namespace LivingVillage.Desktop.Tests

open Microsoft.VisualStudio.TestTools.UnitTesting
open LivingVillage.Kernel
open LivingVillage.Kernel.Sim
open LivingVillage.Desktop
open LivingVillage.Desktop.VillagePresentation

/// P36：情境提示系统契约回归。覆盖距离边界、目标切换、离开消失、隔墙不触发、
/// 对话层输入隔离、提示对象与按键对象一致、布局不遮挡、Esc 关闭当前层、保存反馈。
[<TestClass>]
type P36PromptTests () =

    let atPosition (x: float32) (y: float32) (world: World) : World =
        { world with Avatar = { world.Avatar with Pos = ({ X = x; Y = y } : Vec2) } }

    /// 把所有村民先移到远处，再按给定位置摆放，隔离出唯一候选目标。
    let withNpcsAt (positions: (int * Vec2) list) (world: World) : World =
        let npcs = Array.copy world.Npcs
        for index in 0 .. npcs.Length - 1 do
            npcs.[index] <- { npcs.[index] with Pos = ({ X = 4000.0f; Y = 4000.0f } : Vec2) }
        for (index, position) in positions do
            npcs.[index] <- { npcs.[index] with Pos = position }
        { world with Npcs = npcs }

    let actionText (action: InteractionAction) : string =
        match action with
        | TalkTo _ -> "E 交谈"
        | EnterHome _ -> "E 进屋"
        | ExitHome _ -> "E 出屋"

    let doorCenter : Vec2 =
        { X = float32 (31 * Sim.tilePixels + Sim.tilePixels / 2)
          Y = float32 (23 * Sim.tilePixels + Sim.tilePixels / 2) }

    [<TestMethod>]
    member _.PromptAppearsOnlyInsideInteractionRangeAtBoundary () =
        let baseWorld = Sim.initialWorldN 42UL 4 |> withNpcsAt []
        let avatar : Vec2 = { X = 1600.0f; Y = 800.0f }
        let atBoundary =
            baseWorld
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt [ 0, { X = avatar.X + Sim.chatRangePx; Y = avatar.Y } ]
        let beyond =
            baseWorld
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt [ 0, { X = avatar.X + Sim.chatRangePx + 0.5f; Y = avatar.Y } ]

        Assert.AreEqual<InteractionAction option>(
            Some(TalkTo(NpcId 0)),
            InteractionResolver.resolve atBoundary Outside |> Option.map (fun target -> target.Action))
        Assert.AreEqual<InteractionAction option>(
            None,
            InteractionResolver.resolve beyond Outside |> Option.map (fun target -> target.Action))

    [<TestMethod>]
    member _.PromptSwitchesToTheNearestReachableTargetDeterministically () =
        let baseWorld = Sim.initialWorldN 42UL 4
        let avatar : Vec2 = { X = 1600.0f; Y = 800.0f }
        let competing =
            baseWorld
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt
                [ 0, { X = avatar.X + 72.0f; Y = avatar.Y }
                  1, { X = avatar.X + 48.0f; Y = avatar.Y } ]

        Assert.AreEqual<InteractionAction option>(
            Some(TalkTo(NpcId 1)),
            InteractionResolver.resolve competing Outside |> Option.map (fun target -> target.Action))

        // 走近后最近目标切换为 0 号，仍然一帧只选一个。
        let switched = competing |> atPosition (avatar.X + 64.0f) avatar.Y
        Assert.AreEqual<InteractionAction option>(
            Some(TalkTo(NpcId 0)),
            InteractionResolver.resolve switched Outside |> Option.map (fun target -> target.Action))

    [<TestMethod>]
    member _.PromptDisappearsImmediatelyAfterLeavingRange () =
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition 1600.0f 800.0f
            |> withNpcsAt [ 0, { X = 1632.0f; Y = 800.0f } ]
        let view = M5Interaction.refreshPrompt world M5Interaction.initial
        Assert.AreEqual<string option>(Some "E 交谈", view.Prompt)
        Assert.IsTrue(view.PromptTargetPos.IsSome)

        let left = world |> atPosition 2400.0f 1600.0f
        let cleared = M5Interaction.refreshPrompt left view
        Assert.AreEqual<string option>(None, cleared.Prompt)
        Assert.AreEqual<Vec2 option>(None, cleared.PromptTargetPos)

