namespace FundLab.Api.Tests

open System
open System.Collections.Concurrent
open System.Net.Http
open System.Text.Json
open System.Threading.Tasks
open FundLab.Api
open Xunit

[<Collection("postgres")>]
type OrderTests(fixture: PostgresFixture) =
    let repository () =
        let value = FundRepository(fixture.ConnectionString)
        value.EnsureSchema()
        value

    let seedInstrument () =
        let code = Random.Shared.Next(0, 1000000).ToString("D6")
        let payload =
            {
                Source = "akshare"
                SourceRevision = "akshare-test/eastmoney"
                CollectedAt = DateTimeOffset(2026, 9, 21, 10, 0, 0, TimeSpan.Zero)
                Instruments = [ { Code = code; Name = "订单测试基金"; FundType = None } ]
            }

        repository().UpsertInstruments(payload, "order-test-hash")
        code

    let createFund (initialCash: decimal) =
        let command =
            {
                Name = "订单测试 FOF"
                InitialCash = initialCash
                InitialUnitNav = 1.00000000m
                IsSynthetic = true
            }

        let key = fixture.Key(sprintf "order-fund-%s" (Guid.NewGuid().ToString("N")))

        match repository().CreateFund(key, command) with
        | FundWriteResult.Created fund -> fund.Id
        | other -> failwithf "unexpected fund creation result: %A" other

    let app () = App.createApplication (repository ())

    let orderBody fundCode amount fee =
        sprintf "{\"fundCode\":\"%s\",\"amount\":\"%s\",\"feeAmount\":\"%s\"}" fundCode amount fee

    let postOrder (api) fundId idempotencyKey body =
        PersistenceTestHelpers.invoke
            api
            "POST"
            (sprintf "/api/funds/%O/orders" fundId)
            [
                "Authorization", "Bearer test-token"
                "Idempotency-Key", idempotencyKey
            ]
            body

    let getOrderList (api) fundId =
        PersistenceTestHelpers.invoke
            api
            "GET"
            (sprintf "/api/funds/%O/orders" fundId)
            [ "Authorization", "Bearer test-token" ]
            ""

    let getFund (api) fundId =
        PersistenceTestHelpers.invoke
            api
            "GET"
            (sprintf "/api/funds/%O" fundId)
            [ "Authorization", "Bearer test-token" ]
            ""

    let jsonProperty (body: string) (name: string) =
        use document = JsonDocument.Parse(body)
        document.RootElement.GetProperty(name).GetString()

    let orderCount (body: string) =
        use document = JsonDocument.Parse(body)
        document.RootElement.GetArrayLength()

    [<Fact>]
    member _.``subscription order reserves cash and stays visible as pending``() =
        let code = seedInstrument ()
        let fundId = createFund 1000.00m
        let api = app ()
        let key = fixture.Key("order-happy-path")

        let status, body =
            postOrder api fundId key (orderBody code "100.00" "1.50")

        Assert.Equal(201, status)
        Assert.Contains(sprintf "\"fundCode\":\"%s\"" code, body)
        Assert.Contains("\"amount\":\"100.00\"", body)
        Assert.Contains("\"feeAmount\":\"1.50\"", body)
        Assert.Contains("\"reservedTotal\":\"101.50\"", body)
        Assert.Contains("\"status\":\"submitted\"", body)
        Assert.Contains(sprintf "\"fundId\":\"%O\"" fundId, body)

        let orderId = PersistenceTestHelpers.responseId body

        let fundStatus, fundBody = getFund api fundId
        Assert.Equal(200, fundStatus)
        Assert.Contains("\"availableCash\":\"898.50\"", fundBody)
        Assert.Contains("\"reservedCash\":\"101.50\"", fundBody)

        let listStatus, listBody = getOrderList api fundId
        Assert.Equal(200, listStatus)
        Assert.Equal(1, orderCount listBody)
        Assert.Contains(sprintf "\"id\":\"%O\"" orderId, listBody)

    [<Fact>]
    member _.``subscription order replays the same order for an identical idempotency key``() =
        let code = seedInstrument ()
        let fundId = createFund 500.00m
        let api = app ()
        let key = fixture.Key("order-replay")
        let body = orderBody code "50.00" "2.50"

        let createStatus, createResponse = postOrder api fundId key body
        Assert.Equal(201, createStatus)
        let orderId = PersistenceTestHelpers.responseId createResponse

        let replayStatus, replayResponse = postOrder api fundId key body
        Assert.Equal(200, replayStatus)
        Assert.Equal(orderId, PersistenceTestHelpers.responseId replayResponse)

        let _, fundBody = getFund api fundId
        Assert.Contains("\"availableCash\":\"447.50\"", fundBody)
        Assert.Contains("\"reservedCash\":\"52.50\"", fundBody)

        let _, listBody = getOrderList api fundId
        Assert.Equal(1, orderCount listBody)

