"""
Flask application for Google SSO user management.

Allows users to:
1. Log in with Google (allowed domain only)
2. View their account status if they exist
3. Create a new analyst account with their SSH key
"""

import json
import logging
import os
from datetime import datetime
from pathlib import Path

from flask import Flask, flash, jsonify, redirect, render_template, request, session, url_for

from .auth import auth_bp, login_required
from .config import Config
from .desktop_auth import require_desktop_auth
from .notification_images import images_bp
from .account_service import get_account_details
from .sync_settings_service import get_sync_settings, update_sync_settings

# Jira connector is optional - only loaded if configured
try:
    from connectors.jira.webhook import jira_bp
    JIRA_AVAILABLE = True
except ImportError:
    JIRA_AVAILABLE = False
    jira_bp = None
from .telegram_service import get_telegram_status, link_telegram, unlink_telegram
from .corporate_memory_service import (
    get_knowledge,
    get_stats as get_memory_stats,
    get_user_stats as get_memory_user_stats,
    get_user_votes,
    vote as memory_vote,
)
from .user_service import (
    UserInfo,
    check_user_exists,
    create_user,
    get_username_from_email,
    is_username_available,
    validate_ssh_key,
)

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


def create_app() -> Flask:
    """Create and configure the Flask application."""
    app = Flask(__name__)
    app.config.from_object(Config)

    # Validate configuration
    errors = Config.validate()
    if errors and not app.debug:
        for error in errors:
            logger.warning(f"Configuration warning: {error}")

    # Register core auth blueprint (login_required, login page, logout)
    app.register_blueprint(auth_bp)

    # Auto-discover and register auth providers
    from auth import discover_providers

    for provider_instance in discover_providers():
        provider_instance.init_app(app)
        app.register_blueprint(provider_instance.get_blueprint())

    # Register other blueprints
    app.register_blueprint(images_bp)
    if JIRA_AVAILABLE and jira_bp:
        app.register_blueprint(jira_bp)

    # Register main routes
    register_routes(app)

    # Add template context processor for current year and config
    @app.context_processor
    def inject_now():
        return {"now": datetime.now}

    @app.context_processor
    def inject_config():
        return {"config": Config}

    # Add cache busting for static files
    @app.context_processor
    def inject_static_cache_buster():
        def static_url(filename: str) -> str:
            """Generate static URL with cache-busting query parameter."""
            static_path = Path(app.static_folder) / filename
            if static_path.exists():
                mtime = int(static_path.stat().st_mtime)
                return url_for("static", filename=filename, v=mtime)
            return url_for("static", filename=filename)
        return {"static_url": static_url}

    return app


NOTIFY_SOCKET_PATH = "/data/notifications/bot.sock"

# Path to sync state (written by data sync process)
SYNC_STATE_PATH = Path("/data/src_data/metadata/sync_state.json")
# Local development: fall back to dev_data/metadata/ relative to project root
_DEV_METADATA_PATH = Path(__file__).parent.parent / "dev_data" / "metadata"


def _resolve_metadata_path(filename: str) -> Path:
    """Resolve metadata file path with dev fallback."""
    prod_path = SYNC_STATE_PATH.parent / filename
    if prod_path.exists():
        return prod_path
    dev_path = _DEV_METADATA_PATH / filename
    return dev_path

# Fallback stats (used when sync_state.json is unavailable)
FALLBACK_DATA_STATS = {
    "tables": 0,
    "columns": 0,
    "rows": 0,
    "rows_display": "-",
    "size_mb": 0,
    "size_display": "0 MB",
    "uncompressed_mb": 0,
    "unstructured_gb": 0,
    "unstructured_display": "",
    "last_updated": None,
    "highlights": {},
}


def _load_data_stats() -> dict:
    """Load aggregate data stats from sync_state.json, with hardcoded fallback."""
    try:
        sync_path = _resolve_metadata_path("sync_state.json")
        if sync_path.exists():
            with open(sync_path) as f:
                state = json.load(f)

            tables_data = state.get("tables", {})
            if not tables_data:
                return dict(FALLBACK_DATA_STATS)

            total_tables = len(tables_data)
            total_columns = sum(t.get("columns", 0) for t in tables_data.values())
            total_rows = sum(t.get("rows", 0) for t in tables_data.values())
            total_size_mb = sum(t.get("file_size_mb", 0) for t in tables_data.values())
            total_uncompressed_mb = sum(t.get("uncompressed_mb", 0) for t in tables_data.values())

