import streamlit as st
import firebase_admin
from firebase_admin import credentials, firestore
import pandas as pd

# Set Page Configuration (must be the first Streamlit command)
st.set_page_config(
    page_title="ERP Admin Panel",
    page_icon="🛠️",
    layout="wide",
    initial_sidebar_state="expanded"
)

# Initialize Firebase
try:
    cred = credentials.Certificate("serviceAccountKey.json")
    firebase_admin.initialize_app(cred)
except ValueError:
    # If the app is already initialized, skip re-initialization
    pass

db = firestore.client()

# Default User Authentication
DEFAULT_USERS = {
    "Admin": {"password": "Admin", "role": "Admin"},
    "Manager": {"password": "Manager", "role": "Manager"},
}

def normalize_email(email):
    """Normalize email by converting it to lowercase."""
    return email.strip().lower()

def initialize_default_users():
    """
    Initialize default users in Firestore if they don't already exist.
    """
    for email, user_data in DEFAULT_USERS.items():
        normalized_email = normalize_email(email)
        emp_doc = db.collection("Employees").document(normalized_email).get()
        if not emp_doc.exists:
            with st.spinner(f"⏳ Initializing default user: {email}"):
                db.collection("Employees").document(normalized_email).set({
                    "name": email.capitalize(),  # Use email as name for simplicity
                    "email": normalized_email,
                    "phone": "N/A",  # Default placeholder
                    "designation": "Default User",
                    "role": user_data["role"],
                    "password": user_data["password"],
                    "force_password_change": False  # No need to change default passwords
                })
            st.success(f"✅ Default user '{email}' initialized successfully.")

def login_user(email, password):
    # Normalize email
    email = normalize_email(email)
    
    # Check if the user is a default user (Admin/Manager)
    if email in DEFAULT_USERS and DEFAULT_USERS[email]["password"] == password:
        return DEFAULT_USERS[email]["role"]
    
    # Check if the user exists in Firestore (employees)
    emp_doc = db.collection("Employees").document(email).get()
    if emp_doc.exists:
        emp_data = emp_doc.to_dict()
        if "password" in emp_data and emp_data["password"] == password:
            return emp_data.get("role", "Employee")  # Default role is "Employee"
    
    # If no match is found, return None
    st.error("❌ Invalid credentials. Please try again.")
    return None

# Sidebar Navigation with Icons
st.sidebar.markdown("""
    <style>
    .sidebar .sidebar-content {
        background-color: #e6f7ff; /* Light Blue Background */
        border-radius: 15px;
        box-shadow: 5px 5px 15px rgba(0, 0, 0, 0.2);
    }
    .sidebar .stButton button {
        background-color: #007bff;
        color: white;
        border-radius: 10px;
        padding: 10px;
        font-size: 16px;
        box-shadow: 3px 3px 8px rgba(0, 0, 0, 0.3);
    }
    .sidebar .stButton button:hover {
        background-color: #0056b3;
        transform: scale(1.05);
        transition: all 0.3s ease;
    }
    </style>
""", unsafe_allow_html=True)

st.sidebar.title("🚀 Admin Panel 🛠️")

# Initialize Default Users
if "default_users_initialized" not in st.session_state:
    initialize_default_users()
    st.session_state.default_users_initialized = True

# Login Section
if "logged_in" not in st.session_state:
    st.session_state.logged_in = False
    st.session_state.user_role = None

if not st.session_state.logged_in:
    st.sidebar.subheader("🔑 Login")
    email = st.sidebar.text_input("📧 Email", placeholder="Enter your email")
    password = st.sidebar.text_input("🔒 Password", type="password", placeholder="Enter your password")
    
    if st.sidebar.button("🔓 Login"):
        user_role = login_user(email, password)
        if user_role:
            # Check if the user needs to change their password
            emp_doc = db.collection("Employees").document(normalize_email(email)).get()
            if emp_doc.exists:
                emp_data = emp_doc.to_dict()
                if emp_data.get("force_password_change", False):
                    st.session_state.force_password_change = True
                    st.session_state.temp_email = normalize_email(email)
                    st.experimental_rerun()
            
