module SomhairlesDream.Server.Tests.ApiTests

open System
open System.IO
open System.Net
open System.Net.Http
open System.Text
open System.Text.Json
open System.Threading
open Microsoft.AspNetCore.Builder
open Microsoft.AspNetCore.Hosting
open Microsoft.AspNetCore.TestHost
open Xunit
open SomhairlesDream.Modeling
open SomhairlesDream.Server
open SomhairlesDream.Shared

let private ids : RunIds =
    { ProjectId = "heritage-001"
      RunId = "run-api-001"
      BaseId = "base-000"
      TargetId = "target-003" }

let private withTempDirectory action =
    let path = Path.Combine(Path.GetTempPath(), "somhairles-dream-api-" + Guid.NewGuid().ToString("N"))
    Directory.CreateDirectory(path) |> ignore

    try
        action path
    finally
        if Directory.Exists(path) then
            Directory.Delete(path, true)

type private TestBridge() =
    interface IArtifactBridge with
        member _.Export(request, _) =
            File.WriteAllBytes(request.GlbPath, [| 0x67uy; 0x6Cuy; 0x54uy; byte request.Step.Index |])
            Directory.CreateDirectory(Path.GetDirectoryName(request.LogPath)) |> ignore
            File.WriteAllText(request.LogPath, $"bridge log for {request.Step.StepId}")

            Ok
                { BlenderVersion = "5.0.1"
                  ExportedAt = DateTimeOffset.Parse("2026-09-20T12:00:05Z")
                  ObjectIds = request.Step.ObjectIds
                  VerifiedObjectIds = request.Step.ObjectIds
                  GlbBytes = 4L
                  RenderPath = None
                  RenderedAt = None }

type private BlockingBridge(gate: ManualResetEventSlim) =
    interface IArtifactBridge with
        member _.Export(request, _) =
            gate.Wait()
            (TestBridge() :> IArtifactBridge).Export(request, fun () -> ())

type private StepGatedBridge(gate: ManualResetEventSlim) =
    interface IArtifactBridge with
        member _.Export(request, _) =
            if request.Step.Index > 0 then
                gate.Wait()

            (TestBridge() :> IArtifactBridge).Export(request, fun () -> ())

let private requestBody runId =
    $"{{\"projectId\":\"{ids.ProjectId}\",\"runId\":\"{runId}\",\"baseId\":\"{ids.BaseId}\",\"targetId\":\"{ids.TargetId}\"}}"

let private withAppUsing (bridgeFactory: unit -> IArtifactBridge) action =
    withTempDirectory (fun root ->
        let clock () = DateTimeOffset.Parse("2026-09-20T12:00:00Z")
        let coordinator =
            ArtifactRunCoordinator(
                root,
                bridgeFactory,
                clock,
                TimeSpan.FromSeconds 15.
            )

        let builder = WebApplication.CreateBuilder([||])
        builder.WebHost.UseTestServer() |> ignore
        let app = builder.Build()

        ArtifactRunApi.register
            app
            { Coordinator = coordinator
              Clock = clock
              JsonOptions = JsonSerializerOptions(JsonSerializerDefaults.Web) }

        app.StartAsync().GetAwaiter().GetResult()

        try
            action (app.GetTestClient()) coordinator
        finally
            app.StopAsync().GetAwaiter().GetResult()
            app.DisposeAsync().AsTask().GetAwaiter().GetResult())

let private withApp action = withAppUsing (fun () -> TestBridge() :> IArtifactBridge) action

let private waitFor predicate =
    let deadline = DateTime.UtcNow.AddSeconds(5.)
    let mutable matched = predicate ()

    while not matched && DateTime.UtcNow < deadline do
        Thread.Sleep(10)
        matched <- predicate ()

    matched

[<Fact>]
let ``start endpoint accepts a run and conflicts on its second start`` () =
    withApp (fun client _ ->
        let first =
            use content = new StringContent(requestBody ids.RunId, Encoding.UTF8, "application/json")
            client.PostAsync("/api/runs/start", content).GetAwaiter().GetResult()

