"""
Continuous Workflow Engine - Self-driving automation loop
"""
import asyncio
import logging
import uuid
from datetime import datetime
from typing import Dict, Any, List, Optional
from enum import Enum

from sqlalchemy.ext.asyncio import AsyncSession
from app.core.database import get_db
from app.core.config import get_settings

logger = logging.getLogger(__name__)
settings = get_settings()


class WorkflowState(Enum):
    """Workflow execution states."""
    IDLE = "idle"
    RUNNING = "running"
    COMPLETED = "completed"
    FAILED = "failed"
    PAUSED = "paused"


class WorkflowStage(Enum):
    """Workflow stages."""
    TRIGGER = "trigger"
    REASONING = "reasoning"
    PLANNING = "planning"
    EXECUTION = "execution"
    QUALITY_GATES = "quality_gates"
    DEPLOYMENT = "deployment"
    MONITORING = "monitoring"
    NOTIFICATION = "notification"


class ContinuousWorkflowEngine:
    """
    Self-driving continuous workflow engine.
    Runs the full workflow loop continuously.
    """
    
    def __init__(self):
        self.is_running = False
        self.current_iteration = 0
        self.state = WorkflowState.IDLE
        self.current_stage = None
        self.progress = 0.0
        self.history: List[Dict] = []
        self.subscribers: List[asyncio.Queue] = []
    
    async def start(self):
        """Start the continuous workflow loop."""
        self.is_running = True
        self.state = WorkflowState.RUNNING
        logger.info("🚀 Continuous workflow engine started")
        
        await self._notify({
            "type": "engine_start",
            "timestamp": datetime.utcnow().isoformat(),
        })
        
        while self.is_running:
            try:
                await self._run_iteration()
                self.current_iteration += 1
                await asyncio.sleep(10)  # Brief pause between iterations
            except Exception as e:
                logger.error(f"Workflow iteration error: {e}")
                await self._notify({
                    "type": "error",
                    "error": str(e),
                    "iteration": self.current_iteration,
                })
        
        self.state = WorkflowState.IDLE
    
    async def stop(self):
        """Stop the workflow engine."""
        self.is_running = False
        self.state = WorkflowState.PAUSED
        logger.info("⏸️ Workflow engine paused")
        
        await self._notify({
            "type": "engine_stop",
            "timestamp": datetime.utcnow().isoformat(),
        })
    
    async def _run_iteration(self):
        """Run one complete workflow iteration."""
        iteration_id = str(uuid.uuid4())
        start_time = datetime.utcnow()
        
        logger.info(f"🔄 Starting iteration {self.current_iteration}")
        
        await self._update_stage(WorkflowStage.TRIGGER, 5)
        
        # ===== STAGE 1: TRIGGER =====
        work_available = await self._check_for_work()
        
        if not work_available:
            logger.info("No work available, skipping iteration")
            await self._update_stage(WorkflowStage.TRIGGER, 100)
            await asyncio.sleep(1)
            return
        
        await self._update_stage(WorkflowStage.REASONING, 20)
        
        # ===== STAGE 2: REASONING =====
        analysis = await self._run_reasoning()
        
        await self._update_stage(WorkflowStage.PLANNING, 35)
        
        # ===== STAGE 3: PLANNING =====
        plan = await self._run_planning(analysis)
        
        await self._update_stage(WorkflowStage.EXECUTION, 50)
        
        # ===== STAGE 4: EXECUTION =====
        execution_result = await self._run_execution(plan)
        
        await self._update_stage(WorkflowStage.QUALITY_GATES, 75)
        
        # ===== STAGE 5: QUALITY GATES =====
        quality_passed = await self._run_quality_gates(execution_result)
        
        await self._update_stage(WorkflowStage.DEPLOYMENT, 85)
        
        # ===== STAGE 6: DEPLOYMENT =====
        if quality_passed:
            await self._run_deployment(execution_result)
        
        await self._update_stage(WorkflowStage.MONITORING, 95)
        
        # ===== STAGE 7: MONITORING =====
        await self._run_monitoring()
        
        await self._update_stage(WorkflowStage.NOTIFICATION, 100)
        
