#!/usr/bin/env python3
"""
Startup Orchestrator for MQL5 Trading Automation
Handles automated startup of all trading components with proper sequencing,
logging, and error handling.
"""

from __future__ import annotations

import argparse
import functools
import json
import logging
import os
import platform
import subprocess
import sys
import time
from dataclasses import dataclass
from datetime import datetime
from pathlib import Path
from typing import Optional


# Configuration paths
REPO_ROOT = Path(__file__).resolve().parents[1]
CONFIG_DIR = REPO_ROOT / "config"
LOGS_DIR = REPO_ROOT / "logs"
MT5_DIR = REPO_ROOT / "mt5" / "MQL5"


# OPTIMIZATION: Cache config file reads to avoid redundant I/O
# Note: Cache persists across multiple orchestrator instantiations within the same process.
# This is intentional for performance, as config changes during runtime are not expected.
# To force reload after config change, restart the process or call _load_cached_config.cache_clear()
@functools.lru_cache(maxsize=1)
def _load_cached_config(config_file_path: str) -> Optional[dict]:
    """Load and cache configuration from JSON file."""
    config_path = Path(config_file_path)
    if not config_path.exists():
        return None
    with open(config_path, 'r') as f:
        return json.load(f)


@dataclass
class ComponentConfig:
    """Configuration for a startup component."""
    name: str
    executable: str
    args: list[str]
    working_dir: Optional[str] = None
    wait_seconds: int = 0
    required: bool = True
    platform_specific: Optional[str] = None  # "windows", "linux", or None for all


class StartupOrchestrator:
    """Orchestrates the startup of all trading components."""

    def __init__(self, config_file: Optional[Path] = None, dry_run: bool = False):
        """Initialize the orchestrator."""
        self.config_file = config_file or CONFIG_DIR / "startup_config.json"
        self.dry_run = dry_run
        self.processes: list[subprocess.Popen] = []
        self.setup_logging()
        self.load_config()

    def setup_logging(self) -> None:
        """Setup logging configuration."""
        LOGS_DIR.mkdir(parents=True, exist_ok=True)
        log_file = LOGS_DIR / f"startup_{datetime.now().strftime('%Y%m%d_%H%M%S')}.log"
        
        logging.basicConfig(
            level=logging.INFO,
            format='%(asctime)s - %(levelname)s - %(message)s',
            handlers=[
                logging.FileHandler(log_file),
                logging.StreamHandler(sys.stdout)
            ]
        )
        self.logger = logging.getLogger(__name__)
        self.logger.info(f"Startup orchestrator initialized. Log file: {log_file}")

    def load_config(self) -> None:
        """Load configuration from JSON file."""
        # OPTIMIZATION: Use cached config loader
        self.config_data = _load_cached_config(str(self.config_file))
        
        if self.config_data is None:
            self.logger.warning(f"Config file not found: {self.config_file}")
            self.logger.info("Using default configuration")
            self.components = self.get_default_components()
        else:
            self.components = [
                ComponentConfig(**component_config) for component_config in self.config_data.get('components', [])
            ]
            self.logger.info(f"Loaded configuration from {self.config_file}")
            max_retries = self.config_data.get('settings', {}).get('max_startup_retries', 1)
            if max_retries > 1:
                self.logger.info(f"Retry enabled: up to {max_retries} retries for failed components")

    def get_default_components(self) -> list[ComponentConfig]:
        """Return default component configuration."""
        system = platform.system().lower()
        
        components = [
            ComponentConfig(
                name="MT5 Terminal",
                executable="terminal64.exe" if "windows" in system else "wine terminal64.exe",
                args=[],
                wait_seconds=15,
                required=True,
                platform_specific="windows"
            ),
            ComponentConfig(
                name="Repository Validator",
                executable=sys.executable,
                args=[str(REPO_ROOT / "scripts" / "ci_validate_repo.py")],
                working_dir=str(REPO_ROOT),
                wait_seconds=2,
                required=False,
                platform_specific=None
            ),
        ]
        
        return components

    def check_system_requirements(self) -> bool:
        """Check if system meets requirements."""
        self.logger.info("Checking system requirements...")
        system = platform.system()
        self.logger.info(f"Platform: {system} ({platform.machine()})")
        self.logger.info(f"Python version: {sys.version}")
        
        # Check Python version
        if sys.version_info < (3, 8):
            self.logger.error("Python 3.8 or higher is required")
            return False
        
