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

/// C1 · Access-token UX in the pairing flow (ios-completion §1.1).
///
/// Every branch of the frozen contract is pinned here, because three of the four
/// `POST /auth` outcomes are NOT errors and must be told apart:
/// 204+Set-Cookie = save it · 204 without = this host has no auth (save nothing)
/// · 401 = wrong token · 429 = back off.
@MainActor
@Suite("Pairing access token")
struct PairingTokenViewModelTests {
    // MARK: - Scripted probe (records what the VM asked for, in order)

    private actor ProbeRecorder {
        /// `(endpoint, token)` per host-verification call — the token argument is
        /// what proves the candidate reaches the probe.
        private(set) var verifyCalls: [(origin: String, token: String?)] = []
        private(set) var validateCalls: [String] = []
        private var verifyResults: [Result<HostEndpoint, PairingError>]
        private var validateResults:
            [Result<AccessTokenProbeResult, PairingViewModel.TokenProbeFailure>]

        init(
            verifyResults: [Result<HostEndpoint, PairingError>] = [],
            validateResults: [Result<AccessTokenProbeResult, PairingViewModel.TokenProbeFailure>]
                = []
        ) {
            self.verifyResults = verifyResults
            self.validateResults = validateResults
        }

        func verify(
            _ endpoint: HostEndpoint, _ token: AccessToken?
        ) -> Result<HostEndpoint, PairingError> {
            verifyCalls = verifyCalls + [(endpoint.originHeader, token?.rawValue)]
            guard let next = verifyResults.first else { return .success(endpoint) }
            verifyResults = Array(verifyResults.dropFirst())
            return next
        }

        func validate(
            _ token: AccessToken
        ) -> Result<AccessTokenProbeResult, PairingViewModel.TokenProbeFailure> {
            validateCalls = validateCalls + [token.rawValue]
            guard let next = validateResults.first else { return .success(.valid) }
            validateResults = Array(validateResults.dropFirst())
            return next
        }
    }

    private static let base = "http://192.168.1.5:3000"
    /// 32 chars from the frozen charset — shape-valid, so any rejection in a test
    /// comes from the server outcome, not from validation.
    private static let goodToken = "abcdefghijklmnopqrstuvwxyz012345"

    private func makeViewModel(
        store: any HostStore,
        recorder: ProbeRecorder
    ) -> PairingViewModel {
        PairingViewModel(
            store: store,
            probe: PairingViewModel.Probe(
                verifyHost: { endpoint, token in await recorder.verify(endpoint, token) },
                validateToken: { _, token in await recorder.validate(token) }
            )
        )
    }

    /// Drive the VM to the token prompt the way the user gets there: the host
    /// answers 401, which the probe reports as `originRejected` with the
    /// both-remedies hint.
    private func viewModelAtTokenPrompt(
        store: any HostStore = InMemoryHostStore(),
        recorder: ProbeRecorder
    ) async -> PairingViewModel {
        let viewModel = makeViewModel(store: store, recorder: recorder)
        viewModel.submitManualURL(Self.base)
        await viewModel.confirmConnect()
        viewModel.beginAccessTokenEntry()
        // Loud, not silent: a recorder whose first verification does NOT fail
        // with a 401 would leave the VM elsewhere and make every assertion below
        // vacuous.
        if case .awaitingToken = viewModel.phase {} else {
            Issue.record("harness expected .awaitingToken, got \(viewModel.phase)")
        }
        return viewModel
    }

    // MARK: - 401 → prompt

    @Test("401 配对失败 → 提供「输入访问令牌」，进入令牌输入态")
    func unauthorizedFailureOffersTokenPrompt() async throws {
        // The hint text itself is the probe's (pinned in
        // PairingProbeUnauthorizedTests against the REAL probe); here it stands
        // in verbatim, because the VM must surface it unchanged.
        let hint = "主机以 401 拒绝了这次配对……请输入访问令牌后重试；"
            + "或在主机上设置 ALLOWED_ORIGINS=\(Self.base) 后重启 web-terminal。"
        let recorder = ProbeRecorder(verifyResults: [.failure(.originRejected(hint: hint))])
        let viewModel = makeViewModel(store: InMemoryHostStore(), recorder: recorder)
        viewModel.submitManualURL(Self.base)

        await viewModel.confirmConnect()

