"""
API endpoints for reporting user activity events.

This module provides endpoints for clients to report state changes (working/stopped).
"""
from datetime import datetime
from flask import Blueprint, request, jsonify, current_app
from sqlalchemy.exc import SQLAlchemyError

from app import db
from app.models import WorkEvent

# Create a blueprint for event-related API endpoints
events_bp = Blueprint('events', __name__, url_prefix='/api')

@events_bp.route('/report', methods=['POST'])
def report_event():
    """
    Endpoint for clients to report activity state changes.
    
    Expected JSON payload:
    {
        "user": "username",
        "state": "working|stopped",
        "ts": "2023-07-08T12:30:45Z" (optional, ISO 8601)
    }
    """
    data = request.get_json()
    current_app.logger.info(f"Received report request: {data}") # Log request

    if not data or 'user' not in data or 'state' not in data:
        current_app.logger.warning("Invalid report request payload.")
        return jsonify({
            'success': False,
            'message': 'Missing required fields: user, state'
        }), 400
            
    # Validate state value
    if data['state'] not in ['working', 'stopped']:
        return jsonify({
            'success': False,
            'message': 'Invalid state value. Must be "working" or "stopped"'
        }), 400
    
    # Parse timestamp if provided, otherwise use current time
    timestamp = None
    if 'ts' in data and data['ts']:
        try:
            timestamp = datetime.fromisoformat(data['ts'].replace('Z', '+00:00'))
        except ValueError:
            return jsonify({
                'success': False,
                'message': 'Invalid timestamp format. Use ISO 8601 (YYYY-MM-DDTHH:MM:SSZ)'
            }), 400
    
    # Create and store the event
    user = data['user']
    state = data['state']
    ts_str = data.get('ts') # Optional timestamp

    event_ts = datetime.utcnow()
    if ts_str:
        try:
            # Attempt to parse ISO 8601 format
            event_ts = datetime.fromisoformat(ts_str.replace('Z', '+00:00'))
        except ValueError:
            current_app.logger.warning(f"Invalid timestamp format received: {ts_str}. Using current UTC time.")
            # Optionally return an error here if strict timestamp validation is needed
            # return jsonify({"success": False, "message": "Invalid timestamp format"}), 400

    new_event = WorkEvent(user=user, state=state, ts=event_ts)

    try:
        current_app.logger.info(f"Attempting to add event to database: User={user}, State={state}, TS={event_ts}")
        db.session.add(new_event)
        db.session.commit()
        current_app.logger.info(f"Successfully recorded event: User={user}, State={state}")
        return jsonify({"success": True}), 201
    except SQLAlchemyError as e:
        db.session.rollback()
        current_app.logger.error(f"Database error while recording event: {e}")
        return jsonify({"success": False, "message": "Database error"}), 500
    except Exception as e:
        current_app.logger.error(f"Unexpected error processing report request: {e}")
        return jsonify({"success": False, "message": "Internal server error"}), 500