feature to download the spectrum file (.spec)

frontend/src/components/CalcSpectrum.tsx

@@ -7,6 +7,7 @@ import { Controller, useForm } from "react-hook-form";
 import Switch from "@mui/material/Switch";
 import FormControlLabel from "@mui/material/FormControlLabel";
 import CircularProgress from "@mui/material/CircularProgress";
+import Button from "@mui/material/Button";
 import { CalcSpectrumPlotData, CalcSpectrumResponseData } from "../constants";
 import { FormValues } from "./types";
 import { Database } from "./fields/Database";
@@ -41,6 +42,7 @@ export const CalcSpectrum: React.FC = () => {
   const [useGesia, setUseGesia] = useState(false);
   const [useSlit, setUseSlit] = useState(false); // checking that user wants to apply the slit function or not in available modes
   const [useSimulateSlitFunction, setUseSimulateSlitFunction] = useState(false); // checking the mode and enable or disable slit feature
+  const [downloadButton, setDownloadButton] = useState(false);
   const Schema = yup.object().shape({
     useNonEqi: yup.boolean(),
     use_simulate_slit: yup.boolean(),
@@ -125,7 +127,10 @@ export const CalcSpectrum: React.FC = () => {
     setCalcSpectrumResponse(undefined);
     setError(message);
   };
-  const onSubmit = async (data: FormValues): Promise<void> => {
+  const onSubmit = async (
+    data: FormValues,
+    endpoint: string
+  ): Promise<void> => {
     if (useSlit == true) {
       if (data.mode === "radiance_noslit") {
         data.mode = "radiance";
@@ -136,6 +141,7 @@ export const CalcSpectrum: React.FC = () => {
     }
 
     setLoading(true);
+    setDownloadButton(true);
     console.log(data);
     setError(undefined);
 
@@ -146,26 +152,56 @@ export const CalcSpectrum: React.FC = () => {
       species: data.species,
     });
     import(/* webpackIgnore: true */ "./config.js").then(async (module) => {
-      const rawResponse = await axios.post(
-        module.apiEndpoint + `calculate-spectrum`,
-        data
-      );
-      if (
-        rawResponse.data.data === undefined &&
-        rawResponse.data.error === undefined
-      ) {
-        handleBadResponse("Bad response from backend!");
-      } else {
-        const response = await rawResponse.data;
-        if (response.error) {
-          handleBadResponse(response.error);
+      if (endpoint === "calculate-spectrum") {
+        console.log("calculate-spectrum");
+        const rawResponse = await axios.post(
+          module.apiEndpoint + endpoint,
+          data
+        );
+        if (
+          rawResponse.data.data === undefined &&
+          rawResponse.data.error === undefined
+        ) {
+          handleBadResponse("Bad response from backend!");
         } else {
-          setCalcSpectrumResponse(response);
+          const response = await rawResponse.data;
+          if (response.error) {
+            handleBadResponse(response.error);
+          } else {
+            setCalcSpectrumResponse(response);
+          }
         }
+        setLoading(false);
+      }
+      if (endpoint === "download-spectrum") {
+        setLoading(false);
+        console.log("Download spectrum");
+        await axios({
+          url: module.apiEndpoint + `download-spectrum`,
+          method: "POST",
+          responseType: "blob",
+          data: data,
+          headers: {
+            "Content-Type": "application/json",
+          },
+        })
+          .then((response) => {
+            const url = window.URL.createObjectURL(new Blob([response.data]));
+            const link = document.createElement("a");
+            link.href = url;
+            link.setAttribute("download", "radis.spec");
+            document.body.appendChild(link);
+            link.click();
+          })
+          .catch((error) => {
+            handleBadResponse(error);
+          });
+
+        setDownloadButton(false);
       }
-      setLoading(false); //setLoading(false) is called after the response is received
     });
   };
+
   const databaseWatch = watch("database");
   const modeWatch = watch("mode");
 
@@ -187,6 +223,20 @@ export const CalcSpectrum: React.FC = () => {
     }
   }, [databaseWatch, modeWatch]);
 
+  const DownloadSpectrum: React.FC = () => (
+    <Button
+      id="down-spectrum-button"
+      disabled={downloadButton}
+      variant="contained"
+      color="primary"
+      onClick={handleSubmit((data) => {
+        console.table(data);
+        onSubmit(data, `download-spectrum`);
+      })}
+    >
+      Download spectrum
+    </Button>
+  );
   const UseNonEquilibriumCalculations = () => (
     <Controller
       name="useNonEqi"
@@ -242,7 +292,9 @@ export const CalcSpectrum: React.FC = () => {
     />
   );
   return (
-    <form onSubmit={handleSubmit(onSubmit)}>
+    <form
+      onSubmit={handleSubmit((data) => onSubmit(data, `calculate-spectrum`))}
+    >
       {error ? <ErrorAlert message={error} /> : null}
       <Grid container spacing={2}>
         <Grid item xs={12} sm={8} md={5} lg={4}>
@@ -287,9 +339,9 @@ export const CalcSpectrum: React.FC = () => {
 
             <Grid item xs={12}>
               <Species
-                isNonEquilibrium={false}
+                isNonEquilibrium={isNonEquilibrium}
                 control={control}
-                isGeisa={false}
+                isGeisa={useGesia}
               />
             </Grid>
 
