namespace LivingVillage.Desktop.Tests

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

/// P53：情境提示与输入隔离回归（brief 第 8 条交互硬要求）。
/// 每个用例都断言**显式目标**（NpcId / HomeId），并把「提示文案」与「实际作用对象」
/// 收敛到同一选择规则：提示写「E 交谈」时按 E 必须作用于同一 Npc。
/// 提示层是瞬时叠加层，绝非常驻面板。
[<TestClass>]
type P53InteractionPromptTests () =

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

    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 avatar : Vec2 = { X = 1600.0f; Y = 800.0f }

    let promptTarget (world: World) : InteractionAction option =
        InteractionResolver.resolve world Outside |> Option.map (fun target -> target.Action)

    let promptText (world: World) : string option =
        (M5Interaction.refreshPrompt world M5Interaction.initial).Prompt

    [<TestMethod>]
    member _.PromptAppearsOnlyInsideRangeWithExplicitTarget () =
        let baseWorld = Sim.initialWorldN 42UL 4 |> withNpcsAt []
        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)), promptTarget atBoundary)
        Assert.AreEqual<string>("E 交谈", (InteractionResolver.resolve atBoundary Outside).Value.Text)
        Assert.AreEqual<string option>(Some "E 交谈", promptText atBoundary)
        Assert.AreEqual<InteractionAction option>(None, promptTarget beyond)
        Assert.AreEqual<string option>(None, promptText beyond)

    [<TestMethod>]
    member _.NearestReachableTargetWinsDeterministicallyAndOnlyOneIsShown () =
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt
                [ 0, { X = avatar.X + 72.0f; Y = avatar.Y }
                  1, { X = avatar.X + 48.0f; Y = avatar.Y }
                  2, { X = avatar.X + 60.0f; Y = avatar.Y } ]

        for _ in 1 .. 5 do
            Assert.AreEqual<InteractionAction option>(Some(TalkTo(NpcId 1)), promptTarget world)
        let view = M5Interaction.refreshPrompt world M5Interaction.initial
        Assert.AreEqual<string option>(Some "E 交谈", view.Prompt)
        // 仅一个高亮：提示目标位置就是被选中的 1 号村民，别处不出现第二个提示。
        Assert.AreEqual<Vec2 option>(Some world.Npcs.[1].Pos, view.PromptTargetPos)

        // 走近远端村民：最近目标切换为 0 号，仍然只选一个。
        let switched = world |> atPosition (avatar.X + 84.0f) avatar.Y
        Assert.AreEqual<InteractionAction option>(Some(TalkTo(NpcId 0)), promptTarget switched)

    [<TestMethod>]
    member _.EqualDistanceTieBreaksByStableId () =
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt
                [ 0, { X = avatar.X + 40.0f; Y = avatar.Y }
                  1, { X = avatar.X; Y = avatar.Y + 40.0f } ]
        // 两个候选与玩家的距离平方相同（1600），稳定按 NpcId 升序取 0 号。
        Assert.AreEqual<InteractionAction option>(Some(TalkTo(NpcId 0)), promptTarget world)

    [<TestMethod>]
    member _.PromptDisappearsImmediatelyAfterLeavingWithExplicitNone () =
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt [ 0, { X = avatar.X + 32.0f; Y = avatar.Y } ]
        let shown = M5Interaction.refreshPrompt world M5Interaction.initial
        Assert.AreEqual<string option>(Some "E 交谈", shown.Prompt)
        Assert.IsTrue(shown.PromptTargetPos.IsSome)

        let left = world |> atPosition 3200.0f 2400.0f
        Assert.AreEqual<InteractionAction option>(None, promptTarget left)
        let cleared = M5Interaction.refreshPrompt left shown
        Assert.AreEqual<string option>(None, cleared.Prompt)
        Assert.AreEqual<Vec2 option>(None, cleared.PromptTargetPos)

    [<TestMethod>]
    member _.WallBlocksBothThePromptAndTheInteraction () =
        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.IsFalse(InteractionResolver.hasClearPath wallAvatar wallNpc)
        Assert.AreEqual<InteractionAction option>(None, promptTarget world)
        Assert.AreEqual<string option>(None, promptText world)

        // 隔墙时按 E 不产生世界副作用，面板停在世界层。
        let nextWorld, nextView = M5Interaction.apply Interact world M5Interaction.initial
        Assert.AreEqual<World>(world, nextWorld)
        Assert.AreEqual<M5Panel>(WorldPanel, nextView.Panel)