            # Format rows for display
            if total_rows >= 1_000_000:
                rows_display = f"{total_rows / 1_000_000:.0f}M+"
            elif total_rows >= 1_000:
                rows_display = f"{total_rows / 1_000:.0f}K+"
            else:
                rows_display = str(total_rows)

            # Parse last_updated timestamp
            last_updated = state.get("last_updated")
            last_updated_display = None
            if last_updated:
                try:
                    dt = datetime.fromisoformat(last_updated)
                    last_updated_display = dt.strftime("%Y-%m-%d %H:%M") + " UTC"
                except (ValueError, TypeError):
                    last_updated_display = last_updated[:16] if last_updated else None

            # Format size for display
            size_mb = round(total_size_mb)
            if size_mb >= 1000:
                size_display = f"{size_mb / 1000:.1f} GB"
            else:
                size_display = f"{size_mb} MB"

            return {
                "tables": total_tables,
                "columns": total_columns if total_columns > 0 else FALLBACK_DATA_STATS["columns"],
                "rows": total_rows,
                "rows_display": rows_display,
                "size_mb": size_mb,
                "size_display": size_display,
                "uncompressed_mb": round(total_uncompressed_mb),
                "unstructured_gb": FALLBACK_DATA_STATS["unstructured_gb"],
                "unstructured_display": FALLBACK_DATA_STATS["unstructured_display"],
                "last_updated": last_updated_display,
                "highlights": FALLBACK_DATA_STATS["highlights"],
            }
    except Exception as e:
        logger.warning(f"Could not load data stats from sync_state.json: {e}")

    return dict(FALLBACK_DATA_STATS)


def _load_catalog_data() -> list:
    """Load catalog data by merging data_description.md (YAML) with sync_state.json.

    Returns list of category dicts: [{name, icon_type, tables: [{name, description, rows, rows_display, period}]}]
    """
    import re

    import yaml

    catalog = []

    try:
        # Parse data_description.md YAML block
        desc_path = Path(os.path.dirname(__file__)) / ".." / "docs" / "data_description.md"
        if not desc_path.exists():
            return catalog

        with open(desc_path) as f:
            content = f.read()

        # Extract YAML block between ```yaml and ```
        yaml_match = re.search(r'```yaml\s*\n(.*?)```', content, re.DOTALL)
        if not yaml_match:
            return catalog

        yaml_data = yaml.safe_load(yaml_match.group(1))
        if not yaml_data or "tables" not in yaml_data:
            return catalog

        # Load sync state for row counts
        sync_data = {}
        try:
            sync_path = _resolve_metadata_path("sync_state.json")
            if sync_path.exists():
                with open(sync_path) as f:
                    state = json.load(f)
                sync_data = state.get("tables", {})
        except Exception:
            pass

        # Get folder mapping
        folder_mapping = yaml_data.get("folder_mapping", {})

        # Load category mappings from instance config, with empty fallback
        try:
            from config.loader import load_instance_config, get_instance_value
            _catalog_config = load_instance_config()
            _catalog_categories = get_instance_value(_catalog_config, "catalog", "categories", default={})
            folder_to_category = {k: v.get("label", k) for k, v in _catalog_categories.items()}
            folder_to_icon = {k: v.get("icon", k) for k, v in _catalog_categories.items()}
        except Exception:
            folder_to_category = {}
            folder_to_icon = {}

        # Map bucket to folder
        bucket_to_folder = {}
        for bucket_id, folder_name in folder_mapping.items():
            bucket_to_folder[bucket_id] = folder_name

        # Group tables by category (folder)
        categories = {}
        for table in yaml_data["tables"]:
            table_id = table.get("id", "")
            # Extract bucket from table_id (e.g., "in.c-crm.company" -> "in.c-crm")
            parts = table_id.rsplit(".", 1)
            bucket_id = parts[0] if len(parts) > 1 else ""
            folder = bucket_to_folder.get(bucket_id, "other")

            if folder not in categories:
                categories[folder] = []

