# services/inventory/app/schemas/inventory.py
"""
Pydantic schemas for inventory API requests and responses
"""

from typing import Optional, List, Dict, Any
from datetime import datetime
from decimal import Decimal
from pydantic import BaseModel, Field, validator
from typing import Generic, TypeVar
from enum import Enum

from app.models.inventory import UnitOfMeasure, IngredientCategory, StockMovementType

T = TypeVar('T')


# ===== BASE SCHEMAS =====

class InventoryBaseSchema(BaseModel):
    """Base schema for inventory models"""
    
    class Config:
        from_attributes = True
        use_enum_values = True
        json_encoders = {
            datetime: lambda v: v.isoformat() if v else None,
            Decimal: lambda v: float(v) if v else None
        }


# ===== INGREDIENT SCHEMAS =====

class IngredientCreate(InventoryBaseSchema):
    """Schema for creating ingredients"""
    name: str = Field(..., max_length=255, description="Ingredient name")
    sku: Optional[str] = Field(None, max_length=100, description="SKU code")
    barcode: Optional[str] = Field(None, max_length=50, description="Barcode")
    category: IngredientCategory = Field(..., description="Ingredient category")
    subcategory: Optional[str] = Field(None, max_length=100, description="Subcategory")
    description: Optional[str] = Field(None, description="Ingredient description")
    brand: Optional[str] = Field(None, max_length=100, description="Brand name")
    unit_of_measure: UnitOfMeasure = Field(..., description="Unit of measure")
    package_size: Optional[float] = Field(None, gt=0, description="Package size")
    
    # Pricing
    average_cost: Optional[Decimal] = Field(None, ge=0, description="Average cost per unit")
    standard_cost: Optional[Decimal] = Field(None, ge=0, description="Standard cost per unit")
    
    # Stock management
    low_stock_threshold: float = Field(10.0, ge=0, description="Low stock alert threshold")
    reorder_point: float = Field(20.0, ge=0, description="Reorder point")
    reorder_quantity: float = Field(50.0, gt=0, description="Default reorder quantity")
    max_stock_level: Optional[float] = Field(None, gt=0, description="Maximum stock level")
    
    # Storage requirements
    requires_refrigeration: bool = Field(False, description="Requires refrigeration")
    requires_freezing: bool = Field(False, description="Requires freezing")
    storage_temperature_min: Optional[float] = Field(None, description="Min storage temperature (°C)")
    storage_temperature_max: Optional[float] = Field(None, description="Max storage temperature (°C)")
    storage_humidity_max: Optional[float] = Field(None, ge=0, le=100, description="Max humidity (%)")
    
    # Shelf life
    shelf_life_days: Optional[int] = Field(None, gt=0, description="Shelf life in days")
    storage_instructions: Optional[str] = Field(None, description="Storage instructions")
    
    # Properties
    is_perishable: bool = Field(False, description="Is perishable")
    allergen_info: Optional[Dict[str, Any]] = Field(None, description="Allergen information")
    
    @validator('storage_temperature_max')
    def validate_temperature_range(cls, v, values):
        if v is not None and 'storage_temperature_min' in values and values['storage_temperature_min'] is not None:
            if v <= values['storage_temperature_min']:
                raise ValueError('Max temperature must be greater than min temperature')
        return v
    
    @validator('reorder_point')
    def validate_reorder_point(cls, v, values):
        if 'low_stock_threshold' in values and v <= values['low_stock_threshold']:
            raise ValueError('Reorder point must be greater than low stock threshold')
        return v


class IngredientUpdate(InventoryBaseSchema):
    """Schema for updating ingredients"""
    name: Optional[str] = Field(None, max_length=255, description="Ingredient name")
    sku: Optional[str] = Field(None, max_length=100, description="SKU code")
    barcode: Optional[str] = Field(None, max_length=50, description="Barcode")
    category: Optional[IngredientCategory] = Field(None, description="Ingredient category")
    subcategory: Optional[str] = Field(None, max_length=100, description="Subcategory")
    description: Optional[str] = Field(None, description="Ingredient description")
    brand: Optional[str] = Field(None, max_length=100, description="Brand name")
    unit_of_measure: Optional[UnitOfMeasure] = Field(None, description="Unit of measure")
    package_size: Optional[float] = Field(None, gt=0, description="Package size")
    
    # Pricing
    average_cost: Optional[Decimal] = Field(None, ge=0, description="Average cost per unit")
    standard_cost: Optional[Decimal] = Field(None, ge=0, description="Standard cost per unit")
    
    # Stock management
    low_stock_threshold: Optional[float] = Field(None, ge=0, description="Low stock alert threshold")
    reorder_point: Optional[float] = Field(None, ge=0, description="Reorder point")
    reorder_quantity: Optional[float] = Field(None, gt=0, description="Default reorder quantity")
    max_stock_level: Optional[float] = Field(None, gt=0, description="Maximum stock level")
    
