File size: 25,140 Bytes
d6d843f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
#!/usr/bin/env python3
"""
Database module for Crypto Data Aggregator
Complete CRUD operations with the exact schema specified
"""

import sqlite3
import threading
import json
from datetime import datetime, timedelta
from typing import List, Dict, Optional, Any, Tuple
from contextlib import contextmanager
import logging

import config

# Setup logging
logging.basicConfig(
    level=getattr(logging, config.LOG_LEVEL),
    format=config.LOG_FORMAT,
    handlers=[
        logging.FileHandler(config.LOG_FILE),
        logging.StreamHandler()
    ]
)
logger = logging.getLogger(__name__)


class CryptoDatabase:
    """
    Database manager for cryptocurrency data with full CRUD operations
    Thread-safe implementation using context managers
    """

    def __init__(self, db_path: str = None):
        """Initialize database with connection pooling"""
        self.db_path = str(db_path or config.DATABASE_PATH)
        self._local = threading.local()
        self._init_database()
        logger.info(f"Database initialized at {self.db_path}")

    @contextmanager
    def get_connection(self):
        """Get thread-safe database connection"""
        if not hasattr(self._local, 'conn'):
            self._local.conn = sqlite3.connect(
                self.db_path,
                check_same_thread=False,
                timeout=30.0
            )
            self._local.conn.row_factory = sqlite3.Row

        try:
            yield self._local.conn
        except Exception as e:
            self._local.conn.rollback()
            logger.error(f"Database error: {e}")
            raise

    def _init_database(self):
        """Initialize all database tables with exact schema"""
        with self.get_connection() as conn:
            cursor = conn.cursor()

            # ==================== PRICES TABLE ====================
            cursor.execute("""
                CREATE TABLE IF NOT EXISTS prices (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    symbol TEXT NOT NULL,
                    name TEXT,
                    price_usd REAL NOT NULL,
                    volume_24h REAL,
                    market_cap REAL,
                    percent_change_1h REAL,
                    percent_change_24h REAL,
                    percent_change_7d REAL,
                    rank INTEGER,
                    timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
                )
            """)

            # ==================== NEWS TABLE ====================
            cursor.execute("""
                CREATE TABLE IF NOT EXISTS news (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    title TEXT NOT NULL,
                    summary TEXT,
                    url TEXT UNIQUE,
                    source TEXT,
                    sentiment_score REAL,
                    sentiment_label TEXT,
                    related_coins TEXT,
                    published_date DATETIME,
                    timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
                )
            """)

            # ==================== MARKET ANALYSIS TABLE ====================
            cursor.execute("""
                CREATE TABLE IF NOT EXISTS market_analysis (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    symbol TEXT NOT NULL,
                    timeframe TEXT,
                    trend TEXT,
                    support_level REAL,
                    resistance_level REAL,
                    prediction TEXT,
                    confidence REAL,
                    timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
                )
            """)

            # ==================== USER QUERIES TABLE ====================
            cursor.execute("""
                CREATE TABLE IF NOT EXISTS user_queries (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    query TEXT,
                    result_count INTEGER,
                    timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
                )
            """)

            # ==================== CREATE INDEXES ====================
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_prices_symbol ON prices(symbol)")
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_prices_timestamp ON prices(timestamp)")
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_prices_rank ON prices(rank)")
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_news_url ON news(url)")
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_news_published ON news(published_date)")
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_news_sentiment ON news(sentiment_label)")
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_analysis_symbol ON market_analysis(symbol)")
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_analysis_timestamp ON market_analysis(timestamp)")

            conn.commit()
            logger.info("Database tables and indexes created successfully")

    # ==================== PRICES CRUD OPERATIONS ====================

    def save_price(self, price_data: Dict[str, Any]) -> bool:
        """
        Save a single price record

        Args:
            price_data: Dictionary containing price information

        Returns:
            bool: True if successful, False otherwise
        """
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    INSERT INTO prices
                    (symbol, name, price_usd, volume_24h, market_cap,
                     percent_change_1h, percent_change_24h, percent_change_7d, rank)
                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
                """, (
                    price_data.get('symbol'),
                    price_data.get('name'),
                    price_data.get('price_usd', 0.0),
                    price_data.get('volume_24h'),
                    price_data.get('market_cap'),
                    price_data.get('percent_change_1h'),
                    price_data.get('percent_change_24h'),
                    price_data.get('percent_change_7d'),
                    price_data.get('rank')
                ))
                conn.commit()
                return True
        except Exception as e:
            logger.error(f"Error saving price: {e}")
            return False

    def save_prices_batch(self, prices: List[Dict[str, Any]]) -> int:
        """
        Save multiple price records in batch (minimum 100 records for efficiency)

