Add real NAV series multi-day returns (3d-13)

4 files changed, 149 insertions, 10 deletions

diff --git a/src/FundLab.Api/App.fs b/src/FundLab.Api/App.fs
index 370f503..e359af9 100644
--- a/src/FundLab.Api/App.fs
+++ b/src/FundLab.Api/App.fs
@@ -337,6 +337,27 @@ type MarketNavDatesApiResponse =
         dates: string list
     }
 
+type MarketNavSeriesPointApiResponse =
+    {
+        navDate: string
+        nav: string
+        accumulatedNav: string option
+    }
+
+type MarketNavSeriesApiResponse =
+    {
+        code: string
+        points: MarketNavSeriesPointApiResponse list
+    }
+
+/// The AKShare-backed probes the market endpoints depend on. Injected together
+/// so the app stays repository-only unless a caller really wants market routes.
+type MarketProbes =
+    {
+        NavDates: INavDateProbe
+        NavSeries: INavSeriesProbe
+    }
+
 module App =
     let addOptionFriendlyJson (services: IServiceCollection) =
         let settings =
@@ -1649,13 +1670,49 @@ module App =
                 json ({ code = code.Trim(); dates = dates |> List.map dateText } : MarketNavDatesApiResponse) next ctx
             | Error failure -> marketDataError failure next ctx
 
-    let private navDateProbeRoutes (probe: INavDateProbe) =
-        [ GET >=> route "/market/nav-dates" >=> getMarketNavDates probe ]
+    let private marketNavSeriesPointResponse (point: NavSeriesPoint) : MarketNavSeriesPointApiResponse =
+        {
+            navDate = dateText point.NavDate
+            nav = decimalText point.Nav
+            accumulatedNav = point.AccumulatedNav |> Option.map decimalText
+        }
+
+    let private getMarketNavSeries (probe: INavSeriesProbe) : HttpHandler =
+        fun next ctx ->
+            let code = ctx.Request.Query["code"].ToString()
+            let limitText = ctx.Request.Query["limit"].ToString()
+
+            let limit =
+                if String.IsNullOrWhiteSpace limitText then
+                    Ok 30
+                else
+                    match Int32.TryParse(limitText, NumberStyles.Integer, invariant) with
+                    | true, value when value >= 1 && value <= 250 -> Ok value
+                    | _ -> Error "limit must be an integer between 1 and 250"
+
+            match limit with
+            | Error message -> marketDataError (InvalidMarketDataRequest message) next ctx
+            | Ok value ->
+                match probe.RecentNavSeries(code, value, ctx.RequestAborted) with
+                | Ok points ->
+                    json
+                        ({ code = code.Trim()
+                           points = points |> List.map marketNavSeriesPointResponse }
+                         : MarketNavSeriesApiResponse)
+                        next
+                        ctx
+                | Error failure -> marketDataError failure next ctx
+
+    let private marketProbeRoutes (probes: MarketProbes) =
+        [
+            GET >=> route "/market/nav-dates" >=> getMarketNavDates probes.NavDates
+            GET >=> route "/market/nav-series" >=> getMarketNavSeries probes.NavSeries
+        ]
 
     let private createApplicationInternal
         (repository: FundRepository)
         (marketData: IMarketDataService option)
-        (navDateProbe: INavDateProbe option)
+        (probes: MarketProbes option)
         : HttpHandler =
         let apiRoutes =
             [
@@ -1687,7 +1744,7 @@ module App =
                 GET >=> routef "/funds/%s" (getFund repository)
             ]
             @ (marketData |> Option.map marketDataRoutes |> Option.defaultValue [])
-            @ (navDateProbe |> Option.map navDateProbeRoutes |> Option.defaultValue [])
+            @ (probes |> Option.map marketProbeRoutes |> Option.defaultValue [])
 
         choose [
             GET >=> route "/health" >=> health
@@ -1701,15 +1758,15 @@ module App =
     let createApplicationWithMarketData (repository: FundRepository) (marketData: IMarketDataService) : HttpHandler =
         createApplicationInternal repository (Some marketData) None
 
-    let createApplicationWithNavDateProbe (repository: FundRepository) (probe: INavDateProbe) : HttpHandler =
-        createApplicationInternal repository None (Some probe)
+    let createApplicationWithProbes (repository: FundRepository) (probes: MarketProbes) : HttpHandler =
+        createApplicationInternal repository None (Some probes)
 