    # Storage requirements
    requires_refrigeration: Optional[bool] = Field(None, description="Requires refrigeration")
    requires_freezing: Optional[bool] = Field(None, description="Requires freezing")
    storage_temperature_min: Optional[float] = Field(None, description="Min storage temperature (°C)")
    storage_temperature_max: Optional[float] = Field(None, description="Max storage temperature (°C)")
    storage_humidity_max: Optional[float] = Field(None, ge=0, le=100, description="Max humidity (%)")
    
    # Shelf life
    shelf_life_days: Optional[int] = Field(None, gt=0, description="Shelf life in days")
    storage_instructions: Optional[str] = Field(None, description="Storage instructions")
    
    # Properties
    is_active: Optional[bool] = Field(None, description="Is active")
    is_perishable: Optional[bool] = Field(None, description="Is perishable")
    allergen_info: Optional[Dict[str, Any]] = Field(None, description="Allergen information")


class IngredientResponse(InventoryBaseSchema):
    """Schema for ingredient API responses"""
    id: str
    tenant_id: str
    name: str
    sku: Optional[str]
    barcode: Optional[str]
    category: IngredientCategory
    subcategory: Optional[str]
    description: Optional[str]
    brand: Optional[str]
    unit_of_measure: UnitOfMeasure
    package_size: Optional[float]
    average_cost: Optional[float]
    last_purchase_price: Optional[float]
    standard_cost: Optional[float]
    low_stock_threshold: float
    reorder_point: float
    reorder_quantity: float
    max_stock_level: Optional[float]
    requires_refrigeration: bool
    requires_freezing: bool
    storage_temperature_min: Optional[float]
    storage_temperature_max: Optional[float]
    storage_humidity_max: Optional[float]
    shelf_life_days: Optional[int]
    storage_instructions: Optional[str]
    is_active: bool
    is_perishable: bool
    allergen_info: Optional[Dict[str, Any]]
    created_at: datetime
    updated_at: datetime
    created_by: Optional[str]
    
    # Computed fields
    current_stock: Optional[float] = None
    is_low_stock: Optional[bool] = None
    needs_reorder: Optional[bool] = None


# ===== STOCK SCHEMAS =====

class StockCreate(InventoryBaseSchema):
    """Schema for creating stock entries"""
    ingredient_id: str = Field(..., description="Ingredient ID")
    batch_number: Optional[str] = Field(None, max_length=100, description="Batch number")
    lot_number: Optional[str] = Field(None, max_length=100, description="Lot number")
    supplier_batch_ref: Optional[str] = Field(None, max_length=100, description="Supplier batch reference")
    
    current_quantity: float = Field(..., ge=0, description="Current quantity")
    received_date: Optional[datetime] = Field(None, description="Date received")
    expiration_date: Optional[datetime] = Field(None, description="Expiration date")
    best_before_date: Optional[datetime] = Field(None, description="Best before date")
    
    unit_cost: Optional[Decimal] = Field(None, ge=0, description="Unit cost")
    storage_location: Optional[str] = Field(None, max_length=100, description="Storage location")
    warehouse_zone: Optional[str] = Field(None, max_length=50, description="Warehouse zone")
    shelf_position: Optional[str] = Field(None, max_length=50, description="Shelf position")
    
    quality_status: str = Field("good", description="Quality status")


class StockUpdate(InventoryBaseSchema):
    """Schema for updating stock entries"""
    batch_number: Optional[str] = Field(None, max_length=100, description="Batch number")
    lot_number: Optional[str] = Field(None, max_length=100, description="Lot number")
    supplier_batch_ref: Optional[str] = Field(None, max_length=100, description="Supplier batch reference")
    
    current_quantity: Optional[float] = Field(None, ge=0, description="Current quantity")
    reserved_quantity: Optional[float] = Field(None, ge=0, description="Reserved quantity")
    received_date: Optional[datetime] = Field(None, description="Date received")
    expiration_date: Optional[datetime] = Field(None, description="Expiration date")
    best_before_date: Optional[datetime] = Field(None, description="Best before date")
    
    unit_cost: Optional[Decimal] = Field(None, ge=0, description="Unit cost")
    storage_location: Optional[str] = Field(None, max_length=100, description="Storage location")
    warehouse_zone: Optional[str] = Field(None, max_length=50, description="Warehouse zone")
    shelf_position: Optional[str] = Field(None, max_length=50, description="Shelf position")
    
    is_available: Optional[bool] = Field(None, description="Is available")
    quality_status: Optional[str] = Field(None, description="Quality status")


class StockResponse(InventoryBaseSchema):
    """Schema for stock API responses"""
    id: str
    tenant_id: str
    ingredient_id: str
    batch_number: Optional[str]
    lot_number: Optional[str]
    supplier_batch_ref: Optional[str]
    current_quantity: float
    reserved_quantity: float
    available_quantity: float
    received_date: Optional[datetime]
    expiration_date: Optional[datetime]
    best_before_date: Optional[datetime]
    unit_cost: Optional[float]
    total_cost: Optional[float]
    storage_location: Optional[str]
    warehouse_zone: Optional[str]
    shelf_position: Optional[str]
    is_available: bool
    is_expired: bool
    quality_status: str
    created_at: datetime
    updated_at: datetime
    
