import mariadb
from flask import current_app, request, render_template
import csv

def get_db_connection():
    settings_file = current_app.instance_path + '/external_server.conf'
    settings = {}
    with open(settings_file, 'r') as f:
        for line in f:
            key, value = line.strip().split('=', 1)
            settings[key] = value
    return mariadb.connect(
        user=settings['username'],
        password=settings['password'],
        host=settings['server_domain'],
        port=int(settings['port']),
        database=settings['database_name']
    )

def ensure_warehouse_locations_table():
    try:
        conn = get_db_connection()
        cursor = conn.cursor()
        cursor.execute("SHOW TABLES LIKE 'warehouse_locations'")
        result = cursor.fetchone()
        if not result:
            cursor.execute('''
                CREATE TABLE IF NOT EXISTS warehouse_locations (
                    id BIGINT AUTO_INCREMENT PRIMARY KEY,
                    location_code VARCHAR(12) NOT NULL,
                    size INT,
                    description VARCHAR(250)
                )
            ''')
            conn.commit()
        conn.close()
    except Exception as e:
        print(f"Error ensuring warehouse_locations table: {e}")

# Add warehouse-specific functions below
def add_location(location_code, size, description):
    conn = get_db_connection()
    cursor = conn.cursor()
    try:
        cursor.execute(
            "INSERT INTO warehouse_locations (location_code, size, description) VALUES (?, ?, ?)",
            (location_code, size if size else None, description)
        )
        conn.commit()
        conn.close()
        return "Location added successfully."
    except mariadb.IntegrityError:
        conn.close()
        return "Failed: Location code already exists."

def get_locations():
    conn = get_db_connection()
    cursor = conn.cursor()
    cursor.execute("SELECT id, location_code, size, description FROM warehouse_locations ORDER BY id DESC")
    locations = cursor.fetchall()
    conn.close()
    return locations

def recreate_warehouse_locations_table():
    conn = get_db_connection()
    cursor = conn.cursor()
    cursor.execute("DROP TABLE IF EXISTS warehouse_locations")
    cursor.execute("""
        CREATE TABLE warehouse_locations (
            id INT AUTO_INCREMENT PRIMARY KEY,
            location_code VARCHAR(12) UNIQUE NOT NULL,
            size INT,
            description VARCHAR(250)
        )
    """)
    conn.commit()
    conn.close()

def create_locations_handler():
    message = None
    if request.method == "POST":
        location_code = request.form.get("location_code")
        size = request.form.get("size")
        description = request.form.get("description")
        message = add_location(location_code, size, description)
    locations = get_locations()
    return render_template("create_locations.html", locations=locations, message=message)

def import_locations_csv_handler():
    report = None
    locations = []
    errors = []
    if request.method == 'POST':
        file = request.files.get('csv_file')
        if file and file.filename.endswith('.csv'):
            content = file.read().decode('utf-8').splitlines()
            reader = csv.DictReader(content)
            locations = [(row.get('location_code'), row.get('size'), row.get('description')) for row in reader]
            if request.form.get('create_locations'):
                added = 0
                failed = 0
                errors = []
                for loc in locations:
                    location_code, size, description = loc
                    result = add_location(location_code, size, description)
                    if result and 'success' in result.lower():
                        added += 1
                    else:
                        failed += 1
                        errors.append(location_code)
                report = f"{added} locations were added to warehouse_locations table. {failed} locations failed: {', '.join(errors)}"
    return render_template('import_locations_csv.html', report=report, locations=locations)