🐛 Allowing segmented CSV to be classified

- missing case in delimiter fn
- added support for german csv delimiter

src/lib/class/Eye/EyeClassifier/EyeClassifier.ts

@@ -2,16 +2,22 @@ import type { EyeFileType } from '$lib/type/EyeFile/EyeFileType.js'
 import type { EyeSettingsType } from '$lib/type/Settings/EyeSettings/EyeSettingsType.js'
 
 export class EyeClassifier {
-  classify (slice: string): EyeSettingsType {
+  classify(slice: string): EyeSettingsType {
     const type = this.getTypeFromSlice(slice)
     if (type === 'unknown') throw new Error('Unknown file type')
     const rowDelimiter = '\r\n'
-    const columnDelimiter = this.getColumnDelimiter(type)
+    const columnDelimiter = this.getColumnDelimiter(type, slice)
     const headerRowId = type === 'ogama' ? 8 : 0
-    return { type, rowDelimiter, columnDelimiter, userInputSetting: '', headerRowId }
+    return {
+      type,
+      rowDelimiter,
+      columnDelimiter,
+      userInputSetting: '',
+      headerRowId,
+    }
   }
 
-  getTypeFromSlice (slice: string): EyeFileType {
+  getTypeFromSlice(slice: string): EyeFileType {
     if (this.isTobii(slice)) {
       if (slice.includes('Event')) return 'tobii-with-event'
       return 'tobii'
@@ -25,48 +31,84 @@ export class EyeClassifier {
     return 'unknown'
   }
 
-  getColumnDelimiter (type: EyeFileType): string {
+  getColumnDelimiter(type: EyeFileType, slice: string): string {
     switch (type) {
       case 'tobii':
       case 'tobii-with-event':
       case 'begaze':
       case 'ogama':
         return '\t'
       case 'gazepoint':
-      case 'csv':
         return ','
+      case 'csv':
+      case 'csv-segmented':
+        return this.determineCsvDelimiter(slice)
       case 'varjo':
         return ';'
       default:
         throw new Error('Unknown file type')
     }
   }
 
-  isTobii (slice: string): boolean {
+  isTobii(slice: string): boolean {
     return slice.includes('Recording timestamp')
   }
 
-  isGazePoint (slice: string): boolean {
+  isGazePoint(slice: string): boolean {
     return slice.includes('FPOGS') && slice.includes('FPOGD')
   }
 
-  isBeGaze (slice: string): boolean {
-    return slice.includes('Event Start Trial Time [ms]') && slice.includes('Event End Trial Time [ms]')
+  isBeGaze(slice: string): boolean {
+    return (
+      slice.includes('Event Start Trial Time [ms]') &&
+      slice.includes('Event End Trial Time [ms]')
+    )
   }
 
-  isOgama (slice: string): boolean {
+  isOgama(slice: string): boolean {
     return slice.includes('# Contents: Similarity Measurements of scanpaths.')
   }
 
-  isVarjo (slice: string): boolean {
+  isVarjo(slice: string): boolean {
     return slice.includes('Time') && slice.includes('Actor Label')
   }
 
-  isCsv (slice: string): boolean {
-    return slice.includes('Time') && slice.includes('Participant') && slice.includes('Stimulus') && slice.includes('AOI')
+  isCsv(slice: string): boolean {
+    return (
+      slice.includes('Time') &&
+      slice.includes('Participant') &&
+      slice.includes('Stimulus') &&
+      slice.includes('AOI')
+    )
+  }
+
+  isCsvSegmented(slice: string): boolean {
+    return (
+      slice.includes('From') &&
+      slice.includes('To') &&
+      slice.includes('Participant') &&
+      slice.includes('Stimulus') &&
+      slice.includes('AOI')
+    )
   }
 
-  isCsvSegmented (slice: string): boolean {
-    return slice.includes('From') && slice.includes('To') && slice.includes('Participant') && slice.includes('Stimulus') && slice.includes('AOI')
+  /**
+   * To determine the delimiter used in a CSV file, we count the number of occurrences of the two most common delimiters
+   * (',' and ';') in the header row. The delimiter with the higher count is used.
+   *
+   * @param slice - Text content of the first slice of the file, containing the header row
+   * @returns delimiter used in the CSV file (either ',' or ';')
+   */
+  determineCsvDelimiter(slice: string): string {
+    const internationalDelimiter = ','
+    const germanDelimiter = ';'
+    const headerOnly = slice.split('\r\n')[0]
+    const internationalDelimiterCount = headerOnly.split(
+      internationalDelimiter
+    ).length
+    const germanDelimiterCount = headerOnly.split(germanDelimiter).length
+    return internationalDelimiterCount > germanDelimiterCount
+      ? internationalDelimiter
+      : germanDelimiter
   }
 }