-    let createApplicationWithMarketDataAndProbe
+    let createApplicationWithMarketDataAndProbes
         (repository: FundRepository)
         (marketData: IMarketDataService)
-        (probe: INavDateProbe)
+        (probes: MarketProbes)
         : HttpHandler =
-        createApplicationInternal repository (Some marketData) (Some probe)
+        createApplicationInternal repository (Some marketData) (Some probes)
 
     let createApplication (repository: FundRepository) : HttpHandler =
         createApplicationInternal repository None None
diff --git a/src/FundLab.Api/FundLab.Api.fsproj b/src/FundLab.Api/FundLab.Api.fsproj
index ed2c637..11df882 100644
--- a/src/FundLab.Api/FundLab.Api.fsproj
+++ b/src/FundLab.Api/FundLab.Api.fsproj
@@ -19,6 +19,7 @@
     <Compile Include="Persistence.fs" />
         <Compile Include="MarketDataService.fs" />
         <Compile Include="NavDateProbe.fs" />
+        <Compile Include="NavSeriesProbe.fs" />
         <Compile Include="App.fs" />
     <Compile Include="Program.fs" />
   </ItemGroup>
diff --git a/src/FundLab.Api/NavSeriesProbe.fs b/src/FundLab.Api/NavSeriesProbe.fs
new file mode 100644
index 0000000..7c7a437
--- /dev/null
+++ b/src/FundLab.Api/NavSeriesProbe.fs
@@ -0,0 +1,76 @@
+namespace FundLab.Api
+
+open System
+open System.Collections.Concurrent
+open System.Globalization
+open System.Threading
+
+/// One point of a fund's real net-value series.
+type NavSeriesPoint =
+    {
+        NavDate: DateOnly
+        Nav: decimal
+        AccumulatedNav: decimal option
+    }
+
+/// Read-only probe that returns the most recent NAV points for a fund code.
+/// Like INavDateProbe there is no synthetic fallback: a failure is surfaced as a
+/// MarketDataFailure so the API answers 503 with the underlying reason.
+type INavSeriesProbe =
+    abstract RecentNavSeries: code: string * limit: int * CancellationToken -> Result<NavSeriesPoint list, MarketDataFailure>
+
+/// AKShare-backed series probe. Successful lookups are memoised per code and
+/// calendar day (the F# equivalent of functools cache keyed on code + today), so
+/// the UI can re-read the curve during one day without re-spawning the collector.
+/// Failures are never cached.
+type AkshareNavSeriesProbe(collector: IMarketDataCollector) =
+    let cache = ConcurrentDictionary<string, NavSeriesPoint list>(StringComparer.Ordinal)
+
+    let isFundCode (value: string) =
+        not (String.IsNullOrWhiteSpace value)
+        && value.Length = 6
+        && value |> Seq.forall Char.IsDigit
+
+    let clip limit =
+        if limit < 1 then 1
+        elif limit > 250 then 250
+        else limit
+
+    let todayText () =
+        (ConfirmationPolicy.eventDateFor DateTimeOffset.UtcNow).ToString("yyyy-MM-dd", CultureInfo.InvariantCulture)
+
+    member _.Clear() = cache.Clear()
+
+    interface INavSeriesProbe with
+        member _.RecentNavSeries(code, limit, token) =
+            let normalized = if isNull code then "" else code.Trim()
+
+            if not (isFundCode normalized) then
+                Error(InvalidMarketDataRequest "fund code must contain exactly six digits")
+            else
+                let bounded = clip limit
+                let cacheKey = sprintf "%s|%s" normalized (todayText ())
+
+                match cache.TryGetValue cacheKey with
+                | true, cached -> Ok(cached |> List.truncate bounded)
+                | _ ->
+                    match collector.FetchNav(normalized, token) with
+                    | Error message -> Error(MarketDataCollectorUnavailable message)
+                    | Ok json ->
+                        match MarketData.parseNavPayload json with
+                        | Error message -> Error(InvalidMarketDataPayload message)
+                        | Ok payload ->
+                            let points =
+                                payload.Observations
+                                |> List.filter (fun observation -> observation.Nav > 0m)
+                                |> List.map (fun observation ->
+                                    {
+                                        NavDate = observation.NavDate
+                                        Nav = observation.Nav
+                                        AccumulatedNav = observation.AccumulatedNav
+                                    })
+                                |> List.distinctBy (fun point -> point.NavDate)
+                                |> List.sortByDescending (fun point -> point.NavDate)
+
+                            cache.[cacheKey] <- points
+                            Ok(points |> List.truncate bounded)
diff --git a/src/FundLab.Api/Program.fs b/src/FundLab.Api/Program.fs
index ba5936e..fa58219 100644
--- a/src/FundLab.Api/Program.fs
+++ b/src/FundLab.Api/Program.fs
@@ -20,8 +20,13 @@ let main argv =
     let collector = ProcessMarketDataCollector.FromEnvironment() :> IMarketDataCollector
     let marketData = MarketDataService(repository, collector) :> IMarketDataService
     let navDateProbe = AkshareNavDateProbe(collector) :> INavDateProbe
+    let navSeriesProbe = AkshareNavSeriesProbe(collector) :> INavSeriesProbe
+
+    let probes =
+        { NavDates = navDateProbe
+          NavSeries = navSeriesProbe }
 
     let app = builder.Build()
-    app.UseGiraffe(App.createApplicationWithMarketDataAndProbe repository marketData navDateProbe)
+    app.UseGiraffe(App.createApplicationWithMarketDataAndProbes repository marketData probes)
     app.Run()
     0