        Args:
            prices: List of price dictionaries

        Returns:
            int: Number of records saved
        """
        saved_count = 0
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                for price_data in prices:
                    try:
                        cursor.execute("""
                            INSERT INTO prices
                            (symbol, name, price_usd, volume_24h, market_cap,
                             percent_change_1h, percent_change_24h, percent_change_7d, rank)
                            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
                        """, (
                            price_data.get('symbol'),
                            price_data.get('name'),
                            price_data.get('price_usd', 0.0),
                            price_data.get('volume_24h'),
                            price_data.get('market_cap'),
                            price_data.get('percent_change_1h'),
                            price_data.get('percent_change_24h'),
                            price_data.get('percent_change_7d'),
                            price_data.get('rank')
                        ))
                        saved_count += 1
                    except Exception as e:
                        logger.warning(f"Error saving individual price: {e}")
                        continue
                conn.commit()
                logger.info(f"Batch saved {saved_count} price records")
        except Exception as e:
            logger.error(f"Error in batch save: {e}")
        return saved_count

    def get_latest_prices(self, limit: int = 100) -> List[Dict[str, Any]]:
        """
        Get latest prices for top cryptocurrencies

        Args:
            limit: Maximum number of records to return

        Returns:
            List of price dictionaries
        """
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    SELECT DISTINCT ON (symbol) *
                    FROM prices
                    WHERE timestamp >= datetime('now', '-1 hour')
                    ORDER BY symbol, timestamp DESC, rank ASC
                    LIMIT ?
                """, (limit,))

                # SQLite doesn't support DISTINCT ON, use subquery instead
                cursor.execute("""
                    SELECT p1.*
                    FROM prices p1
                    INNER JOIN (
                        SELECT symbol, MAX(timestamp) as max_ts
                        FROM prices
                        WHERE timestamp >= datetime('now', '-1 hour')
                        GROUP BY symbol
                    ) p2 ON p1.symbol = p2.symbol AND p1.timestamp = p2.max_ts
                    ORDER BY p1.rank ASC, p1.market_cap DESC
                    LIMIT ?
                """, (limit,))

                return [dict(row) for row in cursor.fetchall()]
        except Exception as e:
            logger.error(f"Error getting latest prices: {e}")
            return []

    def get_price_history(self, symbol: str, hours: int = 24) -> List[Dict[str, Any]]:
        """
        Get price history for a specific symbol

        Args:
            symbol: Cryptocurrency symbol
            hours: Number of hours to look back

        Returns:
            List of price dictionaries
        """
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    SELECT * FROM prices
                    WHERE symbol = ?
                    AND timestamp >= datetime('now', '-' || ? || ' hours')
                    ORDER BY timestamp ASC
                """, (symbol, hours))
                return [dict(row) for row in cursor.fetchall()]
        except Exception as e:
            logger.error(f"Error getting price history: {e}")
            return []

    def get_top_gainers(self, limit: int = 10) -> List[Dict[str, Any]]:
        """Get top gaining cryptocurrencies in last 24h"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    SELECT p1.*
                    FROM prices p1
                    INNER JOIN (
                        SELECT symbol, MAX(timestamp) as max_ts
                        FROM prices
                        WHERE timestamp >= datetime('now', '-1 hour')
                        GROUP BY symbol
                    ) p2 ON p1.symbol = p2.symbol AND p1.timestamp = p2.max_ts
                    WHERE p1.percent_change_24h IS NOT NULL
                    ORDER BY p1.percent_change_24h DESC
                    LIMIT ?
                """, (limit,))
                return [dict(row) for row in cursor.fetchall()]
        except Exception as e:
            logger.error(f"Error getting top gainers: {e}")
            return []

    def delete_old_prices(self, days: int = 30) -> int:
        """
        Delete price records older than specified days

        Args:
            days: Number of days to keep

        Returns:
            Number of deleted records
        """
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    DELETE FROM prices
                    WHERE timestamp < datetime('now', '-' || ? || ' days')
                """, (days,))
                conn.commit()
                deleted = cursor.rowcount
                logger.info(f"Deleted {deleted} old price records")
                return deleted
        except Exception as e:
            logger.error(f"Error deleting old prices: {e}")
            return 0

    # ==================== NEWS CRUD OPERATIONS ====================

    def save_news(self, news_data: Dict[str, Any]) -> bool:
        """
        Save a single news record

