"""
Minimal event schemas for services to emit events.

Services send minimal event data with only event_type and metadata.
All enrichment, i18n generation, and priority calculation happens
in the alert_processor service.
"""

from pydantic import BaseModel, Field
from typing import Dict, Any, Literal, Optional
from datetime import datetime
from uuid import UUID


class MinimalEvent(BaseModel):
    """
    Minimal event structure sent by services.

    Services only need to provide:
    - tenant_id: Who this event belongs to
    - event_class: alert, notification, or recommendation
    - event_domain: Business domain (inventory, production, supply_chain, etc.)
    - event_type: Specific event identifier (critical_stock_shortage, production_delay, etc.)
    - service: Source service name
    - metadata: Dictionary with event-specific data

    The alert_processor service enriches this with:
    - i18n keys and parameters
    - Priority score and level
    - Orchestrator context (AI actions)
    - Business impact analysis
    - Urgency assessment
    - User agency determination
    - Smart actions
    """

    tenant_id: str = Field(..., description="Tenant UUID as string")
    event_class: Literal["alert", "notification", "recommendation"] = Field(
        ...,
        description="Event classification - alert requires action, notification is FYI, recommendation is suggestion"
    )
    event_domain: str = Field(
        ...,
        description="Business domain: inventory, production, supply_chain, demand, operations, distribution"
    )
    event_type: str = Field(
        ...,
        description="Specific event type identifier, e.g., critical_stock_shortage, production_delay, po_approval_needed"
    )
    service: str = Field(..., description="Source service name, e.g., inventory, production, procurement")
    metadata: Dict[str, Any] = Field(
        default_factory=dict,
        description="Event-specific data - structure varies by event_type"
    )
    timestamp: Optional[datetime] = Field(
        default=None,
        description="Event timestamp, set automatically if not provided"
    )

    class Config:
        from_attributes = True
        json_schema_extra = {
            "examples": [
                {
                    "tenant_id": "550e8400-e29b-41d4-a716-446655440000",
                    "event_class": "alert",
                    "event_domain": "inventory",
                    "event_type": "critical_stock_shortage",
                    "service": "inventory",
                    "metadata": {
                        "ingredient_id": "123e4567-e89b-12d3-a456-426614174000",
                        "ingredient_name": "Flour",
                        "current_stock": 5.2,
                        "required_stock": 10.0,
                        "shortage_amount": 4.8,
                        "supplier_name": "Flour Supplier Co.",
                        "lead_time_days": 3,
                        "po_id": "PO-12345",
                        "po_amount": 2500.00,
                        "po_status": "pending_approval",
                        "delivery_date": "2025-12-10"
                    }
                },
                {
                    "tenant_id": "550e8400-e29b-41d4-a716-446655440000",
                    "event_class": "alert",
                    "event_domain": "production",
                    "event_type": "production_delay",
                    "service": "production",
                    "metadata": {
                        "batch_id": "987fbc97-4bed-5078-9f07-9141ba07c9f3",
                        "product_name": "Croissant",
                        "batch_number": "B-2025-001",
                        "delay_minutes": 45,
                        "affected_orders": 3,
                        "customer_names": ["Customer A", "Customer B"]
                    }
                },
                {
                    "tenant_id": "550e8400-e29b-41d4-a716-446655440000",
                    "event_class": "notification",
                    "event_domain": "supply_chain",
                    "event_type": "po_approved",
                    "service": "procurement",
                    "metadata": {
                        "po_id": "PO-12345",
                        "po_number": "PO-2025-001",
                        "supplier_name": "Flour Supplier Co.",
                        "total_amount": 2500.00,
                        "currency": "EUR",
                        "approved_at": "2025-12-05T10:30:00Z",
                        "approved_by": "user@example.com"
                    }
                }
            ]
        }


# Event Domain Constants
class EventDomain:
    """Standard event domains"""
    INVENTORY = "inventory"
    PRODUCTION = "production"
    SUPPLY_CHAIN = "supply_chain"
    DEMAND = "demand"
    OPERATIONS = "operations"
    DISTRIBUTION = "distribution"
    FINANCE = "finance"


# Event Class Constants
class EventClass:
    """Event classifications"""
    ALERT = "alert"              # Requires user decision/action
    NOTIFICATION = "notification"  # Informational, no action needed
    RECOMMENDATION = "recommendation"  # Optimization suggestion


# Severity Levels (for routing)
class Severity:
    """Alert severity levels for routing"""
    URGENT = "urgent"    # Immediate attention required
    HIGH = "high"        # Important, address soon
    MEDIUM = "medium"    # Standard priority
    LOW = "low"         # Minor, can wait
    INFO = "info"       # Informational only