import os
import psycopg2
from psycopg2.extras import RealDictCursor
from flask import Flask, render_template, request, redirect, url_for, flash, jsonify, send_from_directory, abort
from werkzeug.utils import secure_filename
from datetime import datetime
import locale
import logging
from flask_talisman import Talisman

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger('ploughshares')

# Get version from environment variable or VERSION file
VERSION = os.environ.get('APP_VERSION')
if not VERSION:
    try:
        # Try to read from VERSION file in the current directory first
        if os.path.exists('VERSION'):
            with open('VERSION', 'r') as f:
                VERSION = f.read().strip()
        # Fall back to the project root VERSION file
        else:
            with open(os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(__file__))), 'VERSION'), 'r') as f:
                VERSION = f.read().strip()
    except:
        VERSION = "unknown"

# Initialize the Flask app
app = Flask(__name__)
app.secret_key = 'supersecretkey'
app.config['UPLOAD_FOLDER'] = 'uploads'
app.config['VERSION'] = VERSION

# Get domain configuration from environment
APP_DOMAIN = os.environ.get('APP_DOMAIN', '')
APP_ENV = os.environ.get('APP_ENV', 'development')

# Configure security headers with Talisman
# Base CSP settings - much more restrictive now that we use local resources
csp = {
    'default-src': ["'self'"],
    'script-src': ["'self'"],
    'style-src': ["'self'"],
    'img-src': ["'self'", "data:"],
    'font-src': ["'self'"],
    'connect-src': "'self'",
    'object-src': "'none'",
    'frame-ancestors': "'none'",
    'base-uri': "'self'",
    'form-action': "'self'"
}

# Add domain-specific CSP settings if domain is provided
if APP_DOMAIN:
    logger.info(f"Configuring CSP for domain: {APP_DOMAIN}")
    # Add domain to connect-src if needed
    if APP_DOMAIN not in csp['connect-src']:
        if isinstance(csp['connect-src'], list):
            csp['connect-src'].append(APP_DOMAIN)
        else:
            csp['connect-src'] = [csp['connect-src'], APP_DOMAIN]
    
    # Update form-action to include the domain
    if isinstance(csp['form-action'], list):
        if APP_DOMAIN not in csp['form-action']:
            csp['form-action'].append(APP_DOMAIN)
    else:
        csp['form-action'] = [csp['form-action'], APP_DOMAIN]

# Configure Permissions-Policy (formerly Feature-Policy)
# Deny access to all browser features that we don't need
permissions_policy = {
    'accelerometer': '()',
    'ambient-light-sensor': '()',
    'autoplay': '()',
    'battery': '()',
    'camera': '()',
    'display-capture': '()',
    'document-domain': '()',
    'encrypted-media': '()',
    'execution-while-not-rendered': '()',
    'execution-while-out-of-viewport': '()',
    'fullscreen': '()',
    'geolocation': '()',
    'gyroscope': '()',
    'hid': '()',
    'idle-detection': '()',
    'magnetometer': '()',
    'microphone': '()',
    'midi': '()',
    'navigation-override': '()',
    'payment': '()',
    'picture-in-picture': '()',
    'publickey-credentials-get': '()',
    'screen-wake-lock': '()',
    'serial': '()',
    'sync-xhr': '()',
    'usb': '()',
    'web-share': '()',
    'xr-spatial-tracking': '()'
}

# Determine if HTTPS should be forced based on environment
force_https = APP_ENV != 'development'
logger.info(f"Environment: {APP_ENV}, Force HTTPS: {force_https}")

# Additional security headers
additional_headers = {
    'Cross-Origin-Embedder-Policy': 'require-corp',
    'Cross-Origin-Resource-Policy': 'same-origin',
    'Cross-Origin-Opener-Policy': 'same-origin'
}

# Initialize Talisman
talisman = Talisman(
    app,
    content_security_policy=csp,
    content_security_policy_nonce_in=['script-src'],
    feature_policy=permissions_policy,
    force_https=force_https,
    force_https_permanent=force_https,
    strict_transport_security=force_https,
    strict_transport_security_preload=force_https,
    strict_transport_security_max_age=31536000,
    strict_transport_security_include_subdomains=force_https,
    referrer_policy='strict-origin-when-cross-origin',
    frame_options='DENY',
    session_cookie_secure=force_https,
    session_cookie_http_only=True
)

# Add additional security headers that Talisman doesn't support natively
@app.after_request
def add_security_headers(response):
    for header, value in additional_headers.items():
        response.headers[header] = value
    return response

# Set locale for currency formatting
try:
    locale.setlocale(locale.LC_ALL, 'en_US.UTF-8')
except locale.Error:
    try:
        locale.setlocale(locale.LC_ALL, '')  # Use system default locale
    except locale.Error:
        pass  # If all fails, we'll use the fallback in the filter

