import APIClient
import Foundation
import Testing
@testable import WebTerm

/// C2 · 纯呈现层（同步带 / 未推送边界 / 相对时间 / 写失败文案）。
///
/// 真源 `docs/plans/w6-project-git-panel.md` 与 web 参照实现
/// `public/projects.ts:615-745 makeSyncBand` —— 本套用例逐条钉住那份"只有一种
/// 状态可以显示为绿色"的规则（RED 清单 36–47，见 docs/plans/ios-completion.md §4）。
@Suite("GitPanelPresentation")
struct GitPanelPresentationTests {
    /// 固定"现在"：2026-07-30T12:00:00Z 的毫秒值，避免用例依赖真实时钟。
    private static let nowMs: Double = 1_785_412_800_000

    private static func minutesAgo(_ minutes: Double) -> Double {
        nowMs - minutes * 60 * 1000
    }

    // MARK: - 同步带（RED 36–43）

    @Test("非 git 目录（sync == nil）→ 无同步带")
    func nonGitHasNoBand() {
        #expect(GitSyncBand.make(sync: nil, dirtyCount: nil, nowMs: Self.nowMs) == nil)
    }

    @Test("↑0 ↓0 + 新鲜 fetch → 唯一允许的「已同步」绿色态")
    func inSyncNeedsFreshFetch() throws {
        let band = try #require(GitSyncBand.make(
            sync: SyncState(
                upstream: "origin/develop", ahead: 0, behind: 0,
                lastFetchMs: Self.minutesAgo(5)
            ),
            dirtyCount: 0, nowMs: Self.nowMs
        ))

        #expect(band.isInSync)
        #expect(band.isBehindVerified)
        #expect(band.canFetch)
        #expect(band.head == .tracking(
            upstream: "origin/develop", ahead: 0, behind: 0
        ))
    }

    @Test("↑0 ↓0 但 fetch 已过期（> FETCH_STALE_MS）→ 不绿，↓ 未核实")
    func staleFetchIsNeverGreen() throws {
        let band = try #require(GitSyncBand.make(
            sync: SyncState(
                upstream: "origin/develop", ahead: 0, behind: 0,
                lastFetchMs: Self.minutesAgo(61)
            ),
            dirtyCount: 0, nowMs: Self.nowMs
        ))

        #expect(!band.isInSync)
        #expect(!band.isBehindVerified)
    }

    @Test("FETCH_STALE_MS 就是 1 小时（镜像 public/projects.ts:615）")
    func staleThresholdMatchesWeb() {
        #expect(GitSyncBand.fetchStaleMs == 60 * 60 * 1000)
    }

    @Test("从未 fetch（lastFetchMs == nil）→ 视为过期，不绿")
    func neverFetchedIsStale() throws {
        let band = try #require(GitSyncBand.make(
            sync: SyncState(upstream: "origin/develop", ahead: 0, behind: 0, lastFetchMs: nil),
            dirtyCount: 0, nowMs: Self.nowMs
        ))

        #expect(!band.isInSync)
        #expect(!band.isBehindVerified)
    }

    @Test("无上游 → 「无上游」，没有 ↑↓，绝不绿（最易犯的 bug）")
    func noUpstreamIsNeverGreen() throws {
        let band = try #require(GitSyncBand.make(
            sync: SyncState(upstream: nil, ahead: nil, behind: nil, lastFetchMs: Self.nowMs),
            dirtyCount: 0, nowMs: Self.nowMs
        ))

        #expect(band.head == .noUpstream)
        #expect(!band.isInSync)
        #expect(band.canFetch)
    }

    @Test("分离 HEAD → 「分离 HEAD」，fetch 禁用，无 ↑↓")
    func detachedDisablesFetch() throws {
        let band = try #require(GitSyncBand.make(
            sync: SyncState(upstream: nil, ahead: nil, behind: nil, lastFetchMs: nil, detached: true),
            dirtyCount: nil, nowMs: Self.nowMs
        ))

        #expect(band.head == .detached)
        #expect(!band.canFetch)
        #expect(!band.isInSync)
    }

    @Test("ahead 读不到（nil）→ 保留 nil（渲染 ↑ —），且不绿")
    func unknownAheadIsNotZero() throws {
        let band = try #require(GitSyncBand.make(
            sync: SyncState(
                upstream: "origin/develop", ahead: nil, behind: 0,
                lastFetchMs: Self.minutesAgo(1)
            ),
            dirtyCount: 0, nowMs: Self.nowMs
        ))

        #expect(band.head == .tracking(upstream: "origin/develop", ahead: nil, behind: 0))
        #expect(!band.isInSync)
    }