        guard case .failed(_, let failure) = viewModel.phase else {
            Issue.record("expected .failed, got \(viewModel.phase)")
            return
        }
        #expect(failure.action == .enterAccessToken)
        // The ambiguity is spelled out: BOTH remedies, since the server answers
        // 401 for a bad token and a rejected Origin alike.
        #expect(failure.message.contains("访问令牌"))
        #expect(failure.message.contains("ALLOWED_ORIGINS=\(Self.base)"))

        viewModel.beginAccessTokenEntry()
        guard case .awaitingToken = viewModel.phase else {
            Issue.record("expected .awaitingToken, got \(viewModel.phase)")
            return
        }
    }

    @Test("非 401 失败不给令牌入口（beginAccessTokenEntry 无副作用）")
    func nonUnauthorizedFailureHasNoTokenEntry() async throws {
        let recorder = ProbeRecorder(verifyResults: [.failure(.timeout)])
        let viewModel = makeViewModel(store: InMemoryHostStore(), recorder: recorder)
        viewModel.submitManualURL(Self.base)
        await viewModel.confirmConnect()

        viewModel.beginAccessTokenEntry()

        guard case .failed(_, let failure) = viewModel.phase else {
            Issue.record("expected .failed, got \(viewModel.phase)")
            return
        }
        #expect(failure.action == .retry)
    }

    // MARK: - Shape validation happens BEFORE any network I/O

    @Test("令牌太短 → 本地就拒（不发 /auth），话术只带长度不带令牌")
    func tooShortTokenIsRejectedLocally() async throws {
        let recorder = ProbeRecorder(verifyResults: [.failure(.originRejected(hint: "401"))])
        let viewModel = await viewModelAtTokenPrompt(recorder: recorder)

        await viewModel.submitAccessToken("short")

        #expect(await recorder.validateCalls.isEmpty)
        let rejection = try #require(viewModel.tokenRejection)
        #expect(rejection.contains("\(5)"))
        #expect(!rejection.contains("short")) // never echo the value
        guard case .awaitingToken = viewModel.phase else {
            Issue.record("expected to stay in .awaitingToken, got \(viewModel.phase)")
            return
        }
    }

    @Test("令牌含非法字符 → 本地就拒，不发 /auth")
    func invalidCharactersRejectedLocally() async throws {
        let recorder = ProbeRecorder(verifyResults: [.failure(.originRejected(hint: "401"))])
        let viewModel = await viewModelAtTokenPrompt(recorder: recorder)

        await viewModel.submitAccessToken("abcdefghijklmnop qrstuv")

        #expect(await recorder.validateCalls.isEmpty)
        #expect(viewModel.tokenRejection?.isEmpty == false)
    }

    // MARK: - The four §1.1 outcomes

    @Test("204+Set-Cookie（valid）→ 带令牌重跑探针，主机连令牌一起入库")
    func validTokenIsSavedWithTheHost() async throws {
        let store = InMemoryHostStore()
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))], // first, unauthenticated
            validateResults: [.success(.valid)]
        )
        let viewModel = await viewModelAtTokenPrompt(store: store, recorder: recorder)

        await viewModel.submitAccessToken(Self.goodToken)

        // The re-verification carried the candidate token (2nd verify call).
        let verifyCalls = await recorder.verifyCalls
        #expect(verifyCalls.count == 2)
        #expect(verifyCalls.first?.token == nil)
        #expect(verifyCalls.last?.token == Self.goodToken)
        // …and the persisted record has it (Keychain in production).
        guard case .paired(let host) = viewModel.phase else {
            Issue.record("expected .paired, got \(viewModel.phase)")
            return
        }
        #expect(host.accessToken?.rawValue == Self.goodToken)
        let stored = try await store.loadAll()
        #expect(stored.count == 1)
        #expect(stored.first?.accessToken?.rawValue == Self.goodToken)
        #expect(try await store.accessToken(host: host.id)?.rawValue == Self.goodToken)
    }

    @Test("204 但没有 Set-Cookie（该主机未启用鉴权）→ 绝不保存令牌，也不声称已认证")
    func authDisabledNeverPersistsAToken() async throws {
        let store = InMemoryHostStore()
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.success(.authDisabled)]
        )
        let viewModel = await viewModelAtTokenPrompt(store: store, recorder: recorder)

        await viewModel.submitAccessToken(Self.goodToken)