        Assert.Equal(HttpStatusCode.Accepted, first.StatusCode)

        let firstSnapshot =
            first.Content.ReadAsStringAsync().GetAwaiter().GetResult()
            |> fun body -> JsonSerializer.Deserialize<RunSnapshot>(body, JsonSerializerOptions(JsonSerializerDefaults.Web))

        Assert.Equal(ids.ProjectId, firstSnapshot.ProjectId)
        Assert.Equal(ids.RunId, firstSnapshot.RunId)

        use duplicateContent = new StringContent(requestBody ids.RunId, Encoding.UTF8, "application/json")
        let duplicate = client.PostAsync("/api/runs/start", duplicateContent).GetAwaiter().GetResult()

        Assert.Equal(HttpStatusCode.Conflict, duplicate.StatusCode))

[<Fact>]
let ``start endpoint rejects invalid resource ids before creating a run`` () =
    withApp (fun client coordinator ->
        let body = requestBody "../outside"
        use content = new StringContent(body, Encoding.UTF8, "application/json")
        let response = client.PostAsync("/api/runs/start", content).GetAwaiter().GetResult()

        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode)
        Assert.True(coordinator.TryFind(ids.ProjectId, "../outside").IsNone))

[<Fact>]
let ``manifest and artifact endpoints expose a completed run and reject traversal`` () =
    withApp (fun client coordinator ->
        let runId = "run-api-complete"

        use content = new StringContent(requestBody runId, Encoding.UTF8, "application/json")
        let start = client.PostAsync("/api/runs/start", content).GetAwaiter().GetResult()
        Assert.Equal(HttpStatusCode.Accepted, start.StatusCode)

        let completed =
            waitFor (fun () ->
                coordinator.TryFind(ids.ProjectId, runId)
                |> Option.exists (fun store -> store.Snapshot().Status = "complete"))

        Assert.True(completed)

        let manifest =
            client
                .GetAsync($"/api/artifacts/manifest?projectId={ids.ProjectId}&runId={runId}")
                .GetAwaiter()
                .GetResult()

        Assert.Equal(HttpStatusCode.OK, manifest.StatusCode)
        let manifestBody = manifest.Content.ReadAsStringAsync().GetAwaiter().GetResult()
        Assert.Contains("\"schemaVersion\":1", manifestBody)

        let glbPath = Uri.EscapeDataString("steps/01-foundation.glb")
        let artifact =
            client
                .GetAsync($"/api/artifacts/file?projectId={ids.ProjectId}&runId={runId}&path={glbPath}")
                .GetAwaiter()
                .GetResult()

        Assert.Equal(HttpStatusCode.OK, artifact.StatusCode)

        let traversalPath = Uri.EscapeDataString("../manifest.json")
        let traversal =
            client
                .GetAsync($"/api/artifacts/file?projectId={ids.ProjectId}&runId={runId}&path={traversalPath}")
                .GetAwaiter()
                .GetResult()

        Assert.Equal(HttpStatusCode.BadRequest, traversal.StatusCode))

[<Fact>]
let ``manifest endpoint reports active runs as conflicts`` () =
    let gate = new ManualResetEventSlim(false)

    try
        withAppUsing
            (fun () -> BlockingBridge(gate) :> IArtifactBridge)
            (fun client coordinator ->
                let runId = "run-api-active"
                use content = new StringContent(requestBody runId, Encoding.UTF8, "application/json")
                let start = client.PostAsync("/api/runs/start", content).GetAwaiter().GetResult()
                Assert.Equal(HttpStatusCode.Accepted, start.StatusCode)

                let manifest =
                    client
                        .GetAsync($"/api/artifacts/manifest?projectId={ids.ProjectId}&runId={runId}")
                        .GetAwaiter()
                        .GetResult()

