# AccManager Backend Server (Python Alternative)
# Requirements: Python 3.8+, Flask, pyodbc

from flask import Flask, request, jsonify, render_template
from flask_cors import CORS
from datetime import datetime
import pyodbc
import json
import os
from dotenv import load_dotenv

load_dotenv()

app = Flask(__name__)
CORS(app)

# SQL Server Connection Settings
DB_SERVER = os.getenv('DB_SERVER', '172.20.235.176')
DB_USER = os.getenv('DB_USER', 'sa')
DB_PASSWORD = os.getenv('DB_PASSWORD', 'robotics@2020')
DB_NAME = os.getenv('DB_NAME', 'AccManager')

# Connection string
CONNECTION_STRING = f'''
    Driver={{ODBC Driver 17 for SQL Server}};
    Server={DB_SERVER};
    Database={DB_NAME};
    UID={DB_USER};
    PWD={DB_PASSWORD};
    TrustServerCertificate=yes;
'''

# Initialize database connection
def get_db_connection():
    try:
        conn = pyodbc.connect(CONNECTION_STRING)
        return conn
    except Exception as e:
        print(f"Database connection error: {e}")
        return None

# Create tables
def create_tables():
    conn = get_db_connection()
    if not conn:
        return False
    
    cursor = conn.cursor()
    
    try:
        # Users table
        cursor.execute('''
            IF NOT EXISTS (SELECT * FROM sys.tables WHERE name = 'Users')
            BEGIN
                CREATE TABLE Users (
                    UserId INT PRIMARY KEY IDENTITY(1,1),
                    Username NVARCHAR(50) UNIQUE NOT NULL,
                    Password NVARCHAR(255) NOT NULL,
                    Email NVARCHAR(100),
                    FullName NVARCHAR(100),
                    Role NVARCHAR(50) NOT NULL,
                    Status NVARCHAR(20) DEFAULT 'Active',
                    CreatedDate DATETIME DEFAULT GETDATE(),
                    LastLogin DATETIME,
                    IsActive BIT DEFAULT 1
                )
            END
        ''')
        
        # Applications table
        cursor.execute('''
            IF NOT EXISTS (SELECT * FROM sys.tables WHERE name = 'Applications')
            BEGIN
                CREATE TABLE Applications (
                    AppId INT PRIMARY KEY IDENTITY(1,1),
                    Name NVARCHAR(100) NOT NULL,
                    Type NVARCHAR(50),
                    Status NVARCHAR(20) DEFAULT 'online',
                    Icon NVARCHAR(50),
                    Description NVARCHAR(500),
                    CreatedDate DATETIME DEFAULT GETDATE(),
                    UpdatedDate DATETIME DEFAULT GETDATE()
                )
            END
        ''')
        
        # Accounts table
        cursor.execute('''
            IF NOT EXISTS (SELECT * FROM sys.tables WHERE name = 'Accounts')
            BEGIN
                CREATE TABLE Accounts (
                    AccountId INT PRIMARY KEY IDENTITY(1,1),
                    UserId INT NOT NULL,
                    AppId INT NOT NULL,
                    AccountUsername NVARCHAR(100),
                    AccountPassword NVARCHAR(255),
                    Email NVARCHAR(100),
                    AccessLevel NVARCHAR(50),
                    Status NVARCHAR(20) DEFAULT 'Active',
                    Notes NVARCHAR(MAX),
                    CreatedDate DATETIME DEFAULT GETDATE(),
                    UpdatedDate DATETIME DEFAULT GETDATE(),
                    FOREIGN KEY (UserId) REFERENCES Users(UserId) ON DELETE CASCADE,
                    FOREIGN KEY (AppId) REFERENCES Applications(AppId) ON DELETE CASCADE
                )
            END
        ''')
        
        # AuditLog table
        cursor.execute('''
            IF NOT EXISTS (SELECT * FROM sys.tables WHERE name = 'AuditLog')
            BEGIN
                CREATE TABLE AuditLog (
                    LogId INT PRIMARY KEY IDENTITY(1,1),
                    UserId INT,
                    Action NVARCHAR(50),
                    TableName NVARCHAR(50),
                    RecordId INT,
                    OldValue NVARCHAR(MAX),
                    NewValue NVARCHAR(MAX),
                    Timestamp DATETIME DEFAULT GETDATE(),
                    FOREIGN KEY (UserId) REFERENCES Users(UserId)
                )
            END
        ''')
        
        conn.commit()
        
        # Insert admin user
        cursor.execute('''
            IF NOT EXISTS (SELECT * FROM Users WHERE Username = 'admin')
            INSERT INTO Users (Username, Password, Email, FullName, Role, IsActive)
            VALUES ('admin', 'admin', 'admin@accmanager.local', 'Administrator', 'admin', 1)
        ''')
        
