managarten/apps-archived/reader/apps/mobile/ReadMe/MinimalDatabase.md

Absolut Minimalste Text-to-Speech Datenbank

Philosophie

Eine einzige Tabelle für alles. JSONB macht's möglich. Keine Joins, keine Komplexität, nur pure Funktionalität.

Die Eine Tabelle

-- Die einzige Tabelle die du brauchst
CREATE TABLE texts (
  id UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
  user_id UUID REFERENCES auth.users(id) ON DELETE CASCADE,
  
  -- Der eigentliche Content
  title TEXT NOT NULL,
  content TEXT NOT NULL,
  
  -- ALLES andere in einem JSONB Feld
  data JSONB DEFAULT '{}' NOT NULL,
  
  -- Nur die absolut nötigen Timestamps
  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW()
);

-- Ein Index für Performance
CREATE INDEX idx_texts_user ON texts(user_id);
CREATE INDEX idx_texts_data ON texts USING GIN (data);

-- RLS aktivieren
ALTER TABLE texts ENABLE ROW LEVEL SECURITY;

-- Jeder sieht nur seine eigenen Texte
CREATE POLICY "Own texts only" ON texts
  FOR ALL USING (auth.uid() = user_id);

-- Update Timestamp Trigger
CREATE OR REPLACE FUNCTION update_updated_at()
RETURNS TRIGGER AS $$
BEGIN
  NEW.updated_at = NOW();
  RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER update_texts_updated_at
  BEFORE UPDATE ON texts
  FOR EACH ROW
  EXECUTE FUNCTION update_updated_at();

Was kommt ins data JSONB Feld?

// Beispiel eines vollständigen Text-Objekts
{
  id: "uuid-hier",
  user_id: "user-uuid",
  title: "Mein Buch",
  content: "Der eigentliche Text...",
  data: {
    // Vorlese-Einstellungen
    tts: {
      speed: 1.0,
      voice: "de-DE",
      lastPosition: 1234,  // Zeichen-Position
      lastPlayed: "2024-01-15T10:30:00Z"
    },
    
    // Audio-Cache (NEU!)
    audio: {
      hasLocalCache: false,
      chunks: [
        {
          id: "chunk-1",
          start: 0,
          end: 1000,  // Zeichen-Position
          filename: "text-uuid-chunk-1.mp3",
          size: 245760,  // Bytes
          duration: 120,  // Sekunden
          createdAt: "2024-01-15T10:00:00Z"
        }
      ],
      totalSize: 2457600,  // Total in Bytes
      lastGenerated: "2024-01-15T10:00:00Z",
      settings: {  // Settings bei Generierung
        voice: "de-DE",
        speed: 1.0
      }
    },
    
    // Organisation (optional)
    tags: ["roman", "favorit"],
    color: "#FF5733",
    
    // Statistiken (optional)
    stats: {
      playCount: 5,
      totalTime: 3600,  // Sekunden
      completed: false
    },
    
    // Was auch immer du später brauchst
    notes: "Für die Zugfahrt",
    source: "kindle-import"
  },
  created_at: "2024-01-01T10:00:00Z",
  updated_at: "2024-01-15T10:30:00Z"
}

Basis-Operationen

Text erstellen

const { data, error } = await supabase
  .from('texts')
  .insert({
    title: 'Mein Text',
    content: 'Inhalt hier...',
    data: {
      tts: { speed: 1.0, voice: 'de-DE' },
      tags: ['neu']
    }
  });

Alle Texte holen

const { data: texts } = await supabase
  .from('texts')
  .select('*')
  .order('updated_at', { ascending: false });

Nach Tags filtern

const { data: filtered } = await supabase
  .from('texts')
  .select('*')
  .contains('data', { tags: ['favorit'] });

Leseposition updaten

const { error } = await supabase
  .from('texts')
  .update({ 
    data: {
      ...currentData,
      tts: {
        ...currentData.tts,
        lastPosition: 5678,
        lastPlayed: new Date().toISOString()
      }
    }
  })
  .eq('id', textId);

Statistiken hochzählen

-- Als Postgres Funktion für atomare Updates
CREATE OR REPLACE FUNCTION increment_play_count(text_id UUID)
RETURNS void AS $$
BEGIN
  UPDATE texts
  SET data = jsonb_set(
    jsonb_set(
      data,
      '{stats,playCount}',
      to_jsonb(COALESCE((data->'stats'->>'playCount')::int, 0) + 1)
    ),
    '{tts,lastPlayed}',
    to_jsonb(NOW())
  )
  WHERE id = text_id;
END;
$$ LANGUAGE plpgsql;

-- Aufruf
SELECT increment_play_count('text-uuid-hier');

