"""
User onboarding progress API routes
"""

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.ext.asyncio import AsyncSession
from typing import Dict, Any, List, Optional
import structlog
from datetime import datetime, timezone
from pydantic import BaseModel

from app.core.database import get_db
from app.services.user_service import UserService
from app.repositories.onboarding_repository import OnboardingRepository
from shared.auth.decorators import get_current_user_dep

logger = structlog.get_logger()
router = APIRouter(tags=["onboarding"])

# Request/Response Models
class OnboardingStepStatus(BaseModel):
    step_name: str
    completed: bool
    completed_at: Optional[datetime] = None
    data: Optional[Dict[str, Any]] = None

class UserProgress(BaseModel):
    user_id: str
    steps: List[OnboardingStepStatus]
    current_step: str
    next_step: Optional[str] = None
    completion_percentage: float
    fully_completed: bool
    last_updated: datetime

class UpdateStepRequest(BaseModel):
    step_name: str
    completed: bool
    data: Optional[Dict[str, Any]] = None

# Define the onboarding steps and their order - matching frontend UnifiedOnboardingWizard step IDs
ONBOARDING_STEPS = [
    # Phase 0: System Steps
    "user_registered",              # Auto-completed: User account created

    # Phase 1: Discovery
    "bakery-type-selection",        # Choose bakery type: production/retail/mixed

    # Phase 2: Core Setup
    "setup",                        # Basic bakery setup and tenant creation

    # Phase 2a: POI Detection (Location Context)
    "poi-detection",                # Detect nearby POIs for location-based ML features

    # Phase 2b: AI-Assisted Inventory Setup (REFACTORED - split into 3 focused steps)
    "upload-sales-data",            # File upload, validation, and AI classification
    "inventory-review",             # Review and confirm AI-detected products with type selection
    "initial-stock-entry",          # Capture initial stock levels

    # Phase 2c: Product Categorization (optional advanced categorization)
    "product-categorization",       # Advanced categorization (may be deprecated)

    # Phase 2d: Suppliers (shared by all paths)
    "suppliers-setup",              # Suppliers configuration

    # Phase 3: Advanced Configuration (all optional)
    "recipes-setup",                # Production recipes (conditional: production/mixed bakery)
    "production-processes",         # Finishing processes (conditional: retail/mixed bakery)
    "quality-setup",                # Quality standards and templates
    "team-setup",                   # Team members and permissions

    # Phase 4: ML & Finalization
    "ml-training",                  # AI model training
    "setup-review",                 # Review all configuration
    "completion"                    # Onboarding completed
]

# Step dependencies - defines which steps must be completed before others
# Steps not listed here have no dependencies (can be completed anytime after user_registered)
STEP_DEPENDENCIES = {
    # Discovery phase
    "bakery-type-selection": ["user_registered"],

    # Core setup - no longer depends on data-source-choice (removed)
    "setup": ["user_registered", "bakery-type-selection"],

    # POI Detection - requires tenant creation (setup)
    "poi-detection": ["user_registered", "setup"],

    # AI-Assisted Inventory Setup - REFACTORED into 3 sequential steps
    "upload-sales-data": ["user_registered", "setup"],
    "inventory-review": ["user_registered", "setup", "upload-sales-data"],
    "initial-stock-entry": ["user_registered", "setup", "upload-sales-data", "inventory-review"],

    # Advanced product categorization (optional, may be deprecated)
    "product-categorization": ["user_registered", "setup", "upload-sales-data"],

    # Suppliers (after inventory review)
    "suppliers-setup": ["user_registered", "setup", "inventory-review"],

    # Advanced configuration (optional, minimal dependencies)
    "recipes-setup": ["user_registered", "setup"],
    "production-processes": ["user_registered", "setup"],
    "quality-setup": ["user_registered", "setup"],
    "team-setup": ["user_registered", "setup"],

    # ML Training - requires AI path completion AND POI detection for location features
    "ml-training": ["user_registered", "setup", "poi-detection", "upload-sales-data", "inventory-review"],

