initial commit

IrisCompanion/iris/Models/HeuristicRanker.swift

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+//
+//  HeuristicRanker.swift
+//  iris
+//
+//  Created by Codex.
+//
+
+import Foundation
+
+struct UserContext: Equatable {
+    var isMoving: Bool
+    var city: String
+
+    init(isMoving: Bool, city: String = "London") {
+        self.isMoving = isMoving
+        self.city = city
+    }
+}
+
+final class HeuristicRanker {
+    private let nowProvider: () -> Int
+    private let lastShownAtProvider: (String) -> Int?
+
+    init(now: @escaping () -> Int = { Int(Date().timeIntervalSince1970) },
+         lastShownAt: @escaping (String) -> Int? = { _ in nil }) {
+        self.nowProvider = now
+        self.lastShownAtProvider = lastShownAt
+    }
+
+    func pickWinner(from candidates: [Candidate], now: Int? = nil, context: UserContext) -> Winner {
+        let currentTime = now ?? nowProvider()
+
+        let valid = candidates
+            .filter { !$0.isExpired(at: currentTime) }
+            .filter { $0.confidence >= 0.0 }
+
+        guard !valid.isEmpty else {
+            return WinnerEnvelope.allQuiet(now: currentTime).winner
+        }
+
+        var best: (candidate: Candidate, score: Double)?
+        for candidate in valid {
+            let baseWeight = baseWeight(for: candidate.type)
+            var score = baseWeight * min(max(candidate.confidence, 0.0), 1.0)
+            if let shownAt = lastShownAtProvider(candidate.id),
+               currentTime - shownAt <= 2 * 60 * 60 {
+                score -= 0.4
+            }
+            if best == nil || score > best!.score {
+                best = (candidate, score)
+            }
+        }
+
+        guard let best else {
+            return WinnerEnvelope.allQuiet(now: currentTime).winner
+        }
+
+        let priority = min(max(best.score, 0.0), 1.0)
+        return Winner(
+            id: best.candidate.id,
+            type: best.candidate.type,
+            title: best.candidate.title.truncated(maxLength: TextConstraints.titleMax),
+            subtitle: best.candidate.subtitle.truncated(maxLength: TextConstraints.subtitleMax),
+            priority: priority,
+            ttlSec: max(1, best.candidate.ttlSec)
+        )
+    }
+
+    private func baseWeight(for type: WinnerType) -> Double {
+        switch type {
+        case .weatherWarning: return 1.0
+        case .weatherAlert: return 0.9
+        case .transit: return 0.75
+        case .poiNearby: return 0.6
+        case .info: return 0.4
+        case .nowPlaying: return 0.25
+        case .currentWeather: return 0.0
+        case .allQuiet: return 0.0
+        }
+    }
+}