# Custom filter for currency formatting
@app.template_filter('currency')
def currency_filter(value):
    if value is None:
        return "$0.00"
    try:
        # Convert to float first, then format to exactly 2 decimal places
        float_value = float(value)
        return f"${float_value:,.2f}"
    except (ValueError, TypeError):
        # Fallback formatting
        return "$0.00"

# --- Database Connection ---
def get_db_connection():
    host = os.environ.get('POSTGRES_HOST', 'db')
    port = os.environ.get('POSTGRES_PORT', '5432')
    dbname = os.environ.get('POSTGRES_DB', 'ploughshares')
    user = os.environ.get('POSTGRES_USER', 'ploughshares')
    password = os.environ.get('POSTGRES_PASSWORD', 'ploughshares_password')
    
    try:
        conn = psycopg2.connect(
            host=host,
            port=port,
            dbname=dbname,
            user=user,
            password=password,
            cursor_factory=RealDictCursor
        )
        conn.autocommit = True
        logger.info(f"Ploughshares v{VERSION} - Connected to PostgreSQL at {host}:{port}")
        return conn
    except psycopg2.OperationalError as e:
        logger.error(f"Error connecting to PostgreSQL: {e}")
        return None

# --- Routes ---
@app.route('/')
def index():
    conn = get_db_connection()
    if conn is None:
        flash("Database connection error", "error")
        return render_template('index.html', transactions=[], version=VERSION)
    
    try:
        with conn.cursor() as cur:
            cur.execute('SELECT * FROM transactions ORDER BY id DESC')
            transactions = cur.fetchall()
    except Exception as e:
        logger.error(f"Database error: {e}")
        flash(f"Database error: {e}", "error")
        transactions = []
    finally:
        conn.close()
        
    return render_template('index.html', transactions=transactions, version=VERSION)

@app.route('/api-docs')
def api_docs():
    server_name = request.host
    return render_template('api_docs.html', server_name=server_name, version=VERSION)

@app.route('/transaction/<int:id>')
def view_transaction(id):
    conn = get_db_connection()
    if conn is None:
        flash("Database connection error", "error")
        abort(404)
    
    transaction = None
    try:
        with conn.cursor() as cur:
            cur.execute('SELECT * FROM transactions WHERE id = %s', (id,))
            transaction = cur.fetchone()
    except Exception as e:
        logger.error(f"Database error: {e}")
        flash(f"Database error: {e}", "error")
    finally:
        conn.close()
    
    if transaction is None:
        abort(404)
        
    return render_template('view_transaction.html', transaction=transaction, version=VERSION)

@app.route('/transaction/add', methods=['GET', 'POST'])
def create_transaction():
    if request.method == 'POST':
        # Get form data and set defaults for missing fields
        data = request.form.to_dict()
        default_fields = {
            'transaction_type': '', 'company_division': '', 'address_1': '', 'address_2': '',
            'city': '', 'province': '', 'region': '', 'postal_code': '', 'source_date': None,
            'source_description': '', 'grant_type': '', 'description': '', 'amount': 0,
            'recipient': '', 'commodity_class': '', 'contract_number': '', 'comments': ''
        }
        
        # Fill in missing fields with defaults
        for field, default in default_fields.items():
            if field not in data:
                data[field] = default
        
        # Handle checkbox fields
        data['is_primary'] = 'is_primary' in data
        
        # Convert amount to float for database storage
        if 'amount' in data and data['amount']:
            try:
                # Remove currency symbols and commas
                clean_amount = data['amount'].replace('$', '').replace(',', '')
                data['amount'] = float(clean_amount)
            except ValueError:
                data['amount'] = 0.0
        
        conn = get_db_connection()
        if conn is None:
            flash("Database connection error", "error")
            return render_template('transaction_form.html', version=VERSION)
        
        try:
            with conn.cursor() as cur:
                cur.execute(
                    """
                    INSERT INTO transactions (
                        transaction_type, company_division, address_1, address_2,
                        city, province, region, postal_code, is_primary, source_date, source_description,
                        grant_type, description, amount, recipient, commodity_class, contract_number, comments
                    ) VALUES (
                        %(transaction_type)s, %(company_division)s, %(address_1)s, %(address_2)s,
                        %(city)s, %(province)s, %(region)s, %(postal_code)s, %(is_primary)s, %(source_date)s,
                        %(source_description)s, %(grant_type)s, %(description)s, %(amount)s, %(recipient)s,
                        %(commodity_class)s, %(contract_number)s, %(comments)s
                    ) RETURNING id
                    """,
                    data
                )
                result = cur.fetchone()
                if result and 'id' in result:
                    new_transaction_id = result['id']
                    conn.commit()
                else:
                    flash("Error creating transaction: Could not get transaction ID", "error")
                    return render_template('transaction_form.html', version=VERSION)
        except Exception as e:
            logger.error(f"Error creating transaction: {e}")
            flash(f"Error creating transaction: {e}", "error")
            return render_template('transaction_form.html', version=VERSION)
        finally:
            conn.close()
            
        return redirect(url_for('view_transaction', id=new_transaction_id))

    return render_template('transaction_form.html', version=VERSION)