    [<Fact>]
    member _.``subscription order rejects conflicting reuse of an idempotency key``() =
        let code = seedInstrument ()
        let fundId = createFund 300.00m
        let api = app ()
        let key = fixture.Key("order-conflict")

        let _, _ = postOrder api fundId key (orderBody code "30.00" "3.00")

        let conflictStatus, conflictBody =
            postOrder api fundId key (orderBody code "31.00" "3.00")

        Assert.Equal(409, conflictStatus)
        Assert.Contains("IDEMPOTENCY_CONFLICT", conflictBody)

        let _, fundBody = getFund api fundId
        Assert.Contains("\"availableCash\":\"267.00\"", fundBody)
        Assert.Contains("\"reservedCash\":\"33.00\"", fundBody)

    [<Fact>]
    member _.``subscription order validates amount fee and catalog input``() =
        let code = seedInstrument ()
        let fundId = createFund 1000.00m
        let api = app ()
        let key = fixture.Key("order-validation")

        let invalidBodies =
            [
                orderBody code "0.00" "1.00"
                orderBody code "-5.00" "1.00"
                orderBody code "10.005" "1.00"
                orderBody code "10.00" "0.00"
                orderBody code "10.00" "1.005"
                "{\"amount\":\"10.00\",\"feeAmount\":\"1.00\"}"
                "{\"fundCode\":123,\"amount\":\"10.00\",\"feeAmount\":\"1.00\"}"
                "{\"fundCode\":\"" + code + "\",\"amount\":\"abc\",\"feeAmount\":\"1.00\"}"
                "[]"
                ""
            ]

        for invalidBody in invalidBodies do
            let status, responseBody = postOrder api fundId key invalidBody
            Assert.Equal(400, status)
            Assert.Contains("INVALID_ORDER_REQUEST", responseBody)

        let _, fundBody = getFund api fundId
        Assert.Contains("\"availableCash\":\"1000.00\"", fundBody)
        Assert.Contains("\"reservedCash\":\"0.00\"", fundBody)

        let _, listBody = getOrderList api fundId
        Assert.Equal(0, orderCount listBody)

        let boundaryStatus, boundaryBody =
            postOrder api fundId key (orderBody code "0.01" "0.01")

        Assert.Equal(201, boundaryStatus)
        Assert.Contains("\"reservedTotal\":\"0.02\"", boundaryBody)

        let _, fundAfterBoundary = getFund api fundId
        Assert.Contains("\"availableCash\":\"999.98\"", fundAfterBoundary)
        Assert.Contains("\"reservedCash\":\"0.02\"", fundAfterBoundary)

    [<Fact>]
    member _.``subscription order requires authentication and an idempotency key``() =
        let fundId = createFund 100.00m
        let api = app ()
        let body = orderBody "000001" "10.00" "1.00"

        let unauthorizedStatus, _ =
            PersistenceTestHelpers.invoke
                api
                "POST"
                (sprintf "/api/funds/%O/orders" fundId)
                [ "Idempotency-Key", fixture.Key("order-unauthorized") ]
                body

        Assert.Equal(401, unauthorizedStatus)

        let missingKeyStatus, missingKeyBody =
            PersistenceTestHelpers.invoke
                api
                "POST"
                (sprintf "/api/funds/%O/orders" fundId)
                [ "Authorization", "Bearer test-token" ]
                body

        Assert.Equal(400, missingKeyStatus)
        Assert.Contains("INVALID_ORDER_REQUEST", missingKeyBody)

    [<Fact>]
    member _.``subscription order rejects unknown funds and unknown fund codes without cash movement``() =
        let code = seedInstrument ()
        let fundId = createFund 800.00m
        let api = app ()

        let invalidIdStatus, invalidIdBody =
            PersistenceTestHelpers.invoke
                api
                "POST"
                "/api/funds/not-a-guid/orders"
                [
                    "Authorization", "Bearer test-token"
                    "Idempotency-Key", fixture.Key("order-bad-id")
                ]
                (orderBody code "10.00" "1.00")

        Assert.Equal(400, invalidIdStatus)
        Assert.Contains("INVALID_FUND_ID", invalidIdBody)

        let unknownFundStatus, unknownFundBody =
            postOrder api (Guid.NewGuid()) (fixture.Key("order-unknown-fund")) (orderBody code "10.00" "1.00")

        Assert.Equal(404, unknownFundStatus)
        Assert.Contains("FUND_NOT_FOUND", unknownFundBody)

        let unknownCodeStatus, unknownCodeBody =
            postOrder api fundId (fixture.Key("order-unknown-code")) (orderBody "999999" "10.00" "1.00")

        Assert.Equal(404, unknownCodeStatus)
        Assert.Contains("INSTRUMENT_NOT_FOUND", unknownCodeBody)

        let _, fundBody = getFund api fundId
        Assert.Contains("\"availableCash\":\"800.00\"", fundBody)
        Assert.Contains("\"reservedCash\":\"0.00\"", fundBody)

        let _, listBody = getOrderList api fundId
        Assert.Equal(0, orderCount listBody)

        let missingListStatus, _ = getOrderList api (Guid.NewGuid())
        Assert.Equal(404, missingListStatus)