            # Update session state for successful login
            st.session_state.logged_in = True
            st.session_state.user_role = user_role
            st.experimental_rerun()
else:
    if "force_password_change" in st.session_state and st.session_state.force_password_change:
        st.header("⚠️ Change Password")
        st.warning("🔒 You must change your password before proceeding.")
        new_password = st.text_input("🔐 New Password", type="password", placeholder="Enter a new password")
        confirm_password = st.text_input("🔒 Confirm Password", type="password", placeholder="Confirm your new password")
        
        if st.button("✅ Save Password"):
            if not new_password or not confirm_password:
                st.error("❌ Please fill in both fields.")
            elif new_password != confirm_password:
                st.error("❌ Passwords do not match.")
            elif len(new_password) < 8 or not any(char.isdigit() for char in new_password) or not any(char.isupper() for char in new_password):
                st.error("❌ Password must be at least 8 characters long, include a number, and an uppercase letter.")
            else:
                # Update password in Firestore
                db.collection("Employees").document(st.session_state.temp_email).update({
                    "password": new_password,
                    "force_password_change": False
                })
                st.success("✅ Password changed successfully!")
                st.session_state.force_password_change = False
                st.session_state.logged_in = True
                st.experimental_rerun()
    else:
        st.sidebar.subheader(f"👋 Welcome, {st.session_state.user_role}")
        menu = {
            "👥 Employee Management": "employee",
            "🛡️ Role Management": "role",
            "🔒 Access Control": "access",
            "📊 Dashboards": "dashboard",
            "📋 Reporting Templates": "report",
            "🤖 Chatbot": "chatbot",
            "🧠 Advanced Analytics": "analytics",
        }
        choice = st.sidebar.radio("📚 Menu", list(menu.keys()))

        # Logout Button
        if st.sidebar.button("🚪 Logout"):
            st.session_state.logged_in = False
            st.session_state.user_role = None
            st.experimental_rerun()

# Theme Selection
st.sidebar.subheader("🎨 Appearance")
theme = st.sidebar.selectbox("🌙 Choose Theme", ["☀️ Light", "🌙 Dark"])
if theme == "☀️ Light":
    st.markdown("""
        <style>
        .stApp {background-color: #e6f7ff; color: black;} /* Light Blue Background */
        </style>
    """, unsafe_allow_html=True)
elif theme == "🌙 Dark":
    st.markdown("""
        <style>
        .stApp {background-color: #1E1E1E; color: white;}
        </style>
    """, unsafe_allow_html=True)

# Main Content
if "logged_in" in st.session_state and st.session_state.logged_in:
    # Role-Based Access Control
    user_role = st.session_state.user_role
    if user_role not in ["Admin", "Manager", "Engineer", "Accountant"]:
        st.error("❌ Unauthorized access. Please contact the administrator.")
        st.stop()

    if menu[choice] == "employee":
        if user_role not in ["Admin", "Manager"]:
            st.error("❌ You do not have permission to access this module.")
            st.stop()

        st.header("👥 Employee Management")
        
        # Real-Time Updates for Employees
        def fetch_employees():
            employees_ref = db.collection("Employees").stream()
            return [{"ID": emp.id, "Name": emp.to_dict()["name"], "Email": emp.to_dict()["email"], "Role": emp.to_dict()["role"]} for emp in employees_ref]

        # Add Employee Form
        with st.form("add_employee_form"):
            st.subheader("📝 Add Employee")
            col1, col2 = st.columns(2)
            with col1:
                name = st.text_input("👤 Name", placeholder="Enter full name", help="Full name of the employee")
                email = st.text_input("📧 Email", placeholder="Enter email address", help="Official email address")
            with col2:
                phone = st.text_input("📞 Phone", placeholder="Enter phone number", help="Contact number")
                designation = st.text_input("💼 Designation", placeholder="Enter job title", help="Job role or position")
            
            role = st.selectbox("🛡️ Role", ["Admin", "Manager", "Engineer", "Accountant"], help="Select the employee's role.")
            temp_password = st.text_input("🔒 Temporary Password", type="password", placeholder="Set a temporary password", help="The employee will be forced to change this on first login.")
            submitted = st.form_submit_button("✅ Save Employee")
            
            if submitted:
                if not name or not email or not phone or not designation or not temp_password:
                    st.error("❌ Please fill in all fields.")
                elif len(temp_password) < 8 or not any(char.isdigit() for char in temp_password) or not any(char.isupper() for char in temp_password):
                    st.error("❌ Temporary password must be at least 8 characters long, include a number, and an uppercase letter.")
                else:
                    # Normalize email before saving
                    normalized_email = normalize_email(email)
                    with st.spinner("⏳ Saving employee details..."):
                        db.collection("Employees").document(normalized_email).set({  # Use normalized email as document ID
                            "name": name,
                            "email": normalized_email,
                            "phone": phone,
                            "designation": designation,
                            "role": role,
                            "password": temp_password,
                            "force_password_change": True  # Enforce password change on first login
                        })
                    st.success("✅ Employee Added Successfully!")
        