        # ===== STAGE 8: NOTIFICATION =====
        await self._run_notification(quality_passed)
        
        # Record iteration
        duration = (datetime.utcnow() - start_time).total_seconds()
        self.history.append({
            "iteration": self.current_iteration,
            "id": iteration_id,
            "start_time": start_time.isoformat(),
            "duration": duration,
            "status": "completed" if quality_passed else "failed",
            "changes": execution_result.get("changes", 0),
        })
        
        logger.info(f"✅ Iteration {self.current_iteration} completed in {duration:.1f}s")
    
    async def _check_for_work(self) -> bool:
        """Check if there's any work to do."""
        # Check for: Git changes, Issues, Alerts, Scheduled tasks
        # For now, simulate with small random chance
        await asyncio.sleep(0.5)
        return True  # Always run for demo
    
    async def _run_reasoning(self) -> Dict:
        """Run reasoning engine."""
        await asyncio.sleep(1)
        
        result = {
            "issues_found": ["code_smell", "test_gap", "security"],
            "priority": "medium",
            "estimated_impact": "medium",
        }
        
        await self._notify({
            "type": "stage_update",
            "stage": "reasoning",
            "data": result,
        })
        
        return result
    
    async def _run_planning(self, analysis: Dict) -> Dict:
        """Run planning system."""
        await asyncio.sleep(1)
        
        result = {
            "tasks": [
                {"type": "code", "files": ["app/services/test.py"]},
                {"type": "test", "coverage_delta": 5},
                {"type": "docs", "files": ["README.md"]},
            ],
            "dependencies": [],
        }
        
        await self._notify({
            "type": "stage_update",
            "stage": "planning",
            "data": result,
        })
        
        return result
    
    async def _run_execution(self, plan: Dict) -> Dict:
        """Run execution engine with agents."""
        await asyncio.sleep(2)
        
        result = {
            "changes": 3,
            "files_modified": ["test.py", "README.md"],
            "tests_added": 10,
            "docs_updated": True,
        }
        
        await self._notify({
            "type": "stage_update",
            "stage": "execution",
            "data": result,
        })
        
        return result
    
    async def _run_quality_gates(self, execution: Dict) -> bool:
        """Run quality gates."""
        await asyncio.sleep(1)
        
        result = {
            "lint": "passed",
            "tests": "passed",
            "security_scan": "passed",
            "all_green": True,
        }
        
        await self._notify({
            "type": "stage_update",
            "stage": "quality_gates",
            "data": result,
        })
        
        return True
    
    async def _run_deployment(self, execution: Dict):
        """Run deployment."""
        await asyncio.sleep(1)
        
        await self._notify({
            "type": "stage_update",
            "stage": "deployment",
            "data": {"deployed": True, "environment": "production"},
        })
    
    async def _run_monitoring(self):
        """Run monitoring."""
        await asyncio.sleep(0.5)
        
        await self._notify({
            "type": "stage_update",
            "stage": "monitoring",
            "data": {"metrics_collected": True},
        })
    
    async def _run_notification(self, success: bool):
        """Run notification."""
        await self._notify({
            "type": "stage_update",
            "stage": "notification",
            "data": {
                "sent": True,
                "channels": ["telegram"],
                "status": "success" if success else "failed",
            },
        })
    
    async def _update_stage(self, stage: WorkflowStage, progress: float):
        """Update current stage and notify subscribers."""
        self.current_stage = stage
        self.progress = progress
        
        await self._notify({
            "type": "stage_change",
            "stage": stage.value,
            "progress": progress,
            "iteration": self.current_iteration,
            "state": self.state.value,
        })
    
    async def _notify(self, message: Dict):
        """Send notification to all subscribers."""
        for queue in self.subscribers:
            try:
                await queue.put(message)
            except:
                pass
    
    def subscribe(self) -> asyncio.Queue:
        """Subscribe to workflow updates."""
        queue = asyncio.Queue()
        self.subscribers.append(queue)
        return queue
    
    def unsubscribe(self, queue: asyncio.Queue):
        """Unsubscribe from updates."""
        if queue in self.subscribers:
            self.subscribers.remove(queue)
    
    def get_status(self) -> Dict:
        """Get current workflow status."""
        return {
            "is_running": self.is_running,
            "iteration": self.current_iteration,
            "state": self.state.value,
            "current_stage": self.current_stage.value if self.current_stage else None,
            "progress": self.progress,
            "history": self.history[-10:],  # Last 10 iterations
        }


# Global workflow engine instance
workflow_engine = ContinuousWorkflowEngine()