Introduce Calculate Elo API for external use.

This should make it possible for external use to calculate the ELo based on Either (Ptnml or WDL) and elo0, elo1 bounds (elo_model is optional and defaults to "normalized").

The format is:
https://tests.stockfishchess.org/api/calc_elo?LL=93&LD=18711&DD=58877&WD=18739&WW=100&elo0=-1.75&elo1=0.25

needs testing.

server/fishtest/__init__.py

@@ -118,6 +118,7 @@ def group_finder(username, request):
     config.add_route("api_download_nn", "/api/nn/{id}")
     config.add_route("api_get_elo", "/api/get_elo/{id}")
     config.add_route("api_actions", "/api/actions")
+    config.add_route("api_calc_elo", "/api/calc_elo")
 
     config.scan()
     return config.make_wsgi_app()

server/fishtest/api.py

@@ -347,6 +347,91 @@ def get_elo(self):
         run["elo"] = a
         return run
 
+    @view_config(route_name="api_calc_elo")
+    def calc_elo(self):
+        W = self.request.params.get("W")
+        D = self.request.params.get("D")
+        L = self.request.params.get("L")
+        LL = self.request.params.get("LL")
+        LD = self.request.params.get("LD")
+        DD = self.request.params.get("DD")
+        WD = self.request.params.get("WD")
+        WW = self.request.params.get("WW")
+        elo0 = self.request.params.get("elo0")
+        elo1 = self.request.params.get("elo1")
+        elo_model = self.request.params.get("elo_model", "normalized")
+
+        if elo_model not in ["BayesElo", "logistic", "normalized"]:
+            self.handle_error(
+                "Valid Elo models are: BayesElo, logistic, and normalized."
+            )
+
+        isPtnml = all(
+            value is not None
+            and (
+                (
+                    isinstance(value, (int, float))
+                    or isinstance(value, str)
+                    and value.replace(".", "").replace("-", "").isdigit()
+                )
+                and float(value) >= 0
+            )
+            for value in [LL, LD, DD, WD, WW, elo0, elo1]
+        )
+
+        isWdl = not isPtnml and all(
+            value is not None
+            and (
+                (
+                    isinstance(value, (int, float))
+                    or isinstance(value, str)
+                    and value.replace(".", "").replace("-", "").isdigit()
+                )
+                and float(value) >= 0
+            )
+            for value in [W, D, L, elo0, elo1]
+        )
+
+        if not isPtnml and not isWdl:
+            self.handle_error(
+                "Invalid or missing parameters. Please provide all values as valid numbers."
+            )
+
+        if isPtnml:
+            LL = int(LL)
+            LD = int(LD)
+            DD = int(DD)
+            WD = int(WD)
+            WW = int(WW)
+            if (LL + LD + DD + WD + WW) * 2 > 2**32:
+                self.handle_error("Number of games exceeds the limit.")
+            if LL + LD + DD + WD + WW == 0:
+                self.handle_error("No games to calculate Elo.")
+            results = {
+                "pentanomial": [LL, LD, DD, WD, WW],
+            }
+        if isWdl:
+            W = int(W)
+            D = int(D)
+            L = int(L)
+            if W + D + L > 2**32:
+                self.handle_error("Number of games exceeds the limit.")
+            if W + D + L == 0:
+                self.handle_error("No games to calculate Elo.")
+            results = {
+                "wins": W,
+                "draws": D,
+                "losses": L,
+            }
+        elo0 = float(elo0)
+        elo1 = float(elo1)
+        alpha = 0.05
+        beta = 0.05
+        a = SPRT_elo(
+            results, alpha=alpha, beta=beta, elo0=elo0, elo1=elo1, elo_model=elo_model
+        )
+        return a
+
     @view_config(route_name="api_request_task")
     def request_task(self):
         self.validate_request("/api/request_task")