"""
Pydantic models for Instant PromQL Query tool input validation.

Defines InstantQueryRequest: query (required) and optional RFC3339 evaluation time.
"""

from datetime import datetime
from typing import Optional

from pydantic import BaseModel, Field, field_validator

# Internal labels to exclude from output per spec (FR-013)
EXCLUDE_LABELS = {"__address__"}


def filter_display_labels(labels: dict[str, str]) -> dict[str, str]:
    """
    Exclude internal labels for display.
    Excludes __address__; redundant instance is handled in formatting.
    """
    return {k: v for k, v in labels.items() if k not in EXCLUDE_LABELS}


class InstantQueryRequest(BaseModel):
    """
    Input model for instant query requests.

    Validates PromQL query string and optional RFC3339 evaluation timestamp.
    """

    query: str = Field(
        ...,
        description="PromQL query string to execute",
        min_length=1,
        examples=['up{job="prometheus"}', "rate(http_requests_total[5m])"],
    )
    time: Optional[str] = Field(
        default=None,
        description="Optional evaluation time in RFC3339 format (default: now)",
        examples=["2024-01-01T12:00:00Z"],
    )
    cluster_id: str = Field(
        ...,
        description="Cluster identifier",
    )
    env: str = Field(
        ...,
        description="Environment name used in biz_type resolution (e.g. prod, staging, dev)",
    )
    deploy_type: str = Field(
        ...,
        description=(
            "Cluster deploy type used in biz_type resolution "
            "(dedicated, premium, resource_pool, starter, essential)"
        ),
    )

    @field_validator("time")
    @classmethod
    def validate_time(cls, v: Optional[str]) -> Optional[str]:
        if v is None or not v.strip():
            return None
        try:
            datetime.fromisoformat(v.replace("Z", "+00:00"))
            return v.strip()
        except ValueError as e:
            raise ValueError(f"Invalid timestamp format: {v}. Must be RFC3339/ISO8601.") from e

    @field_validator("env", "deploy_type", mode="before")
    @classmethod
    def normalize_scope_text(cls, v: str) -> str:
        return v.strip().lower()

    @field_validator("cluster_id", mode="before")
    @classmethod
    def normalize_cluster_id(cls, v: object) -> str:
        if not isinstance(v, str):
            raise ValueError("cluster_id must be a string. Quote numeric IDs explicitly.")
        return str(v).strip()