()

# ---------------------------------------------------------------------------
# 5. Evaluation routine
# ---------------------------------------------------------------------------
def run_evaluation():
    predictions = []
    references = []
    raw_outputs = []  # Store full model outputs for display
    
    for sample in test_data:
        question = sample["question"]
        reference_answer = sample["answer"]
        
        # Model inference
        model_output = generate_answer(question)
        predicted_answer = parse_answer(model_output)
        
        predictions.append(predicted_answer)
        references.append(reference_answer)
        raw_outputs.append({
            "question": question,
            "model_output": model_output,
            "parsed_answer": predicted_answer,
            "reference": reference_answer
        })
    
    # Normalize answers
    def normalize_answer(ans):
        return str(ans).lower().strip()
    
    norm_preds = [normalize_answer(p) for p in predictions]
    norm_refs = [normalize_answer(r) for r in references]
    
    # Compute accuracy
    results = accuracy_metric.compute(predictions=norm_preds, references=norm_refs)
    accuracy = results["accuracy"]
    
    # Create visualization
    correct_count = sum(p == r for p, r in zip(norm_preds, norm_refs))
    incorrect_count = len(test_data) - correct_count
    
    fig, ax = plt.subplots(figsize=(8, 6))
    bars = ax.bar(["Correct", "Incorrect"], 
                 [correct_count, incorrect_count],
                 color=["#2ecc71", "#e74c3c"])
    
    # Add value labels on bars
    for bar in bars:
        height = bar.get_height()
        ax.text(bar.get_x() + bar.get_width()/2., height,
                f'{int(height)}',
                ha='center', va='bottom')
    
    ax.set_title("Evaluation Results")
    ax.set_ylabel("Count")
    ax.set_ylim([0, len(test_data) + 0.5])  # Add some padding at top
    
    # Convert plot to base64
    buf = io.BytesIO()
    plt.savefig(buf, format="png", bbox_inches='tight', dpi=300)
    buf.seek(0)
    plt.close(fig)
    data = base64.b64encode(buf.read()).decode("utf-8")
    
    # Create detailed results HTML
    details_html = """
    <div style="margin-top: 20px;">
        <h3>Detailed Results:</h3>
        <table style="width:100%; border-collapse: collapse;">
            <tr style="background-color: #f5f5f5;">
                <th style="padding: 8px; border: 1px solid #ddd;">Question</th>
                <th style="padding: 8px; border: 1px solid #ddd;">Model Output</th>
                <th style="padding: 8px; border: 1px solid #ddd;">Parsed Answer</th>
                <th style="padding: 8px; border: 1px solid #ddd;">Reference</th>
            </tr>
    """
    
    for result in raw_outputs:
        details_html += f"""
            <tr>
                <td style="padding: 8px; border: 1px solid #ddd;">{result['question']}</td>
                <td style="padding: 8px; border: 1px solid #ddd;">{result['model_output']}</td>
                <td style="padding: 8px; border: 1px solid #ddd;">{result['parsed_answer']}</td>
                <td style="padding: 8px; border: 1px solid #ddd;">{result['reference']}</td>
            </tr>
        """
    
    details_html += "</table></div>"
    
    # Combine plot and details
    full_html = f"""
    <div>
        <img src="data:image/png;base64,{data}" style="width:100%; max-width:600px;">
        {details_html}
    </div>
    """
    
    return f"Accuracy: {accuracy:.2f}", full_html

# ---------------------------------------------------------------------------
# 6. Gradio Interface
# ---------------------------------------------------------------------------
with gr.Blocks() as demo:
    gr.Markdown("# Mistral-7B Math Evaluation Demo")
    gr.Markdown("""
    This demo evaluates Mistral-7B on basic math problems.
    Press the button below to run the evaluation.
    """)
    
    eval_button = gr.Button("Run Evaluation", variant="primary")
    output_text = gr.Textbox(label="Results")
    output_plot = gr.HTML(label="Visualization and Details")
    
    eval_button.click(
        fn=run_evaluation,
        inputs=None,
        outputs=[output_text, output_plot]
    )

demo.launch()