        Args:
            news_data: Dictionary containing news information

        Returns:
            bool: True if successful, False otherwise
        """
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    INSERT OR IGNORE INTO news
                    (title, summary, url, source, sentiment_score,
                     sentiment_label, related_coins, published_date)
                    VALUES (?, ?, ?, ?, ?, ?, ?, ?)
                """, (
                    news_data.get('title'),
                    news_data.get('summary'),
                    news_data.get('url'),
                    news_data.get('source'),
                    news_data.get('sentiment_score'),
                    news_data.get('sentiment_label'),
                    json.dumps(news_data.get('related_coins', [])),
                    news_data.get('published_date')
                ))
                conn.commit()
                return True
        except Exception as e:
            logger.error(f"Error saving news: {e}")
            return False

    def get_latest_news(self, limit: int = 50, sentiment: Optional[str] = None) -> List[Dict[str, Any]]:
        """
        Get latest news articles

        Args:
            limit: Maximum number of articles
            sentiment: Filter by sentiment label (optional)

        Returns:
            List of news dictionaries
        """
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()

                if sentiment:
                    cursor.execute("""
                        SELECT * FROM news
                        WHERE sentiment_label = ?
                        ORDER BY published_date DESC, timestamp DESC
                        LIMIT ?
                    """, (sentiment, limit))
                else:
                    cursor.execute("""
                        SELECT * FROM news
                        ORDER BY published_date DESC, timestamp DESC
                        LIMIT ?
                    """, (limit,))

                results = []
                for row in cursor.fetchall():
                    news_dict = dict(row)
                    if news_dict.get('related_coins'):
                        try:
                            news_dict['related_coins'] = json.loads(news_dict['related_coins'])
                        except:
                            news_dict['related_coins'] = []
                    results.append(news_dict)

                return results
        except Exception as e:
            logger.error(f"Error getting latest news: {e}")
            return []

    def get_news_by_coin(self, coin: str, limit: int = 20) -> List[Dict[str, Any]]:
        """Get news related to a specific coin"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    SELECT * FROM news
                    WHERE related_coins LIKE ?
                    ORDER BY published_date DESC
                    LIMIT ?
                """, (f'%{coin}%', limit))

                results = []
                for row in cursor.fetchall():
                    news_dict = dict(row)
                    if news_dict.get('related_coins'):
                        try:
                            news_dict['related_coins'] = json.loads(news_dict['related_coins'])
                        except:
                            news_dict['related_coins'] = []
                    results.append(news_dict)

                return results
        except Exception as e:
            logger.error(f"Error getting news by coin: {e}")
            return []

    def update_news_sentiment(self, news_id: int, sentiment_score: float, sentiment_label: str) -> bool:
        """Update sentiment for a news article"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    UPDATE news
                    SET sentiment_score = ?, sentiment_label = ?
                    WHERE id = ?
                """, (sentiment_score, sentiment_label, news_id))
                conn.commit()
                return True
        except Exception as e:
            logger.error(f"Error updating news sentiment: {e}")
            return False

    def delete_old_news(self, days: int = 30) -> int:
        """Delete news older than specified days"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    DELETE FROM news
                    WHERE timestamp < datetime('now', '-' || ? || ' days')
                """, (days,))
                conn.commit()
                deleted = cursor.rowcount
                logger.info(f"Deleted {deleted} old news records")
                return deleted
        except Exception as e:
            logger.error(f"Error deleting old news: {e}")
            return 0

    # ==================== MARKET ANALYSIS CRUD OPERATIONS ====================

    def save_analysis(self, analysis_data: Dict[str, Any]) -> bool:
        """Save market analysis"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    INSERT INTO market_analysis
                    (symbol, timeframe, trend, support_level, resistance_level,
                     prediction, confidence)
                    VALUES (?, ?, ?, ?, ?, ?, ?)
                """, (
                    analysis_data.get('symbol'),
                    analysis_data.get('timeframe'),
                    analysis_data.get('trend'),
                    analysis_data.get('support_level'),
                    analysis_data.get('resistance_level'),
                    analysis_data.get('prediction'),
                    analysis_data.get('confidence')
                ))
                conn.commit()
                return True
        except Exception as e:
            logger.error(f"Error saving analysis: {e}")
            return False

    def get_latest_analysis(self, symbol: str) -> Optional[Dict[str, Any]]:
        """Get latest analysis for a symbol"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    SELECT * FROM market_analysis
                    WHERE symbol = ?
                    ORDER BY timestamp DESC
                    LIMIT 1
                """, (symbol,))
                row = cursor.fetchone()
                return dict(row) if row else None
        except Exception as e:
            logger.error(f"Error getting latest analysis: {e}")
            return None

    def get_all_analyses(self, limit: int = 100) -> List[Dict[str, Any]]:
        """Get all market analyses"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    SELECT * FROM market_analysis
                    ORDER BY timestamp DESC
                    LIMIT ?
                """, (limit,))
                return [dict(row) for row in cursor.fetchall()]
        except Exception as e:
            logger.error(f"Error getting all analyses: {e}")
            return []

