implement cancel command,

implement single data source logic,
implement better output messages logic

Data/expenses.json

@@ -1,18 +1,35 @@
 {
   "entertainment": {
     "limit": 1000,
-    "expenses": 0
+    "expenses": 0,
+    "displayName": "Развлечения",
+    "abbreviations": [
+      "разв"
+    ]
   },
   "extra": {
     "limit": 1000,
-    "expenses": 0
+    "expenses": 0,
+    "displayName": "Резерв",
+    "abbreviations": [
+      "ост"
+    ]
   },
   "transport": {
     "limit": 1000,
-    "expenses": 0
+    "expenses": 0,
+    "displayName": "Транспорт",
+    "abbreviations": [
+      "транс",
+      "транспорт"
+    ]
   },
   "food": {
     "limit": 1000,
-    "expenses": 0
+    "expenses": 0,
+    "displayName": "Еда",
+    "abbreviations": [
+      "еда"
+    ]
   }
 }

Service/FileService.js

@@ -34,6 +34,26 @@ class FileService {
             })
         })
     }
+
+    cancel(element) {
+        fs.readFile(appRoot + '/Data/expenses.json', 'utf-8', (err, data) => {
+            const json = JSON.parse(data)
+            const keys = Object.keys(json)
+
+            for (let i = 0; i < keys.length; i++) {
+                if (keys[i] === element.type) {
+                    json[keys[i]].expenses -= parseInt(element.amount)
+                    break
+                }
+            }
+
+            const jsonToWrite = JSON.stringify(json, null, 2)
+
+            fs.writeFile(appRoot + '/Data/expenses.json', jsonToWrite, err => {
+                if (err) throw err
+            })
+        })
+    }
 }
 
 module.exports = FileService

Service/SpendingsService.js

@@ -5,6 +5,7 @@ class SpendingsService {
         try {
             const parsedMessage = this._parseMessage(message)
             this.fileService.write(parsedMessage)
+            this.spendingsHistory.push(parsedMessage)
             return 'good'
         } catch {
             return 'error'
@@ -17,9 +18,9 @@ class SpendingsService {
 
         let message = ''
 
-        Object.keys(json).forEach((key, i) => {
+        Object.keys(json).forEach(key => {
             const percentage = Math.round(json[key].expenses / json[key].limit * 100)
-            message += `${key}: ${json[key].expenses} / ${json[key].limit} (${percentage} %)\n`
+            message += `${json[key].displayName}: ${json[key].expenses} / ${json[key].limit} (${percentage} %)\n`
         })
 
         return message
@@ -36,7 +37,33 @@ class SpendingsService {
     }
 
     itemsAvailible() {
-        return JSON.stringify(this.types, null, 2)
+        try {
+            const data = this.fileService.read()
+            const json = JSON.parse(data)
+            const keys = Object.keys(json)
+            let message = ''
+
+            for (let i = 0; i < keys.length; i++) {
+                message += `${json[keys[i]].displayName} : ${json[keys[i]].abbreviations}\n`
+            }
+
+            return message
+        } catch {
+            return 'error'
+        }
+    }
+
+    cancelLastOperation() {
+        try {
+            if (this.spendingsHistory.length === 0) {
+                return 'no history. nothing to cancel'
+            }
+            let element = this.spendingsHistory.pop()
+            this.fileService.cancel(element)
+            return 'good'
+        } catch {
+            return 'error'
+        }
     }
 
     _parseMessage(message) {
@@ -51,19 +78,24 @@ class SpendingsService {
     }
 
     _typeForAbbreviation(abbreviation) {
-        return this.types[abbreviation]
-    }
+        const data = this.fileService.read()
+        const json = JSON.parse(data)
+        const keys = Object.keys(json)
 
-    constructor() {
-        this.types = {
-            'разв': 'entertainment',
-            'транс': 'transport',
-            'ост': 'extra',
-            'еда': 'food'
+        for (let i = 0; i < keys.length; i++) {
+            if (json[keys[i]].abbreviations.includes(abbreviation)) {
+                return keys[i]
+            }
         }
 
+        return null
+    }
+
+    constructor() {
         this.fileService = new FileService()
+        this.spendingsHistory = Array()
     }
+
 }
 
 module.exports = SpendingsService

app.js

@@ -35,6 +35,11 @@ bot.command('items', ctx => {
     ctx.reply(message)
 })
 
+bot.command('cancel', ctx => {
+    const message = spendingsService.cancelLastOperation()
+    ctx.reply(message)
+})
+
 bot.launch().catch(e => {
     console.log(e.message)
 })