    # Review and completion
    "setup-review": ["user_registered", "setup"],
    "completion": ["user_registered", "setup"]  # Minimal requirements for completion
}

class OnboardingService:
    """Service for managing user onboarding progress"""
    
    def __init__(self, db: AsyncSession):
        self.db = db
        self.user_service = UserService(db)
        self.onboarding_repo = OnboardingRepository(db)
    
    async def get_user_progress(self, user_id: str) -> UserProgress:
        """Get current onboarding progress for user"""
        
        # Get user's onboarding data from user preferences or separate table
        user_progress_data = await self._get_user_onboarding_data(user_id)
        
        # Calculate current status for each step
        steps = []
        completed_steps = []
        
        for step_name in ONBOARDING_STEPS:
            step_data = user_progress_data.get(step_name, {})
            is_completed = step_data.get("completed", False)
            
            if is_completed:
                completed_steps.append(step_name)
            
            steps.append(OnboardingStepStatus(
                step_name=step_name,
                completed=is_completed,
                completed_at=step_data.get("completed_at"),
                data=step_data.get("data", {})
            ))
        
        # Determine current and next step
        current_step = self._get_current_step(completed_steps)
        next_step = self._get_next_step(completed_steps)
        
        # Calculate completion percentage
        completion_percentage = (len(completed_steps) / len(ONBOARDING_STEPS)) * 100
        
        # Check if fully completed
        fully_completed = len(completed_steps) == len(ONBOARDING_STEPS)
        
        return UserProgress(
            user_id=user_id,
            steps=steps,
            current_step=current_step,
            next_step=next_step,
            completion_percentage=completion_percentage,
            fully_completed=fully_completed,
            last_updated=datetime.now(timezone.utc)
        )
    
    async def update_step(self, user_id: str, update_request: UpdateStepRequest) -> UserProgress:
        """Update a specific onboarding step"""
        
        step_name = update_request.step_name
        
        # Validate step name
        if step_name not in ONBOARDING_STEPS:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"Invalid step name: {step_name}"
            )
        
        # Check dependencies if marking as completed
        if update_request.completed:
            can_complete = await self._can_complete_step(user_id, step_name)
            if not can_complete:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail=f"Cannot complete step {step_name}: dependencies not met"
                )
        
        # Update the step
        await self._update_user_onboarding_data(
            user_id,
            step_name,
            {
                "completed": update_request.completed,
                "completed_at": datetime.now(timezone.utc).isoformat() if update_request.completed else None,
                "data": update_request.data or {}
            }
        )

        # Try to update summary and handle partial failures gracefully
        try:
            # Update the user's onboarding summary
            await self._update_user_summary(user_id)
        except HTTPException as he:
            # If it's a 207 Multi-Status (partial success), log warning but continue
            if he.status_code == status.HTTP_207_MULTI_STATUS:
                logger.warning(f"Summary update failed for user {user_id}, step {step_name}: {he.detail}")
                # Continue execution - the step update was successful
            else:
                # Re-raise other HTTP exceptions
                raise

        # Return updated progress
        return await self.get_user_progress(user_id)
    
    async def get_next_step(self, user_id: str) -> Dict[str, Any]:
        """Get the next required step for user"""
        progress = await self.get_user_progress(user_id)
        
        if progress.fully_completed:
            return {"step": "dashboard_accessible", "completed": True}
        
        return {"step": progress.next_step or progress.current_step}
    
    async def can_access_step(self, user_id: str, step_name: str) -> Dict[str, Any]:
        """Check if user can access a specific step"""
        
        if step_name not in ONBOARDING_STEPS:
            return {"can_access": False, "reason": "Invalid step name"}
        
        can_access = await self._can_complete_step(user_id, step_name)
        return {"can_access": can_access}
    
    async def complete_onboarding(self, user_id: str) -> Dict[str, Any]:
        """Mark entire onboarding as complete"""
        
        # Ensure all steps are completed
        progress = await self.get_user_progress(user_id)
        
        if not progress.fully_completed:
            incomplete_steps = [
                step.step_name for step in progress.steps if not step.completed
            ]
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"Cannot complete onboarding: incomplete steps: {incomplete_steps}"
            )
        