    [<TestMethod>]
    member _.PromptNeverTriggersThroughAWall () =
        // 民居西墙世界瓦片 (31,22)；玩家在墙东侧紧邻，村民在墙后，水平距离在交谈范围内，
        // 但视线被墙体挡住 -> 不得触发。
        let wallAvatar : Vec2 =
            { X = float32 (32 * Sim.tilePixels + Sim.tilePixels / 2)
              Y = float32 (22 * Sim.tilePixels + Sim.tilePixels / 2) }
        let wallNpc : Vec2 =
            { X = float32 (31 * Sim.tilePixels + Sim.tilePixels / 2)
              Y = float32 (22 * Sim.tilePixels + Sim.tilePixels / 2) }
        let world =
            Sim.initialWorldN 42UL 1
            |> atPosition wallAvatar.X wallAvatar.Y
            |> withNpcsAt [ 0, wallNpc ]

        Assert.IsTrue(InteractionResolver.hasClearPath wallAvatar wallNpc |> not)
        Assert.AreEqual<InteractionAction option>(
            None,
            InteractionResolver.resolve world Outside |> Option.map (fun target -> target.Action))
        Assert.AreEqual<string option>(None, (M5Interaction.refreshPrompt world M5Interaction.initial).Prompt)

    [<TestMethod>]
    member _.OpenDialogueLayerIsolatesWorldInteractionCommands () =
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition 1600.0f 800.0f
            |> withNpcsAt [ 0, { X = 1632.0f; Y = 800.0f } ]
        let dialogueView =
            { M5Interaction.initial with
                Panel = DialoguePanel
                Menu = Some { Target = NpcId 0; Options = Sim.dialogueOptions } }

        Assert.IsFalse(M5Interaction.worldInputAllowed dialogueView)

        // E（Interact）在对白层打开时不得穿透重开/改选目标。
        let interactWorld, interactView = M5Interaction.apply Interact world dialogueView
        Assert.AreEqual<World>(world, interactWorld)
        Assert.AreEqual<M5Panel>(DialoguePanel, interactView.Panel)
        Assert.IsTrue(interactView.Menu.IsSome)

        // Q（Observe）同样被隔离。
        let observeWorld, observeView = M5Interaction.apply Observe world dialogueView
        Assert.AreEqual<World>(world, observeWorld)
        Assert.AreEqual<M5Panel>(DialoguePanel, observeView.Panel)
        Assert.AreEqual<Observation list>([], observeView.Observations)

    [<TestMethod>]
    member _.PromptObjectAlwaysMatchesTheInteractTarget () =
        // 村民：提示文本与 resolve 的动作一致，按 E 后菜单目标是同一村民。
        let npcWorld =
            Sim.initialWorldN 42UL 4
            |> atPosition 1600.0f 800.0f
            |> withNpcsAt [ 0, { X = 1632.0f; Y = 800.0f } ]
        let npcTarget = InteractionResolver.resolve npcWorld Outside
        Assert.IsTrue(npcTarget.IsSome)
        Assert.AreEqual<string>(actionText npcTarget.Value.Action, npcTarget.Value.Text)
        let npcView = M5Interaction.refreshPrompt npcWorld M5Interaction.initial
        Assert.AreEqual<string option>(Some npcTarget.Value.Text, npcView.Prompt)
        let _, npcInteracted = M5Interaction.apply Interact npcWorld M5Interaction.initial
        Assert.AreEqual<M5Panel>(DialoguePanel, npcInteracted.Panel)
        Assert.AreEqual<NpcId>(NpcId 0, npcInteracted.Menu.Value.Target)

        // 民居门：提示 "E 进屋"，按 E 后进入同一民居。
        let doorWorld =
            Sim.initialWorldN 42UL 4
            |> withNpcsAt []
            |> atPosition doorCenter.X doorCenter.Y
        let doorTarget = InteractionResolver.resolve doorWorld Outside
        Assert.IsTrue(doorTarget.IsSome)
        Assert.AreEqual<string>("E 进屋", doorTarget.Value.Text)
        Assert.AreEqual<string>(actionText doorTarget.Value.Action, doorTarget.Value.Text)
        let _, doorInteracted = M5Interaction.apply Interact doorWorld M5Interaction.initial
        Assert.AreEqual<HomeMode>(Inside(HomeId 1), doorInteracted.HomeMode)

