Design a language detection system.

Focus on the core components of a language detection system, including the input data types (text, audio, etc.) and the algorithms that could be employed, such as n-grams, character frequency analysis, or machine learning models. Discuss how you would handle edge cases, such as mixed-language inputs or dialect variations. Consider the scalability of your solution and how it would perform in real-time applications. Finally, address the importance of accuracy and how you would evaluate the system's performance, including metrics like precision, recall, and F1 score.