"""
app/models.py — All typed request/response models for OpenEnv API contract.
Pydantic V2 with strict validators. Never deviate from this contract.
"""
from pydantic import BaseModel, field_validator
from typing import Optional, Dict, Any, List


class StepAction(BaseModel):
    code: str
    filename: str
    task_id: str
    session_id: str

    @field_validator("code")
    @classmethod
    def code_not_empty(cls, v: str) -> str:
        if not v.strip():
            raise ValueError("code cannot be empty")
        if len(v) > 50_000:
            raise ValueError("code exceeds 50KB limit — split into smaller modules")
        return v

    @field_validator("filename")
    @classmethod
    def filename_valid(cls, v: str) -> str:
        if not v.strip():
            raise ValueError("filename cannot be empty")
        return v


class StepObservation(BaseModel):
    scores: Dict[str, float]
    total_reward: float
    feedback: Dict[str, str]
    codegraph: Dict[str, Any]
    done: bool
    step_count: int


class ResetObservation(BaseModel):
    session_id: str
    task_id: str
    problem_statement: str
    difficulty: str
    cwe_targets: List[str]
    codegraph: Dict[str, Any]
    starter_code: str
    naive_baseline: Dict[str, Any]


class StateResponse(BaseModel):
    task_id: str
    step: int
    done: bool
    codegraph: Dict[str, Any]
    difficulty: Optional[str] = None
    cwe_targets: Optional[List[str]] = None