import sqlite3
from datetime import datetime

DB_PATH = 'snmp_monitor.db'

def init_db():
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    
    # Targets table (devices to monitor)
    c.execute('''
        CREATE TABLE IF NOT EXISTS targets (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            name TEXT,
            ip_address TEXT NOT NULL,
            port INTEGER DEFAULT 161,
            community TEXT NOT NULL,
            period_minutes INTEGER DEFAULT 5,
            modem_type TEXT DEFAULT 'rv50',
            enabled INTEGER DEFAULT 1,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )
    ''')
    
    # Readings table (stored SNMP data)
    c.execute('''
        CREATE TABLE IF NOT EXISTS readings (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            target_id INTEGER NOT NULL,
            bytes_sent INTEGER,
            bytes_recv INTEGER,
            timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            FOREIGN KEY (target_id) REFERENCES targets(id)
        )
    ''')
    
    # Check if modem_type column exists, add it if not (for existing databases)
    try:
        c.execute('SELECT modem_type FROM targets LIMIT 1')
    except sqlite3.OperationalError:
        c.execute('ALTER TABLE targets ADD COLUMN modem_type TEXT DEFAULT "rv50"')
        conn.commit()
    
    conn.commit()
    conn.close()

def add_target(name, ip_address, port, community, period_minutes, modem_type='rv50'):
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute('''
        INSERT INTO targets (name, ip_address, port, community, period_minutes, modem_type)
        VALUES (?, ?, ?, ?, ?, ?)
    ''', (name, ip_address, port, community, period_minutes, modem_type))
    conn.commit()
    target_id = c.lastrowid
    conn.close()
    return target_id

def get_all_targets():
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    c = conn.cursor()
    c.execute('SELECT * FROM targets ORDER BY id')
    targets = c.fetchall()
    conn.close()
    return targets

def get_target(target_id):
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    c = conn.cursor()
    c.execute('SELECT * FROM targets WHERE id = ?', (target_id,))
    target = c.fetchone()
    conn.close()
    return target

def update_target(target_id, name, ip_address, port, community, period_minutes, enabled, modem_type='rv50'):
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute('''
        UPDATE targets 
        SET name=?, ip_address=?, port=?, community=?, period_minutes=?, enabled=?, modem_type=?
        WHERE id=?
    ''', (name, ip_address, port, community, period_minutes, enabled, modem_type, target_id))
    conn.commit()
    conn.close()

def delete_target(target_id):
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute('DELETE FROM readings WHERE target_id = ?', (target_id,))
    c.execute('DELETE FROM targets WHERE id = ?', (target_id,))
    conn.commit()
    conn.close()

def add_reading(target_id, bytes_sent, bytes_recv):
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute('''
        INSERT INTO readings (target_id, bytes_sent, bytes_recv)
        VALUES (?, ?, ?)
    ''', (target_id, bytes_sent, bytes_recv))
    conn.commit()
    conn.close()

def get_readings(target_id, hours=24):
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    c = conn.cursor()
    c.execute('''
        SELECT * FROM readings 
        WHERE target_id = ? 
        AND timestamp >= datetime('now', '-{} hours')
        ORDER BY timestamp
    '''.format(hours), (target_id,))
    readings = c.fetchall()
    conn.close()
    return readings

def get_latest_reading(target_id):
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    c = conn.cursor()
    c.execute('''
        SELECT * FROM readings 
        WHERE target_id = ? 
        ORDER BY timestamp DESC 
        LIMIT 1
    ''', (target_id,))
    reading = c.fetchone()
    conn.close()
    return reading