Extract fetch functions to separate file

web/src/harmonie/fetchGrib.ts

@@ -0,0 +1,54 @@
+import { apiHost } from '../consts'
+import { fetchBuffer, fetchJson } from '../helpers/fetch'
+import { getFakeHourPrecipitation, isPrecipitation } from './draw/precipitation'
+import { getFakeWindDirection, isWindSpeed } from './draw/windDirection'
+import { GribMessage } from './interfaces'
+import { fetchWindData, isCalculatedWindDirection } from './draw/windDirection'
+import { fetchHourPrecipitationData, isCalculatedHourPrecipitation } from './draw/precipitation'
+
+export function fetchGribList(): Promise<string[]> {
+    return fetchJson(`${apiHost}/api/show/grib-list`)
+        .then((fileList: string[]) => {
+            return fileList.sort((a: string, b: string) => a < b ? 1 : -1)
+        })
+}
+
+export function fetchGribListStructure(): Promise<GribMessage[]> {
+    return fetchJson(`${apiHost}/api/show/grib-all-structure`)
+        .then((gribList: GribMessage[]) => {
+            return [
+                ...gribList,
+                ...gribList.filter(isWindSpeed).map(getFakeWindDirection),
+                ...gribList.filter(isPrecipitation).map(getFakeHourPrecipitation),
+            ].sort((a, b) => a.title > b.title ? 1 : -1)
+        })
+}
+
+export function fetchGribBinaries(
+    grib: GribMessage,
+    gribList: GribMessage[],
+) {
+    const fileName = `harmonie_${grib.time.referenceTime}_${grib.time.forecastTime}.grib`
+    const bitmaskSection = grib.sections.find(section => section.id === 6)
+    const binarySection = grib.sections.find(section => section.id === 7)
+    if (!bitmaskSection || !binarySection) throw new Error('Grib does not have binary or bitmap section')
+
+    const bitmaskOffset = bitmaskSection.offset + 6
+    const bitmaskLength = bitmaskSection.size - 6
+    const bitmaskPromise = bitmaskSection.size > 6
+        ? fetchBuffer(`${apiHost}/api/grib/binary-chunk/${bitmaskOffset}/${bitmaskLength}/${fileName}`).then(b=>[b])
+        : Promise.resolve([])
+
+    const binaryOffset = binarySection.offset + 5
+    const binaryLength = binarySection.size - 5
+    let fetchPromise: Promise<[GribMessage[], ArrayBuffer[], ArrayBuffer[]]> = Promise.all([
+            Promise.resolve([grib]),
+            fetchBuffer(`${apiHost}/api/grib/binary-chunk/${binaryOffset}/${binaryLength}/${fileName}`).then(b=>[b]),
+            bitmaskPromise,
+        ])
+
+    if(isCalculatedWindDirection(grib)) fetchPromise = fetchWindData(grib, gribList)
+    if(isCalculatedHourPrecipitation(grib)) fetchPromise = fetchHourPrecipitationData(grib, gribList)
+    
+    return fetchPromise
+}