namespace LivingVillage.Kernel.Tests

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

module private TradeBiasHarness =

    let quotedWorld () : World = Sim.initialWorldN 42UL 4

    let quote (buyer: NpcId) (seller: NpcId) (item: ItemKind) (world: World) : float32 =
        match Sim.quotePrice { Buyer = buyer; Seller = seller; Item = item; Quantity = 1 } world with
        | Some price -> price
        | None -> Assert.Fail("quote expected"); Unchecked.defaultof<float32>

[<TestClass>]
type TradeBiasTests () =

    // ---- 默认（无职业）= 旧行为基准 ----

    [<TestMethod>]
    member _.NoOccupationKeepsTheHistoricQuoteUnchanged () =
        Assert.AreEqual<float32>(1.0f, Occupation.quoteBiasOf None true)
        Assert.AreEqual<float32>(1.0f, Occupation.quoteBiasOf None false)
        Assert.AreEqual<float32 option>(Some 10.0f, Occupation.biasedQuote None true (Some 10.0f))
        Assert.AreEqual<float32 option>(None, Occupation.biasedQuote None true None)

    [<TestMethod>]
    member _.FarmerAndFisherStayUnbiasedLikeTheDefaultPath () =
        for kind in [ Occupation.Farmer; Occupation.Fisher ] do
            Assert.AreEqual<float32>(1.0f, Occupation.quoteBiasOf (Some kind) true)
            Assert.AreEqual<float32>(1.0f, Occupation.quoteBiasOf (Some kind) false)

    // ---- 货郎：买卖双向有利偏移（±3.00%，4 位定点基点）----

    [<TestMethod>]
    member _.PeddlerBuysCheaperAndSellsDearer () =
        Assert.AreEqual<float32>(0.97f, Occupation.quoteBiasOf (Some Occupation.Peddler) true)
        Assert.AreEqual<float32>(1.03f, Occupation.quoteBiasOf (Some Occupation.Peddler) false)

    // ---- 书生：解读行情的小幅加成（±1.00%）----

    [<TestMethod>]
    member _.ScholarGetsASmallerFavorableEdgeThanPeddler () =
        let scholarBuy = Occupation.quoteBiasOf (Some Occupation.Scholar) true
        let peddlerBuy = Occupation.quoteBiasOf (Some Occupation.Peddler) true
        Assert.AreEqual<float32>(0.99f, scholarBuy)
        Assert.AreEqual<float32>(1.01f, Occupation.quoteBiasOf (Some Occupation.Scholar) false)
        Assert.IsTrue(scholarBuy > peddlerBuy, "scholar edge must stay inside the peddler edge")

    // ---- 确定性与设计区间 [0.95, 1.05] ----

    [<TestMethod>]
    member _.BiasIsDeterministicAndInsideTheDesignBand () =
        for kind in Occupation.all do
            for playerIsBuyer in [ true; false ] do
                let first = Occupation.quoteBiasOf (Some kind) playerIsBuyer
                let second = Occupation.quoteBiasOf (Some kind) playerIsBuyer
                Assert.AreEqual<float32>(first, second)
                Assert.IsTrue(0.95f <= first && first <= 1.05f, $"{kind} bias {first} escaped the band")

    // ---- 与既有 Sim.quotePrice（Food 10.0f 路径）复合 ----

    [<TestMethod>]
    member _.BiasComposesWithTheExistingQuotePath () =
        let world = TradeBiasHarness.quotedWorld ()
        let baseBuy = TradeBiasHarness.quote (NpcId 0) (NpcId 1) Food world
        let baseSell = TradeBiasHarness.quote (NpcId 1) (NpcId 0) Food world
        Assert.AreEqual<float32>(baseBuy * 0.97f, (Occupation.biasedQuote (Some Occupation.Peddler) true (Some baseBuy)).Value)
        Assert.AreEqual<float32>(baseSell * 1.03f, (Occupation.biasedQuote (Some Occupation.Peddler) false (Some baseSell)).Value)
        Assert.AreEqual<float32>(baseBuy, (Occupation.biasedQuote None true (Some baseBuy)).Value)