        # Update user's isOnboardingComplete flag
        await self.user_service.update_user_field(
            user_id, 
            "is_onboarding_complete", 
            True
        )
        
        return {"success": True, "message": "Onboarding completed successfully"}
    
    def _get_current_step(self, completed_steps: List[str]) -> str:
        """Determine current step based on completed steps"""
        for step in ONBOARDING_STEPS:
            if step not in completed_steps:
                return step
        return ONBOARDING_STEPS[-1]  # All completed
    
    def _get_next_step(self, completed_steps: List[str]) -> Optional[str]:
        """Determine next step based on completed steps"""
        current_step = self._get_current_step(completed_steps)
        current_index = ONBOARDING_STEPS.index(current_step)
        
        if current_index < len(ONBOARDING_STEPS) - 1:
            return ONBOARDING_STEPS[current_index + 1]
        
        return None  # No next step
    
    async def _can_complete_step(self, user_id: str, step_name: str) -> bool:
        """Check if user can complete a specific step"""
        
        # Get required dependencies for this step
        required_steps = STEP_DEPENDENCIES.get(step_name, [])
        
        if not required_steps:
            return True  # No dependencies
        
        # Check if all required steps are completed
        user_progress_data = await self._get_user_onboarding_data(user_id)
        
        for required_step in required_steps:
            if not user_progress_data.get(required_step, {}).get("completed", False):
                return False
        
        # SPECIAL VALIDATION FOR ML TRAINING STEP
        if step_name == "ml-training":
            # ML training requires AI-assisted path completion
            # Check if upload-sales-data and inventory-review are completed
            upload_complete = user_progress_data.get("upload-sales-data", {}).get("completed", False)
            inventory_complete = user_progress_data.get("inventory-review", {}).get("completed", False)

            if upload_complete and inventory_complete:
                # Validate sales data was imported
                upload_data = user_progress_data.get("upload-sales-data", {}).get("data", {})
                inventory_data = user_progress_data.get("inventory-review", {}).get("data", {})

                # Check if sales data was processed
                has_sales_data = (
                    upload_data.get("validationResult", {}).get("is_valid", False) or
                    upload_data.get("aiSuggestions", []) or
                    inventory_data.get("inventoryItemsCreated", 0) > 0
                )

                if has_sales_data:
                    logger.info(f"ML training allowed for user {user_id}: AI path with sales data")
                    return True

            # AI path not complete or no sales data
            logger.warning(f"ML training blocked for user {user_id}: No inventory data from AI path")
            return False
        
        return True
    
    async def _get_user_onboarding_data(self, user_id: str) -> Dict[str, Any]:
        """Get user's onboarding progress data from storage"""
        try:
            # Get all onboarding steps for the user from database
            steps = await self.onboarding_repo.get_user_progress_steps(user_id)
            
            # Convert to the expected dictionary format
            progress_data = {}
            for step in steps:
                progress_data[step.step_name] = {
                    "completed": step.completed,
                    "completed_at": step.completed_at,
                    "data": step.step_data or {}
                }
            
            return progress_data
            
        except Exception as e:
            logger.error(f"Error getting onboarding data for user {user_id}: {e}")
            return {}
    
    async def _update_user_onboarding_data(
        self, 
        user_id: str, 
        step_name: str, 
        step_data: Dict[str, Any]
    ):
        """Update user's onboarding step data"""
        try:
            # Extract the completion status and other data
            completed = step_data.get("completed", False)
            data_payload = step_data.get("data", {})
            
            # Update the step in database
            updated_step = await self.onboarding_repo.upsert_user_step(
                user_id=user_id,
                step_name=step_name,
                completed=completed,
                step_data=data_payload
            )

            logger.info(f"Successfully updated onboarding step for user {user_id}: {step_name} = {step_data}")
            return updated_step
            
        except Exception as e:
            logger.error(f"Error updating onboarding data for user {user_id}, step {step_name}: {e}")
            raise
    
    async def _update_user_summary(self, user_id: str):
        """Update user's onboarding summary after step changes"""
        try:
            # Get updated progress
            user_progress_data = await self._get_user_onboarding_data(user_id)

