"""Skill schemas for AGI skill library and compilation."""

from datetime import datetime, timezone
from enum import Enum
from typing import Any

from pydantic import BaseModel, Field, field_validator


def _utc_now() -> datetime:
    return datetime.now(timezone.utc)


class SkillKind(str, Enum):
    """Type of skill."""

    WORKFLOW = "workflow"
    PROCEDURE = "procedure"
    TOOL_NATIVE = "tool_native"
    COMPOSITE = "composite"


class Skill(BaseModel):
    """Reusable skill: declarative description + executable steps."""

    skill_id: str = Field(..., min_length=1)
    name: str = Field(..., min_length=1)
    description: str = Field(default="")
    kind: SkillKind = Field(default=SkillKind.WORKFLOW)
    steps: list[dict[str, Any]] = Field(default_factory=list, description="Declarative steps (plan-like)")
    tool_names: list[str] = Field(default_factory=list, description="Tools this skill uses")
    version: int = Field(default=1, ge=1)
    metadata: dict[str, Any] = Field(default_factory=dict)
    created_at: datetime = Field(default_factory=_utc_now)

    @field_validator("skill_id", "name")
    @classmethod
    def validate_non_whitespace(cls, v: str) -> str:
        if not v.strip():
            raise ValueError("Field cannot be empty or whitespace")
        return v


class SkillVersionInfo(BaseModel):
    """Version and performance tracking for a skill."""

    skill_id: str = Field(..., min_length=1)
    version: int = Field(..., ge=1)
    success_count: int = Field(default=0, ge=0)
    failure_count: int = Field(default=0, ge=0)
    last_success_at: datetime | None = Field(default=None)
    regression_test_ids: list[str] = Field(default_factory=list)