import os
import subprocess
import math

def install(package):
    subprocess.check_call(["pip", "install", package])

# Install required libraries
install("numpy")
install("pandas")
install("torch")
install("transformers")
install("gradio")

import numpy as np
import pandas as pd
import torch
from transformers import AutoModel, AutoTokenizer
import gradio as gr

# Updated formulas in clear mathematical notation
formulas = {
    "Wiener Index (W)": "W = Σ₍u,v₎ d(u,v)\nwhere d(u,v) is the shortest path distance between vertices u and v.",
    "First Zagreb Index (M₁)": "M₁ = Σ₍v ∈ V(G)₎ deg(v)",
    "Second Zagreb Index (M₂)": "M₂ = Σ₍uv ∈ E(G)₎ [deg(u) × deg(v)]",
    "Randić Index (R)": "R = Σ₍uv ∈ E(G)₎ 1/√(deg(u) × deg(v))",
    "Atom-Bond Connectivity Index (ABC)": "ABC = Σ₍uv ∈ E(G)₎ √((deg(u) + deg(v) - 2)/(deg(u) × deg(v)))",
    "Augmented Zagreb Index (AZI)": "AZI = Σ₍uv ∈ E(G)₎ [ (deg(u) × deg(v))/(deg(u) + deg(v) - 2) ]³",
    "Geometric-Arithmetic Index (GA)": "GA = Σ₍uv ∈ E(G)₎ [2×√(deg(u)×deg(v))/(deg(u)+deg(v))]",
    "Sum-Connectivity Index (SCI)": "SCI = Σ₍uv ∈ E(G)₎ 1/√(deg(u) + deg(v))",
    "Harmonic Index (Harm)": "Harm = Σ₍uv ∈ E(G)₎ [2/(deg(u)+deg(v))]",
    "Gutman Index (Gut)": "Gut = Σ₍u,v, u<v₎ [deg(u) × deg(v) × d(u,v)]",
    "Eccentric Connectivity Index (ECI)": "ECI = Σ₍v ∈ V(G)₎ [deg(v) × ecc(v)]",
    "Total Eccentricity (TE)": "TE = Σ₍v ∈ V(G)₎ ecc(v)",
    "Harary Index (H)": "H = Σ₍u,v₎ 1/d(u,v)"
}

def solve_index(index, user_input):
    try:
        if index == "Wiener Index (W)":
            # Expected input: Comma-separated shortest-path distances, e.g. "1,1,1"
            distances = list(map(float, user_input.split(',')))
            result = sum(distances)
            steps = [
                f"1. **Extract the shortest-path distances:**  {distances}",
                f"2. **Sum all distances:**  " + " + ".join(map(str, distances)) + f" = {result}"
            ]
            output = "### **Wiener Index (W)**\n\n"
            output += "**Formula:**\n" + formulas["Wiener Index (W)"] + "\n\n"
            output += "**Required Input:** List of shortest-path distances between every vertex pair (comma-separated).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** W = {result}."
            return output

        elif index == "First Zagreb Index (M₁)":
            # Expected input: Comma-separated vertex degrees, e.g. "2,3,4"
            degrees = list(map(float, user_input.split(',')))
            result = sum(degrees)
            steps = [
                f"1. **Vertex degrees:**  {degrees}",
                f"2. **Sum the degrees:**  " + " + ".join(map(str, degrees)) + f" = {result}"
            ]
            output = "### **First Zagreb Index (M₁)**\n\n"
            output += "**Formula:**\n" + formulas["First Zagreb Index (M₁)"] + "\n\n"
            output += "**Required Input:** List of vertex degrees (comma-separated).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** M₁ = {result}."
            return output

        elif index == "Second Zagreb Index (M₂)":
            # Expected input: Comma-separated edge degree pairs, e.g. "2-3,3-2"
            edge_degrees = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            products = [d1 * d2 for d1, d2 in edge_degrees]
            result = sum(products)
            steps = [
                f"1. **Edge degree pairs:**  {edge_degrees}",
                f"2. **Products:**  {products}",
                f"3. **Sum products:**  " + " + ".join(map(str, products)) + f" = {result}"
            ]
            output = "### **Second Zagreb Index (M₂)**\n\n"
            output += "**Formula:**\n" + formulas["Second Zagreb Index (M₂)"] + "\n\n"
            output += "**Required Input:** Edge degree pairs in the form d(u)-d(v) (comma-separated).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** M₂ = {result}."
            return output