        // Still in the prompt, told the truth, and NOTHING was stored.
        guard case .awaitingToken = viewModel.phase else {
            Issue.record("expected .awaitingToken, got \(viewModel.phase)")
            return
        }
        #expect(viewModel.tokenRejection == PairingCopy.tokenNotRequired)
        #expect(try await store.loadAll().isEmpty)
        // No second verification either — re-probing unauthenticated would just
        // reproduce the same failure (the cause is not the token).
        #expect(await recorder.verifyCalls.count == 1)
    }

    @Test("authDisabled 之后即使配对成功也不带令牌入库（候选已被清掉）")
    func authDisabledClearsTheCandidate() async throws {
        let store = InMemoryHostStore()
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.success(.authDisabled)]
        )
        let viewModel = await viewModelAtTokenPrompt(store: store, recorder: recorder)
        await viewModel.submitAccessToken(Self.goodToken)

        // Back to confirm, then a (now succeeding) retry of the whole flow.
        viewModel.cancelAccessTokenEntry()
        await viewModel.confirmConnect()

        guard case .paired(let host) = viewModel.phase else {
            Issue.record("expected .paired, got \(viewModel.phase)")
            return
        }
        #expect(host.accessToken == nil)
        #expect(await recorder.verifyCalls.last?.token == nil)
    }

    @Test("401（令牌错）→ 留在输入态给出「令牌不正确」，不入库")
    func invalidTokenKeepsThePrompt() async throws {
        let store = InMemoryHostStore()
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.success(.invalidToken)]
        )
        let viewModel = await viewModelAtTokenPrompt(store: store, recorder: recorder)

        await viewModel.submitAccessToken(Self.goodToken)

        #expect(viewModel.tokenRejection == PairingCopy.tokenInvalid)
        #expect(try await store.loadAll().isEmpty)
        guard case .awaitingToken = viewModel.phase else {
            Issue.record("expected .awaitingToken, got \(viewModel.phase)")
            return
        }
    }

    @Test("429 → 「稍后再试」话术，不入库")
    func rateLimitedKeepsThePrompt() async throws {
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.success(.rateLimited)]
        )
        let viewModel = await viewModelAtTokenPrompt(recorder: recorder)

        await viewModel.submitAccessToken(Self.goodToken)

        #expect(viewModel.tokenRejection == PairingCopy.tokenRateLimited)
    }

    @Test("/auth 传输失败 → 网络话术（不吞错、不假装令牌错）")
    func transportFailureIsSurfaced() async throws {
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.failure(.unreachable("Connection refused"))]
        )
        let viewModel = await viewModelAtTokenPrompt(recorder: recorder)

        await viewModel.submitAccessToken(Self.goodToken)

        let rejection = try #require(viewModel.tokenRejection)
        #expect(rejection.contains("Connection refused"))
        #expect(rejection != PairingCopy.tokenInvalid)
    }

    // MARK: - Recovering an already-paired host

    @Test("对同一 origin 再配对一次 = 原地更新（复用 id、不重复添加、补上令牌）")
    func repairingSameOriginUpdatesInPlace() async throws {
        // Arrange: a host paired before the server enabled WEBTERM_TOKEN.
        let store = InMemoryHostStore()
        let url = try #require(URL(string: Self.base))
        let endpoint = try #require(HostEndpoint(baseURL: url))
        let existing = HostRegistry.Host(id: UUID(), name: "书房 Mac", endpoint: endpoint)
        _ = try await store.upsert(existing)
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.success(.valid)]
        )
        let viewModel = await viewModelAtTokenPrompt(store: store, recorder: recorder)

        // Act
        await viewModel.submitAccessToken(Self.goodToken)

        // Assert: ONE host, same id (every lastSessionId/watermark keyed by it
        // survives), original name kept, token now present.
        let hosts = try await store.loadAll()
        #expect(hosts.count == 1)
        #expect(hosts.first?.id == existing.id)
        #expect(hosts.first?.name == "书房 Mac")
        #expect(hosts.first?.accessToken?.rawValue == Self.goodToken)
    }