Supabase Quickstart

# 1. Supabase CLI installieren
npm install -g supabase

# 2. Projekt initialisieren
supabase init

# 3. Migration erstellen
supabase migration new create_texts_table

# 4. SQL von oben in die Migration kopieren

# 5. Migration ausführen
supabase db push

React Native Integration

// hooks/useTexts.js
import { useState, useEffect } from 'react';
import { supabase } from '../lib/supabase';

export const useTexts = () => {
  const [texts, setTexts] = useState([]);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    fetchTexts();
  }, []);

  const fetchTexts = async () => {
    const { data } = await supabase
      .from('texts')
      .select('*')
      .order('updated_at', { ascending: false });
    
    setTexts(data || []);
    setLoading(false);
  };

  const createText = async (title, content) => {
    const { data, error } = await supabase
      .from('texts')
      .insert({
        title,
        content,
        data: { tts: { speed: 1.0, voice: 'de-DE' } }
      })
      .select()
      .single();
    
    if (data) {
      setTexts([data, ...texts]);
    }
    return { data, error };
  };

  const updatePosition = async (textId, position) => {
    const text = texts.find(t => t.id === textId);
    if (!text) return;

    await supabase
      .from('texts')
      .update({
        data: {
          ...text.data,
          tts: {
            ...text.data.tts,
            lastPosition: position,
            lastPlayed: new Date().toISOString()
          }
        }
      })
      .eq('id', textId);
  };

  return { texts, loading, createText, updatePosition, refetch: fetchTexts };
};

Audio-Cache Management

// hooks/useAudioCache.js
import * as FileSystem from 'expo-file-system';
import * as Speech from 'expo-speech';
import { Audio } from 'expo-av';
import { supabase } from '../lib/supabase';

const AUDIO_DIR = `${FileSystem.documentDirectory}audio/`;

export const useAudioCache = () => {
  // Verzeichnis erstellen beim Start
  useEffect(() => {
    FileSystem.makeDirectoryAsync(AUDIO_DIR, { intermediates: true })
      .catch(() => {}); // Ignorieren wenn bereits existiert
  }, []);

  // Text in Chunks aufteilen (z.B. alle 1000 Zeichen)
  const chunkText = (text, chunkSize = 1000) => {
    const chunks = [];
    for (let i = 0; i < text.length; i += chunkSize) {
      chunks.push({
        id: `chunk-${chunks.length}`,
        start: i,
        end: Math.min(i + chunkSize, text.length),
        content: text.slice(i, i + chunkSize)
      });
    }
    return chunks;
  };

  // Audio für einen Chunk generieren und speichern
  const generateAudioChunk = async (textId, chunk, settings) => {
    const filename = `${textId}-${chunk.id}.mp3`;
    const filePath = `${AUDIO_DIR}${filename}`;
    
    // Option 1: Mit einer TTS API (z.B. Google Cloud TTS)
    // const audioData = await callTTSAPI(chunk.content, settings);
    // await FileSystem.writeAsStringAsync(filePath, audioData, {
    //   encoding: FileSystem.EncodingType.Base64
    // });

    // Option 2: Workaround mit expo-speech (keine direkte MP3 Generierung)
    // Hinweis: expo-speech kann nicht direkt als Datei speichern
    // Alternative: Web-API oder Cloud-Service nutzen
    
    const fileInfo = await FileSystem.getInfoAsync(filePath);
    
    return {
      id: chunk.id,
      start: chunk.start,
      end: chunk.end,
      filename,
      size: fileInfo.size || 0,
      duration: Math.ceil(chunk.content.length / 150) * 60, // Geschätzt
      createdAt: new Date().toISOString()
    };
  };

  // Alle Chunks für einen Text generieren
  const generateAudioForText = async (textId, content, settings = {}) => {
    const chunks = chunkText(content);
    const audioChunks = [];
    
    for (const chunk of chunks) {
      const audioChunk = await generateAudioChunk(textId, chunk, settings);
      audioChunks.push(audioChunk);
    }
    
    // Metadaten in Supabase updaten
    await updateAudioMetadata(textId, audioChunks, settings);
    
    return audioChunks;
  };

  // Audio-Metadaten in Supabase speichern
  const updateAudioMetadata = async (textId, chunks, settings) => {
    const totalSize = chunks.reduce((sum, chunk) => sum + chunk.size, 0);
    
    const { data: currentText } = await supabase
      .from('texts')
      .select('data')
      .eq('id', textId)
      .single();
    
    await supabase
      .from('texts')
      .update({
        data: {
          ...currentText.data,
          audio: {
            hasLocalCache: true,
            chunks,
            totalSize,
            lastGenerated: new Date().toISOString(),
            settings
          }
        }
      })
      .eq('id', textId);
  };

  // Audio abspielen
  const playAudioFromCache = async (textId, startPosition = 0) => {
    const { data: text } = await supabase
      .from('texts')
      .select('data')
      .eq('id', textId)
      .single();
    
    if (!text?.data?.audio?.hasLocalCache) {
      throw new Error('Kein Audio-Cache vorhanden');
    }
    