            # Get sync info
            sync_info = sync_data.get(table_id, {})
            rows = sync_info.get("rows", 0)

            # Format rows
            if rows >= 1_000_000:
                rows_display = f"{rows / 1_000_000:.1f}M"
            elif rows >= 1_000:
                rows_display = f"{rows:,}"
            else:
                rows_display = str(rows) if rows > 0 else "-"

            # Determine if "large" badge
            rows_large = rows >= 1_000_000

            categories[folder].append({
                "name": table.get("name", ""),
                "description": table.get("description", ""),
                "rows": rows,
                "rows_display": rows_display,
                "rows_large": rows_large,
            })

        # Build ordered catalog (from instance config or use discovered folders)
        try:
            category_order = get_instance_value(_catalog_config, "catalog", "order", default=list(folder_to_category.keys()))
        except Exception:
            category_order = list(folder_to_category.keys())
        for folder in category_order:
            if folder in categories:
                catalog.append({
                    "name": folder_to_category.get(folder, folder),
                    "icon_type": folder_to_icon.get(folder, folder),
                    "tables": categories[folder],
                    "count": len(categories[folder]),
                })

    except Exception as e:
        logger.warning(f"Could not load catalog data: {e}")

    return catalog


def _send_welcome_message(username: str) -> None:
    """Send a welcome message to the user via bot socket after linking."""
    try:
        import httpx

        transport = httpx.HTTPTransport(uds=NOTIFY_SOCKET_PATH)
        with httpx.Client(transport=transport, timeout=10) as client:
            client.post(
                "http://localhost/send",
                json={
                    "user": username,
                    "text": (
                        f"Account linked!\n\n"
                        f"Your server login: *{username}*\n"
                        f"Notifications dir: `~/user/notifications/`\n\n"
                        f"To create notification scripts, ask your local AI assistant "
                        f"(Claude Code). It knows how to build them for you.\n\n"
                        f"You will receive alerts from your scripts here."
                    ),
                    "parse_mode": "Markdown",
                },
            )
    except Exception as e:
        logger.warning(f"Failed to send welcome message to {username}: {e}")


def register_routes(app: Flask) -> None:
    """Register main application routes."""

    @app.route("/")
    def index():
        """Redirect to dashboard or login."""
        if "user" in session:
            return redirect(url_for("dashboard"))
        return redirect(url_for("auth.login"))

    @app.route("/dashboard")
    @login_required
    def dashboard():
        """Show user dashboard with account info or registration form."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        # Check if user exists on the system
        user_info = check_user_exists(username)

        # Check if username is available (for new registrations)
        username_available, username_error = is_username_available(username)

        # Read bootstrap YAML for Claude Code setup instructions
        bootstrap_yaml = ""
        try:
            bootstrap_path = os.path.join(os.path.dirname(__file__), "..", "docs", "setup", "bootstrap.yaml")
            with open(bootstrap_path, "r") as f:
                bootstrap_yaml_template = f.read()

            # Inject username and server info into template
            bootstrap_yaml = bootstrap_yaml_template.replace("{username}", username)
            bootstrap_yaml = bootstrap_yaml.replace("{server_host}", Config.SERVER_HOST)
            bootstrap_yaml = bootstrap_yaml.replace("{server_hostname}", Config.SERVER_HOSTNAME)
            webapp_url = f"https://{Config.SERVER_HOSTNAME}" if Config.SERVER_HOSTNAME else ""
            bootstrap_yaml = bootstrap_yaml.replace("{webapp_url}", webapp_url)

        except Exception as e:
            logger.warning(f"Could not read bootstrap.yaml: {e}")

        # Get Telegram link status
        telegram_status = get_telegram_status(username)

        # Get desktop app link status
        from .desktop_auth import get_desktop_status
        desktop_status = get_desktop_status(username)

        # Load data stats
        data_stats = _load_data_stats()
        catalog_data = _load_catalog_data()

        # Load sync settings (for existing users)
        sync_settings = get_sync_settings(username) if user_info.exists else None