@@ -315,6 +367,9 @@ export const CalcSpectrum: React.FC = () => {
             <Grid item xs={12}>
               <CalcSpectrumButton />
             </Grid>
+            <Grid item xs={12}>
+              <DownloadSpectrum />
+            </Grid>
           </Grid>
         </Grid>
 

server/main.py

@@ -1,22 +1,25 @@
+import radis
+import os
 from typing import List, Optional
-from fastapi import FastAPI
+from fastapi import BackgroundTasks, FastAPI
 from pydantic import BaseModel
-import radis
 from fastapi.middleware.cors import CORSMiddleware
 from pydantic.typing import Literal
+from fastapi.responses import FileResponse
+
+
 # for high resolution
 radis.config["GRIDPOINTS_PER_LINEWIDTH_WARN_THRESHOLD"] = 7
-app = FastAPI()
 
+app = FastAPI()
 app.add_middleware(
     CORSMiddleware,
     allow_origins=["*"],
     allow_credentials=True,
     allow_methods=["*"],
     allow_headers=["*"],
 )
-
-
+# structure of the request
 class Species(BaseModel):
     molecule: str
     mole_fraction: float
@@ -32,36 +35,72 @@ class Payload(BaseModel):
     trot: Optional[float] = None
     path_length: float
     simulate_slit: Optional[int] = None
-    mode: Literal["absorbance", "transmittance_noslit", "radiance_noslit", "transmittance", "radiance"]
+    use_simulate_slit: bool
+    mode: Literal[
+        "absorbance",
+        "transmittance_noslit",
+        "radiance_noslit",
+        "transmittance",
+        "radiance",
+    ]
     database: Literal["hitran", "geisa"]
-    use_simulate_slit: bool = False
 
 
+# calculating the spectrum return back the spectrum
+def calculate_spectrum(payload):
+    print(">> Payload : ")
+    print(payload)
+    spectrum = radis.calc_spectrum(
+        payload.min_wavenumber_range,
+        payload.max_wavenumber_range,
+        molecule=[species.molecule for species in payload.species],
+        mole_fraction={
+            species.molecule: species.mole_fraction for species in payload.species
+        },
+        # TODO: Hard-coding "1,2,3" as the isotopologue for the time-being
+        isotope={species.molecule: "1,2,3" for species in payload.species},
+        pressure=payload.pressure,
+        Tgas=payload.tgas,
+        Tvib=payload.tvib,
+        Trot=payload.trot,
+        path_length=payload.path_length,
+        export_lines=False,
+        wstep="auto",
+        databank=payload.database,
+        use_cached=True,
+    )
+    return spectrum
+
+
+# create the folder in server for better organization
+def create_download_directory():
+    if os.path.exists("DOWNLOADED_SPECFILES"):
+        print(" >> Folder already exists ")
+    else:
+        print(">> creating DOWNLOADED_SPECFILES folder")
+        os.mkdir("DOWNLOADED_SPECFILES")
+
+
+# delete the file after giving the file response back to the user
+def delete_spec(file_path: str):
+
+    if os.path.exists(file_path):
+        print(" >> Removing file......")
+        os.remove(file_path)
+        print(" >>  File removed")
+    else:
+        print(" >> File is not found ")
+
+
+# "/calculate-spectrum " --> to calculate the spectrum and return back the x and y coordinates
 @app.post("/calculate-spectrum")
-async def calculate_spectrum(payload: Payload):
+async def calc_spectrum(payload: Payload):
     print(payload)
 
     try:
-        spectrum = radis.calc_spectrum(
-            payload.min_wavenumber_range,
-            payload.max_wavenumber_range,
-            molecule=[species.molecule for species in payload.species],
-            mole_fraction={
-                species.molecule: species.mole_fraction for species in payload.species
-            },
-            # TODO: Hard-coding "1,2,3" as the isotopologue for the time-being
-            isotope={species.molecule: "1,2,3" for species in payload.species},
-            pressure=payload.pressure,
-            Tgas=payload.tgas,
-            Tvib=payload.tvib,
-            Trot=payload.trot,
-            path_length=payload.path_length,
-            export_lines=False,
-            wstep="auto",
-            databank=payload.database,
-            use_cached=True,
-        )
+        spectrum = calculate_spectrum(payload)
         if payload.use_simulate_slit is True:
+            print("Applying simulate slit")
             spectrum.apply_slit(payload.simulate_slit, "nm")
 
     except radis.misc.warning.EmptyDatabaseError:
@@ -94,3 +133,33 @@ async def calculate_spectrum(payload: Payload):
                 "units": spectrum.units[payload.mode],
             },
         }
+
+
+# "/download-spectrum"--> to return back the .spec file and delete that file after giving the fileresponse back
+@app.post("/download-spectrum")
+async def download_spec(payload: Payload, background_tasks: BackgroundTasks):
+
+    try:
+        create_download_directory()
+        spectrum = calculate_spectrum(payload)
+        file_name_spec= spectrum.get_name()
+        file_name = f"{file_name_spec}.spec"
+        file_path = f"DOWNLOADED_SPECFILES/{file_name}"
+        if payload.use_simulate_slit is True:
+            print(" >> Applying simulate slit")
+            spectrum.apply_slit(payload.simulate_slit, "nm")
+    # returning the error response
+    except radis.misc.warning.EmptyDatabaseError:
+        return {"error": "No line in the specified wavenumber range"}
+    except Exception as exc:
+        print("Error", exc)
+        return {"error": str(exc)}
+    else:
+        spectrum.store(file_path, compress=True, if_exists_then="replace")
+        # running as a background task to delete the .spec file after giving the file response back
+        background_tasks.add_task(delete_spec, file_path)
+        return FileResponse(
+            file_path, media_type="application/octet-stream", filename=file_name
+        )
+
+