        # Insert sample applications
        cursor.execute('''
            IF (SELECT COUNT(*) FROM Applications) = 0
            BEGIN
                INSERT INTO Applications (Name, Type, Status, Icon, Description)
                VALUES 
                    ('AWS', 'Cloud', 'online', 'cloud', 'Amazon Web Services'),
                    ('GitHub', 'VCS', 'online', 'code', 'GitHub - Version Control'),
                    ('Google Workspace', 'Collaboration', 'online', 'mail', 'Google Workspace'),
                    ('Nginx Proxy', 'Infra', 'offline', 'dns', 'Nginx Web Server')
            END
        ''')
        
        conn.commit()
        cursor.close()
        conn.close()
        return True
        
    except Exception as e:
        print(f"Table creation error: {e}")
        return False

# ==========================================
# Routes: Health Check
# ==========================================

@app.route('/api/health', methods=['GET'])
def health():
    conn = get_db_connection()
    if conn:
        conn.close()
        return jsonify({"status": "OK", "database": "Connected"}), 200
    else:
        return jsonify({"status": "ERROR", "database": "Disconnected"}), 500

# ==========================================
# Routes: Authentication
# ==========================================

@app.route('/api/auth/login', methods=['POST'])
def login():
    try:
        data = request.get_json()
        username = data.get('username')
        password = data.get('password')
        
        conn = get_db_connection()
        if not conn:
            return jsonify({"success": False, "message": "Database connection failed"}), 500
        
        cursor = conn.cursor()
        cursor.execute('''
            SELECT UserId, Username, Email, FullName, Role, Status 
            FROM Users 
            WHERE Username = ? AND Password = ? AND IsActive = 1
        ''', (username, password))
        
        user = cursor.fetchone()
        
        if user:
            cursor.execute('UPDATE Users SET LastLogin = GETDATE() WHERE UserId = ?', user[0])
            conn.commit()
            
            return jsonify({
                "success": True,
                "message": "Login successful",
                "user": {
                    "UserId": user[0],
                    "username": user[1],
                    "email": user[2],
                    "fullname": user[3],
                    "role": user[4],
                    "status": user[5]
                }
            }), 200
        else:
            return jsonify({
                "success": False,
                "message": "Invalid username or password"
            }), 401
            
    except Exception as e:
        return jsonify({"success": False, "message": str(e)}), 500
    finally:
        if conn:
            conn.close()

# ==========================================
# Routes: Users
# ==========================================

@app.route('/api/users', methods=['GET'])
def get_users():
    try:
        conn = get_db_connection()
        if not conn:
            return jsonify({"success": False, "message": "Database connection failed"}), 500
        
        cursor = conn.cursor()
        cursor.execute('''
            SELECT UserId, Username, Email, FullName, Role, Status, CreatedDate 
            FROM Users 
            ORDER BY CreatedDate DESC
        ''')
        
        users = []
        for row in cursor.fetchall():
            users.append({
                "UserId": row[0],
                "Username": row[1],
                "Email": row[2],
                "FullName": row[3],
                "Role": row[4],
                "Status": row[5],
                "CreatedDate": str(row[6])
            })
        
        return jsonify({"success": True, "data": users}), 200
        
    except Exception as e:
        return jsonify({"success": False, "message": str(e)}), 500
    finally:
        if conn:
            conn.close()

@app.route('/api/users/<int:user_id>', methods=['GET'])
def get_user(user_id):
    try:
        conn = get_db_connection()
        if not conn:
            return jsonify({"success": False, "message": "Database connection failed"}), 500
        
        cursor = conn.cursor()
        cursor.execute('SELECT * FROM Users WHERE UserId = ?', (user_id,))
        
        user = cursor.fetchone()
        
        if user:
            return jsonify({
                "success": True,
                "data": {"UserId": user[0], "Username": user[1]}
            }), 200
        else:
            return jsonify({"success": False, "message": "User not found"}), 404
            
    except Exception as e:
        return jsonify({"success": False, "message": str(e)}), 500
    finally:
        if conn:
            conn.close()

@app.route('/api/users', methods=['POST'])
def create_user():
    try:
        data = request.get_json()
        
        conn = get_db_connection()
        if not conn:
            return jsonify({"success": False, "message": "Database connection failed"}), 500
        
        cursor = conn.cursor()
        cursor.execute('''
            INSERT INTO Users (Username, Password, Email, FullName, Role, IsActive)
            VALUES (?, ?, ?, ?, ?, 1)
        ''', (data['username'], data['password'], data['email'], 
              data['fullname'], data['role']))
        
        conn.commit()
        
        return jsonify({
            "success": True,
            "message": "User created"
        }), 201
        
    except Exception as e:
        return jsonify({"success": False, "message": str(e)}), 500
    finally:
        if conn:
            conn.close()

