"""Job model — persistent asynchronous job state.

RabbitMQ delivers work messages. MongoDB is the source of truth for job
lifecycle. Worker processes update Job records as they progress through
queued → running → completed|failed|cancelled.

Do not use RabbitMQ queues as the permanent job database.
"""

from __future__ import annotations

from typing import Any, Optional, Dict
from pydantic import Field

from asf_domain.base import (
    ASFBaseModel,
    TenantScopedModel,
    ASFFieldID,
    UTCDatetime,
    JobStatus,
    JobPriority,
    JobType,
    generate_id,
)


class JobUsage(ASFBaseModel):
    """Optional resource / cost usage tracked for a job."""

    input_tokens: Optional[int] = Field(None, ge=0)
    output_tokens: Optional[int] = Field(None, ge=0)
    gpu_seconds: Optional[float] = Field(None, ge=0)
    cpu_seconds: Optional[float] = Field(None, ge=0)
    estimated_cost: Optional[float] = Field(
        None,
        ge=0,
        description="Estimated cost in tenant currency (EUR/USD). Approximate, used for metering only.",
    )
    extra: Dict[str, Any] = Field(default_factory=dict)


class JobBase(ASFBaseModel):
    type: JobType = Field(
        ...,
        description="Logical job class. Used for routing to the correct RabbitMQ queue.",
    )
    priority: JobPriority = JobPriority.NORMAL
    payload: Dict[str, Any] = Field(
        default_factory=dict,
        description="The actual work payload (e.g. {artifact_id, prompt, model_preference}).",
    )
    correlation_id: Optional[str] = Field(
        None,
        max_length=128,
        description="Optional correlation id propagated across logs, events, child jobs.",
    )


class JobCreate(JobBase):
    """Create payload. tenant_id/project_id/requested_by are injected server-side."""

    project_id: Optional[ASFFieldID] = None
    model: Optional[str] = Field(
        None,
        max_length=128,
        description="Preferred model / engine, only meaningful for AI job types. "
        "Ultimate routing decision belongs to the AI Gateway.",
    )


class JobUpdate(ASFBaseModel):
    """Updates issued by workers as the job progresses."""

    status: Optional[JobStatus] = None
    worker: Optional[str] = Field(
        None, max_length=255, description="Identifier of the worker process claiming this job."
    )
    started_at: Optional[UTCDatetime] = None
    completed_at: Optional[UTCDatetime] = None
    result: Optional[Dict[str, Any]] = None
    error: Optional[str] = Field(None, max_length=2000)
    error_detail: Optional[Dict[str, Any]] = None
    usage: Optional[JobUsage] = None
    progress_percent: Optional[int] = Field(None, ge=0, le=100)


class Job(TenantScopedModel, JobBase):
    """Persistent job record — the authoritative source of truth."""

    id: ASFFieldID = Field(default_factory=generate_id)
    project_id: Optional[ASFFieldID] = None
    status: JobStatus = JobStatus.QUEUED
    requested_by: Optional[ASFFieldID] = Field(
        None, description="User that requested the job, or null for system jobs."
    )
    worker: Optional[str] = None
    model: Optional[str] = None
    created_at: UTCDatetime = ...
    started_at: Optional[UTCDatetime] = None
    completed_at: Optional[UTCDatetime] = None
    result: Optional[Dict[str, Any]] = None
    error: Optional[str] = None
    error_detail: Optional[Dict[str, Any]] = None
    usage: JobUsage = Field(default_factory=JobUsage)
    progress_percent: Optional[int] = Field(None, ge=0, le=100)
    retries: int = Field(0, ge=0, description="How many times this job has been retried.")