        # Gather account widget details (notification scripts, cron, last sync)
        account_details = get_account_details(username) if user_info.exists else None

        # Activity Center summary for dashboard widget (empty fallback)
        activity_summary = {}

        return render_template(
            "dashboard.html",
            user=user,
            username=username,
            user_info=user_info,
            username_available=username_available,
            username_error=username_error,
            server_host=Config.SERVER_HOST,
            server_hostname=Config.SERVER_HOSTNAME,
            bootstrap_yaml=bootstrap_yaml,
            telegram_status=telegram_status,
            desktop_status=desktop_status,
            data_stats=data_stats,
            catalog_data=catalog_data,
            sync_settings=sync_settings,
            account_details=account_details,
            activity_summary=activity_summary,
        )

    @app.route("/catalog")
    @login_required
    def catalog():
        """Data catalog page."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        data_stats = _load_data_stats()
        catalog_data = _load_catalog_data()
        sync_settings = get_sync_settings(username)
        return render_template(
            "catalog.html",
            data_stats=data_stats,
            catalog_data=catalog_data,
            sync_settings=sync_settings,
        )

    @app.route("/api/catalog/profile/<table_name>")
    @login_required
    def catalog_profile(table_name):
        """Return profiler data for a single table."""
        profiles_path = _resolve_metadata_path("profiles.json")
        try:
            if not profiles_path.exists():
                return jsonify({"error": "Profiler data not available yet"}), 404

            with open(profiles_path) as f:
                profiles = json.load(f)

            table_profile = profiles.get("tables", {}).get(table_name)
            if not table_profile:
                return jsonify({"error": f"No profile for table '{table_name}'"}), 404

            return jsonify(table_profile)
        except Exception as e:
            logger.error(f"Error loading profile for {table_name}: {e}")
            return jsonify({"error": "Failed to load profile data"}), 500

    @app.route("/api/metrics/<path:metric_path>")
    @login_required
    def api_metric(metric_path):
        """API endpoint to serve metric definition as structured JSON."""
        import re

        # Validate path to prevent directory traversal (allow category/file.yml pattern)
        if not re.match(r"^[a-z_]+/[a-z_]+\.yml$", metric_path):
            return jsonify({"error": "Invalid metric path"}), 400

        # Try production path first, fall back to local dev path
        docs_dir = Path("/data/docs/metrics")
        if not docs_dir.exists():
            # Local development: use docs/metrics relative to project root
            docs_dir = Path(__file__).parent.parent / "docs" / "metrics"

        file_path = docs_dir / metric_path

        # Security check: ensure path stays within docs_dir
        try:
            if not file_path.is_file() or not file_path.resolve().is_relative_to(
                docs_dir.resolve()
            ):
                return jsonify({"error": "Metric file not found"}), 404
        except (ValueError, OSError):
            return jsonify({"error": "Invalid path"}), 400

        # Parse metric YAML and return structured JSON
        try:
            from webapp.utils.metric_parser import MetricParser

            parser = MetricParser(docs_dir)
            metric_data = parser.parse_metric(metric_path)
            return jsonify(metric_data)
        except Exception as e:
            logger.error(f"Error parsing metric {metric_path}: {e}")
            return jsonify({"error": f"Failed to parse metric: {str(e)}"}), 500

    @app.route("/docs/metrics/<path:metric_path>")
    @login_required
    def serve_metric(metric_path):
        """Serve metric definition YAML files (legacy endpoint for backward compatibility)."""
        import re

        # Validate path to prevent directory traversal (allow category/file.yml pattern)
        if not re.match(r"^[a-z_]+/[a-z_]+\.yml$", metric_path):
            return render_template("error.html", error="Invalid metric path", code=400), 400

        docs_dir = Path("/data/docs/metrics")
        file_path = docs_dir / metric_path

        # Security check: ensure path stays within docs_dir
        try:
            if not file_path.is_file() or not file_path.resolve().is_relative_to(
                docs_dir.resolve()
            ):
                return (
                    render_template("error.html", error="Metric file not found", code=404),
                    404,
                )
        except (ValueError, OSError):
            return render_template("error.html", error="Invalid path", code=400), 400

        from flask import send_file as flask_send_file

        return flask_send_file(file_path, mimetype="text/plain")