        # Display Employees
        st.subheader("📋 All Employees")
        employees_data = fetch_employees()
        df = pd.DataFrame(employees_data)
        st.dataframe(df, use_container_width=True)
        
        # Modify or Remove Employee
        if user_role == "Admin":
            st.subheader("📝 Modify or Remove Employee")
            selected_employee = st.selectbox("👥 Select Employee to Modify/Remove", [emp["Email"] for emp in employees_data])
            
            if selected_employee:
                emp_doc = db.collection("Employees").document(selected_employee).get()
                if emp_doc.exists:
                    emp_data = emp_doc.to_dict()
                    
                    # Modify Employee Form
                    with st.form("modify_employee_form"):
                        st.subheader("📝 Modify Employee Details")
                        col1, col2 = st.columns(2)
                        with col1:
                            name = st.text_input("👤 Name", value=emp_data.get("name", ""), help="Full name of the employee")
                            email = st.text_input("📧 Email", value=emp_data.get("email", ""), help="Official email address")
                        with col2:
                            phone = st.text_input("📞 Phone", value=emp_data.get("phone", ""), help="Contact number")
                            designation = st.text_input("💼 Designation", value=emp_data.get("designation", ""), help="Job role or position")
                        
                        role = st.selectbox("🛡️ Role", ["Admin", "Manager", "Engineer", "Accountant"], index=["Admin", "Manager", "Engineer", "Accountant"].index(emp_data.get("role", "Employee")))
                        submitted = st.form_submit_button("✅ Update Employee")
                        
                        if submitted:
                            # Normalize email before saving
                            normalized_email = normalize_email(email)
                            with st.spinner("⏳ Updating employee details..."):
                                db.collection("Employees").document(normalized_email).update({
                                    "name": name,
                                    "email": normalized_email,
                                    "phone": phone,
                                    "designation": designation,
                                    "role": role
                                })
                            st.success("✅ Employee Updated Successfully!")
                    
                    # Remove Employee Button
                    if st.button("🗑️ Remove Employee"):
                        with st.spinner("⏳ Removing employee..."):
                            db.collection("Employees").document(selected_employee).delete()
                        st.success("✅ Employee Removed Successfully!")

        # Export Data as CSV
        if not df.empty:
            csv = df.to_csv(index=False).encode('utf-8')
            st.download_button(
                label="📥 Download Employee Data as CSV",
                data=csv,
                file_name="employees.csv",
                mime="text/csv"
            )

    elif menu[choice] == "role":
        if user_role not in ["Admin"]:
            st.error("❌ You do not have permission to access this module.")
            st.stop()

        st.header("🛡️ Role Management")
        
        # Add Role Form
        with st.form("add_role_form"):
            st.subheader("📝 Add Role")
            role_name = st.text_input("📜 Role Name", placeholder="Enter role name", help="Name of the role")
            col1, col2 = st.columns(2)
            with col1:
                project_management = st.checkbox("📊 Project Management Access", help="Grant access to project management tools")
                finance_access = st.checkbox("💰 Finance Access", help="Grant access to financial tools")
            with col2:
                hr_access = st.checkbox("👥 HR Access", help="Grant access to HR tools")
            
            submitted = st.form_submit_button("✅ Save Role")
            if submitted:
                if not role_name:
                    st.error("❌ Please enter a role name.")
                else:
                    with st.spinner("⏳ Saving role details..."):
                        db.collection("Roles").add({
                            "role_name": role_name,
                            "permissions": {
                                "Project Management": project_management,
                                "Finance": finance_access,
                                "HR": hr_access
                            }
                        })
                    st.success(f"✅ Role '{role_name}' Added Successfully!")
        
        # Display Roles
        st.subheader("📋 All Roles")
        roles_ref = db.collection("Roles").stream()
        role_data = [{"ID": role.id, "Role Name": role.to_dict()["role_name"], "Permissions": role.to_dict()["permissions"]} for role in roles_ref]
        st.table(pd.DataFrame(role_data))

    elif menu[choice] == "access":
        st.header("🔒 Access Control")
        st.write("Control access to modules based on roles here.")
        # Example: Simulate role-based access control
        user_role = st.selectbox("🛡️ Select User Role", ["Admin", "Manager", "Engineer", "Accountant"])
        if user_role == "Admin":
            st.info("✅ Full Access Granted.")
        elif user_role == "Manager":
            st.info("✅ Access to Project Management and Dashboards.")
        else:
            st.warning("⚠️ Limited Access.")

    elif menu[choice] == "dashboard":
        st.header("📊 Admin Dashboards")
        
