#!/usr/bin/env python3
"""Storage Manager for NewsArchiver - Phase 2.3

Organizes archived data by newspaper, manages SQLite cache database,
stores both raw HTML and extracted content.
"""

import json
import logging
import os
import sqlite3
import sys
from datetime import datetime
from pathlib import Path
from typing import List, Optional

from content_extractor import ArticleData

try:
    import feedgenerator
    FEEDGENERATOR_AVAILABLE = True
except ImportError:
    FEEDGENERATOR_AVAILABLE = False

SCRIPT_DIR = Path(__file__).parent
ARCHIVE_DIR = SCRIPT_DIR / 'archival_data'
ARCHIVE_DIR.mkdir(exist_ok=True)

logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(levelname)s - %(message)s',
    handlers=[
        logging.StreamHandler(sys.stdout),
        logging.FileHandler(ARCHIVE_DIR / 'processing.log', encoding='utf-8')
    ]
)
logger = logging.getLogger(__name__)

DB_PATH = ARCHIVE_DIR / 'cache.db'
WEBSITES_DIR = ARCHIVE_DIR / 'websites'


def _get_db_connection() -> sqlite3.Connection:
    """Get database connection with row factory."""
    conn = sqlite3.connect(
        DB_PATH,
        timeout=30.0,
        isolation_level=None
    )
    conn.row_factory = sqlite3.Row
    conn.execute('PRAGMA journal_mode=WAL')
    conn.execute('PRAGMA busy_timeout=30000')
    return conn


def _init_database() -> None:
    """Initialize database schema."""
    with _get_db_connection() as conn:
        cursor = conn.cursor()
        
        cursor.execute('''
            CREATE TABLE IF NOT EXISTS articles (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                source_name TEXT NOT NULL,
                article_url TEXT NOT NULL UNIQUE,
                article_guid TEXT,
                title TEXT,
                author TEXT,
                publish_date TEXT,
                content_text TEXT,
                content_html TEXT,
                archive_file_path TEXT,
                metadata_file_path TEXT,
                status TEXT DEFAULT 'pending',
                error_message TEXT,
                extraction_method TEXT,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            )
        ''')
        
        cursor.execute('''
            CREATE TABLE IF NOT EXISTS article_archives (
                article_url TEXT PRIMARY KEY,
                source_name TEXT,
                archive_file_path TEXT,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            )
        ''')
        
        cursor.execute('''
            CREATE TABLE IF NOT EXISTS processing_log (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                source_name TEXT,
                timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                action TEXT,
                status TEXT,
                message TEXT
            )
        ''')
        
        cursor.execute('CREATE INDEX IF NOT EXISTS idx_articles_source ON articles(source_name)')
        cursor.execute('CREATE INDEX IF NOT EXISTS idx_articles_url ON articles(article_url)')
        cursor.execute('CREATE INDEX IF NOT EXISTS idx_articles_status ON articles(status)')
        
        # Add extraction_method column if it doesn't exist
        try:
            cursor.execute('ALTER TABLE articles ADD COLUMN extraction_method TEXT')
            conn.commit()
        except sqlite3.OperationalError:
            pass
        
        cursor.execute('CREATE INDEX IF NOT EXISTS idx_articles_extraction_method ON articles(extraction_method)')
        cursor.execute('CREATE INDEX IF NOT EXISTS idx_article_archives_url ON article_archives(article_url)')
        cursor.execute('CREATE INDEX IF NOT EXISTS idx_article_archives_source ON article_archives(source_name)')
        
        logger.debug("Database initialized at %s", DB_PATH)


def _ensure_directory_structure(source_name: str, date_str: str) -> tuple:
    """Ensure directory structure exists for a source and date.
    
    Args:
        source_name: Newspaper source name
        date_str: Date string in YYYY-MM-DD format
        
    Returns:
        Tuple of (html_dir, articles_dir) Path objects
    """
    source_dir = WEBSITES_DIR / source_name
    html_dir = source_dir / 'html' / date_str
    articles_dir = source_dir / 'articles' / date_str
    
    html_dir.mkdir(parents=True, exist_ok=True)
    articles_dir.mkdir(parents=True, exist_ok=True)
    
    return html_dir, articles_dir


def _get_next_file_index(html_dir: Path, articles_dir: Path) -> int:
    """Get next available file index for article naming.
    
