from datetime import datetime
from typing import Optional, Dict, Any
from pydantic import BaseModel, Field
from bson import ObjectId


class PyObjectId(ObjectId):
    """Custom ObjectId type for Pydantic"""
    @classmethod
    def __get_validators__(cls):
        yield cls.validate

    @classmethod
    def validate(cls, v):
        if not ObjectId.is_valid(v):
            raise ValueError("Invalid ObjectId")
        return ObjectId(v)

    @classmethod
    def __get_pydantic_json_schema__(cls, field_schema):
        field_schema.update(type="string")


class PipelineStats(BaseModel):
    """Pipeline statistics"""
    total_processed: int = Field(default=0)
    success_count: int = Field(default=0)
    error_count: int = Field(default=0)
    last_run: Optional[datetime] = None
    average_duration_seconds: Optional[float] = None


class Pipeline(BaseModel):
    """Pipeline data model for process management"""

    id: Optional[PyObjectId] = Field(default=None, alias="_id")
    name: str = Field(..., min_length=1, max_length=100)
    type: str = Field(..., description="Type: rss_collector, translator, image_generator")
    status: str = Field(default="stopped", description="Status: running, stopped, error")
    config: Dict[str, Any] = Field(default_factory=dict)
    schedule: Optional[str] = Field(default=None, description="Cron expression for scheduling")
    stats: PipelineStats = Field(default_factory=PipelineStats)
    last_run: Optional[datetime] = None
    next_run: Optional[datetime] = None
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow)

    class Config:
        populate_by_name = True
        arbitrary_types_allowed = True
        json_encoders = {ObjectId: str}
        json_schema_extra = {
            "example": {
                "name": "RSS Collector - Politics",
                "type": "rss_collector",
                "status": "running",
                "config": {
                    "interval_minutes": 30,
                    "max_articles": 100,
                    "categories": ["politics"]
                },
                "schedule": "*/30 * * * *",
                "stats": {
                    "total_processed": 1523,
                    "success_count": 1500,
                    "error_count": 23,
                    "average_duration_seconds": 45.2
                }
            }
        }