                Assert.Equal(HttpStatusCode.Conflict, manifest.StatusCode)
                gate.Set()

                Assert.True(
                    waitFor (fun () ->
                        coordinator.TryFind(ids.ProjectId, runId)
                        |> Option.exists (fun store -> store.Snapshot().Status = "complete")))
            )
    finally
        gate.Set()
        gate.Dispose()

[<Fact>]
let ``step artifacts stream while a run is still active`` () =
    let gate = new ManualResetEventSlim(false)

    try
        withAppUsing
            (fun () -> StepGatedBridge(gate) :> IArtifactBridge)
            (fun client coordinator ->
                let runId = "run-api-steps"
                use content = new StringContent(requestBody runId, Encoding.UTF8, "application/json")
                let start = client.PostAsync("/api/runs/start", content).GetAwaiter().GetResult()
                Assert.Equal(HttpStatusCode.Accepted, start.StatusCode)

                Assert.True(
                    waitFor (fun () ->
                        coordinator.TryFind(ids.ProjectId, runId)
                        |> Option.exists (fun store ->
                            let snapshot = store.Snapshot()
                            snapshot.Status = "running" && snapshot.CompletedSteps.Length = 1)))

                let glbPath = Uri.EscapeDataString("steps/01-foundation.glb")
                let stepsUrl = $"/api/artifacts/steps?projectId={ids.ProjectId}&runId={runId}&path={glbPath}"

                let stepArtifact =
                    client.GetAsync(stepsUrl).GetAwaiter().GetResult()

                Assert.Equal(HttpStatusCode.OK, stepArtifact.StatusCode)
                Assert.Equal("model/gltf-binary", stepArtifact.Content.Headers.ContentType.MediaType)

                let traversalPath = Uri.EscapeDataString("../manifest.json")
                let traversalUrl = $"/api/artifacts/steps?projectId={ids.ProjectId}&runId={runId}&path={traversalPath}"

                let traversal =
                    client.GetAsync(traversalUrl).GetAwaiter().GetResult()

                Assert.Equal(HttpStatusCode.BadRequest, traversal.StatusCode)

                let missingPath = Uri.EscapeDataString("steps/03-cabin.glb")
                let missingUrl = $"/api/artifacts/steps?projectId={ids.ProjectId}&runId={runId}&path={missingPath}"

                let missing =
                    client.GetAsync(missingUrl).GetAwaiter().GetResult()

                Assert.Equal(HttpStatusCode.NotFound, missing.StatusCode)
                gate.Set()

                Assert.True(
                    waitFor (fun () ->
                        coordinator.TryFind(ids.ProjectId, runId)
                        |> Option.exists (fun store -> store.Snapshot().Status = "complete")))
            )
    finally
        gate.Set()
        gate.Dispose()

[<Fact>]
let ``events endpoint streams only the selected run`` () =
    withApp (fun client _ ->
        let runId = "run-api-events"
        use content = new StringContent(requestBody runId, Encoding.UTF8, "application/json")
        let start = client.PostAsync("/api/runs/start", content).GetAwaiter().GetResult()
        Assert.Equal(HttpStatusCode.Accepted, start.StatusCode)

        use response =
            client
                .GetAsync(
                    $"/api/runs/events?projectId={ids.ProjectId}&runId={runId}",
                    HttpCompletionOption.ResponseHeadersRead
                )
                .GetAwaiter()
                .GetResult()

        Assert.Equal(HttpStatusCode.OK, response.StatusCode)
        use reader = new StreamReader(response.Content.ReadAsStream())
        let line = reader.ReadLine()
        Assert.StartsWith("data: ", line)
        Assert.Contains(runId, line)

        let unknown =
            client
                .GetAsync($"/api/runs/events?projectId={ids.ProjectId}&runId=run-api-missing")
                .GetAwaiter()
                .GetResult()

        Assert.Equal(HttpStatusCode.NotFound, unknown.StatusCode))