        # Check if MT5 directory exists
        if not MT5_DIR.exists():
            self.logger.error(f"MT5 directory not found: {MT5_DIR}")
            return False
        
        self.logger.info("System requirements check passed")
        return True

    def is_component_compatible(self, component: ComponentConfig) -> bool:
        """Check if component is compatible with current platform."""
        if component.platform_specific is None:
            return True
        
        current_platform = platform.system().lower()
        if "windows" in current_platform:
            return component.platform_specific == "windows"
        elif "linux" in current_platform:
            return component.platform_specific in ["linux", "wsl"]
        else:
            return False

    def find_mt5_executable(self, preferred_path: str) -> Optional[str]:
        """Find MT5 executable, trying preferred path first, then fallback paths."""
        # Check preferred path first
        if Path(preferred_path).exists():
            self.logger.info(f"Found MT5 at preferred path: {preferred_path}")
            return preferred_path
        
        self.logger.info(f"Preferred MT5 path not found: {preferred_path}")
        self.logger.info("Trying fallback paths...")
        
        # Fallback paths (check all possible MT5 installations)
        fallback_paths = [
            "C:\\Program Files\\MetaTrader 5 EXNESS\\terminal64.exe",
            "C:\\Program Files\\Exness Terminal\\terminal64.exe",
            "C:\\Program Files\\MetaTrader 5\\terminal64.exe",
            os.path.expandvars("%APPDATA%\\MetaQuotes\\Terminal\\terminal64.exe"),
            "C:\\Program Files (x86)\\Exness Terminal\\terminal64.exe",
            "C:\\Program Files (x86)\\MetaTrader 5\\terminal64.exe"
        ]
        
        # Remove preferred path from fallback list to avoid duplicate check
        fallback_paths = [fallback_path for fallback_path in fallback_paths if fallback_path != preferred_path]
        
        for fallback_path in fallback_paths:
            if Path(fallback_path).exists():
                self.logger.info(f"Using fallback MT5 path: {fallback_path}")
                return fallback_path
        
        self.logger.error("No MT5 Terminal found in any of the checked paths")
        return None

    def start_component(self, component: ComponentConfig) -> bool:
        """Start a single component."""
        if not self.is_component_compatible(component):
            self.logger.info(f"Skipping {component.name} (platform incompatible)")
            return True

        self.logger.info(f"Starting {component.name}...")
        
        if self.dry_run:
            self.logger.info(f"[DRY RUN] Would execute: {component.executable} {' '.join(component.args)}")
            return True

        try:
            # For MT5 Terminal, check if executable exists, try fallback paths if not
            executable = component.executable
            if "terminal64.exe" in executable or "MT5" in component.name or "Exness" in component.name:
                found_path = self.find_mt5_executable(executable)
                if not found_path:
                    self.logger.error(f"MT5 Terminal not found. Tried: {executable}")
                    if component.required:
                        return False
                    else:
                        self.logger.warning(f"Skipping optional component: {component.name}")
                        return True
                executable = found_path
            
            cmd = [executable] + component.args
            working_dir = component.working_dir or str(REPO_ROOT)
            
            process = subprocess.Popen(
                cmd,
                cwd=working_dir,
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE,
                creationflags=subprocess.CREATE_NEW_CONSOLE if platform.system() == "Windows" else 0
            )
            
            self.processes.append(process)
            self.logger.info(f"Started {component.name} (PID: {process.pid})")
            
            if component.wait_seconds > 0:
                self.logger.info(f"Waiting {component.wait_seconds} seconds for {component.name} to initialize...")
                time.sleep(component.wait_seconds)
            
            # Check if process is still running
            if process.poll() is not None:
                stdout, stderr = process.communicate()
                if process.returncode != 0:
                    self.logger.error(f"{component.name} failed with exit code {process.returncode}")
                    if stderr:
                        self.logger.error(f"Error: {stderr.decode()}")
                    return not component.required
                else:
                    self.logger.info(f"{component.name} completed successfully")
            
            return True
            
        except FileNotFoundError:
            self.logger.error(f"Executable not found: {component.executable}")
            return not component.required
        except Exception as e:
            self.logger.error(f"Failed to start {component.name}: {e}")
            return not component.required

    def start_all(self) -> bool:
        """Start all configured components with retry logic."""
        if not self.check_system_requirements():
            return False

        self.logger.info("=" * 60)
        self.logger.info("Starting all components...")
        self.logger.info("=" * 60)
        
        # Load retry settings from config
        max_retries = 1  # Default to 1 attempt (no retry)
        if hasattr(self, 'config_data') and self.config_data:
            max_retries = self.config_data.get('settings', {}).get('max_startup_retries', 1)
        
        success = True
        for component in self.components:
            retry_count = 0
            component_success = False
            
            while retry_count <= max_retries:
                if retry_count > 0:
                    self.logger.info(f"Retry attempt {retry_count}/{max_retries} for {component.name}...")
                    time.sleep(2)  # Brief delay before retry
                
                component_success = self.start_component(component)
                
                if component_success:
                    break
                
                retry_count += 1
            
            if not component_success:
                if component.required:
                    self.logger.error(f"Failed to start required component: {component.name} after {retry_count} attempt(s)")
                    success = False
                    break
                else:
                    self.logger.warning(f"Optional component {component.name} failed but continuing...")
        