        # Employee Count by Role
        st.subheader("👥 Employees by Role")
        roles_count = {}
        employees_ref = db.collection("Employees").stream()
        for emp in employees_ref:
            role = emp.to_dict()["role"]
            roles_count[role] = roles_count.get(role, 0) + 1
        
        roles = list(roles_count.keys())
        counts = list(roles_count.values())
        
        # Bar Chart
        st.bar_chart(pd.DataFrame({"Role": roles, "Count": counts}).set_index("Role"))
        
        # Pie Chart
        st.subheader("📊 Role Distribution")
        fig = px.pie(names=roles, values=counts, title="Role Distribution")
        st.plotly_chart(fig)

    elif menu[choice] == "report":
        st.header("📋 Reporting Templates")
        
        # Add Template Form
        with st.form("add_template_form"):
            st.subheader("📝 Add Report Template")
            template_name = st.text_input("📄 Template Name", placeholder="Enter template name", help="Name of the report template")
            fields = st.text_area("📋 Fields (comma-separated)", "Project Name, Start Date, End Date", help="Enter fields separated by commas.")
            
            submitted = st.form_submit_button("✅ Save Template")
            if submitted:
                if not template_name or not fields:
                    st.error("❌ Please fill in all fields.")
                else:
                    with st.spinner("⏳ Saving report template..."):
                        db.collection("Reports").add({
                            "template_name": template_name,
                            "fields": fields.split(",")
                        })
                    st.success(f"✅ Template '{template_name}' Added Successfully!")
        
        # Display Templates
        st.subheader("📋 All Templates")
        templates_ref = db.collection("Reports").stream()
        template_data = [{"ID": temp.id, "Template Name": temp.to_dict()["template_name"], "Fields": temp.to_dict()["fields"]} for temp in templates_ref]
        st.table(pd.DataFrame(template_data))

    elif menu[choice] == "chatbot":
        st.header("🤖 Chatbot")
        
        # Load QA model
        qa_pipeline = pipeline("question-answering")
        
        # Chatbot Interface
        st.subheader("💬 Ask a Question")
        question = st.text_input("❓ Your Question")
        context = "The Admin module allows you to manage employees, roles, and access control. Use the sidebar to navigate."
        
        if st.button("🔍 Get Answer"):
            try:
                result = qa_pipeline(question=question, context=context)
                st.write("💡 Answer:", result["answer"])
            except Exception as e:
                st.error(f"❌ An error occurred: {e}")

    elif menu[choice] == "analytics":
        st.header("🧠 Advanced Analytics")
        
        # Predictive Analytics: Role Recommendations
        st.subheader("👥 Employee Role Recommendations")
        employees_ref = db.collection("Employees").stream()
        employee_data = [{"Name": emp.to_dict()["name"], "Role": emp.to_dict()["role"]} for emp in employees_ref]
        df = pd.DataFrame(employee_data)
        
        if not df.empty:
            # Encode roles for clustering
            role_mapping = {role: idx for idx, role in enumerate(df["Role"].unique())}
            df["Role_Encoded"] = df["Role"].map(role_mapping)
            
            # Perform K-Means Clustering
            kmeans = KMeans(n_clusters=len(role_mapping), random_state=42)
            df["Cluster"] = kmeans.fit_predict(df[["Role_Encoded"]])
            
            # Display Recommendations
            st.write("👥 Clustered Employees:")
            st.dataframe(df)
            
            # Predict Role for New Employee
            st.subheader("🎯 Predict Role for New Employee")
            new_employee_name = st.text_input("👤 New Employee Name")
            if st.button("🔮 Predict Role"):
                if not new_employee_name:
                    st.error("❌ Please enter the employee's name.")
                else:
                    # Randomly assign a cluster (for demonstration purposes)
                    predicted_cluster = np.random.randint(0, len(role_mapping))
                    predicted_role = [role for role, idx in role_mapping.items() if idx == predicted_cluster][0]
                    st.success(f"🎯 Recommended Role for {new_employee_name}: {predicted_role}")
        
        # Anomaly Detection
        st.subheader("⚠️ Anomaly Detection in Employee Data")
        if not df.empty:
            # Use Isolation Forest for anomaly detection
            iso_forest = IsolationForest(contamination=0.1, random_state=42)
            df["Anomaly"] = iso_forest.fit_predict(df[["Role_Encoded"]])
            anomalies = df[df["Anomaly"] == -1]
            
            st.write("⚠️ Detected Anomalies:")
            st.dataframe(anomalies)

# Notifications Feature
st.sidebar.subheader("🔔 Notifications")
st.sidebar.info("🎉 New feature: Advanced reporting tools added!")
st.sidebar.warning("⏰ Reminder: Save your changes before navigating away.")