    Args:
        html_dir: Directory containing HTML files
        articles_dir: Directory containing JSON files
        
    Returns:
        Next available index (1-indexed)
    """
    def get_max_index(directory: Path, extension: str) -> int:
        max_idx = 0
        if directory.exists():
            for file in directory.glob(f'*{extension}'):
                try:
                    name = file.stem
                    if name.startswith('article_'):
                        idx = int(name.replace('article_', ''))
                        max_idx = max(max_idx, idx)
                except ValueError:
                    continue
        return max_idx
    
    html_idx = get_max_index(html_dir, '.html')
    json_idx = get_max_index(articles_dir, '.json')
    
    return max(html_idx, json_idx) + 1


def _log_processing(source_name: str, action: str, status: str, message: str) -> None:
    """Log processing action to database.
    
    Args:
        source_name: Newspaper source name
        action: Action performed
        status: Status of action
        message: Log message
    """
    try:
        with _get_db_connection() as conn:
            cursor = conn.cursor()
            cursor.execute(
                'INSERT INTO processing_log (source_name, action, status, message) VALUES (?, ?, ?, ?)',
                (source_name, action, status, message)
            )
    except Exception as e:
        logger.error("Failed to log processing: %s", str(e))


def _save_archive_mapping(article_url: str, source_name: str, archive_file_path: str) -> None:
    """Save mapping between article URL and archive file path.
    
    Args:
        article_url: Article URL
        source_name: Newspaper source name
        archive_file_path: Path to archived HTML file
    """
    try:
        with _get_db_connection() as conn:
            cursor = conn.cursor()
            cursor.execute('''
                INSERT OR REPLACE INTO article_archives (article_url, source_name, archive_file_path)
                VALUES (?, ?, ?)
            ''', (article_url, source_name, archive_file_path))
        logger.debug("Saved archive mapping: %s -> %s", article_url, archive_file_path)
    except Exception as e:
        logger.error("Failed to save archive mapping: %s", str(e))


def save_article(source_name: str, article_data: ArticleData) -> str:
    """Save article to storage and update cache.
    
    Args:
        source_name: Newspaper source name (e.g., 'reuters', 'bbc')
        article_data: ArticleData object with article content
        
    Returns:
        Status message describing the result
    """
    try:
        _init_database()
        
        publish_date = article_data.publish_date
        if publish_date:
            try:
                date_obj = datetime.fromisoformat(publish_date.replace('Z', '+00:00'))
                date_str = date_obj.strftime('%Y-%m-%d')
            except (ValueError, AttributeError):
                date_str = datetime.now().strftime('%Y-%m-%d')
        else:
            date_str = datetime.now().strftime('%Y-%m-%d')
        
        html_dir, articles_dir = _ensure_directory_structure(source_name, date_str)
        
        file_index = _get_next_file_index(html_dir, articles_dir)
        file_prefix = f'article_{file_index:03d}'
        
        archive_file_path = html_dir / f'{file_prefix}.html'
        metadata_file_path = articles_dir / f'{file_prefix}.json'
        
        if article_data.raw_html:
            with open(archive_file_path, 'w', encoding='utf-8') as f:
                f.write(article_data.raw_html)
        
        metadata = {
            'id': file_index,
            'source_name': source_name,
            'url': article_data.url,
            'title': article_data.title,
            'author': article_data.author,
            'publish_date': article_data.publish_date,
            'content_text': article_data.content_text,
            'content_html': article_data.content_html,
            'tags': article_data.tags,
            'language': article_data.language,
            'extraction_method': article_data.extraction_method,
            'archive_file': f'{file_prefix}.html',
            'metadata_file': f'{file_prefix}.json',
            'saved_at': datetime.now().isoformat()
        }
        
        with open(metadata_file_path, 'w', encoding='utf-8') as f:
            json.dump(metadata, f, indent=2, ensure_ascii=False)
        
        with _get_db_connection() as conn:
            cursor = conn.cursor()
            