    @Test(
        "dirtyCount：nil → 未检查（不是 clean）、0 → clean、3 → changed(3)",
        arguments: [
            (Int?.none, GitSyncBand.Dirty.unknown),
            (Int?(0), GitSyncBand.Dirty.clean),
            (Int?(3), GitSyncBand.Dirty.changed(3)),
        ] as [(Int?, GitSyncBand.Dirty)]
    )
    func dirtyTriState(dirtyCount: Int?, expected: GitSyncBand.Dirty) throws {
        let band = try #require(GitSyncBand.make(
            sync: SyncState(upstream: "origin/x", ahead: 0, behind: 0, lastFetchMs: Self.nowMs),
            dirtyCount: dirtyCount, nowMs: Self.nowMs
        ))

        #expect(band.dirty == expected)
    }

    // MARK: - 未推送边界（RED 44–46）

    @Test("边界画在最后一个 unpushed 之后，且只画一次")
    func boundaryAfterLastUnpushed() {
        let commits = [
            CommitLogEntry(hash: "aaa", at: 3, subject: "c", unpushed: true),
            CommitLogEntry(hash: "bbb", at: 2, subject: "b", unpushed: true),
            CommitLogEntry(hash: "ccc", at: 1, subject: "a", unpushed: false),
        ]

        #expect(GitLogBoundary.index(commits: commits, upstream: "origin/develop") == 1)
    }

    @Test("unpushed 只在严格 true 时生效（nil ≠ false ≠ true）")
    func nilUnpushedDrawsNoBoundary() {
        let commits = [
            CommitLogEntry(hash: "aaa", at: 2, subject: "c", unpushed: nil),
            CommitLogEntry(hash: "bbb", at: 1, subject: "b", unpushed: false),
        ]

        #expect(GitLogBoundary.index(commits: commits, upstream: "origin/develop") == nil)
    }

    @Test("无上游 → 完全不画边界（没有可比对的东西）")
    func noUpstreamDrawsNoBoundary() {
        let commits = [CommitLogEntry(hash: "aaa", at: 1, subject: "c", unpushed: true)]

        #expect(GitLogBoundary.index(commits: commits, upstream: nil) == nil)
    }

    @Test("未推送提交排在已推送之下（老日期 merge）→ 边界仍在最后一个 unpushed 之后")
    func interleavedUnpushedStillBounds() {
        let commits = [
            CommitLogEntry(hash: "aaa", at: 5, subject: "new pushed", unpushed: false),
            CommitLogEntry(hash: "bbb", at: 4, subject: "merge of old branch", unpushed: true),
            CommitLogEntry(hash: "ccc", at: 3, subject: "older pushed", unpushed: false),
        ]

        #expect(GitLogBoundary.index(commits: commits, upstream: "origin/develop") == 1)
    }

    // MARK: - 相对时间

    @Test(
        "相对时间：秒/分/时/天各档非空且互不相同",
        arguments: [0.5, 5, 90, 60 * 26] as [Double]
    )
    func relativeTimeBuckets(minutes: Double) {
        let label = GitTimeFormat.relative(fromMs: Self.minutesAgo(minutes), nowMs: Self.nowMs)

        #expect(!label.isEmpty)
    }

    @Test("未来时间戳（主机时钟漂移）→ 退化为「刚刚」，不出现负数")
    func futureTimestampDegrades() {
        let label = GitTimeFormat.relative(fromMs: Self.nowMs + 60_000, nowMs: Self.nowMs)

        #expect(!label.contains("-"))
    }

    // MARK: - 写失败文案（RED 47）

    @Test("服务器安全文案原样显示（绝不吞、绝不自造）")
    func serverMessageIsSurfacedVerbatim() {
        let text = GitWriteFeedback.message(
            status: 409, serverMessage: "Nothing staged to commit.", fallback: "兜底"
        )

        #expect(text.contains("Nothing staged to commit."))
    }

    @Test("服务器没给 message → 兜底中文文案（非空）")
    func missingServerMessageFallsBack() {
        let text = GitWriteFeedback.message(status: 500, serverMessage: nil, fallback: "提交失败")

        #expect(!text.isEmpty)
        #expect(text.contains("提交失败"))
    }

    @Test("抛出的 APIClientError → 其自带话术（.unauthorized 引导补令牌）")
    func thrownAPIErrorUsesItsOwnCopy() {
        let text = GitWriteFeedback.message(for: APIClientError.unauthorized, fallback: "兜底")

        #expect(text == APIClientError.unauthorized.message)
    }

    @Test("非 APIClientError（传输层）→ 兜底文案，不 crash")
    func transportErrorFallsBack() {
        let text = GitWriteFeedback.message(
            for: URLError(.notConnectedToInternet), fallback: "推送失败"
        )

        #expect(text.contains("推送失败"))
    }
}