sunzehao
/
cesium_three_nodejs


			
				
					
						
						
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							const path = require('path');
const axios = require('axios');
const { extractDOM } = require("./jsDom.js");

let basicGfsList = [];
let gfsFile = "";
let rootPage = {};
let cycleList = [];

const { leftlon, rightlon, toplat, bottomlat } = require("./region.js");

/**
  * 
  * @param {String} degree 气象模型精度，需自己找可选值，非要列举几个的话: ["gfs_0p25","gfs_0p50","gfs_1p00"]
  * @param {Number} step 步进数值，此参数不需要传入，自行递归
  * @returns 
  */
async function getGrib2FileUrl(degree = "gfs_1p00", step = 0) {
    if (basicGfsList.length) {
        gfsFile = basicGfsList[0 + step];
        const cyclePage = await axios.get(`https://nomads.ncep.noaa.gov/find_subdirs_files.php?ds=${degree}&path=&subdir_num=0&subdir_name=${gfsFile}`);
        cycleList = extractDOM(`<html><body>${cyclePage.data}</body></html>`, ".selectable .subdir_1");
    } else {
        rootPage = await axios.get(`https://nomads.ncep.noaa.gov/gribfilter.php?ds=${degree}`);
        const gfsList = extractDOM(rootPage.data, "#div_subdir_0 .subdir_0");
        for (let i = 0; i < gfsList.length; i++) {
            basicGfsList.push(gfsList[i].innerHTML);
        }
        gfsFile = basicGfsList[0 + step];
        cycleList = extractDOM(rootPage.data, "#div_subdir_1 .subdir_1");
    }

    const optionPage = await axios.get(`https://nomads.ncep.noaa.gov/find_subdirs_files.php?ds=${degree}&path=/${basicGfsList[0 + step]}&subdir_num=1&subdir_name=${cycleList[0].innerHTML}`);
    const optionList = extractDOM(`<html><body>${optionPage.data}</body></html>`, "#file_selector option");

    if (optionList) {
        let grb2FileList = [];
        for (let i = 1; i < optionList.length; i++) {
            grb2FileList.push({
                url: `https://nomads.ncep.noaa.gov/cgi-bin/filter_${degree}.pl?dir=/${basicGfsList[0 + step]}/${cycleList[0].innerHTML}/atmos&file=${optionList[i].getAttribute("value")}&all_var=on&all_lev=on&toplat=${toplat}&leftlon=${leftlon}&rightlon=${rightlon}&bottomlat=${bottomlat}`,
                filePath: path.join(__dirname, `../model/grib2/${degree}/${basicGfsList[0 + step]}/${cycleList[0].innerHTML}`),
                fileName: optionList[i].getAttribute("value"),
            });
        }

        const urls = JSON.parse(JSON.stringify(grb2FileList));
        basicGfsList = [];
        gfsFile = "";
        rootPage = {};
        return urls;
    } else {
        console.log(`${degree}第${step}个模型内未找到数据，切换下一个模型`);
        return getGrib2FileUrl(degree, ++step);
    }
}

// 提取DOM元素函数
module.exports = {
    getGrib2FileUrl
}