Stirling 2.0 (#3928)

# Description of Changes

<!--

File context for managing files between tools and views
Optimisation for large files
Updated Split to work with new file system and match Matts stepped
design closer

-->

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

---------

Co-authored-by: Anthony Stirling <[email protected]>

frontend/src/hooks/tools/split/useSplitParameters.ts

@@ -0,0 +1,71 @@
+import { useState } from 'react';
+import { SPLIT_MODES, SPLIT_TYPES, ENDPOINTS, type SplitMode, type SplitType } from '../../../constants/splitConstants';
+import { SplitParameters } from '../../../components/tools/split/SplitSettings';
+
+export interface SplitParametersHook {
+  mode: SplitMode | '';
+  parameters: SplitParameters;
+  setMode: (mode: SplitMode | '') => void;
+  updateParameter: (parameter: keyof SplitParameters, value: string | boolean) => void;
+  resetParameters: () => void;
+  validateParameters: () => boolean;
+  getEndpointName: () => string;
+}
+
+const initialParameters: SplitParameters = {
+  pages: '',
+  hDiv: '2',
+  vDiv: '2',
+  merge: false,
+  splitType: SPLIT_TYPES.SIZE,
+  splitValue: '',
+  bookmarkLevel: '1',
+  includeMetadata: false,
+  allowDuplicates: false,
+};
+
+export const useSplitParameters = (): SplitParametersHook => {
+  const [mode, setMode] = useState<SplitMode | ''>('');
+  const [parameters, setParameters] = useState<SplitParameters>(initialParameters);
+
+  const updateParameter = (parameter: keyof SplitParameters, value: string | boolean) => {
+    setParameters(prev => ({ ...prev, [parameter]: value }));
+  };
+
+  const resetParameters = () => {
+    setParameters(initialParameters);
+    setMode('');
+  };
+
+  const validateParameters = () => {
+    if (!mode) return false;
+
+    switch (mode) {
+      case SPLIT_MODES.BY_PAGES:
+        return parameters.pages.trim() !== "";
+      case SPLIT_MODES.BY_SECTIONS:
+        return parameters.hDiv !== "" && parameters.vDiv !== "";
+      case SPLIT_MODES.BY_SIZE_OR_COUNT:
+        return parameters.splitValue.trim() !== "";
+      case SPLIT_MODES.BY_CHAPTERS:
+        return parameters.bookmarkLevel !== "";
+      default:
+        return false;
+    }
+  };
+
+  const getEndpointName = () => {
+    if (!mode) return ENDPOINTS[SPLIT_MODES.BY_PAGES];
+    return ENDPOINTS[mode as SplitMode];
+  };
+
+  return {
+    mode,
+    parameters,
+    setMode,
+    updateParameter,
+    resetParameters,
+    validateParameters,
+    getEndpointName,
+  };
+};