            try:
                cursor.execute('''
                    INSERT OR IGNORE INTO articles 
                    (source_name, article_url, article_guid, title, author, publish_date, 
                     content_text, content_html, archive_file_path, metadata_file_path, status, extraction_method)
                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
                ''', (
                    source_name,
                    article_data.url,
                    getattr(article_data, 'guid', None),
                    article_data.title,
                    article_data.author,
                    article_data.publish_date,
                    article_data.content_text,
                    article_data.content_html,
                    str(archive_file_path),
                    str(metadata_file_path),
                    'archived' if not article_data.error else 'failed',
                    article_data.extraction_method
                ))
            except sqlite3.IntegrityError:
                cursor.execute('''
                    UPDATE articles 
                    SET title = ?, author = ?, publish_date = ?, 
                        content_text = ?, content_html = ?, 
                        archive_file_path = ?, metadata_file_path = ?, 
                        status = ?, extraction_method = ?, updated_at = CURRENT_TIMESTAMP
                    WHERE article_url = ? AND source_name = ?
                ''', (
                    article_data.title,
                    article_data.author,
                    article_data.publish_date,
                    article_data.content_text,
                    article_data.content_html,
                    str(archive_file_path),
                    str(metadata_file_path),
                    'archived' if not article_data.error else 'failed',
                    article_data.extraction_method,
                    article_data.url,
                    source_name
                ))
        
        _save_archive_mapping(article_data.url, source_name, str(archive_file_path))
        
        _log_processing(
            source_name,
            'save_article',
            'success',
            f'Saved article: {article_data.url} -> {metadata_file_path.name}'
        )
        
        logger.info("Article saved: %s -> %s", article_data.url, metadata_file_path.name)
        
        return f"Article saved: {metadata_file_path.name}"
        
    except Exception as e:
        error_msg = f"Failed to save article: {str(e)}"
        logger.error(error_msg)
        _log_processing(source_name, 'save_article', 'error', error_msg)
        return error_msg


def get_article(source_name: str, article_id: int) -> Optional[ArticleData]:
    """Retrieve article from storage.
    
    Args:
        source_name: Newspaper source name
        article_id: Database ID of article
        
    Returns:
        ArticleData object or None if not found
    """
    try:
        _init_database()
        
        with _get_db_connection() as conn:
            cursor = conn.cursor()
            cursor.execute('''
                SELECT * FROM articles 
                WHERE id = ? AND source_name = ?
            ''', (article_id, source_name))
            
            row = cursor.fetchone()
        
        if not row:
            return None
        
        archive_path = Path(row['archive_file_path']) if row['archive_file_path'] else None
        archive_content = None
        if archive_path and archive_path.exists():
            archive_content = archive_path.read_text(encoding='utf-8')
        
        article = ArticleData(
            url=row['article_url'],
            title=row['title'],
            author=row['author'],
            publish_date=row['publish_date'],
            content_text=row['content_text'],
            content_html=row['content_html'],
            raw_html=archive_content,
            archive_file_path=str(archive_path) if archive_path else None,
            tags=None,
            language=None,
            metadata=None,
            extraction_method=None,
            error=row['error_message'],
            guid=row['article_guid'],
            id=row['id'],
            source_name=source_name
        )
        
        return article
        
    except Exception as e:
        logger.error("Failed to get article %d: %s", article_id, str(e))
        return None


def get_articles_by_source(source_name: str, limit: int = 50, offset: int = 0) -> List[ArticleData]:
    """Get paginated articles for a source.
    
    Args:
        source_name: Newspaper source name
        limit: Maximum number of articles to return
        offset: Number of articles to skip
        
    Returns:
        List of ArticleData objects
    """
    try:
        _init_database()
        
        with _get_db_connection() as conn:
            cursor = conn.cursor()
            cursor.execute('''
                SELECT * FROM articles 
                WHERE source_name = ?
                ORDER BY publish_date DESC, created_at DESC
                LIMIT ? OFFSET ?
            ''', (source_name, limit, offset))
            
            rows = cursor.fetchall()
        
        articles = []
        for row in rows:
            archive_path = Path(row['archive_file_path']) if row['archive_file_path'] else None
            archive_content = None
            if archive_path and archive_path.exists():
                archive_content = archive_path.read_text(encoding='utf-8')
            
            article = ArticleData(
                url=row['article_url'],
                title=row['title'],
                author=row['author'],
                publish_date=row['publish_date'],
                content_text=row['content_text'],
                content_html=row['content_html'],
                raw_html=archive_content,
                archive_file_path=str(archive_path) if archive_path else None,
                tags=None,
                language=None,
                metadata=None,
                extraction_method=None,
                error=row['error_message'],
                guid=row['article_guid'],
                id=row['id'],
                source_name=source_name
            )
            
            articles.append(article)
        
        return articles
        
    except Exception as e:
        logger.error("Failed to get articles for %s: %s", source_name, str(e))
        return []


def update_article_status(source_name: str, article_url: str, status: str, error: str = None) -> None:
    """Update article status in cache.
    
