grammargem/Sources/GrammaGem/AI/MLXEngine.swift
BigMarc f5faa27f88 GrammaGem — open-source, on-device macOS writing assistant
Native SwiftUI menu-bar app: global hotkey → capture selected text (AX API /
clipboard fallback) → grammar (Harper) / local AI (MLX) → replace in place.
Free/paid entitlement gate + Lemon Squeezy device-cap licensing, $0 marginal
cost per user. Heavyweight engines behind protocol stubs so it builds out of the box.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-16 13:56:26 +02:00

92 lines
3.6 KiB
Swift

import Foundation
/// STUB standing in for the real MLX-backed local LLM.
///
/// TODO(real-integration): load the model via mlx-swift from
/// `ModelManager.modelsDirectory`, build the prompt from the action's system
/// prompt + the user's text, and stream tokens (target: first token < 1s on
/// M-series). Everything stays on-device — this method must never hit the network.
///
/// The stub produces deterministic, plausible transformations so the capture →
/// engine → replace loop and the entitlement gating can be exercised end-to-end
/// without the multi-gigabyte model present.
final class MLXEngine: AIEngine {
private let ready: Bool
init(ready: Bool = true) {
self.ready = ready
}
var isReady: Bool { ready }
func run(_ action: AIAction, on text: String) async throws -> String {
guard ready else { throw AIEngineError.modelNotReady }
let trimmed = text.trimmingCharacters(in: .whitespacesAndNewlines)
guard !trimmed.isEmpty else { return text }
switch action {
case .rewriteClarity, .rewrite:
return tidy(trimmed)
case .adjustTone(let tone):
return apply(tone: tone, to: tidy(trimmed))
case .ask(let instruction):
return follow(instruction: instruction, on: trimmed)
case .translate(let language):
return "[\(language)] " + tidy(trimmed)
case .applyMode(let mode):
return applyMode(mode, to: trimmed)
}
}
func detectTone(_ text: String) async -> Tone {
let lower = text.lowercased()
if lower.contains("!") || lower.contains("🚀") { return .punchy }
if lower.contains("therefore") || lower.contains("hereby") { return .academic }
if lower.contains("hey") || lower.contains("lol") { return .friendly }
return .professional
}
// MARK: - Deterministic stand-in transforms
private func tidy(_ s: String) -> String {
var out = s
out = out.replacingOccurrences(of: " i ", with: " I ")
out = out.replacingOccurrences(of: "lmk", with: "let me know")
out = out.replacingOccurrences(of: "u ", with: "you ")
if let first = out.first, first.isLowercase {
out.replaceSubrange(out.startIndex...out.startIndex, with: String(first).uppercased())
}
if let last = out.last, !".!?".contains(last) { out.append(".") }
return out
}
private func apply(tone: Tone, to s: String) -> String {
switch tone {
case .professional: return s
case .friendly: return "Hi! " + s
case .confident: return s.replacingOccurrences(of: "I think ", with: "")
case .academic: return "It is worth noting that " + s.prefix(1).lowercased() + s.dropFirst()
case .punchy: return s.replacingOccurrences(of: ". ", with: ".\n")
}
}
private func follow(instruction: String, on s: String) -> String {
let i = instruction.lowercased()
if i.contains("short") { return String(s.split(separator: " ").prefix(8).joined(separator: " ")) + "." }
if i.contains("formal") { return apply(tone: .academic, to: tidy(s)) }
if i.contains("translate") { return "[translated] " + tidy(s) }
return tidy(s)
}
private func applyMode(_ mode: WritingMode, to s: String) -> String {
switch mode.id {
case "email": return "Hi,\n\n\(tidy(s))\n\nThanks!"
case "post": return apply(tone: .punchy, to: tidy(s))
case "academic": return apply(tone: .academic, to: tidy(s))
case "slack": return s.lowercased()
case "code": return "// " + tidy(s)
default: return tidy(s)
}
}
}