# Phase 3: Refactor Large Files Plan

## Overview
Split files over 300 lines into focused modules. Keep public APIs stable - don't rename exports unless clearly a mistake.

## High Priority Files (Audit Findings)

### 1. `src/lib/game/store.ts` (2464 lines) - MONOLITHIC LEGACY STORE
**Status**: Mid-refactor - project has started moving to slice architecture (`/stores/` directory)
**Action**: Complete migration to slice-based architecture
- New architecture exists: `gameStore.ts`, `manaStore.ts`, `skillStore.ts`, `combatStore.ts`, `prestigeStore.ts`
- Migrate all remaining imports from `store.ts` to new stores
- Deprecate and eventually remove `store.ts`
- **Complexity**: 3+ steps → Requires sub-agent delegation

### 2. `src/lib/game/skill-evolution.ts` (2312 lines) - ALL SKILL TREES
**Action**: Split by skill category
- Separate files for: mana skills, combat skills, study skills, element skills
- Extract helper functions (`createPerk`, `createUpgrade`, etc.) to `skill-utils.ts`
- Keep `SKILL_EVOLUTION_PATHS` as the main export
- **Complexity**: 3+ steps → Requires sub-agent delegation

### 3. `src/lib/game/constants.ts` (1436 lines) - MIXED CONSTANTS
**Action**: Split into domain-specific files
- `elements.ts` (element definitions)
- `guardians.ts` (guardian definitions)
- `spells.ts` (spell definitions)
- `skills.ts` (skill definitions)
- `prestige.ts` (prestige definitions)
- `room-config.ts` (room types, swarm config, etc.)
- Keep `constants.ts` as barrel file exporting from all split files
- **Complexity**: 3+ steps → Requires sub-agent delegation

### 4. `src/lib/game/data/enchantment-effects.ts` (846 lines) - ENCHANTMENT DATA
**Action**: Split by category or move data to JSON
- Separate files: `spell-enchants.ts`, `mana-enchants.ts`, `combat-enchants.ts`, etc.
- Keep `ENCHANTMENT_EFFECTS` as main export
- **Complexity**: 2-3 steps → Consider sub-agent

### 5. `src/components/game/tabs/CraftingTab.tsx` (965 lines) - CRAFTING UI
**Action**: Split by crafting stage
- `EnchantmentDesigner.tsx` (design stage)
- `EnchantmentPreparer.tsx` (prepare stage)
- `EnchantmentApplier.tsx` (apply stage)
- `EquipmentCrafter.tsx` (craft stage)
- Keep `CraftingTab.tsx` as coordinator
- **Complexity**: 2-3 steps → Consider sub-agent

## Medium Priority Files

### 6. `src/lib/game/types.ts` (516 lines) - TYPE DEFINITIONS
**Action**: Split into domain-specific type files
- `types/elements.ts`, `types/attunements.ts`, `types/spells.ts`, etc.
- Keep `types/index.ts` as barrel file

### 7. `src/lib/game/computed-stats.ts` (492 lines) - MIXED UTILITIES
**Action**: Split by responsibility
- `formatting.ts` (fmt, fmtDec)
- `floor-utils.ts` (floor HP, floor element)
- `mana-utils.ts` (computeMaxMana, computeRegen, etc.)
- `combat-utils.ts` (calcDamage, calcInsight, etc.)

### 8. `src/lib/game/utils.ts` (372 lines) - MIXED UTILITIES
**Action**: Same as computed-stats.ts - split by responsibility

## Low Priority Files (Acceptable Size/Structure)
- `src/lib/game/stores/gameStore.ts` (509 lines) - Good coordinator
- `src/lib/game/store/craftingSlice.ts` (644 lines) - Well-structured slice
- `src/components/game/tabs/DebugTab.tsx` (700 lines) - Debug UI, can split if desired
- `src/app/page.tsx` (465 lines) - Main page, could lazy load tabs

## Guidelines
1. Keep public APIs stable - don't rename exports unless mistake
2. Don't change game balance values
3. Don't refactor working code just for style
4. Don't introduce new dependencies
5. When in doubt, flag it and move on
6. Verify build after each file split
7. Commit regularly

## Execution Order
1. Start with `store.ts` (highest priority, completes architecture migration)
2. Then `skill-evolution.ts` (second largest)
3. Then `constants.ts` (mixed constants)
4. Other files as time permits

## Verification
- Run `npm run build` after each refactoring step
- Run `npm run test` if tests exist
- Commit changes regularly with descriptive messages