    [<TestMethod>]
    member _.EscapeClosesTheCurrentLayerBackToWorld () =
        let world = Sim.initialWorldN 42UL 0
        for panel in [ DialoguePanel; NeedsPanel; ObservationPanel; ChroniclePanel; TaskPanel ] do
            let view = { M5Interaction.initial with Panel = panel }
            let _, closed = M5Interaction.apply ClosePanel world view
            Assert.IsTrue(closed.Panel = WorldPanel, sprintf "Esc 应关闭面板 %A" panel)
            Assert.IsTrue(closed.Menu.IsNone, sprintf "关闭 %A 后应清空菜单" panel)

    [<TestMethod>]
    member _.PauseHelpAndControlsPageReturnToThePreviousLayerOnEscape () =
        let control = SimulationControl.initial
        let playing = MenuState.create control true |> MenuState.enterGame
        let helpState, paused = MenuState.enterPauseHelp control playing
        Assert.AreEqual<MenuPage>(Controls, helpState.Page)
        Assert.IsTrue(paused.Paused)
        Assert.AreEqual<MenuPage>(Playing, helpState.ReturnPage)

        let returnedState, restored = MenuState.exitPauseHelp control helpState
        Assert.AreEqual<MenuPage>(Playing, returnedState.Page)
        Assert.IsFalse(restored.Paused)

        let backState, _ = MenuState.update Back helpState
        Assert.AreEqual<MenuPage>(Playing, backState.Page)

    [<TestMethod>]
    member _.SaveFeedbackUsesATransientChineseToast () =
        let success =
            { M5Interaction.initial with
                Status = "save succeeded"
                StatusTick = Some 100L }
        Assert.AreEqual<string>("保存成功", M5Interaction.statusText success)
        Assert.AreEqual<string option>(Some "保存成功", M5Interaction.transientStatusLine 180L success)
        Assert.AreEqual<string option>(
            None,
            M5Interaction.transientStatusLine (100L + M5Interaction.statusDisplayDurationTicks) success)

        let failed =
            { M5Interaction.initial with
                Status = "save failed"
                StatusTick = Some 100L }
        Assert.AreEqual<string>("保存失败", M5Interaction.statusText failed)
        Assert.AreEqual<string option>(Some "保存失败", M5Interaction.transientStatusLine 120L failed)

    [<TestMethod>]
    member _.PromptLayoutFitsSmallAndLargeWindowsWithoutCoveringHud () =
        for (width, height) in [ (800, 600); (1024, 576); (1280, 720); (1920, 1080) ] do
            let anchors : (int * int) list =
                [ (16, 16)
                  (width / 2, height / 2)
                  (width - 40, FloatingPrompt.hudTopBarHeight + 4)
                  (24, height - FloatingPrompt.hudBottomBandHeight - 4)
                  (width - 24, height - 24) ]
            for (anchorX, anchorY) in anchors do
                for text in [ "E 交谈"; "E 进屋"; "E 出屋" ] do
                    let rect =
                        FloatingPrompt.layout width height (float32 anchorX) (float32 anchorY) 0.0f 0.0f 2 text
                    Assert.IsTrue(rect.Width > 0, sprintf "提示宽度被截为 0 (%dx%d)" width height)
                    Assert.IsTrue(
                        rect.X >= 0 && rect.X + rect.Width <= width,
                        sprintf "水平越界 %dx%d anchor=(%d,%d) %A" width height anchorX anchorY rect)
                    Assert.IsTrue(
                        rect.Y >= 0 && rect.Y + rect.Height <= height,
                        sprintf "垂直越界 %dx%d anchor=(%d,%d) %A" width height anchorX anchorY rect)
                    Assert.IsTrue(
                        rect.Y >= FloatingPrompt.hudTopBarHeight,
                        sprintf "遮挡顶部状态条 %dx%d" width height)
                    Assert.IsTrue(
                        rect.Y + rect.Height <= height - FloatingPrompt.hudBottomBandHeight + 8,
                        sprintf "遮挡底部 HUD 带 %dx%d" width height)