import requests
import gzip
import csv
import io
from datetime import datetime, timedelta, timezone
from typing import List, Optional
from .base import BaseExchange, Trade
from bs4 import BeautifulSoup

# Browser User-Agent für Zugriff (gettex prüft User-Agent!)
HEADERS = {
    'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
    'Accept-Language': 'de-DE,de;q=0.9,en;q=0.8',
    'Referer': 'https://www.gettex.de/'
}

# gettex Download-Basis-URLs
GETTEX_PAGE_URL = "https://www.gettex.de/handel/delayed-data/posttrade-data/"
# Die Download-URL ist auf der gettex-Webseite als Direkt-Link verfügbar
# Basis-URL für fileadmin Downloads (gefunden durch Seitenanalyse)
GETTEX_DOWNLOAD_BASE = "https://www.gettex.de/fileadmin/posttrade-data/"


class GettexExchange(BaseExchange):
    """
    gettex Exchange (Bayerische Börse)
    Kombiniert MUNC und MUND Daten.
    
    Dateiformat: posttrade.YYYYMMDD.HH.mm.{munc|mund}.csv.gz
    """
    
    @property
    def name(self) -> str:
        return "GETTEX"
    
    def _get_file_list_from_page(self) -> List[dict]:
        """
        Parst die gettex Seite und extrahiert Download-Links.
        Gibt Liste von dicts mit 'filename' und 'url' zurück.
        """
        files = []
        
        try:
            response = requests.get(GETTEX_PAGE_URL, headers=HEADERS, timeout=30)
            response.raise_for_status()
            
            soup = BeautifulSoup(response.text, 'html.parser')
            
            # Suche nach Links zu CSV.gz Dateien
            for link in soup.find_all('a'):
                href = link.get('href', '')
                text = link.get_text(strip=True)
                
                # Prüfe den Link-Text oder href auf posttrade CSV.gz Dateien
                if href and 'posttrade' in href.lower() and '.csv.gz' in href.lower():
                    # Vollständige URL erstellen
                    if not href.startswith('http'):
                        url = f"https://www.gettex.de{href}" if href.startswith('/') else f"https://www.gettex.de/{href}"
                    else:
                        url = href
                    filename = href.split('/')[-1]
                    files.append({'filename': filename, 'url': url})
                    
                elif text and 'posttrade' in text.lower() and '.csv.gz' in text.lower():
                    # Link-Text ist der Dateiname, href könnte die URL sein
                    filename = text
                    if href:
                        if not href.startswith('http'):
                            url = f"https://www.gettex.de{href}" if href.startswith('/') else f"https://www.gettex.de/{href}"
                        else:
                            url = href
                    else:
                        # Fallback: Versuche verschiedene URL-Patterns
                        url = f"https://www.gettex.de/fileadmin/posttrade-data/{filename}"
                    files.append({'filename': filename, 'url': url})
            
            print(f"[GETTEX] Found {len(files)} files on page")
            
        except Exception as e:
            print(f"[GETTEX] Error fetching page: {e}")
        
        return files
    
    def _generate_expected_files(self, target_date: datetime.date) -> List[str]:
        """
        Generiert erwartete Dateinamen basierend auf dem Datum.
        gettex veröffentlicht Dateien alle 15 Minuten während des Handels.
        
        Dateiformat: posttrade.YYYYMMDD.HH.mm.{munc|mund}.csv.gz
        """
        files = []
        date_str = target_date.strftime('%Y%m%d')
        
        # Handelszeiten: ca. 08:00 - 22:00 MEZ
        # In UTC: 07:00 - 21:00 (Winter) / 06:00 - 20:00 (Sommer)
        # Generiere für alle 15-Minuten-Intervalle
        
        for hour in range(6, 23):  # 06:00 - 22:45 UTC (abdeckend)
            for minute in [0, 15, 30, 45]:
                time_str = f"{hour:02d}.{minute:02d}"
                files.append(f"posttrade.{date_str}.{time_str}.munc.csv.gz")
                files.append(f"posttrade.{date_str}.{time_str}.mund.csv.gz")
        