            # Calculate current status
            completed_steps = []
            for step_name in ONBOARDING_STEPS:
                if user_progress_data.get(step_name, {}).get("completed", False):
                    completed_steps.append(step_name)

            # Determine current and next step
            current_step = self._get_current_step(completed_steps)
            next_step = self._get_next_step(completed_steps)

            # Calculate completion percentage
            completion_percentage = (len(completed_steps) / len(ONBOARDING_STEPS)) * 100

            # Check if fully completed
            fully_completed = len(completed_steps) == len(ONBOARDING_STEPS)

            # Format steps count
            steps_completed_count = f"{len(completed_steps)}/{len(ONBOARDING_STEPS)}"

            # Update summary in database
            await self.onboarding_repo.upsert_user_summary(
                user_id=user_id,
                current_step=current_step,
                next_step=next_step,
                completion_percentage=completion_percentage,
                fully_completed=fully_completed,
                steps_completed_count=steps_completed_count
            )

            logger.debug(f"Successfully updated onboarding summary for user {user_id}")

        except Exception as e:
            logger.error(f"Error updating onboarding summary for user {user_id}: {e}",
                        extra={"user_id": user_id, "error_type": type(e).__name__})
            # Raise a warning-level HTTPException to inform frontend without breaking the flow
            # This allows the step update to succeed while alerting about summary issues
            raise HTTPException(
                status_code=status.HTTP_207_MULTI_STATUS,
                detail=f"Step updated successfully, but summary update failed: {str(e)}"
            )

# API Routes

@router.get("/api/v1/auth/me/onboarding/progress", response_model=UserProgress)
async def get_user_progress(
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):
    """Get current user's onboarding progress"""

    try:
        onboarding_service = OnboardingService(db)
        progress = await onboarding_service.get_user_progress(current_user["user_id"])
        return progress

    except Exception as e:
        logger.error(f"Get onboarding progress error: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to get onboarding progress"
        )

@router.get("/api/v1/auth/users/{user_id}/onboarding/progress", response_model=UserProgress)
async def get_user_progress_by_id(
    user_id: str,
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):
    """
    Get onboarding progress for a specific user
    Available for service-to-service calls and admin users
    """

    # Allow service tokens or admin users
    user_type = current_user.get("type", "user")
    user_role = current_user.get("role", "user")

    if user_type != "service" and user_role not in ["admin", "super_admin"]:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Insufficient permissions to access other users' onboarding progress"
        )

    try:
        onboarding_service = OnboardingService(db)
        progress = await onboarding_service.get_user_progress(user_id)
        return progress

    except Exception as e:
        logger.error(f"Get onboarding progress error for user {user_id}: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to get onboarding progress"
        )

@router.put("/api/v1/auth/me/onboarding/step", response_model=UserProgress)
async def update_onboarding_step(
    update_request: UpdateStepRequest,
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):
    """Update a specific onboarding step"""
    
    try:
        onboarding_service = OnboardingService(db)
        progress = await onboarding_service.update_step(
            current_user["user_id"], 
            update_request
        )
        return progress
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Update onboarding step error: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to update onboarding step"
        )

@router.get("/api/v1/auth/me/onboarding/next-step")
async def get_next_step(
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):
    """Get next required step for user"""
    
    try:
        onboarding_service = OnboardingService(db)
        result = await onboarding_service.get_next_step(current_user["user_id"])
        return result
        
    except Exception as e:
        logger.error(f"Get next step error: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to get next step"
        )

@router.get("/api/v1/auth/me/onboarding/can-access/{step_name}")
async def can_access_step(
    step_name: str,
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):
    """Check if user can access a specific step"""
    
    try:
        onboarding_service = OnboardingService(db)
        result = await onboarding_service.can_access_step(
            current_user["user_id"], 
            step_name
        )
        return result
        
    except Exception as e:
        logger.error(f"Can access step error: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to check step access"
        )

@router.post("/api/v1/auth/me/onboarding/complete")
async def complete_onboarding(
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):
    """Complete entire onboarding process"""
    
    try:
        onboarding_service = OnboardingService(db)
        result = await onboarding_service.complete_onboarding(current_user["user_id"])
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Complete onboarding error: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to complete onboarding"
        )