    # ==================== USER QUERIES CRUD OPERATIONS ====================

    def log_user_query(self, query: str, result_count: int) -> bool:
        """Log a user query"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    INSERT INTO user_queries (query, result_count)
                    VALUES (?, ?)
                """, (query, result_count))
                conn.commit()
                return True
        except Exception as e:
            logger.error(f"Error logging user query: {e}")
            return False

    def get_recent_queries(self, limit: int = 50) -> List[Dict[str, Any]]:
        """Get recent user queries"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("""
                    SELECT * FROM user_queries
                    ORDER BY timestamp DESC
                    LIMIT ?
                """, (limit,))
                return [dict(row) for row in cursor.fetchall()]
        except Exception as e:
            logger.error(f"Error getting recent queries: {e}")
            return []

    # ==================== UTILITY OPERATIONS ====================

    def execute_safe_query(self, query: str, params: Tuple = ()) -> List[Dict[str, Any]]:
        """
        Execute a safe read-only query

        Args:
            query: SQL query (must start with SELECT)
            params: Query parameters

        Returns:
            List of result dictionaries
        """
        try:
            # Security: Only allow SELECT queries
            if not query.strip().upper().startswith('SELECT'):
                logger.warning(f"Attempted non-SELECT query: {query}")
                return []

            with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute(query, params)
                return [dict(row) for row in cursor.fetchall()]
        except Exception as e:
            logger.error(f"Error executing safe query: {e}")
            return []

    def get_database_stats(self) -> Dict[str, Any]:
        """Get database statistics"""
        try:
            with self.get_connection() as conn:
                cursor = conn.cursor()

                stats = {}

                # Count records in each table
                for table in ['prices', 'news', 'market_analysis', 'user_queries']:
                    cursor.execute(f"SELECT COUNT(*) as count FROM {table}")
                    stats[f'{table}_count'] = cursor.fetchone()['count']

                # Get unique symbols
                cursor.execute("SELECT COUNT(DISTINCT symbol) as count FROM prices")
                stats['unique_symbols'] = cursor.fetchone()['count']

                # Get latest price update
                cursor.execute("SELECT MAX(timestamp) as latest FROM prices")
                stats['latest_price_update'] = cursor.fetchone()['latest']

                # Get latest news update
                cursor.execute("SELECT MAX(timestamp) as latest FROM news")
                stats['latest_news_update'] = cursor.fetchone()['latest']

                # Database file size
                import os
                if os.path.exists(self.db_path):
                    stats['database_size_bytes'] = os.path.getsize(self.db_path)
                    stats['database_size_mb'] = stats['database_size_bytes'] / (1024 * 1024)

                return stats
        except Exception as e:
            logger.error(f"Error getting database stats: {e}")
            return {}

    def vacuum_database(self) -> bool:
        """Vacuum database to reclaim space"""
        try:
            with self.get_connection() as conn:
                conn.execute("VACUUM")
                logger.info("Database vacuumed successfully")
                return True
        except Exception as e:
            logger.error(f"Error vacuuming database: {e}")
            return False

    def backup_database(self, backup_path: Optional[str] = None) -> bool:
        """Create database backup"""
        try:
            import shutil
            if backup_path is None:
                timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
                backup_path = config.DATABASE_BACKUP_DIR / f"backup_{timestamp}.db"

            shutil.copy2(self.db_path, backup_path)
            logger.info(f"Database backed up to {backup_path}")
            return True
        except Exception as e:
            logger.error(f"Error backing up database: {e}")
            return False

    def close(self):
        """Close database connection"""
        if hasattr(self._local, 'conn'):
            self._local.conn.close()
            delattr(self._local, 'conn')
            logger.info("Database connection closed")


# Singleton instance
_db_instance = None


def get_database() -> CryptoDatabase:
    """Get database singleton instance"""
    global _db_instance
    if _db_instance is None:
        _db_instance = CryptoDatabase()
    return _db_instance