    [<TestMethod>]
    member _.OpenLayersIsolateWorldInteractionAndClearThePrompt () =
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt [ 0, { X = avatar.X + 32.0f; Y = avatar.Y } ]
        let panels = [ DialoguePanel; NeedsPanel; ObservationPanel; ChroniclePanel; TaskPanel ]
        for panel in panels do
            let view =
                { M5Interaction.initial with
                    Panel = panel
                    Menu = (if panel = DialoguePanel then Some { Target = NpcId 0; Options = Sim.dialogueOptions } else None) }
            Assert.IsFalse(M5Interaction.worldInputAllowed view, sprintf "%A 不得放行世界输入" panel)
            let nextWorld, nextView = M5Interaction.apply Interact world view
            Assert.AreEqual<World>(world, nextWorld)
            Assert.IsTrue((panel = nextView.Panel), sprintf "%A 开启时 Interact 不得改选目标" panel)
            Assert.AreEqual<string option>(None, (M5Interaction.refreshPrompt world view).Prompt)
        // 世界层里非对话面板命令不得误开对话；买卖键只在对话层生效。
        let worldLayer = M5Interaction.initial
        Assert.IsFalse(M5Interaction.worldInputAllowed { worldLayer with Panel = TaskPanel })
        let _, bought = M5Interaction.apply BuyFromTarget world worldLayer
        Assert.AreEqual<string option>(None, bought.Menu |> Option.map (fun m -> m.Target.ToString()))

    [<TestMethod>]
    member _.EscapeClosesTheCurrentLayerAndRecomputesTheWorldPrompt () =
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt [ 0, { X = avatar.X + 32.0f; Y = avatar.Y } ]
        for panel in [ DialoguePanel; NeedsPanel; ObservationPanel; ChroniclePanel; TaskPanel ] do
            let view =
                { M5Interaction.initial with
                    Panel = panel
                    Menu = (if panel = DialoguePanel then Some { Target = NpcId 0; Options = Sim.dialogueOptions } else None) }
            let _, closed = M5Interaction.apply ClosePanel world view
            Assert.IsTrue((closed.Panel = WorldPanel), sprintf "Esc 应关闭 %A" panel)
            Assert.IsTrue(closed.Menu.IsNone, sprintf "关闭 %A 后应清空菜单" panel)
            Assert.AreEqual<string option>(Some "E 交谈", closed.Prompt)

    [<TestMethod>]
    member _.PromptTextAlwaysMatchesTheActedTarget () =
        // 文案映射唯一来源。
        Assert.AreEqual<string>("E 交谈", InteractionResolver.actionText (TalkTo(NpcId 0)))
        Assert.AreEqual<string>("E 进屋", InteractionResolver.actionText (EnterHome(HomeId 1)))
        Assert.AreEqual<string>("E 出屋", InteractionResolver.actionText (ExitHome(HomeId 1)))

        // 多候选中提示 1 号村民 → 按 E 必须作用于同一 1 号村民。
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt
                [ 0, { X = avatar.X + 72.0f; Y = avatar.Y }
                  1, { X = avatar.X + 40.0f; Y = avatar.Y } ]
        let target = InteractionResolver.resolve world Outside
        Assert.AreEqual<InteractionAction option>(Some(TalkTo(NpcId 1)), target |> Option.map (fun t -> t.Action))
        Assert.AreEqual<string>(InteractionResolver.actionText target.Value.Action, target.Value.Text)
        let view = M5Interaction.refreshPrompt world M5Interaction.initial
        Assert.AreEqual<string option>(Some target.Value.Text, view.Prompt)
        Assert.AreEqual<Vec2 option>(Some world.Npcs.[1].Pos, view.PromptTargetPos)

        let _, interacted = M5Interaction.apply Interact world M5Interaction.initial
        Assert.AreEqual<M5Panel>(DialoguePanel, interacted.Panel)
        Assert.AreEqual<NpcId>(NpcId 1, interacted.Menu.Value.Target)

    [<TestMethod>]
    member _.PromptLayerIsTransientNotAPersistentPanel () =
        // 初始世界层无提示、无面板；靠近只补一条瞬时提示，不新开面板。
        Assert.AreEqual<M5Panel>(WorldPanel, M5Interaction.initial.Panel)
        Assert.AreEqual<string option>(None, M5Interaction.initial.Prompt)
        let world =
            Sim.initialWorldN 42UL 4
            |> atPosition avatar.X avatar.Y
            |> withNpcsAt [ 0, { X = avatar.X + 32.0f; Y = avatar.Y } ]
        let shown = M5Interaction.refreshPrompt world M5Interaction.initial
        Assert.AreEqual<M5Panel>(WorldPanel, shown.Panel)
        Assert.IsTrue(shown.Menu.IsNone)
        // 面板一旦开启，提示立即消失，且刷新多帧都保持无提示（非常驻）。
        let opened = { shown with Panel = TaskPanel }
        for _ in 1 .. 5 do
            let refreshed = M5Interaction.refreshPrompt world opened
            Assert.AreEqual<string option>(None, refreshed.Prompt)