gregExtractor/README.md

gregExtractor

gregExtractor is a dual-mode mod scaffolder for Data Center (Unity IL2CPP + MelonLoader).

It runs as:

• Desktop GUI (gregExtractor or gregExtractor --gui) using Avalonia.
• CLI tool (gregExtractor extract, gregExtractor create ...) using Spectre.Console.Cli.

Both modes use the exact same shared service layer.

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What it does

1. Statically reads IL2CPP dummy assemblies (Assembly-CSharp.dll) with Mono.Cecil.
2. Classifies discovered methods into groups using hook_groups.json + heuristics.
3. Writes extraction output:
   • game_hooks.json
   • unknown_hooks.json
4. Generates ready-to-edit mod templates for different use cases.
5. Generates coverage reports (coverage_report.json + coverage_report.md) by comparing:
   • Assembly methods (Assembly-CSharp.dll)
   • planned hooks (game_hooks.json)
   • implemented Harmony patches (framework sources)
6. Synchronizes framework target files via hook diff (sync) with dry-run and optional git stat output.

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Wiki

• wiki/README.md
• wiki/cli.md
• wiki/ui.md
• wiki/known-issues.md

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Command line usage

Extract hooks

gregExtractor extract
gregExtractor extract --path "C:\Program Files (x86)\Steam\steamapps\common\Data Center\MelonLoader\Il2CppAssemblies"

Create mod scaffold

gregExtractor create MyEconomyMod --type harmonyPatch --category Economy
gregExtractor create MyServerMod --type customServer --path "D:\dcmods"

Analyze coverage

gregExtractor coverage
gregExtractor coverage --path "C:\Program Files (x86)\Steam\steamapps\common\Data Center\MelonLoader\Il2CppAssemblies"
gregExtractor coverage --sources ".\Hooks;.\framework" --out ".\coverage_report" --open

Sync framework files

gregExtractor sync --source ".\gregCore\src" --dry-run
gregExtractor sync --source ".\gregCore\src" --git --force

Supported --type values:

• harmonyPatch
• customServer
• customUI
• customWorld
• customFurniture
• customNPC

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GUI usage

gregExtractor
gregExtractor --gui

GUI capabilities:

• Auto-detect game + IL2CPP paths.
• Start extraction with live progress/logging.
• Review hooks grouped by category.
• Generate mod scaffolds with selected template/category.
• Open generated output folder.
• Coverage tab for in-app report generation and review.
• Dedicated Sync tab for diff preview + controlled framework update runs.

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Project architecture

gregExtractor/
├── Program.cs
├── Models/
├── Services/
├── Commands/
├── Utils/
└── GUI/

Shared Core Services

• Services/ExtractorService.cs: Mono.Cecil extraction pipeline.
• Services/HookClassifier.cs: JSON-driven + heuristic classification.
• Services/TemplateService.cs: scaffold generation.
• Utils/SteamLocator.cs: Steam + library + game path discovery.

No service performs direct console output; services only report via IProgress<string>.

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Build

dotnet restore
dotnet build

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Configuration

hook_groups.json at project root is the classification source of truth.

If missing or malformed, extraction still works, but groups may fall back to heuristics and Uncategorized.

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Generated mod files

Every generated C# file includes this required header:

// UNITY 6: All Unity API calls must run on the Main Thread!
// Use MelonCoroutines for asynchronous operations.
// Generated by gregExtractor v1.0 — https://dcmods.com

Generated Harmony templates default to Postfix patches and include commented Prefix examples.

gregCore integration points are intentionally generated as commented TODOs until package release is finalized.

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Environment assumptions

Generated mod projects use:

• $(MODS_GAME_DIR)\\MelonLoader\\net6\\MelonLoader.dll
• $(MODS_GAME_DIR)\\MelonLoader\\net6\\0Harmony.dll
• $(MODS_GAME_DIR)\\MelonLoader\\Il2CppAssemblies\\Assembly-CSharp.dll

Set MODS_GAME_DIR in your shell/CI before building generated mods.

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Troubleshooting

Auto-detect fails

• Ensure Steam is installed and readable from registry.
• Ensure the game exists in a Steam library.
• Use --path manually.

Assembly-CSharp.dll not found

• Start the game once with MelonLoader installed.
• Verify MelonLoader\\Il2CppAssemblies exists.

Empty or unexpected groups

• Verify hook_groups.json is valid JSON.
• Run extraction again after game updates.