    @app.route("/register", methods=["POST"])
    @login_required
    def register():
        """Create a new analyst account."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        # Check if user already exists
        user_info = check_user_exists(username)
        if user_info.exists:
            flash("Your account already exists.", "info")
            return redirect(url_for("dashboard"))

        # Get and validate SSH key
        # Normalize whitespace: collapse newlines/tabs/multiple spaces to single spaces
        # Users often paste keys with line breaks from terminal wrapping
        ssh_key = " ".join(request.form.get("ssh_key", "").split())

        is_valid, error = validate_ssh_key(ssh_key)
        if not is_valid:
            flash(error, "error")
            return redirect(url_for("dashboard"))

        # Create the user
        success, message = create_user(username, ssh_key)

        if success:
            flash(message, "success")
            logger.info(f"Account created for {email} (username: {username})")
        else:
            flash(message, "error")
            logger.error(f"Failed to create account for {email}: {message}")

        return redirect(url_for("dashboard"))

    @app.route("/api/telegram/verify", methods=["POST"])
    @login_required
    def telegram_verify():
        """Verify a Telegram verification code and link the account."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        data = request.get_json(silent=True) or {}
        code = data.get("code", "").strip()

        if not code:
            return jsonify({"error": "Verification code is required"}), 400

        success, message = link_telegram(username, code)
        if success:
            logger.info(f"Telegram linked for {username}")
            # Send welcome message via bot socket
            _send_welcome_message(username)
            return jsonify({"ok": True, "message": message})
        return jsonify({"error": message}), 400

    @app.route("/api/telegram/unlink", methods=["POST"])
    @login_required
    def telegram_unlink():
        """Unlink Telegram from the account."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        success, message = unlink_telegram(username)
        if success:
            logger.info(f"Telegram unlinked for {username}")
            return jsonify({"ok": True, "message": message})
        return jsonify({"error": message}), 400

    @app.route("/api/telegram/status")
    @login_required
    def telegram_status():
        """Get Telegram link status."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)
        status = get_telegram_status(username)
        return jsonify(status)

    @app.route("/download/<filename>")
    @login_required
    def download(filename):
        """Serve downloadable files (e.g., desktop app)."""
        import re

        if not re.match(r"^[a-zA-Z0-9_\-]+\.(zip|dmg)$", filename):
            return render_template("error.html", error="Invalid filename", code=400), 400

        download_dir = Path("/data/downloads")
        file_path = download_dir / filename
        if not file_path.is_file():
            return render_template("error.html", error="File not found", code=404), 404

        from flask import send_file as flask_send_file

        return flask_send_file(file_path, as_attachment=True)

    @app.route("/api/desktop/scripts")
    def desktop_scripts():
        """List notification scripts for the authenticated desktop user."""
        username = require_desktop_auth()
        from services.telegram_bot.status import get_script_list_structured
        scripts = get_script_list_structured(username)
        return jsonify(scripts)

    @app.route("/api/desktop/scripts/run", methods=["POST"])
    def desktop_run_script():
        """Run a notification script on-demand for the authenticated desktop user."""
        username = require_desktop_auth()
        data = request.get_json(silent=True) or {}
        script_name = data.get("name", "").strip()
        if not script_name:
            return jsonify({"error": "Missing 'name' field"}), 400

        from services.telegram_bot.runner import run_user_script
        from services.telegram_bot.dispatch import dispatch_to_ws_gateway

        output = run_user_script(username, script_name)
        if output is None:
            return jsonify({"error": f"Script '{script_name}' failed or not found"}), 500

        if output.get("notify", False):
            dispatch_to_ws_gateway(username, output, script_name)

        return jsonify({"ok": True})

    @app.route("/api/sync-settings")
    @login_required
    def sync_settings_get():
        """Get sync settings for current user."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)
        settings = get_sync_settings(username)
        return jsonify(settings)

