import Foundation
import HostRegistry
import Testing
import WireProtocol
@testable import WebTerm

/// T-iOS-15 · Cold-start selection logic (pure): which root screen boots, and
/// whether the session list should highlight "继续上次" for the active host.
@MainActor
@Suite("ColdStartPolicy")
struct ColdStartPolicyTests {
    private final class StubLastSessionStore: LastSessionStore, @unchecked Sendable {
        private let stored: [UUID: UUID]
        init(stored: [UUID: UUID] = [:]) { self.stored = stored }
        func lastSessionId(host: UUID) -> UUID? { stored[host] }
        func setLastSessionId(_ id: UUID?, host: UUID) {}
    }

    private static func makeHost(name: String = "mac") throws -> HostRegistry.Host {
        let url = try #require(URL(string: "http://192.168.1.5:3000"))
        let endpoint = try #require(HostEndpoint(baseURL: url))
        return HostRegistry.Host(id: UUID(), name: name, endpoint: endpoint)
    }

    // MARK: - Root route: no paired host → Pairing; else SessionList

    @Test("无配对 host → 冷启动进 Pairing")
    func noHostsBootsIntoPairing() {
        #expect(ColdStartPolicy.initialRoute(pairedHostCount: 0) == .pairing)
    }

    @Test("有配对 host → 冷启动进 SessionList")
    func pairedHostsBootIntoSessionList() {
        #expect(ColdStartPolicy.initialRoute(pairedHostCount: 1) == .sessions)
        #expect(ColdStartPolicy.initialRoute(pairedHostCount: 3) == .sessions)
    }

    // MARK: - "继续上次" highlight

    @Test("active host 存有 lastSessionId → 给出继续上次目标")
    func continueLastReturnsStoredSession() throws {
        let host = try Self.makeHost()
        let sessionId = UUID()
        let store = StubLastSessionStore(stored: [host.id: sessionId])

        let target = ColdStartPolicy.continueLastSessionId(activeHost: host, store: store)

        #expect(target == sessionId)
    }

    @Test("该 host 无记录 → 无继续上次高亮")
    func continueLastNilWithoutRecord() throws {
        let host = try Self.makeHost()
        let other = UUID()
        let store = StubLastSessionStore(stored: [other: UUID()])

        #expect(ColdStartPolicy.continueLastSessionId(activeHost: host, store: store) == nil)
    }

    @Test("尚无 active host（hosts 未加载/为空）→ 无高亮")
    func continueLastNilWithoutActiveHost() {
        let store = StubLastSessionStore()
        #expect(ColdStartPolicy.continueLastSessionId(activeHost: nil, store: store) == nil)
    }
}