    # Related data
    ingredient: Optional[IngredientResponse] = None


# ===== STOCK MOVEMENT SCHEMAS =====

class StockMovementCreate(InventoryBaseSchema):
    """Schema for creating stock movements"""
    ingredient_id: str = Field(..., description="Ingredient ID")
    stock_id: Optional[str] = Field(None, description="Stock ID")
    movement_type: StockMovementType = Field(..., description="Movement type")
    quantity: float = Field(..., description="Quantity moved")
    
    unit_cost: Optional[Decimal] = Field(None, ge=0, description="Unit cost")
    reference_number: Optional[str] = Field(None, max_length=100, description="Reference number")
    supplier_id: Optional[str] = Field(None, description="Supplier ID")
    
    notes: Optional[str] = Field(None, description="Movement notes")
    reason_code: Optional[str] = Field(None, max_length=50, description="Reason code")
    movement_date: Optional[datetime] = Field(None, description="Movement date")


class StockMovementResponse(InventoryBaseSchema):
    """Schema for stock movement API responses"""
    id: str
    tenant_id: str
    ingredient_id: str
    stock_id: Optional[str]
    movement_type: StockMovementType
    quantity: float
    unit_cost: Optional[float]
    total_cost: Optional[float]
    quantity_before: Optional[float]
    quantity_after: Optional[float]
    reference_number: Optional[str]
    supplier_id: Optional[str]
    notes: Optional[str]
    reason_code: Optional[str]
    movement_date: datetime
    created_at: datetime
    created_by: Optional[str]
    
    # Related data
    ingredient: Optional[IngredientResponse] = None


# ===== ALERT SCHEMAS =====

class StockAlertResponse(InventoryBaseSchema):
    """Schema for stock alert API responses"""
    id: str
    tenant_id: str
    ingredient_id: str
    stock_id: Optional[str]
    alert_type: str
    severity: str
    title: str
    message: str
    current_quantity: Optional[float]
    threshold_value: Optional[float]
    expiration_date: Optional[datetime]
    is_active: bool
    is_acknowledged: bool
    acknowledged_by: Optional[str]
    acknowledged_at: Optional[datetime]
    is_resolved: bool
    resolved_by: Optional[str]
    resolved_at: Optional[datetime]
    resolution_notes: Optional[str]
    created_at: datetime
    updated_at: datetime
    
    # Related data
    ingredient: Optional[IngredientResponse] = None


# ===== DASHBOARD AND SUMMARY SCHEMAS =====

class InventorySummary(InventoryBaseSchema):
    """Inventory dashboard summary"""
    total_ingredients: int
    total_stock_value: float
    low_stock_alerts: int
    expiring_soon_items: int
    expired_items: int
    out_of_stock_items: int
    
    # By category
    stock_by_category: Dict[str, Dict[str, Any]]
    
    # Recent activity
    recent_movements: int
    recent_purchases: int
    recent_waste: int


class StockLevelSummary(InventoryBaseSchema):
    """Stock level summary for an ingredient"""
    ingredient_id: str
    ingredient_name: str
    unit_of_measure: str
    total_quantity: float
    available_quantity: float
    reserved_quantity: float
    
    # Status indicators
    is_low_stock: bool
    needs_reorder: bool
    has_expired_stock: bool
    
    # Batch information
    total_batches: int
    oldest_batch_date: Optional[datetime]
    newest_batch_date: Optional[datetime]
    next_expiration_date: Optional[datetime]
    
    # Cost information
    average_unit_cost: Optional[float]
    total_stock_value: Optional[float]


# ===== REQUEST/RESPONSE WRAPPER SCHEMAS =====

class PaginatedResponse(BaseModel, Generic[T]):
    """Generic paginated response"""
    items: List[T]
    total: int
    page: int
    size: int
    pages: int
    
    class Config:
        from_attributes = True


class InventoryFilter(BaseModel):
    """Inventory filtering parameters"""
    category: Optional[IngredientCategory] = None
    is_active: Optional[bool] = None
    is_low_stock: Optional[bool] = None
    needs_reorder: Optional[bool] = None
    search: Optional[str] = None
    
    
class StockFilter(BaseModel):
    """Stock filtering parameters"""
    ingredient_id: Optional[str] = None
    is_available: Optional[bool] = None
    is_expired: Optional[bool] = None
    expiring_within_days: Optional[int] = None
    storage_location: Optional[str] = None
    quality_status: Optional[str] = None


# Type aliases for paginated responses
IngredientListResponse = PaginatedResponse[IngredientResponse]
StockListResponse = PaginatedResponse[StockResponse]
StockMovementListResponse = PaginatedResponse[StockMovementResponse]
StockAlertListResponse = PaginatedResponse[StockAlertResponse]