    Args:
        source_name: Newspaper source name
        article_url: Article URL
        status: New status (pending, archived, failed)
        error: Error message if status is failed
    """
    try:
        _init_database()
        
        conn = _get_db_connection()
        cursor = conn.cursor()
        cursor.execute('''
            UPDATE articles 
            SET status = ?, error_message = ?, updated_at = CURRENT_TIMESTAMP
            WHERE article_url = ? AND source_name = ?
        ''', (status, error, article_url, source_name))
        
        conn.commit()
        conn.close()
        
        if error:
            _log_processing(
                source_name,
                'update_status',
                'error',
                f'Updated {article_url} status to {status}: {error}'
            )
        else:
            _log_processing(
                source_name,
                'update_status',
                'success',
                f'Updated {article_url} status to {status}'
            )
        
        logger.info("Updated article status: %s -> %s", article_url, status)
        
    except Exception as e:
        logger.error("Failed to update article status: %s", str(e))


def get_source_stats(source_name: str) -> dict:
    """Get statistics for a news source.
    
    Args:
        source_name: Newspaper source name
        
    Returns:
        Dictionary with source statistics
    """
    try:
        _init_database()
        
        conn = _get_db_connection()
        cursor = conn.cursor()
        
        cursor.execute('''
            SELECT 
                COUNT(*) as total,
                SUM(CASE WHEN status = 'archived' THEN 1 ELSE 0 END) as archived,
                SUM(CASE WHEN status = 'failed' THEN 1 ELSE 0 END) as failed,
                SUM(CASE WHEN status = 'pending' THEN 1 ELSE 0 END) as pending,
                MIN(created_at) as first_archived,
                MAX(created_at) as last_archived,
                MAX(publish_date) as latest_article_date
            FROM articles 
            WHERE source_name = ?
        ''', (source_name,))
        
        row = cursor.fetchone()
        conn.close()
        
        stats = {
            'source_name': source_name,
            'total_articles': row['total'] or 0,
            'archived': row['archived'] or 0,
            'failed': row['failed'] or 0,
            'pending': row['pending'] or 0,
            'first_archived': row['first_archived'],
            'last_archived': row['last_archived'],
            'latest_article_date': row['latest_article_date']
        }
        
        _log_processing(
            source_name,
            'get_stats',
            'success',
            f'Stats: {stats["total_articles"]} total, {stats["archived"]} archived, {stats["failed"]} failed'
        )
        
        return stats
        
    except Exception as e:
        logger.error("Failed to get stats for %s: %s", source_name, str(e))
        return {
            'source_name': source_name,
            'total_articles': 0,
            'archived': 0,
            'failed': 0,
            'pending': 0
        }


def get_all_sources() -> List[str]:
    """Get list of all sources in the archive.
    
    Returns:
        List of source names
    """
    try:
        _init_database()
        
        conn = _get_db_connection()
        cursor = conn.cursor()
        cursor.execute('''
            SELECT DISTINCT source_name FROM articles ORDER BY source_name
        ''')
        
        sources = [row['source_name'] for row in cursor.fetchall()]
        conn.close()
        
        return sources
        
    except Exception as e:
        logger.error("Failed to get sources: %s", str(e))
        return []


def get_latest_articles(limit: int = 50) -> List[ArticleData]:
    """Get latest articles across all sources.
    
    Args:
        limit: Maximum number of articles to return
        
    Returns:
        List of ArticleData objects ordered by publish_date DESC
    """
    try:
        _init_database()
        
        conn = _get_db_connection()
        cursor = conn.cursor()
        cursor.execute('''
            SELECT * FROM articles 
            ORDER BY publish_date DESC, created_at DESC
            LIMIT ?
        ''', (limit,))
        
        rows = cursor.fetchall()
        conn.close()
        
        articles = []
        for row in rows:
            archive_path = Path(row['archive_file_path']) if row['archive_file_path'] else None
            archive_content = None
            if archive_path and archive_path.exists():
                archive_content = archive_path.read_text(encoding='utf-8')
            
            article = ArticleData(
                url=row['article_url'],
                title=row['title'],
                author=row['author'],
                publish_date=row['publish_date'],
                content_text=row['content_text'],
                content_html=row['content_html'],
                raw_html=archive_content,
                archive_file_path=str(archive_path) if archive_path else None,
                tags=None,
                language=None,
                metadata=None,
                extraction_method=None,
                error=row['error_message'],
                guid=row['article_guid'],
                id=row['id'],
                source_name=row['source_name']
            )
            
            articles.append(article)
        
        return articles
        
    except Exception as e:
        logger.error("Failed to get latest articles: %s", str(e))
        return []


def get_source_directory(source_name: str) -> Path:
    """Get the directory path for a source.
    