        # Auch frühe Dateien vom Folgetag (nach Mitternacht UTC)
        next_date = target_date + timedelta(days=1)
        next_date_str = next_date.strftime('%Y%m%d')
        for hour in range(0, 3):  # 00:00 - 02:45 UTC
            for minute in [0, 15, 30, 45]:
                time_str = f"{hour:02d}.{minute:02d}"
                files.append(f"posttrade.{next_date_str}.{time_str}.munc.csv.gz")
                files.append(f"posttrade.{next_date_str}.{time_str}.mund.csv.gz")
        
        return files
    
    def _download_and_parse_file(self, filename: str) -> List[Trade]:
        """Lädt eine CSV.gz Datei und parst die Trades"""
        trades = []
        
        try:
            # Vollständige URL
            url = f"{GETTEX_DOWNLOAD_BASE}{filename}"
            
            response = requests.get(url, headers=HEADERS, timeout=60)
            
            if response.status_code == 404:
                # Datei existiert nicht - normal für Zeiten ohne Handel
                return []
            
            response.raise_for_status()
            
            # Gzip entpacken
            with gzip.GzipFile(fileobj=io.BytesIO(response.content)) as f:
                csv_text = f.read().decode('utf-8')
            
            lines = csv_text.strip().split('\n')
            if not lines:
                return []
            
            # Extrahiere Datum aus Dateinamen (Format: posttrade.YYYYMMDD.HH.MM.xxx.csv.gz)
            date_str = None
            parts = filename.split('.')
            if len(parts) >= 4:
                date_str = parts[1]  # YYYYMMDD
            
            # Gettex CSV hat KEINEN Header!
            # Format: ISIN,Zeit,Währung,Preis,Menge
            # z.B.: DE000BAY0017,09:15:03.638460,EUR,45.775,22
            for line in lines:
                if not line.strip():
                    continue
                try:
                    trade = self._parse_headerless_csv_line(line, date_str)
                    if trade:
                        trades.append(trade)
                except Exception:
                    continue
            
            if trades:
                print(f"[GETTEX] Parsed {len(trades)} trades from {filename}")
                    
        except requests.exceptions.HTTPError as e:
            if e.response.status_code != 404:
                print(f"[GETTEX] HTTP error downloading {filename}: {e}")
        except Exception as e:
            print(f"[GETTEX] Error downloading {filename}: {e}")
        
        return trades
    
    def _parse_headerless_csv_line(self, line: str, date_str: str = None) -> Optional[Trade]:
        """
        Parst eine headerlose CSV-Zeile im gettex Format.
        Format: ISIN,Zeit,Währung,Preis,Menge
        z.B.: DE000BAY0017,09:15:03.638460,EUR,45.775,22
        """
        try:
            parts = line.strip().split(',')
            if len(parts) < 5:
                return None
            
            isin = parts[0].strip()
            time_str = parts[1].strip()
            # currency = parts[2].strip()  # nicht benötigt
            price_str = parts[3].strip()
            qty_str = parts[4].strip()
            
            # Validierung
            if not isin or len(isin) != 12:  # ISIN ist immer 12 Zeichen
                return None
            
            price = float(price_str)
            quantity = float(qty_str)
            
            if price <= 0 or quantity <= 0:
                return None
            
            # Timestamp bauen
            # date_str ist YYYYMMDD, time_str ist HH:MM:SS.ffffff
            if date_str and len(date_str) == 8:
                year = date_str[:4]
                month = date_str[4:6]
                day = date_str[6:8]
                date_part = f"{year}-{month}-{day}"
            else:
                # Fallback: heute
                date_part = datetime.now(timezone.utc).strftime('%Y-%m-%d')
            
            # Zeit parsen (z.B. 09:15:03.638460)
            ts_str = f"{date_part}T{time_str}"
            
            # Mikrosekunden kürzen wenn zu lang
            if '.' in ts_str:
                base, frac = ts_str.rsplit('.', 1)
                if len(frac) > 6:
                    frac = frac[:6]
                ts_str = f"{base}.{frac}"
            
            timestamp = datetime.fromisoformat(ts_str)
            timestamp = timestamp.replace(tzinfo=timezone.utc)
            
            return Trade(
                exchange=self.name,
                symbol=isin,
                isin=isin,
                price=price,
                quantity=quantity,
                timestamp=timestamp
            )
            
        except Exception:
            return None
    
    def _parse_csv_row(self, row: dict) -> Optional[Trade]:
        """
        Parst eine CSV-Zeile zu einem Trade.
        