    @app.route("/api/sync-settings", methods=["POST"])
    @login_required
    def sync_settings_update():
        """Update sync settings for current user."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        data = request.get_json(silent=True) or {}
        datasets = data.get("datasets", {})

        if not datasets:
            return jsonify({"error": "Missing datasets field"}), 400

        success, message = update_sync_settings(username, datasets)
        if success:
            logger.info(f"Sync settings updated for {username}")
            return jsonify({"ok": True, "message": message})
        return jsonify({"error": message}), 400

    # ─────────────────────────────────────────────────────────────────
    # Corporate Memory routes
    # ─────────────────────────────────────────────────────────────────

    @app.route("/corporate-memory")
    @login_required
    def corporate_memory():
        """Corporate Memory knowledge browser page."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        # Get stats for header
        stats = get_memory_stats()
        user_stats = get_memory_user_stats(username)

        # Get user's votes for highlighting
        user_votes = get_user_votes(username)

        # Get initial page of knowledge
        knowledge = get_knowledge(page=0, per_page=20)

        return render_template(
            "corporate_memory.html",
            stats=stats,
            user_stats=user_stats,
            user_votes=user_votes,
            knowledge=knowledge,
        )

    # ─────────────────────────────────────────────────────────────────
    # Activity Center routes
    # ─────────────────────────────────────────────────────────────────

    @app.route("/activity-center")
    @login_required
    def activity_center():
        """Activity Center page - enterprise data intelligence overview."""
        activity = {}
        return render_template("activity_center.html", activity=activity)

    @app.route("/api/corporate-memory/knowledge")
    @login_required
    def api_corporate_memory_knowledge():
        """Get knowledge items with optional filtering."""
        category = request.args.get("category")
        search = request.args.get("search")
        page = request.args.get("page", 0, type=int)
        per_page = request.args.get("per_page", 20, type=int)
        sort = request.args.get("sort", "score")
        my_rules = request.args.get("my_rules", "").lower() == "true"

        # Get username for my_rules filter
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        # Limit per_page to reasonable maximum
        per_page = min(per_page, 100)

        result = get_knowledge(
            category=category,
            search=search,
            page=page,
            per_page=per_page,
            sort=sort,
            username=username,
            my_rules=my_rules,
        )
        return jsonify(result)

    @app.route("/api/corporate-memory/stats")
    @login_required
    def api_corporate_memory_stats():
        """Get corporate memory statistics for dashboard."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        stats = get_memory_stats()
        user_stats = get_memory_user_stats(username)

        return jsonify({
            **stats,
            **user_stats,
        })

    @app.route("/api/corporate-memory/vote", methods=["POST"])
    @login_required
    def api_corporate_memory_vote():
        """Vote on a knowledge item."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        data = request.get_json(silent=True) or {}
        item_id = data.get("item_id")
        vote_value = data.get("vote", 0)

        if not item_id:
            return jsonify({"error": "Missing item_id"}), 400

        try:
            vote_value = int(vote_value)
        except (TypeError, ValueError):
            return jsonify({"error": "Invalid vote value"}), 400

        success, message = memory_vote(username, item_id, vote_value)
        if success:
            return jsonify({"ok": True, "message": message})
        return jsonify({"error": message}), 400

    @app.route("/api/corporate-memory/my-votes")
    @login_required
    def api_corporate_memory_my_votes():
        """Get current user's votes."""
        user = session.get("user", {})
        email = user.get("email", "")
        username = get_username_from_email(email)

        votes = get_user_votes(username)
        return jsonify({"votes": votes})

    @app.route("/health")
    def health():
        """
        Health check endpoint for monitoring.

        Returns detailed status of services, disk, load, and recent activity.
        Returns 200 if healthy, 503 if degraded.
        """
        from webapp.health_service import health_check

        response, status_code = health_check()
        return response, status_code

    @app.errorhandler(404)
    def not_found(e):
        """Handle 404 errors."""
        return render_template("error.html", error="Page not found", code=404), 404

    @app.errorhandler(500)
    def server_error(e):
        """Handle 500 errors."""
        logger.exception("Server error")
        return render_template("error.html", error="Internal server error", code=500), 500


# Create the app instance for Gunicorn
app = create_app()


if __name__ == "__main__":
    # Development server
    app.run(debug=True, host="127.0.0.1", port=5000)