feat: add search and recent queries

Implements: https://todo.sr.ht/~ccleberg/hutch/47
Implements: https://todo.sr.ht/~ccleberg/hutch/48

1 files changed, 65 insertions, 0 deletions

diff --git a/Hutch/Views/Search/ScopedSearchHistoryStore.swift b/Hutch/Views/Search/ScopedSearchHistoryStore.swift
new file mode 100644
index 0000000..e009376
--- /dev/null
+++ b/Hutch/Views/Search/ScopedSearchHistoryStore.swift
@@ -0,0 +1,65 @@
+import Foundation
+
+struct ScopedSearchHistoryEntry: Codable, Hashable, Identifiable, Sendable {
+    let scopeID: String
+    let query: String
+    let createdAt: Date
+
+    var id: String {
+        "\(scopeID):\(query.lowercased())"
+    }
+}
+
+enum ScopedSearchHistoryStore {
+    private static let maximumEntriesPerScope = 8
+
+    static func load(scopeID: String, defaults: UserDefaults = .standard) -> [ScopedSearchHistoryEntry] {
+        loadAll(defaults: defaults)[scopeID] ?? []
+    }
+
+    static func record(
+        query: String,
+        scopeID: String,
+        defaults: UserDefaults = .standard,
+        now: Date = .now
+    ) {
+        let normalizedQuery = query.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !normalizedQuery.isEmpty else { return }
+
+        var allEntries = loadAll(defaults: defaults)
+        var scopeEntries = allEntries[scopeID] ?? []
+        scopeEntries.removeAll {
+            $0.query.compare(normalizedQuery, options: [.caseInsensitive, .diacriticInsensitive]) == .orderedSame
+        }
+        scopeEntries.insert(
+            ScopedSearchHistoryEntry(scopeID: scopeID, query: normalizedQuery, createdAt: now),
+            at: 0
+        )
+        allEntries[scopeID] = Array(scopeEntries.prefix(maximumEntriesPerScope))
+        save(allEntries, defaults: defaults)
+    }
+
+    static func clear(scopeID: String, defaults: UserDefaults = .standard) {
+        var allEntries = loadAll(defaults: defaults)
+        allEntries.removeValue(forKey: scopeID)
+        save(allEntries, defaults: defaults)
+    }
+
+    private static func loadAll(defaults: UserDefaults) -> [String: [ScopedSearchHistoryEntry]] {
+        guard let data = defaults.data(forKey: AppStorageKeys.scopedSearchHistory) else {
+            return [:]
+        }
+
+        do {
+            return try JSONDecoder().decode([String: [ScopedSearchHistoryEntry]].self, from: data)
+        } catch {
+            defaults.removeObject(forKey: AppStorageKeys.scopedSearchHistory)
+            return [:]
+        }
+    }
+
+    private static func save(_ entries: [String: [ScopedSearchHistoryEntry]], defaults: UserDefaults) {
+        guard let data = try? JSONEncoder().encode(entries) else { return }
+        defaults.set(data, forKey: AppStorageKeys.scopedSearchHistory)
+    }
+}