Final answer:
To solve the issue of a long method with intertwined local variables that does not allow the Extract Method to be applied, decompose the problem into subproblems. Isolate sections of code, rearrange operations, introduce parameter objects, and break dependencies to create manageable chunks that can be refactored into separate methods or classes.
Step-by-step explanation:
When faced with a long method where local variables are so intertwined that you cannot apply [Extract Method], one possible solution is to decompose the problem into subproblems. This involves breaking down the complex method into smaller, manageable chunks, each of which can be tackled individually. It is important to approach this by identifying the local variables and their interactions, then seeing if any group of variables or related logic can be separated out into a new method or class.
Even when variables seem too entangled, there may still be logical groupings that can be identified. Refactor your method by first isolating sections of the code that could potentially be extracted, regardless of current variable dependencies. These sections might not be immediately extractable due to the entanglement but identifying these can set you on a path to methodically detangle and eventually encapsulate them into their own methods, objects, or even classes.
Lastly, revisit the code to rearrange the sequence of operations or to introduce parameter objects or result objects to break dependencies. This gradual process of refactoring can eventually allow for a clean application of the Extract Method technique, and transform a long, complex method into a series of smaller, more manageable and maintainable pieces.