import * as fs from "fs/promises";
import { parseString } from "xml2js";  

export function generateTrimlogInput(filename, name = "Walk") {
  return new Promise(async(resolve, reject) => {
    parseString(await fs.readFile(filename, "utf-8"), (err, res) => {
      if (err != null) {
        reject(err);
      }

      const data = res.TrainingCenterDatabase.Activities[0].Activity[0];
      const map = {};
  
      const date = new Date(res.TrainingCenterDatabase.Activities[0].Activity[0].Id[0]);
      const dateStr = `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(date.getDate())}`
  
      let totalCalories = 0;
      let minAltitude = null;
      let maxAltitude = null;
  
      for (const lap of data.Lap) {
        totalCalories += parseFloat(lap.Calories[0]) || 0;
  
        for (const tp of lap.Track[0].Trackpoint) {
          const point = {
            time: tp.Time[0],
            longitude: parseFloat(tp.Position?.[0]?.LongitudeDegrees[0]),
            latitude: parseFloat(tp.Position?.[0]?.LatitudeDegrees[0]),
            altitude: parseFloat(tp.AltitudeMeters[0]),
            distance: parseFloat(tp.DistanceMeters[0]),
            heartrate: parseFloat(tp.HeartRateBpm?.[0].Value?.[0]),
          };
  
          if (minAltitude == null || point.altitude < minAltitude) {
            minAltitude = point.altitude;
          }
          if (maxAltitude == null || point.altitude > maxAltitude) {
            maxAltitude = point.altitude;
          }
  
          map[tp.Time[0]] = point;
        }
      }

      const out = {
        date: dateStr,
        contents: [{rawActivity: {
          kind: "Walking",
          sets: [],
          effortScale: 1,
          weight: 0,
          measurements: Object.keys(map).sort().map(k => map[k]).map(p => ({
            seconds: Math.round((new Date(p.time) - date) / 1000),
            meters: p.distance,
            pulse: p.heartrate,
          }))
        }}],
        description: name,
        tags: [
          { key: "tcx:Time", value: res.TrainingCenterDatabase.Activities[0].Activity[0].Id[0] },
          { key: "tcx:TotalCalories", value: totalCalories.toFixed(1) },
          { key: "tcx:MaximumAltitude", value: maxAltitude.toFixed(1) },
          { key: "tcx:MinimumAltitude", value: minAltitude.toFixed(1) },
        ]
      }
  
      resolve(out);
    });
  })
}

export function today() {
  const date = new Date();
  return `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(date.getDate())}`;
}

function pad(n) {return n > 9 ? n.toString() : `0${n}`}

/*

{
    "date": "2023-12-31",
    "contents": [
        {
            "rawActivity": {
                "kind": "Walking",
                "sets": [],
                "measurements": [
                    {
                        "seconds": 1234,
                        "calories": 4321,
                        "meters": 432553
                    },
                    {
                        "seconds": 2468,
                        "calories": 42342,
                        "meters": 3424
                    },
                    {
                        "seconds": 3702,
                        "calories": 23423,
                        "meters": 2342
                    },
                    {
                        "seconds": 4936,
                        "calories": 23423,
                        "meters": 2342
                    }
                ],
                "effortScale": 1,
                "weight": 0
            }
        }
    ],
    "description": "asdfasdfasdf",
    "tags": []
} 

*/