const fs = require('fs');
const path = require('path');
const dayjs = require('dayjs');
const { exec } = require('child_process');
const { v4: uuidv4 } = require('uuid');

const { getSubdirectories, getFilesInDirectory } = require('./folder_reader.js');

async function getLastNewModel(degree) {
    let gfsList = null;
    let hourList = null;
    gfsList = await getSubdirectories(path.join(__dirname, `../../model/grib2/${degree}`));

    if (gfsList?.length) {
        let dates = [];
        for (let i = 0; i < gfsList.length; i++) {
            const filePath = gfsList[i].split("\\");
            dates.push({
                fileName: filePath[filePath.length - 1],
                path: gfsList[i],
                date: Number(filePath[filePath.length - 1].split(".")[1])
            });
        }

        dates.sort((a, b) => {
            return b.date - a.date;
        });


        hourList = await getSubdirectories(path.join(__dirname, `../../model/grib2/${degree}/${dates[0].fileName}`));

        if (hourList?.length) {
            let hours = [];
            for (let i = 0; i < hourList.length; i++) {
                const filePath = hourList[i].split("\\");
                hours.push({
                    fileName: filePath[filePath.length - 1],
                    path: hourList[i],
                    date: Number(filePath[filePath.length - 1])
                });
            }

            hours.sort((a, b) => {
                return b.date - a.date;
            });

            const fileList = await getFilesInDirectory(hours[0].path);

            // return global.downloadManager.manager.getStatus();
            return {
                utcData: convertUtcDateForChinaDate(hours[0].path.split("gfs.")[1].split("\\")[0], hours[0].date - 8),
                chinaData: convertUtcDateForChinaDate(hours[0].path.split("gfs.")[1].split("\\")[0], hours[0].date),
                ...hours[0],
                list: fileList?.length ? fileList : []
            };
        }

        return [];

    }
    return [];

}

// utc 时间转中国时间
function convertUtcDateForChinaDate(day, hour) {
    return dayjs(`${day} ${hour}:00`).add(8, 'hour').format("YYYY-MM-DD HH:mm:ss");
}

exports.getGlobalWeatherData = async (req, res) => {
    const fileList = await getLastNewModel("gfs_1p00");

    // 定义中国区域的经纬度范围
    const CHINA_REGION = {
        minLon: 70,   // 东经70度
        maxLon: 140,  // 东经140度
        minLat: 15,   // 北纬15度
        maxLat: 55    // 北纬55度
    };
    const uniqueId = uuidv4();
    const tempTxtFilePath = path.join(__dirname, `../../model/model_${uniqueId}.txt`);
    const regionCommand=`-small_grib ${CHINA_REGION.minLon}:${CHINA_REGION.maxLon} ${CHINA_REGION.minLat}:${CHINA_REGION.maxLat} ${tempTxtFilePath}`;

    const command = `"${path.join(__dirname, "../../wgrib2/wgrib2.exe")}" "${fileList.list[0]}" -match "TCDC:1000 mb" -text ${tempTxtFilePath}`;

    exec(command, (error, stdout, stderr) => {
        // 读取提取的数据文件
        // const readFileRes = fs.readFileSync(tempTxtFilePath, { encoding: "utf-8" });

        // 将数据返回给前端
        res.rescc("成功", 200, stdout);
    });
}