Better memory and time usage

.gitignore

@@ -8,6 +8,7 @@ node_modules
 # testing
 coverage
 *.sqlite3
+data/
 
 # production
 build/

server/cli/import.js

@@ -4,42 +4,40 @@ const db = require("../models")
 const Airport = db['Airport']
 const Flight = db['Flight']
 
-db.sequelize.sync()
+db.sequelize.sync().then(() => (async () => {
+    // Refresh airport data
+    let airportData = await fs.promises.readFile(`${__dirname}/../data/airports.json`, 'utf-8')
+    airportData = JSON.parse(airportData)
 
-fs.readFile(__dirname + '/../data/airports.json', 'utf-8', (error, data) => {
-    if (error) {
-        console.log(error)
-        return
-    }
-
-    data = JSON.parse(data)
-    Airport.findAll({attributes: ['icao_code', 'iata_code']}).then(results => {
     let icao_codes = []
     let iata_codes = []
-        results.forEach(result => {
+    let results = await Airport.findAll({attributes: ['icao_code', 'iata_code']})
+    for (let result of results) {
         if (result.icao_code)
             icao_codes.push(result.icao_code)
         if (result.iata_code)
             iata_codes.push(result.iata_code)
-        })
-
-        Airport.bulkCreate(data['response'].filter(airport => !icao_codes.includes(airport.icao_code)
-            && !iata_codes.includes(airport.iata_code))).then()
-    }).then(() => {
-        Airport.findAll({attributes: ['icao_code']}).then(airports => {
-            airports.forEach(airport => {
-                fs.readFile(__dirname + `/../data/routes/${airport.icao_code}.json`, 'utf-8', (error, data) => {
-                    if (error) {
-                        console.log(error)
-                        return
     }
+    // Import all not-imported airports
+    await Airport.bulkCreate(airportData['response'].filter(airport => !icao_codes.includes(airport.icao_code)
+        && !iata_codes.includes(airport.iata_code)))
 
-                    data = JSON.parse(data)
-                    Flight.destroy({where: {dep_icao: airport.icao_code}}).then(() => {
-                        Flight.bulkCreate(data['response']).then()
-                    })
-                })
-            })
-        })
-    })
-})
+    // Import flight routes per departure
+    let airports = await Airport.findAll({attributes: ['icao_code']})
+    for (let airport of airports) {
+        const airportRoutesFile = `${__dirname}/../data/routes/${airport.icao_code}.json`
+        // Ignore unexisting files
+        if (!(await fs.promises.stat(airportRoutesFile).catch(() => false)))
+            continue
+
+        // Read routes
+        let flightsData = await fs.promises.readFile(airportRoutesFile, 'utf-8')
+        flightsData = JSON.parse(flightsData)
+
+        // First remove old routes
+        await Flight.destroy({where: {dep_icao: airport.icao_code}})
+
+        // Then import new routes
+        await Flight.bulkCreate(flightsData['response'])
+    }
+})())