        elif index == "Randić Index (R)":
            # Expected input: Comma-separated edge degree pairs, e.g. "2-3,3-2"
            edge_degrees = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            values = [1 / math.sqrt(d1 * d2) for d1, d2 in edge_degrees]
            result = sum(values)
            steps = [f"1. **Edge degree pairs:**  {edge_degrees}"]
            for (d1, d2), v in zip(edge_degrees, values):
                steps.append(f"2. **For edge {d1}-{d2}:** 1/√({d1}×{d2}) = {v:.4f}")
            steps.append("3. **Sum:**  " + " + ".join(f"{v:.4f}" for v in values) + f" = {result:.4f}")
            output = "### **Randić Index (R)**\n\n"
            output += "**Formula:**\n" + formulas["Randić Index (R)"] + "\n\n"
            output += "**Required Input:** Edge degree pairs (e.g., 2-3,3-2).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** R = {result:.4f}."
            return output

        elif index == "Atom-Bond Connectivity Index (ABC)":
            # Expected input: Comma-separated edge degree pairs, e.g. "2-3,3-2"
            edge_degrees = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            values = [ math.sqrt((d1 + d2 - 2) / (d1 * d2)) for d1, d2 in edge_degrees ]
            result = sum(values)
            steps = [f"1. **Edge degree pairs:**  {edge_degrees}"]
            for (d1, d2), v in zip(edge_degrees, values):
                steps.append(f"2. **For edge {d1}-{d2}:** √(({d1}+{d2}-2)/({d1}×{d2})) = {v:.4f}")
            steps.append("3. **Sum:**  " + " + ".join(f"{v:.4f}" for v in values) + f" = {result:.4f}")
            output = "### **Atom-Bond Connectivity Index (ABC)**\n\n"
            output += "**Formula:**\n" + formulas["Atom-Bond Connectivity Index (ABC)"] + "\n\n"
            output += "**Required Input:** Edge degree pairs (e.g., 2-3,3-2).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** ABC = {result:.4f}."
            return output

        elif index == "Augmented Zagreb Index (AZI)":
            # Expected input: Comma-separated edge degree pairs, e.g. "2-3,3-2"
            edge_degrees = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            values = []
            for d1, d2 in edge_degrees:
                denominator = d1 + d2 - 2
                val = (d1 * d2 / denominator) ** 3 if denominator != 0 else 0
                values.append(val)
            result = sum(values)
            steps = [f"1. **Edge degree pairs:**  {edge_degrees}"]
            for (d1, d2), v in zip(edge_degrees, values):
                denominator = d1 + d2 - 2
                steps.append(f"2. **For edge {d1}-{d2}:** Compute ( {d1}×{d2} / ({d1}+{d2}-2) )³ with denominator={denominator} → {v:.4f}")
            steps.append("3. **Sum:**  " + " + ".join(f"{v:.4f}" for v in values) + f" = {result:.4f}")
            output = "### **Augmented Zagreb Index (AZI)**\n\n"
            output += "**Formula:**\n" + formulas["Augmented Zagreb Index (AZI)"] + "\n\n"
            output += "**Required Input:** Edge degree pairs (e.g., 2-3,3-2); ensure (deg(u)+deg(v)-2) ≠ 0.\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** AZI = {result:.4f}."
            return output

        elif index == "Geometric-Arithmetic Index (GA)":
            # Expected input: Comma-separated edge degree pairs, e.g. "2-3,3-2"
            edge_degrees = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            values = [ (2 * math.sqrt(d1 * d2))/(d1 + d2) for d1, d2 in edge_degrees ]
            result = sum(values)
            steps = [f"1. **Edge degree pairs:**  {edge_degrees}"]
            for (d1, d2), v in zip(edge_degrees, values):
                steps.append(f"2. **For edge {d1}-{d2}:**  2×√({d1}×{d2})/({d1}+{d2}) = {v:.4f}")
            steps.append("3. **Sum:**  " + " + ".join(f"{v:.4f}" for v in values) + f" = {result:.4f}")
            output = "### **Geometric-Arithmetic Index (GA)**\n\n"
            output += "**Formula:**\n" + formulas["Geometric-Arithmetic Index (GA)"] + "\n\n"
            output += "**Required Input:** Edge degree pairs (e.g., 2-3,3-2).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** GA = {result:.4f}."
            return output