    @Test("原地更新不会因为「用户没改名字」而把主机名覆盖成 IP")
    func repairingKeepsUserChosenName() async throws {
        let store = InMemoryHostStore()
        let url = try #require(URL(string: Self.base))
        let endpoint = try #require(HostEndpoint(baseURL: url))
        _ = try await store.upsert(
            HostRegistry.Host(id: UUID(), name: "书房 Mac", endpoint: endpoint)
        )
        let viewModel = makeViewModel(store: store, recorder: ProbeRecorder())
        viewModel.submitManualURL(Self.base)

        await viewModel.confirmConnect()

        #expect(try await store.loadAll().first?.name == "书房 Mac")
    }

    @Test("重新配对时用户改了名字 → 采用新名字")
    func repairingAdoptsEditedName() async throws {
        let store = InMemoryHostStore()
        let url = try #require(URL(string: Self.base))
        let endpoint = try #require(HostEndpoint(baseURL: url))
        _ = try await store.upsert(
            HostRegistry.Host(id: UUID(), name: "旧名字", endpoint: endpoint)
        )
        let viewModel = makeViewModel(store: store, recorder: ProbeRecorder())
        viewModel.submitManualURL(Self.base)
        viewModel.hostName = "客厅 Mac"

        await viewModel.confirmConnect()

        #expect(try await store.loadAll().first?.name == "客厅 Mac")
    }

    @Test("重新配对（未输新令牌）不会丢掉已保存的令牌")
    func repairingPreservesStoredToken() async throws {
        let store = InMemoryHostStore()
        let url = try #require(URL(string: Self.base))
        let endpoint = try #require(HostEndpoint(baseURL: url))
        let token = try AccessToken(validating: Self.goodToken)
        _ = try await store.upsert(HostRegistry.Host(
            id: UUID(), name: "书房 Mac", endpoint: endpoint, accessToken: token
        ))
        let viewModel = makeViewModel(store: store, recorder: ProbeRecorder())
        viewModel.submitManualURL(Self.base)

        await viewModel.confirmConnect()

        #expect(try await store.loadAll().first?.accessToken == token)
    }

    // MARK: - Secret hygiene

    @Test("取消令牌输入 → 回到确认页，候选令牌被丢弃")
    func cancellingTokenEntryDropsTheCandidate() async throws {
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.success(.valid)]
        )
        let viewModel = await viewModelAtTokenPrompt(recorder: recorder)

        viewModel.cancelAccessTokenEntry()

        guard case .confirming = viewModel.phase else {
            Issue.record("expected .confirming, got \(viewModel.phase)")
            return
        }
        #expect(viewModel.tokenRejection == nil)
        await viewModel.confirmConnect()
        #expect(await recorder.verifyCalls.last?.token == nil)
    }

    @Test("换一个配对目标不会继承上一个目标的令牌")
    func newTargetDoesNotInheritTheToken() async throws {
        let recorder = ProbeRecorder(validateResults: [.success(.valid)])
        let viewModel = makeViewModel(store: InMemoryHostStore(), recorder: recorder)
        viewModel.submitManualURL(Self.base)
        await viewModel.confirmConnect() // succeeds → paired
        // A fresh VM state is what the sheet gives on re-entry; here we assert the
        // reset path itself.
        viewModel.cancel()
        viewModel.submitManualURL("http://192.168.1.9:3000")

        await viewModel.confirmConnect()

        #expect(await recorder.verifyCalls.last?.token == nil)
        #expect(await recorder.verifyCalls.last?.origin == "http://192.168.1.9:3000")
    }

    @Test("令牌绝不出现在任何可观察状态里（阶段/话术/主机描述）")
    func tokenNeverLeaksIntoObservableState() async throws {
        let store = InMemoryHostStore()
        let recorder = ProbeRecorder(
            verifyResults: [.failure(.originRejected(hint: "401"))],
            validateResults: [.success(.valid)]
        )
        let viewModel = await viewModelAtTokenPrompt(store: store, recorder: recorder)

        await viewModel.submitAccessToken(Self.goodToken)

        guard case .paired(let host) = viewModel.phase else {
            Issue.record("expected .paired, got \(viewModel.phase)")
            return
        }
        #expect(!String(describing: viewModel.phase).contains(Self.goodToken))
        #expect(!host.description.contains(Self.goodToken))
        #expect(host.description.contains("hasAccessToken: true")) // presence only
        #expect(viewModel.tokenRejection == nil)
    }
}