"""Server sync client for multi-user transcription."""

import requests
import json
from typing import Optional
from datetime import datetime
import threading
import queue
from concurrent.futures import ThreadPoolExecutor


class ServerSyncClient:
    """Client for syncing transcriptions to a PHP server."""

    def __init__(self, url: str, room: str, passphrase: str, user_name: str):
        """
        Initialize server sync client.

        Args:
            url: Server URL (e.g., http://example.com/transcription/server.php)
            room: Room name
            passphrase: Room passphrase
            user_name: User's display name
        """
        self.url = url
        self.room = room
        self.passphrase = passphrase
        self.user_name = user_name

        # Queue for sending transcriptions asynchronously
        self.send_queue = queue.Queue()
        self.is_running = False
        self.send_thread: Optional[threading.Thread] = None

        # Thread pool for parallel HTTP requests (max 3 concurrent)
        self.executor = ThreadPoolExecutor(max_workers=3)

        # Statistics
        self.sent_count = 0
        self.error_count = 0
        self.last_error: Optional[str] = None

    def start(self):
        """Start the sync client."""
        if self.is_running:
            return

        self.is_running = True
        self.send_thread = threading.Thread(target=self._send_loop, daemon=True)
        self.send_thread.start()
        print(f"Server sync started: room={self.room}")

    def stop(self):
        """Stop the sync client."""
        self.is_running = False
        if self.send_thread:
            self.send_thread.join(timeout=2.0)
        # Shutdown executor and wait for pending requests
        self.executor.shutdown(wait=False)  # Don't wait - let pending requests finish in background
        print("Server sync stopped")

    def send_transcription(self, text: str, timestamp: Optional[datetime] = None):
        """
        Send a transcription to the server (non-blocking).

        Args:
            text: Transcription text
            timestamp: Timestamp (defaults to now)
        """
        if timestamp is None:
            timestamp = datetime.now()

        # Debug: Log when transcription is queued
        import time
        queue_time = time.time()

        # Add to queue
        self.send_queue.put({
            'text': text,
            'timestamp': timestamp.strftime("%H:%M:%S"),
            'queue_time': queue_time  # For debugging
        })

    def _send_loop(self):
        """Background thread for sending transcriptions."""
        while self.is_running:
            try:
                # Get transcription from queue (with shorter timeout for responsiveness)
                try:
                    trans_data = self.send_queue.get(timeout=0.1)
                except queue.Empty:
                    continue

                # Send to server in parallel using thread pool
                # This allows multiple requests to be in-flight simultaneously
                self.executor.submit(self._send_to_server, trans_data)

            except Exception as e:
                print(f"Error in server sync send loop: {e}")
                self.error_count += 1
                self.last_error = str(e)

    def _send_to_server(self, trans_data: dict):
        """
        Send a transcription to the server (PHP or Node.js).

        Args:
            trans_data: Dictionary with 'text' and 'timestamp'
        """
        import time
        send_start = time.time()

        try:
            # Debug: Calculate queue delay
            if 'queue_time' in trans_data:
                queue_delay = (send_start - trans_data['queue_time']) * 1000
                print(f"[Server Sync] Queue delay: {queue_delay:.0f}ms")

            # Prepare payload
            payload = {
                'room': self.room,
                'passphrase': self.passphrase,
                'user_name': self.user_name,
                'text': trans_data['text'],
                'timestamp': trans_data['timestamp']
            }

            # Detect server type and send appropriately
            # PHP servers have "server.php" in URL and need ?action=send
            # Node.js servers have "/api/send" in URL and don't need it
            request_start = time.time()
            if 'server.php' in self.url:
                # PHP server - add action parameter
                response = requests.post(
                    self.url,
                    params={'action': 'send'},
                    json=payload,
                    timeout=2.0  # Reduced timeout for faster failure detection
                )
            else:
                # Node.js server - no action parameter
                response = requests.post(
                    self.url,
                    json=payload,
                    timeout=2.0  # Reduced timeout for faster failure detection
                )

            request_time = (time.time() - request_start) * 1000
            print(f"[Server Sync] HTTP request: {request_time:.0f}ms, Status: {response.status_code}")

            # Check response
            if response.status_code == 200:
                self.sent_count += 1
                self.last_error = None
            else:
                error_msg = f"Server returned {response.status_code}"
                try:
                    error_data = response.json()
                    if 'error' in error_data:
                        error_msg = error_data['error']
                except:
                    pass

                print(f"Server sync error: {error_msg}")
                self.error_count += 1
                self.last_error = error_msg

        except requests.exceptions.Timeout:
            print("Server sync timeout")
            self.error_count += 1
            self.last_error = "Request timeout"

        except requests.exceptions.ConnectionError:
            print("Server sync connection error")
            self.error_count += 1
            self.last_error = "Connection error"

        except Exception as e:
            print(f"Server sync error: {e}")
            self.error_count += 1
            self.last_error = str(e)

    def get_stats(self) -> dict:
        """Get sync statistics."""
        return {
            'sent': self.sent_count,
            'errors': self.error_count,
            'last_error': self.last_error,
            'queue_size': self.send_queue.qsize()
        }

    def is_healthy(self) -> bool:
        """Check if sync is working (no recent errors)."""
        # Consider healthy if less than 10% error rate
        total = self.sent_count + self.error_count
        if total == 0:
            return True
        return (self.error_count / total) < 0.1