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

/// F1 · 令牌门主机上的缩略图管线。
///
/// 缺口：`SessionThumbnailPipeline.live()` 自建了一个**没有令牌源**的
/// `URLSessionHTTPTransport`，于是在开了 `WEBTERM_TOKEN` 的主机上
/// `GET /live-sessions/:id/preview` 一律 401；而本管线按设计**永不抛错**
/// （失败即占位图），401 就被静默降级成「每一张缩略图都是占位符」，
/// 屏幕上没有任何原因可查。
///
/// 这里钉三件事：
/// 1. 令牌真的到了 preview 请求头上（走的是**生产的**盖章代码路径
///    `URLSessionHTTPTransport.authenticated`，不是测试里重写一遍）；
/// 2. 只读纪律零回归 —— preview 是 RO，**绝不**带 `Origin`（Origin-iff-G）；
/// 3. 没有令牌 / 令牌不对（401）时依旧**优雅降级**成占位图，不崩不抛。
@MainActor
@Suite("SessionThumbnail 令牌接线")
struct SessionThumbnailTokenTests {
    /// 32 个合法字符（§1.1 字符集 `[A-Za-z0-9._~+/=-]`，长度 16–512）。
    private static let token = "0123456789abcdefghijklmnopqrstuv"
    private static let base = "http://192.168.1.20:3000"

    // MARK: - Fixtures

    /// 生产的盖章逻辑（`URLSessionHTTPTransport.authenticated`）串在一个可脚本化
    /// 的记录器前面：真实 Cookie 代码路径，零网络。
    private struct StampingTransport: HTTPTransport {
        let stamper: URLSessionHTTPTransport
        let recorder: FakeHTTPTransport

        func send(_ request: URLRequest) async throws -> (Data, HTTPURLResponse) {
            try await recorder.send(await stamper.authenticated(request))
        }
    }

    private func makeEndpoint(_ base: String = SessionThumbnailTokenTests.base) throws
        -> HostEndpoint {
        let url = try #require(URL(string: base))
        return try #require(HostEndpoint(baseURL: url))
    }

    private func makeStore(token: String?) async throws -> InMemoryHostStore {
        let store = InMemoryHostStore()
        _ = try await store.upsert(
            HostRegistry.Host(
                id: UUID(), name: "mac", endpoint: try makeEndpoint(),
                accessToken: try token.map { try AccessToken(validating: $0) }
            )
        )
        return store
    }

    private func previewURL(_ sessionId: UUID) throws -> URL {
        try #require(
            URL(string: "\(Self.base)/live-sessions/\(sessionId.uuidString.lowercased())/preview")
        )
    }

    private func previewBody(_ sessionId: UUID) throws -> Data {
        try #require("""
        {"id":"\(sessionId.uuidString.lowercased())","cols":80,"rows":24,"data":"hello"}
        """.data(using: .utf8))
    }

    /// 装配一条**默认生产形状**的管线，只把网络出口换成记录器。
    private func makePipeline(
        store: any HostStore
    ) -> (pipeline: SessionThumbnailPipeline, recorder: FakeHTTPTransport) {
        let recorder = FakeHTTPTransport()
        let transport = StampingTransport(
            stamper: AppEnvironment.thumbnailTransport(
                hostStore: store, identityProvider: { nil }
            ),
            recorder: recorder
        )
        return (SessionThumbnailPipeline.live(http: transport), recorder)
    }

    // MARK: - 令牌门主机

    @Test("令牌门主机：preview 请求带上 Cookie: webterm_auth=<t>，且缩略图真渲染出来")
    func previewRequestCarriesTheAccessTokenCookie() async throws {
        // Arrange
        let sessionId = UUID()
        let (pipeline, recorder) = makePipeline(store: try await makeStore(token: Self.token))
        await recorder.queueSuccess(
            url: try previewURL(sessionId), body: try previewBody(sessionId)
        )

        // Act
        let image = await pipeline.thumbnail(
            for: SessionThumbnailRequest(
                endpoint: try makeEndpoint(), sessionId: sessionId, lastOutputAt: 1
            )
        )

        // Assert
        let requests = await recorder.recordedRequests
        #expect(requests.count == 1)
        #expect(requests.first?.value(forHTTPHeaderField: AccessTokenCookie.header)
            == "\(AccessTokenCookie.name)=\(Self.token)")
        #expect(!image.isPlaceholder, "带上令牌后 preview 应当成功并渲染")
    }