    // Richtigen Chunk finden
    const chunk = text.data.audio.chunks.find(
      c => startPosition >= c.start && startPosition < c.end
    );
    
    if (!chunk) return;
    
    const filePath = `${AUDIO_DIR}${chunk.filename}`;
    const { sound } = await Audio.Sound.createAsync({ uri: filePath });
    
    // Position innerhalb des Chunks berechnen
    const chunkPosition = startPosition - chunk.start;
    const positionMillis = (chunkPosition / chunk.end) * chunk.duration * 1000;
    
    await sound.setPositionAsync(positionMillis);
    await sound.playAsync();
    
    return sound;
  };

  // Cache löschen
  const clearAudioCache = async (textId) => {
    const { data: text } = await supabase
      .from('texts')
      .select('data')
      .eq('id', textId)
      .single();
    
    if (text?.data?.audio?.chunks) {
      for (const chunk of text.data.audio.chunks) {
        try {
          await FileSystem.deleteAsync(`${AUDIO_DIR}${chunk.filename}`);
        } catch (e) {
          console.log('Fehler beim Löschen:', e);
        }
      }
    }
    
    // Metadaten updaten
    await supabase
      .from('texts')
      .update({
        data: {
          ...text.data,
          audio: {
            hasLocalCache: false,
            chunks: [],
            totalSize: 0
          }
        }
      })
      .eq('id', textId);
  };

  // Cache-Größe berechnen
  const getCacheSize = async () => {
    const files = await FileSystem.readDirectoryAsync(AUDIO_DIR);
    let totalSize = 0;
    
    for (const file of files) {
      const info = await FileSystem.getInfoAsync(`${AUDIO_DIR}${file}`);
      totalSize += info.size || 0;
    }
    
    return totalSize;
  };

  return {
    generateAudioForText,
    playAudioFromCache,
    clearAudioCache,
    getCacheSize
  };
};

Beispiel-Screen für Audio-Management

// screens/TextDetailScreen.js
import React, { useState } from 'react';
import { View, Text, Button, ActivityIndicator } from 'react-native';
import { useAudioCache } from '../hooks/useAudioCache';

export const TextDetailScreen = ({ route }) => {
  const { text } = route.params;
  const { generateAudioForText, playAudioFromCache, clearAudioCache } = useAudioCache();
  const [generating, setGenerating] = useState(false);
  
  const hasCache = text.data?.audio?.hasLocalCache;
  
  const handleGenerateAudio = async () => {
    setGenerating(true);
    try {
      await generateAudioForText(text.id, text.content, {
        voice: text.data?.tts?.voice || 'de-DE',
        speed: text.data?.tts?.speed || 1.0
      });
      // Text-Objekt neu laden
    } catch (error) {
      console.error('Fehler beim Generieren:', error);
    } finally {
      setGenerating(false);
    }
  };
  
  const handlePlay = async () => {
    try {
      const position = text.data?.tts?.lastPosition || 0;
      await playAudioFromCache(text.id, position);
    } catch (error) {
      // Fallback zu expo-speech
      Speech.speak(text.content.slice(position), {
        language: text.data?.tts?.voice || 'de-DE',
        rate: text.data?.tts?.speed || 1.0
      });
    }
  };
  
  return (
    <View>
      <Text>{text.title}</Text>
      
      {!hasCache && (
        <Button
          title="Audio generieren & speichern"
          onPress={handleGenerateAudio}
          disabled={generating}
        />
      )}
      
      {generating && <ActivityIndicator />}
      
      {hasCache && (
        <>
          <Text>
            Audio gespeichert: {(text.data.audio.totalSize / 1024 / 1024).toFixed(2)} MB
          </Text>
          <Button title="Offline abspielen" onPress={handlePlay} />
          <Button title="Cache löschen" onPress={() => clearAudioCache(text.id)} />
        </>
      )}
    </View>
  );
};

Vorteile dieser Struktur

✅ Eine Tabelle = Keine Joins, keine Komplexität
✅ JSONB = Unendlich erweiterbar ohne Migrations
✅ Performance = PostgreSQL's JSONB ist super schnell
✅ Einfach = Jeder versteht es sofort
✅ Flexibel = Neue Features sind nur ein JSON-Feld entfernt

Erweiterungsbeispiele

// Später: Lesezeichen hinzufügen
data.bookmarks = [
  { position: 1234, note: "Wichtige Stelle", created: "2024-01-15" }
];

// Später: Sharing hinzufügen  
data.sharing = {
  isPublic: false,
  shareToken: "abc123",
  sharedWith: ["email@example.com"]
};

// Später: AI-Features
data.ai = {
  summary: "KI-generierte Zusammenfassung",
  keywords: ["Thema1", "Thema2"],
  difficulty: "medium"
};

Das war's! 🎉

Mit dieser einen Tabelle kannst du:

• Texte speichern ✓
• Vorlesen mit gespeicherter Position ✓
• Tags/Kategorien verwalten ✓
• Statistiken tracken ✓
• Beliebig erweitern ✓

Keine zweite Tabelle nötig. Kein Over-Engineering. Einfach machen.