        if success:
            self.logger.info("=" * 60)
            self.logger.info("All components started successfully")
            self.logger.info(f"Total processes: {len(self.processes)}")
            self.logger.info("=" * 60)
        else:
            self.logger.error("Startup sequence failed")
        
        return success

    def stop_all(self) -> None:
        """Stop all running processes."""
        self.logger.info("Stopping all processes...")
        for process in self.processes:
            try:
                process.terminate()
                process.wait(timeout=5)
                self.logger.info(f"Stopped process {process.pid}")
            except subprocess.TimeoutExpired:
                process.kill()
                self.logger.warning(f"Force killed process {process.pid}")
            except Exception as e:
                self.logger.error(f"Error stopping process {process.pid}: {e}")

    def monitor_processes(self, duration: Optional[int] = None) -> None:
        """Monitor running processes."""
        self.logger.info("Monitoring processes... Press Ctrl+C to stop")
        
        start_time = time.time()
        try:
            while True:
                if duration and (time.time() - start_time) > duration:
                    self.logger.info("Monitoring duration reached")
                    break
                
                # Check process status
                for i, process in enumerate(self.processes):
                    if process.poll() is not None:
                        self.logger.warning(f"Process {process.pid} has exited with code {process.returncode}")
                
                time.sleep(10)  # Check every 10 seconds
                
        except KeyboardInterrupt:
            self.logger.info("Monitoring interrupted by user")

    def create_default_config(self) -> None:
        """Create default configuration file."""
        CONFIG_DIR.mkdir(exist_ok=True)
        
        default_config = {
            "components": [
                {
                    "name": "Repository Validator",
                    "executable": sys.executable,
                    "args": [str(REPO_ROOT / "scripts" / "ci_validate_repo.py")],
                    "working_dir": str(REPO_ROOT),
                    "wait_seconds": 2,
                    "required": False,
                    "platform_specific": None
                },
                {
                    "name": "MT5 Terminal",
                    "executable": "C:\\Program Files\\Exness Terminal\\terminal64.exe",
                    "args": ["/portable"],
                    "wait_seconds": 15,
                    "required": True,
                    "platform_specific": "windows"
                },
                {
                    "name": "Custom Python Script",
                    "executable": sys.executable,
                    "args": [str(REPO_ROOT / "scripts" / "your_custom_script.py")],
                    "working_dir": str(REPO_ROOT),
                    "wait_seconds": 5,
                    "required": False,
                    "platform_specific": None
                }
            ]
        }
        
        with open(self.config_file, 'w') as f:
            json.dump(default_config, f, indent=2)
        
        self.logger.info(f"Created default configuration at {self.config_file}")


def main() -> int:
    """Main entry point."""
    parser = argparse.ArgumentParser(
        description="Startup orchestrator for MQL5 trading automation"
    )
    parser.add_argument(
        "--config",
        type=Path,
        help="Path to configuration file (JSON)"
    )
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="Print actions without executing them"
    )
    parser.add_argument(
        "--create-config",
        action="store_true",
        help="Create default configuration file"
    )
    parser.add_argument(
        "--monitor",
        type=int,
        metavar="SECONDS",
        help="Monitor processes for specified duration (0 = infinite)"
    )
    
    args = parser.parse_args()
    
    orchestrator = StartupOrchestrator(
        config_file=args.config,
        dry_run=args.dry_run
    )
    
    if args.create_config:
        orchestrator.create_default_config()
        return 0
    
    try:
        if not orchestrator.start_all():
            return 1
        
        if args.monitor is not None:
            monitor_duration = None if args.monitor == 0 else args.monitor
            orchestrator.monitor_processes(duration=monitor_duration)
        else:
            # If no monitor specified, keep processes running (don't stop them)
            orchestrator.logger.info("Processes started. Use --monitor to monitor or let them run independently.")
        
        return 0
        
    except KeyboardInterrupt:
        orchestrator.logger.info("Interrupted by user")
        return 130
    except Exception as e:
        orchestrator.logger.error(f"Unexpected error: {e}", exc_info=True)
        return 1
    finally:
        # Only stop processes if monitor was NOT used (monitor keeps them alive)
        # When monitor is used (even 0 for infinite), don't stop processes
        if args.monitor is None:
            # Only stop if explicitly not monitoring - but for auto-start, we want to keep running
            # So we'll skip stopping when run from scheduled task
            pass  # Don't stop processes - let them run independently


if __name__ == "__main__":
    sys.exit(main())