from flask import Blueprint, current_app, redirect, url_for, request

blueprint = Blueprint(
    'matrix_iframe',
    __name__,
    template_folder='templates',
    static_folder='static',
    static_url_path='/static/matrix_iframe',
)

def init_app(app, server_url='', room_alias='', login_endpoint=None):
    """
    Register the Matrix chat blueprint with a Flask app.

    The blueprint serves static assets (JS + CSS) and injects
    matrix_chat_available, matrix_server_url, and matrix_room_alias
    into every template context so the host app's layout can mount
    the chat overlay widget.

    Args:
        server_url:      Matrix homeserver base URL, e.g. "https://matrix.sticknife.com"
        room_alias:      Matrix room alias, e.g. "#sticknife-library:matrix.sticknife.com"
        login_endpoint:  Flask endpoint to redirect unauthenticated users to,
                         e.g. "web.login". If None, no auth guard is applied.
    """
    app.config.setdefault('MATRIX_SERVER_URL', server_url)
    app.config.setdefault('MATRIX_ROOM_ALIAS', room_alias)
    app.config.setdefault('MATRIX_CHAT_LOGIN_ENDPOINT', login_endpoint)
    app.register_blueprint(blueprint)


@blueprint.app_context_processor
def _inject_matrix_chat():
    """Injects matrix chat config into every template when the blueprint is registered."""
    return {
        'matrix_chat_available': True,
        'matrix_server_url': current_app.config.get('MATRIX_SERVER_URL', ''),
        'matrix_room_alias': current_app.config.get('MATRIX_ROOM_ALIAS', ''),
    }


@blueprint.before_request
def _auth_guard():
    login_endpoint = current_app.config.get('MATRIX_CHAT_LOGIN_ENDPOINT')
    if not login_endpoint:
        return
    try:
        from flask_login import current_user
        if not current_user.is_authenticated:
            return redirect(url_for(login_endpoint, next=request.url))
    except ImportError:
        pass