    Args:
        source_name: Newspaper source name
        
    Returns:
        Path to source directory
    """
    return WEBSITES_DIR / source_name


def get_archive_file_path_from_db(article_url: str, source_name: str = None) -> Optional[str]:
    """Get archive file path from database mapping.
    
    Args:
        article_url: Article URL
        source_name: Newspaper source name (optional, for filtering)
        
    Returns:
        Archive file path if found, None otherwise
    """
    try:
        _init_database()
        
        conn = _get_db_connection()
        cursor = conn.cursor()
        
        if source_name:
            cursor.execute('''
                SELECT archive_file_path FROM article_archives 
                WHERE article_url = ? AND source_name = ?
            ''', (article_url, source_name))
        else:
            cursor.execute('''
                SELECT archive_file_path FROM article_archives 
                WHERE article_url = ?
            ''', (article_url,))
        
        row = cursor.fetchone()
        conn.close()
        
        return row['archive_file_path'] if row else None
        
    except Exception as e:
        logger.error("Failed to get archive file path from DB: %s", str(e))
        return None


def get_daily_articles(source_name: str, date_str: str) -> List[ArticleData]:
    """Get articles for a specific date.
    
    Args:
        source_name: Newspaper source name
        date_str: Date string in YYYY-MM-DD format
        
    Returns:
        List of ArticleData objects
    """
    try:
        source_dir = get_source_directory(source_name)
        articles_dir = source_dir / 'articles' / date_str
        
        if not articles_dir.exists():
            return []
        
        articles = []
        for json_file in sorted(articles_dir.glob('article_*.json')):
            try:
                with open(json_file, 'r', encoding='utf-8') as f:
                    metadata = json.load(f)
                
                archive_filename = metadata.get('archive_file', '')
                archive_path = source_dir / 'html' / date_str / archive_filename if archive_filename else None
                archive_content = None
                if archive_path and archive_path.exists():
                    archive_content = archive_path.read_text(encoding='utf-8')
                
                article = ArticleData(
                    url=metadata.get('url', ''),
                    title=metadata.get('title'),
                    author=metadata.get('author'),
                    publish_date=metadata.get('publish_date'),
                    content_text=metadata.get('content_text'),
                    content_html=metadata.get('content_html'),
                    raw_html=archive_content,
                    archive_file_path=str(archive_path) if archive_path else None,
                    tags=metadata.get('tags'),
                    language=metadata.get('language'),
                    metadata=metadata,
                    extraction_method=metadata.get('extraction_method'),
                    source_name=source_name
                )
                
                articles.append(article)
                
            except Exception as e:
                logger.warning("Failed to load article from %s: %s", json_file, str(e))
                continue
        
        return articles
        
    except Exception as e:
        logger.error("Failed to get daily articles for %s on %s: %s", source_name, date_str, str(e))
        return []


def initialize_storage() -> None:
    """Initialize the storage system.
    
    Creates database, directory structure, and logs initialization.
    """
    logger.info("Initializing storage system...")
    
    _init_database()
    
    (WEBSITES_DIR / 'sample').mkdir(parents=True, exist_ok=True)
    (WEBSITES_DIR / 'sample' / 'html').mkdir(exist_ok=True)
    (WEBSITES_DIR / 'sample' / 'articles').mkdir(exist_ok=True)
    
    _log_processing('system', 'initialize', 'success', 'Storage system initialized')
    
    logger.info("Storage system initialized at %s", ARCHIVE_DIR)


if __name__ == '__main__':
    initialize_storage()
    
    sources = get_all_sources()
    print(f"Sources in archive: {sources}")
    
    if sources:
        for source in sources:
            stats = get_source_stats(source)
            print(f"\n{source}:")
            print(f"  Total: {stats['total_articles']}")
            print(f"  Archived: {stats['archived']}")
            print(f"  Failed: {stats['failed']}")