        Unterstützte Spalten (RTS1/RTS2 Format, verschiedene Varianten):
        - ISIN / FinInstrmId / Isin: Instrument Identifier
        - Pric / Price / pric: Preis
        - Qty / Quantity / qty: Menge
        - TrdDtTm / TradingDateTime / TrdgDtTm: Trading Date/Time
        - TrdDt / TradingDate: Trading Date
        - TrdTm / TradingTime: Trading Time
        """
        try:
            # ISIN - versuche verschiedene Spaltennamen
            isin = None
            for key in ['ISIN', 'Isin', 'isin', 'FinInstrmId', 'FinInstrmId.Id', 'Id']:
                if key in row and row[key]:
                    isin = str(row[key]).strip()
                    break
            
            if not isin:
                return None
            
            # Preis - versuche verschiedene Spaltennamen
            price = None
            for key in ['Pric', 'Price', 'pric', 'price', 'Pric.Pric.MntryVal.Amt', 'TradPric']:
                if key in row and row[key]:
                    price_str = str(row[key]).replace(',', '.').strip()
                    try:
                        price = float(price_str)
                        if price > 0:
                            break
                    except ValueError:
                        continue
            
            if not price or price <= 0:
                return None
            
            # Menge - versuche verschiedene Spaltennamen
            quantity = None
            for key in ['Qty', 'Quantity', 'qty', 'quantity', 'TradQty', 'Qty.Unit']:
                if key in row and row[key]:
                    qty_str = str(row[key]).replace(',', '.').strip()
                    try:
                        quantity = float(qty_str)
                        if quantity > 0:
                            break
                    except ValueError:
                        continue
            
            if not quantity or quantity <= 0:
                return None
            
            # Timestamp - versuche verschiedene Formate
            ts_str = None
            
            # Erst kombiniertes Feld versuchen
            for key in ['TrdDtTm', 'TradingDateTime', 'TrdgDtTm', 'Timestamp', 'timestamp']:
                if key in row and row[key]:
                    ts_str = str(row[key]).strip()
                    break
            
            # Falls nicht gefunden, separate Felder kombinieren
            if not ts_str:
                trd_dt = None
                trd_tm = '00:00:00'
                
                for key in ['TrdDt', 'TradingDate', 'Date', 'date']:
                    if key in row and row[key]:
                        trd_dt = str(row[key]).strip()
                        break
                
                for key in ['TrdTm', 'TradingTime', 'Time', 'time']:
                    if key in row and row[key]:
                        trd_tm = str(row[key]).strip()
                        break
                
                if trd_dt:
                    ts_str = f"{trd_dt}T{trd_tm}"
            
            if not ts_str:
                return None
            
            # Parse Timestamp (UTC)
            ts_str = ts_str.replace('Z', '+00:00')
            if 'T' not in ts_str:
                ts_str = ts_str.replace(' ', 'T')
            
            # Entferne Mikrosekunden wenn zu lang
            if '.' in ts_str:
                parts = ts_str.split('.')
                if len(parts) > 1:
                    ms_part = parts[1].split('+')[0].split('-')[0]
                    if len(ms_part) > 6:
                        ts_str = parts[0] + '.' + ms_part[:6]
                        if '+' in parts[1]:
                            ts_str += '+' + parts[1].split('+')[1]
                        elif '-' in parts[1][1:]:
                            ts_str += '-' + parts[1].split('-')[-1]
            
            timestamp = datetime.fromisoformat(ts_str)
            if timestamp.tzinfo is None:
                timestamp = timestamp.replace(tzinfo=timezone.utc)
            
            return Trade(
                exchange=self.name,
                symbol=isin,
                isin=isin,
                price=price,
                quantity=quantity,
                timestamp=timestamp
            )
            
        except Exception as e:
            # Nur bei den ersten paar Fehlern loggen
            return None
    
    def _get_last_trading_day(self, from_date) -> datetime.date:
        """
        Findet den letzten Handelstag (überspringt Wochenenden).
        Montag=0, Sonntag=6
        """
        date = from_date
        # Wenn Samstag (5), gehe zurück zu Freitag
        if date.weekday() == 5:
            date = date - timedelta(days=1)
        # Wenn Sonntag (6), gehe zurück zu Freitag
        elif date.weekday() == 6:
            date = date - timedelta(days=2)
        return date

    def fetch_latest_trades(self, include_yesterday: bool = True, since_date: datetime = None) -> List[Trade]:
        """
        Holt alle Trades vom letzten Handelstag (überspringt Wochenenden).
        """
        all_trades = []
        