    [<Fact>]
    member _.``subscription order refuses insufficient available cash atomically``() =
        let code = seedInstrument ()
        let fundId = createFund 10.00m
        let api = app ()

        let status, body = postOrder api fundId (fixture.Key("order-insufficient")) (orderBody code "6.00" "5.00")

        Assert.Equal(409, status)
        Assert.Contains("INSUFFICIENT_FUNDS", body)

        let _, fundBody = getFund api fundId
        Assert.Contains("\"availableCash\":\"10.00\"", fundBody)
        Assert.Contains("\"reservedCash\":\"0.00\"", fundBody)

        let _, listBody = getOrderList api fundId
        Assert.Equal(0, orderCount listBody)

    [<Fact>]
    member _.``concurrent subscription orders reserve exactly the affordable amount``() =
        let code = seedInstrument ()
        let fundId = createFund 10.00m
        let api = app ()
        let body = orderBody code "3.50" "0.50"
        let statuses = ConcurrentBag<int>()

        Parallel.For(
            0,
            8,
            fun index ->
                let key = fixture.Key(sprintf "order-concurrent-%s-%d" (Guid.NewGuid().ToString("N")) index)
                let status, _ = postOrder api fundId key body
                statuses.Add(status)
        )
        |> ignore

        Assert.Equal(2, (statuses |> Seq.filter (fun status -> status = 201) |> Seq.length))
        Assert.Equal(6, (statuses |> Seq.filter (fun status -> status = 409) |> Seq.length))

        let _, fundBody = getFund api fundId
        Assert.Contains("\"availableCash\":\"2.00\"", fundBody)
        Assert.Contains("\"reservedCash\":\"8.00\"", fundBody)

        let _, listBody = getOrderList api fundId
        Assert.Equal(2, orderCount listBody)

    [<Fact>]
    member _.``real Kestrel API preserves subscription orders and idempotency across process restart``() =
        let code = seedInstrument ()
        let key = fixture.Key("order-restart")

        use firstProcess = new ApiProcess(fixture.ConnectionString)
        PersistenceTestHelpers.waitForApi firstProcess

        use client = new HttpClient()
        client.BaseAddress <- Uri(firstProcess.BaseAddress)

        let fundBody =
            "{\"name\":\"订单重启 FOF\",\"initialCash\":\"100.00\",\"initialUnitNav\":\"1.00000000\",\"isSynthetic\":true}"

        let fundStatus, fundResponse =
            PersistenceTestHelpers.send
                client
                "POST"
                "/api/funds"
                (Some "test-token")
                (Some(fixture.Key("order-restart-fund")))
                fundBody

        Assert.Equal(201, fundStatus)
        let fundId = PersistenceTestHelpers.responseId fundResponse

        let createStatus, createResponse =
            PersistenceTestHelpers.send
                client
                "POST"
                (sprintf "/api/funds/%O/orders" fundId)
                (Some "test-token")
                (Some key)
                (orderBody code "60.00" "4.00")

        Assert.Equal(201, createStatus)
        Assert.Contains("\"reservedTotal\":\"64.00\"", createResponse)
        Assert.Contains("\"status\":\"submitted\"", createResponse)
        let orderId = PersistenceTestHelpers.responseId createResponse

        firstProcess.Stop() |> ignore

        use restartedProcess = new ApiProcess(fixture.ConnectionString)
        PersistenceTestHelpers.waitForApi restartedProcess

        use restartedClient = new HttpClient()
        restartedClient.BaseAddress <- Uri(restartedProcess.BaseAddress)

        let restartedFundStatus, restartedFundBody =
            PersistenceTestHelpers.send
                restartedClient
                "GET"
                (sprintf "/api/funds/%O" fundId)
                (Some "test-token")
                None
                ""

        Assert.Equal(200, restartedFundStatus)
        Assert.Contains("\"availableCash\":\"36.00\"", restartedFundBody)
        Assert.Contains("\"reservedCash\":\"64.00\"", restartedFundBody)

        let restartedOrderListStatus, restartedOrderListBody =
            PersistenceTestHelpers.send
                restartedClient
                "GET"
                (sprintf "/api/funds/%O/orders" fundId)
                (Some "test-token")
                None
                ""

        Assert.Equal(200, restartedOrderListStatus)
        Assert.Equal(1, orderCount restartedOrderListBody)
        Assert.Contains(sprintf "\"id\":\"%O\"" orderId, restartedOrderListBody)

        let replayStatus, replayResponse =
            PersistenceTestHelpers.send
                restartedClient
                "POST"
                (sprintf "/api/funds/%O/orders" fundId)
                (Some "test-token")
                (Some key)
                (orderBody code "60.00" "4.00")

        Assert.Equal(200, replayStatus)
        Assert.Equal(orderId, PersistenceTestHelpers.responseId replayResponse)