@app.route('/transaction/<int:id>/edit', methods=['GET', 'POST'])
def update_transaction(id):
    conn = get_db_connection()
    if conn is None:
        flash("Database connection error", "error")
        abort(404)
    
    if request.method == 'POST':
        # Get form data and set defaults for missing fields
        data = request.form.to_dict()
        default_fields = {
            'transaction_type': '', 'company_division': '', 'address_1': '', 'address_2': '',
            'city': '', 'province': '', 'region': '', 'postal_code': '', 'source_date': None,
            'source_description': '', 'grant_type': '', 'description': '', 'amount': 0,
            'recipient': '', 'commodity_class': '', 'contract_number': '', 'comments': ''
        }
        
        # Fill in missing fields with defaults
        for field, default in default_fields.items():
            if field not in data:
                data[field] = default
        
        # Handle checkbox fields
        data['is_primary'] = 'is_primary' in data
        data['id'] = id
        
        # Convert amount to float for database storage
        if 'amount' in data and data['amount']:
            try:
                # Remove currency symbols and commas
                clean_amount = data['amount'].replace('$', '').replace(',', '')
                data['amount'] = float(clean_amount)
            except ValueError:
                data['amount'] = 0.0
        
        try:
            with conn.cursor() as cur:
                cur.execute(
                    """
                    UPDATE transactions
                    SET transaction_type = %(transaction_type)s,
                        company_division = %(company_division)s,
                        address_1 = %(address_1)s,
                        address_2 = %(address_2)s,
                        city = %(city)s,
                        province = %(province)s,
                        region = %(region)s,
                        postal_code = %(postal_code)s,
                        is_primary = %(is_primary)s,
                        source_date = %(source_date)s,
                        source_description = %(source_description)s,
                        grant_type = %(grant_type)s,
                        description = %(description)s,
                        amount = %(amount)s,
                        recipient = %(recipient)s,
                        commodity_class = %(commodity_class)s,
                        contract_number = %(contract_number)s,
                        comments = %(comments)s
                    WHERE id = %(id)s
                    """,
                    data
                )
                conn.commit()
        except Exception as e:
            logger.error(f"Error updating transaction: {e}")
            flash(f"Error updating transaction: {e}", "error")
            return render_template('transaction_form.html', transaction=data, version=VERSION)
        finally:
            conn.close()
            
        return redirect(url_for('view_transaction', id=id))

    transaction = None
    try:
        with conn.cursor() as cur:
            cur.execute('SELECT * FROM transactions WHERE id = %s', (id,))
            transaction = cur.fetchone()
    except Exception as e:
        logger.error(f"Error retrieving transaction: {e}")
        flash(f"Error retrieving transaction: {e}", "error")
    finally:
        conn.close()
    
    if transaction is None:
        abort(404)
        
    return render_template('transaction_form.html', transaction=transaction, version=VERSION)

def bootstrap_database():
    """
    Checks if the database is empty and initializes the schema if needed.
    Test data can be loaded separately using the tests/generate_test_data.py script.
    """
    logger.info(f"Ploughshares v{VERSION} - Checking database...")
    conn = get_db_connection()
    if conn is None:
        logger.error("Database connection failed. Exiting.")
        exit(1)

    try:
        # Check if the transactions table exists
        with conn.cursor() as cur:
            cur.execute("SELECT EXISTS (SELECT FROM information_schema.tables WHERE table_name = 'transactions')")
            result = cur.fetchone()
            
            # If table doesn't exist, initialize the schema
            if not result or not result.get('exists', False):
                logger.info(f"Ploughshares v{VERSION} - Transactions table not found. Initializing schema...")
                
                # Read schema.sql file
                try:
                    with open('schema.sql', 'r') as f:
                        schema_sql = f.read()
                    
                    # Execute schema SQL
                    with conn.cursor() as schema_cur:
                        schema_cur.execute(schema_sql)
                    logger.info(f"Ploughshares v{VERSION} - Schema initialized successfully.")
                except Exception as schema_error:
                    logger.error(f"Error initializing schema: {schema_error}")
            else:
                # Check if the table is empty
                try:
                    with conn.cursor() as cur:
                        cur.execute("SELECT COUNT(*) FROM transactions")
                        result = cur.fetchone()
                        if result and 'count' in result:
                            count = result['count']
                            if count == 0:
                                logger.info(f"Ploughshares v{VERSION} - Database is empty. You can populate it with test data using the tests/generate_test_data.py script.")
                        else:
                            logger.error("Could not get count from database")
                except Exception as count_error:
                    logger.error(f"Error counting transactions: {count_error}")
    except Exception as e:
        logger.error(f"Error checking database: {e}")
    finally:
        conn.close()

if __name__ == '__main__':
    logger.info(f"Starting Ploughshares v{VERSION}")
    bootstrap_database()
    port = int(os.environ.get('FLASK_RUN_PORT', 5001))
    app.run(host='0.0.0.0', port=port)