        elif index == "Sum-Connectivity Index (SCI)":
            # Expected input: Comma-separated edge degree pairs, e.g. "2-3,3-2"
            edge_degrees = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            values = [ 1 / math.sqrt(d1 + d2) for d1, d2 in edge_degrees ]
            result = sum(values)
            steps = [f"1. **Edge degree pairs:**  {edge_degrees}"]
            for (d1, d2), v in zip(edge_degrees, values):
                steps.append(f"2. **For edge {d1}-{d2}:**  1/√({d1}+{d2}) = {v:.4f}")
            steps.append("3. **Sum:**  " + " + ".join(f"{v:.4f}" for v in values) + f" = {result:.4f}")
            output = "### **Sum-Connectivity Index (SCI)**\n\n"
            output += "**Formula:**\n" + formulas["Sum-Connectivity Index (SCI)"] + "\n\n"
            output += "**Required Input:** Edge degree pairs (e.g., 2-3,3-2).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** SCI = {result:.4f}."
            return output

        elif index == "Harmonic Index (Harm)":
            # Expected input: Comma-separated edge degree pairs, e.g. "2-3,3-2"
            edge_degrees = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            values = [ 2 / (d1 + d2) for d1, d2 in edge_degrees ]
            result = sum(values)
            steps = [f"1. **Edge degree pairs:**  {edge_degrees}"]
            for (d1, d2), v in zip(edge_degrees, values):
                steps.append(f"2. **For edge {d1}-{d2}:**  2/({d1}+{d2}) = {v:.4f}")
            steps.append("3. **Sum:**  " + " + ".join(f"{v:.4f}" for v in values) + f" = {result:.4f}")
            output = "### **Harmonic Index (Harm)**\n\n"
            output += "**Formula:**\n" + formulas["Harmonic Index (Harm)"] + "\n\n"
            output += "**Required Input:** Edge degree pairs (e.g., 2-3,3-2).\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** Harm = {result:.4f}."
            return output

        elif index == "Gutman Index (Gut)":
            # Expected input: Two lists separated by a semicolon.
            # First list: vertex degrees (comma-separated), e.g. "2,2,2"
            # Second list: distances for each unordered vertex pair in lex order (comma-separated), e.g. "1,1,1"
            parts = user_input.split(';')
            if len(parts) != 2:
                return "Invalid input. Use format: degrees;distances  e.g., 2,2,2;1,1,1"
            degrees = list(map(float, parts[0].strip().split(',')))
            distances = list(map(float, parts[1].strip().split(',')))
            # For n vertices the unordered pairs are n choose 2. Check count:
            n = len(degrees)
            if len(distances) != (n*(n-1))//2:
                return f"Invalid number of distances. For {n} vertices, you must provide {(n*(n-1))//2} distances."
            # Sum over pairs in lex order: pairs: (0,1), (0,2), ..., (n-2,n-1)
            total = 0
            pair_index = 0
            for i in range(n):
                for j in range(i+1, n):
                    total += degrees[i] * degrees[j] * distances[pair_index]
                    pair_index += 1
            steps = [
                f"1. **Vertex Degrees:**  {degrees}",
                f"2. **Distances for unordered pairs (in order):**  {distances}",
                f"3. **Computed Gutman sum:**  Gut = {total}"
            ]
            output = "### **Gutman Index (Gut)**\n\n"
            output += "**Formula:**\n" + formulas["Gutman Index (Gut)"] + "\n\n"
            output += "**Required Input:** Enter vertex degrees and distances as: `deg₁,deg₂,...,degₙ; d(1,2),d(1,3),...,d(n-1,n)`\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** Gut = {total}"
            return output

        elif index == "Eccentric Connectivity Index (ECI)":
            # Expected input: Comma-separated vertex pairs as "deg-ecc" (e.g., "2-1,3-1,2-1")
            pairs = [tuple(map(float, pair.split('-'))) for pair in user_input.split(',')]
            values = [deg * ecc for deg, ecc in pairs]
            result = sum(values)
            steps = [
                f"1. **Extract the (deg, ecc) pairs for vertices:**  {pairs}",
                f"2. **Multiply each pair:**  " + " + ".join(f"{deg}×{ecc}" for deg, ecc in pairs) + f" = {result}"
            ]
            output = "### **Eccentric Connectivity Index (ECI)**\n\n"
            output += "**Formula:**\n" + formulas["Eccentric Connectivity Index (ECI)"] + "\n\n"
            output += "**Required Input:** Enter each vertex as deg-ecc (comma-separated), e.g., 2-1,3-1,2-1\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** ECI = {result}"
            return output