    @Test("preview 是只读路由：带令牌也绝不带 Origin（Origin-iff-G 零回归）")
    func previewStaysOriginFree() async throws {
        // Arrange
        let sessionId = UUID()
        let (pipeline, recorder) = makePipeline(store: try await makeStore(token: Self.token))
        await recorder.queueSuccess(
            url: try previewURL(sessionId), body: try previewBody(sessionId)
        )

        // Act
        _ = await pipeline.thumbnail(
            for: SessionThumbnailRequest(
                endpoint: try makeEndpoint(), sessionId: sessionId, lastOutputAt: 1
            )
        )

        // Assert
        let requests = await recorder.recordedRequests
        #expect(requests.first?.value(forHTTPHeaderField: "Origin") == nil)
    }

    // MARK: - 无令牌 / 令牌不对

    @Test("主机没有令牌 → 请求逐字不带 Cookie（LAN 零配置主机零回归）")
    func tokenlessHostSendsNoCookie() async throws {
        // Arrange
        let sessionId = UUID()
        let (pipeline, recorder) = makePipeline(store: try await makeStore(token: nil))
        await recorder.queueSuccess(
            url: try previewURL(sessionId), body: try previewBody(sessionId)
        )

        // Act
        let image = await pipeline.thumbnail(
            for: SessionThumbnailRequest(
                endpoint: try makeEndpoint(), sessionId: sessionId, lastOutputAt: 1
            )
        )

        // Assert
        let requests = await recorder.recordedRequests
        #expect(requests.first?.value(forHTTPHeaderField: AccessTokenCookie.header) == nil)
        #expect(!image.isPlaceholder)
    }

    @Test("令牌缺失导致 401 → 降级成占位图，不崩不抛（管线的错误 UI 就是占位图）")
    func unauthorizedDegradesToPlaceholder() async throws {
        // Arrange：主机记录里没有令牌，服务器要求令牌 → 401。
        let sessionId = UUID()
        let (pipeline, recorder) = makePipeline(store: try await makeStore(token: nil))
        await recorder.queueSuccess(
            url: try previewURL(sessionId), status: 401,
            body: try #require(#"{"error":"unauthorized"}"#.data(using: .utf8))
        )

        // Act
        let image = await pipeline.thumbnail(
            for: SessionThumbnailRequest(
                endpoint: try makeEndpoint(), sessionId: sessionId, lastOutputAt: 1
            )
        )

        // Assert
        #expect(image == .placeholder)
        #expect(await recorder.recordedRequests.count == 1)
    }

    @Test("主机根本不在存储里（存储读不到该 origin）→ 无 Cookie，仍不崩")
    func unknownOriginDegradesGracefully() async throws {
        // Arrange：存储里是另一台主机。
        let sessionId = UUID()
        let store = InMemoryHostStore()
        let otherEndpoint = try makeEndpoint("http://192.168.1.99:3000")
        _ = try await store.upsert(
            HostRegistry.Host(
                id: UUID(), name: "other", endpoint: otherEndpoint,
                accessToken: try AccessToken(validating: Self.token)
            )
        )
        let (pipeline, recorder) = makePipeline(store: store)
        await recorder.queueSuccess(
            url: try previewURL(sessionId), body: try previewBody(sessionId)
        )

        // Act
        let image = await pipeline.thumbnail(
            for: SessionThumbnailRequest(
                endpoint: try makeEndpoint(), sessionId: sessionId, lastOutputAt: 1
            )
        )

        // Assert：绝不把别台主机的令牌发出去。
        let requests = await recorder.recordedRequests
        #expect(requests.first?.value(forHTTPHeaderField: AccessTokenCookie.header) == nil)
        #expect(!image.isPlaceholder)
    }

    // MARK: - 组合根装配本身

    @Test("thumbnailTransport 就是 App 的同一条盖章传输（按 origin 取本主机令牌）")
    func thumbnailTransportStampsPerOrigin() async throws {
        // Arrange
        let transport = AppEnvironment.thumbnailTransport(
            hostStore: try await makeStore(token: Self.token), identityProvider: { nil }
        )
        let mine = URLRequest(url: try previewURL(UUID()))
        let other = URLRequest(
            url: try #require(URL(string: "http://192.168.1.99:3000/live-sessions"))
        )

        // Act
        let stamped = await transport.authenticated(mine)
        let untouched = await transport.authenticated(other)

        // Assert
        #expect(stamped.value(forHTTPHeaderField: AccessTokenCookie.header)
            == "\(AccessTokenCookie.name)=\(Self.token)")
        #expect(untouched.value(forHTTPHeaderField: AccessTokenCookie.header) == nil)
    }
}