# ==========================================
# Routes: Applications
# ==========================================

@app.route('/api/applications', methods=['GET'])
def get_applications():
    try:
        conn = get_db_connection()
        if not conn:
            return jsonify({"success": False, "message": "Database connection failed"}), 500
        
        cursor = conn.cursor()
        cursor.execute('SELECT * FROM Applications ORDER BY Name')
        
        apps = []
        for row in cursor.fetchall():
            apps.append({
                "AppId": row[0],
                "Name": row[1],
                "Type": row[2],
                "Status": row[3],
                "Icon": row[4],
                "Description": row[5]
            })
        
        return jsonify({"success": True, "data": apps}), 200
        
    except Exception as e:
        return jsonify({"success": False, "message": str(e)}), 500
    finally:
        if conn:
            conn.close()

# ==========================================
# Routes: Accounts
# ==========================================

@app.route('/api/accounts/user/<int:user_id>', methods=['GET'])
def get_accounts(user_id):
    try:
        conn = get_db_connection()
        if not conn:
            return jsonify({"success": False, "message": "Database connection failed"}), 500
        
        cursor = conn.cursor()
        cursor.execute('''
            SELECT a.*, app.Name, app.Type 
            FROM Accounts a
            JOIN Applications app ON a.AppId = app.AppId
            WHERE a.UserId = ?
            ORDER BY a.CreatedDate DESC
        ''', (user_id,))
        
        accounts = []
        for row in cursor.fetchall():
            accounts.append({
                "AccountId": row[0],
                "UserId": row[1],
                "AppId": row[2],
                "AccountUsername": row[3],
                "AccountPassword": row[4],
                "AppName": row[12],
                "AppType": row[13]
            })
        
        return jsonify({"success": True, "data": accounts}), 200
        
    except Exception as e:
        return jsonify({"success": False, "message": str(e)}), 500
    finally:
        if conn:
            conn.close()

# ==========================================
# Routes: Database Info
# ==========================================

@app.route('/api/database/info', methods=['GET'])
def database_info():
    try:
        conn = get_db_connection()
        if not conn:
            return jsonify({"success": False, "message": "Database connection failed"}), 500
        
        cursor = conn.cursor()
        
        # Get tables
        cursor.execute('''
            SELECT TABLE_NAME 
            FROM INFORMATION_SCHEMA.TABLES 
            WHERE TABLE_SCHEMA = 'dbo'
            ORDER BY TABLE_NAME
        ''')
        tables = [row[0] for row in cursor.fetchall()]
        
        # Get statistics
        cursor.execute('SELECT COUNT(*) FROM Users')
        user_count = cursor.fetchone()[0]
        
        cursor.execute('SELECT COUNT(*) FROM Applications')
        app_count = cursor.fetchone()[0]
        
        cursor.execute('SELECT COUNT(*) FROM Accounts')
        account_count = cursor.fetchone()[0]
        
        return jsonify({
            "success": True,
            "database": "AccManager",
            "server": DB_SERVER,
            "tables": tables,
            "statistics": {
                "users": user_count,
                "applications": app_count,
                "accounts": account_count
            }
        }), 200
        
    except Exception as e:
        return jsonify({"success": False, "message": str(e)}), 500
    finally:
        if conn:
            conn.close()

# ==========================================
# Error Handlers
# ==========================================

@app.errorhandler(404)
def not_found(error):
    return jsonify({"error": "Not found"}), 404

@app.errorhandler(500)
def server_error(error):
    return jsonify({"error": "Internal server error"}), 500

# ==========================================
# Startup
# ==========================================

if __name__ == '__main__':
    print("\n========================================")
    print("AccManager Backend Server (Python)")
    print("========================================")
    print(f"Server: {DB_SERVER}")
    print(f"Database: {DB_NAME}")
    print(f"User: {DB_USER}")
    
    # Initialize database
    print("\nInitializing database...")
    if create_tables():
        print("✓ Database tables created/verified")
    else:
        print("✗ Database initialization failed")
    
    print("\n✓ Server running on http://localhost:5000")
    print("\nAPI Endpoints:")
    print("  /api/health")
    print("  /api/auth/login")
    print("  /api/users")
    print("  /api/applications")
    print("  /api/accounts/user/<id>")
    print("  /api/database/info")
    print("========================================\n")
    
    app.run(debug=True, host='localhost', port=5000)