        elif index == "Total Eccentricity (TE)":
            # Expected input: Comma-separated eccentricities of all vertices, e.g. "1,1,2"
            ecc_values = list(map(float, user_input.split(',')))
            result = sum(ecc_values)
            steps = [
                f"1. **Eccentricities:**  {ecc_values}",
                f"2. **Sum the eccentricities:**  " + " + ".join(map(str, ecc_values)) + f" = {result}"
            ]
            output = "### **Total Eccentricity (TE)**\n\n"
            output += "**Formula:**\n" + formulas["Total Eccentricity (TE)"] + "\n\n"
            output += "**Required Input:** List of vertex eccentricities (comma-separated), e.g., 1,1,2\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** TE = {result}"
            return output

        elif index == "Harary Index (H)":
            # Expected input: Comma-separated shortest-path distances, e.g. "1,1,1"
            distances = list(map(float, user_input.split(',')))
            values = [1/d for d in distances if d > 0]
            result = sum(values)
            steps = [
                f"1. **Shortest-path distances:**  {distances}",
                f"2. **Reciprocals:**  " + " + ".join(f"1/{d}" for d in distances if d > 0) + f" = {result:.4f}"
            ]
            output = "### **Harary Index (H)**\n\n"
            output += "**Formula:**\n" + formulas["Harary Index (H)"] + "\n\n"
            output += "**Required Input:** List of shortest-path distances between each vertex pair (comma-separated), e.g., 1,1,1\n\n"
            output += "**Step-by-step solution:**\n" + "\n".join(steps) + "\n\n"
            output += f"**Answer:** H = {result:.4f}"
            return output

        else:
            return "Index not recognized."
    except Exception as e:
        return f"Error in processing input: {e}"

def update_input_placeholder(index):
    placeholders = {
        "Wiener Index (W)": "Enter distances (e.g., 1,1,1)",
        "First Zagreb Index (M₁)": "Enter vertex degrees (e.g., 2,3,4)",
        "Second Zagreb Index (M₂)": "Enter edge degree pairs (e.g., 2-3,3-2)",
        "Randić Index (R)": "Enter edge degree pairs (e.g., 2-3,3-2)",
        "Atom-Bond Connectivity Index (ABC)": "Enter edge degree pairs (e.g., 2-3,3-2)",
        "Augmented Zagreb Index (AZI)": "Enter edge degree pairs (e.g., 2-3,3-2)",
        "Geometric-Arithmetic Index (GA)": "Enter edge degree pairs (e.g., 2-3,3-2)",
        "Sum-Connectivity Index (SCI)": "Enter edge degree pairs (e.g., 2-3,3-2)",
        "Harmonic Index (Harm)": "Enter edge degree pairs (e.g., 2-3,3-2)",
        "Gutman Index (Gut)": "Enter degrees;distances (e.g., 2,2,2;1,1,1)",
        "Eccentric Connectivity Index (ECI)": "Enter deg-ecc pairs (e.g., 2-1,3-1,2-1)",
        "Total Eccentricity (TE)": "Enter eccentricities (e.g., 1,1,2)",
        "Harary Index (H)": "Enter distances (e.g., 1,1,1)"
    }
    return placeholders.get(index, "Enter input as required"), formulas.get(index, "")

# Updated list of indices for the dropdown
index_options = [
    "Wiener Index (W)",
    "First Zagreb Index (M₁)",
    "Second Zagreb Index (M₂)",
    "Randić Index (R)",
    "Atom-Bond Connectivity Index (ABC)",
    "Augmented Zagreb Index (AZI)",
    "Geometric-Arithmetic Index (GA)",
    "Sum-Connectivity Index (SCI)",
    "Harmonic Index (Harm)",
    "Gutman Index (Gut)",
    "Eccentric Connectivity Index (ECI)",
    "Total Eccentricity (TE)",
    "Harary Index (H)"
]

with gr.Blocks() as demo:
    gr.Markdown("## Topological Index Calculator\n\nSelect an index, review its formula, enter the required values as described, and click **Solve** to see a detailed, step-by-step solution.")
    index_dropdown = gr.Dropdown(index_options, label="Select an Index")
    formula_box = gr.Textbox(label="Formula", interactive=False)
    input_box = gr.Textbox(label="Enter Values")
    solve_button = gr.Button("Solve")
    output_box = gr.Textbox(label="Step-by-Step Solution", interactive=False, lines=20)

    index_dropdown.change(fn=lambda idx: update_input_placeholder(idx),
                          inputs=[index_dropdown],
                          outputs=[input_box, formula_box])
    solve_button.click(fn=solve_index,
                       inputs=[index_dropdown, input_box],
                       outputs=[output_box])

demo.launch()