        # Zieldatum bestimmen
        if since_date:
            target_date = since_date.date() if hasattr(since_date, 'date') else since_date
        else:
            target_date = (datetime.now(timezone.utc) - timedelta(days=1)).date()
        
        # Überspringe Wochenenden
        original_date = target_date
        target_date = self._get_last_trading_day(target_date)
        
        if target_date != original_date:
            print(f"[{self.name}] Skipping weekend: {original_date} -> {target_date}")
        
        print(f"[{self.name}] Fetching trades for date: {target_date}")
        
        # Versuche zuerst, Dateien von der Webseite zu laden
        page_files = self._get_file_list_from_page()
        
        if page_files:
            # Filtere Dateien für das Zieldatum
            target_str = target_date.strftime('%Y%m%d')
            next_day = target_date + timedelta(days=1)
            next_day_str = next_day.strftime('%Y%m%d')
            
            target_files = []
            for f in page_files:
                filename = f['filename']
                # Dateien vom Zieldatum oder frühe Morgenstunden des nächsten Tages
                if target_str in filename:
                    target_files.append(f)
                elif next_day_str in filename:
                    # Frühe Morgenstunden (00:00 - 02:45) gehören zum Vortag
                    try:
                        # Format: posttrade.YYYYMMDD.HH.MM.{munc|mund}.csv.gz
                        parts = filename.split('.')
                        if len(parts) >= 4:
                            hour = int(parts[2])
                            if hour < 3:
                                target_files.append(f)
                    except:
                        pass
            
            print(f"[{self.name}] Found {len(target_files)} files for target date from page")
            
            # Lade Dateien von der Webseite
            for f in target_files:
                trades = self._download_file_by_url(f['url'], f['filename'])
                if trades:
                    all_trades.extend(trades)
        
        # Fallback: Versuche erwartete Dateinamen
        if not all_trades:
            print(f"[{self.name}] No files from page, trying generated filenames...")
            expected_files = self._generate_expected_files(target_date)
            print(f"[{self.name}] Trying {len(expected_files)} potential files")
            
            successful_files = 0
            for filename in expected_files:
                trades = self._download_and_parse_file(filename)
                if trades:
                    all_trades.extend(trades)
                    successful_files += 1
            
            print(f"[{self.name}] Successfully downloaded {successful_files} files")
        
        print(f"[{self.name}] Total trades fetched: {len(all_trades)}")
        
        return all_trades
    
    def _download_file_by_url(self, url: str, filename: str) -> List[Trade]:
        """Lädt eine Datei direkt von einer URL"""
        trades = []
        
        try:
            response = requests.get(url, headers=HEADERS, timeout=60)
            
            if response.status_code == 404:
                return []
            
            response.raise_for_status()
            
            # Gzip entpacken
            with gzip.GzipFile(fileobj=io.BytesIO(response.content)) as f:
                csv_text = f.read().decode('utf-8')
            
            lines = csv_text.strip().split('\n')
            if not lines:
                return []
            
            # Extrahiere Datum aus Dateinamen (Format: posttrade.YYYYMMDD.HH.MM.xxx.csv.gz)
            date_str = None
            parts = filename.split('.')
            if len(parts) >= 4:
                date_str = parts[1]  # YYYYMMDD
            
            # Gettex CSV hat KEINEN Header!
            # Format: ISIN,Zeit,Währung,Preis,Menge
            for line in lines:
                if not line.strip():
                    continue
                try:
                    trade = self._parse_headerless_csv_line(line, date_str)
                    if trade:
                        trades.append(trade)
                except Exception:
                    continue
            
            if trades:
                print(f"[{self.name}] Parsed {len(trades)} trades from {filename}")
                    
        except requests.exceptions.HTTPError as e:
            if e.response.status_code != 404:
                print(f"[{self.name}] HTTP error downloading {url}: {e}")
        except Exception as e:
            print(f"[{self.name}] Error downloading {url}: {e}")
        
        return trades