# models/schema/inventory.py
from datetime import datetime

from pydantic import BaseModel, ConfigDict, Field


class InventoryBase(BaseModel):
    product_id: int = Field(..., description="Product ID in vendor catalog")
    location: str = Field(..., description="Storage location")


class InventoryCreate(InventoryBase):
    """Set exact inventory quantity (replaces existing)."""

    quantity: int = Field(..., description="Exact inventory quantity", ge=0)


class InventoryAdjust(InventoryBase):
    """Add or remove inventory quantity."""

    quantity: int = Field(
        ..., description="Quantity to add (positive) or remove (negative)"
    )


class InventoryUpdate(BaseModel):
    """Update inventory fields."""

    quantity: int | None = Field(None, ge=0)
    reserved_quantity: int | None = Field(None, ge=0)
    location: str | None = None


class InventoryReserve(BaseModel):
    """Reserve inventory for orders."""

    product_id: int
    location: str
    quantity: int = Field(..., gt=0)


class InventoryResponse(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: int
    product_id: int
    vendor_id: int
    location: str
    quantity: int
    reserved_quantity: int
    gtin: str | None
    created_at: datetime
    updated_at: datetime

    @property
    def available_quantity(self):
        return max(0, self.quantity - self.reserved_quantity)


class InventoryLocationResponse(BaseModel):
    location: str
    quantity: int
    reserved_quantity: int
    available_quantity: int


class ProductInventorySummary(BaseModel):
    """Inventory summary for a product."""

    product_id: int
    vendor_id: int
    product_sku: str | None
    product_title: str
    total_quantity: int
    total_reserved: int
    total_available: int
    locations: list[InventoryLocationResponse]


class InventoryListResponse(BaseModel):
    inventories: list[InventoryResponse]
    total: int
    skip: int
    limit: int


class InventoryMessageResponse(BaseModel):
    """Simple message response for inventory operations."""

    message: str


class InventorySummaryResponse(BaseModel):
    """Inventory summary response for marketplace product service."""

    gtin: str
    total_quantity: int
    locations: list[InventoryLocationResponse]


# ============================================================================
# Admin Inventory Schemas
# ============================================================================


class AdminInventoryCreate(BaseModel):
    """Admin version of inventory create - requires explicit vendor_id."""

    vendor_id: int = Field(..., description="Target vendor ID")
    product_id: int = Field(..., description="Product ID in vendor catalog")
    location: str = Field(..., description="Storage location")
    quantity: int = Field(..., description="Exact inventory quantity", ge=0)


class AdminInventoryAdjust(BaseModel):
    """Admin version of inventory adjust - requires explicit vendor_id."""

    vendor_id: int = Field(..., description="Target vendor ID")
    product_id: int = Field(..., description="Product ID in vendor catalog")
    location: str = Field(..., description="Storage location")
    quantity: int = Field(
        ..., description="Quantity to add (positive) or remove (negative)"
    )
    reason: str | None = Field(None, description="Reason for adjustment")


class AdminInventoryItem(BaseModel):
    """Inventory item with vendor info for admin list view."""

    model_config = ConfigDict(from_attributes=True)

    id: int
    product_id: int
    vendor_id: int
    vendor_name: str | None = None
    vendor_code: str | None = None
    product_title: str | None = None
    product_sku: str | None = None
    location: str
    quantity: int
    reserved_quantity: int
    available_quantity: int
    gtin: str | None = None
    created_at: datetime
    updated_at: datetime


class AdminInventoryListResponse(BaseModel):
    """Cross-vendor inventory list for admin."""

    inventories: list[AdminInventoryItem]
    total: int
    skip: int
    limit: int
    vendor_filter: int | None = None
    location_filter: str | None = None


class AdminInventoryStats(BaseModel):
    """Inventory statistics for admin dashboard."""

    total_entries: int
    total_quantity: int
    total_reserved: int
    total_available: int
    low_stock_count: int
    vendors_with_inventory: int
    unique_locations: int


class AdminLowStockItem(BaseModel):
    """Low stock item for admin alerts."""

    id: int
    product_id: int
    vendor_id: int
    vendor_name: str | None = None
    product_title: str | None = None
    location: str
    quantity: int
    reserved_quantity: int
    available_quantity: int


class AdminVendorWithInventory(BaseModel):
    """Vendor with inventory entries."""

    id: int
    name: str
    vendor_code: str


class AdminVendorsWithInventoryResponse(BaseModel):
    """Response for vendors with inventory list."""

    vendors: list[AdminVendorWithInventory]


class AdminInventoryLocationsResponse(BaseModel):
    """Response for unique inventory locations."""

    locations: list[str]