namespace LivingVillage.Desktop.Tests

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

[<TestClass>]
type SampleTests () =

    let areEqual (expected: 'T) (actual: 'T) = Assert.AreEqual<'T>(expected, actual)

    let freshWorld () = WorldBootstrap.initialWorld 42UL Sim.npcCount

    let freshView (world: World) = M5Interaction.refreshPrompt world M5Interaction.initial

    let driveUntil (maxFrames: int) (stop: SampleScript.SampleState -> bool) =
        let mutable world = freshWorld ()
        let mutable view = freshView world
        let mutable state = SampleScript.initial
        let mutable frames = 0
        while frames < maxFrames && not (stop state) do
            let nextWorld, nextView, nextState = SampleScript.runFrame world view state
            world <- nextWorld
            view <- nextView
            state <- nextState
            frames <- frames + 1
        world, view, state, frames

    [<TestMethod>]
    member _.SampleScriptStartsWalkingTowardHomeDoor () =
        let spawnWorld = freshWorld ()
        let movedWorld =
            List.fold (fun w _ -> Sim.step { Input = { MoveX = -1.0f; MoveY = 0.0f } } w) spawnWorld [ 1..12 ]
        let view = freshView movedWorld
        let state, action = SampleScript.step movedWorld view SampleScript.initial
        areEqual SampleScript.ApproachDoor state.Stage
        match action with
        | SampleScript.MoveTo target -> areEqual SampleScript.doorWorldCenter target
        | other -> Assert.Fail(sprintf "expected MoveTo toward the door, got %A" other)

    [<TestMethod>]
    member _.SampleScriptEntersTheHomeThroughTheDoor () =
        let _world, view, state, frames = driveUntil 2400 (fun s -> s.Stage = SampleScript.InspectInterior)
        Assert.IsTrue(
            frames < 2400,
            sprintf "home entry never confirmed; stage=%A frames=%d" state.Stage frames)
        areEqual (Inside (HomeId 1)) view.HomeMode

    [<TestMethod>]
    member _.SampleScriptCompletesTheVillageTourWithADialogue () =
        let _world, view, state, frames =
            driveUntil 22000 (fun s -> s.Stage = SampleScript.SampleComplete)
        areEqual SampleScript.SampleComplete state.Stage
        Assert.IsFalse(state.TimedOut, sprintf "tour timed out; stage=%A frames=%d" state.Stage frames)
        Assert.IsTrue(state.DialogueTarget.IsSome, "no dialogue was opened during the tour")
        areEqual Outside view.HomeMode
        areEqual WorldPanel view.Panel