"""
Adapter: Instruction Crossover via DSPy.

Implements CrossoverPort — combines two parent prompts into a child.
"""
from __future__ import annotations

import asyncio

import dspy

from prometheus.domain.entities import Prompt
from prometheus.domain.ports import CrossoverPort
from prometheus.infrastructure.dspy_modules import InstructionCrossover
from prometheus.infrastructure.retry import async_retry_with_backoff


class DSPyCrossoverAdapter(CrossoverPort):
    """Uses DSPy to combine two parent instructions into a child."""

    def __init__(
        self,
        lm: dspy.LM,
        max_retries: int = 3,
        retry_delay_base: float = 1.0,
    ) -> None:
        self._lm = lm
        self._crossover = InstructionCrossover()
        self._max_retries = max_retries
        self._retry_delay_base = retry_delay_base
        self.call_count: int = 0

    async def crossover(
        self,
        parent_a: Prompt,
        parent_b: Prompt,
        task_description: str,
    ) -> Prompt:
        async def _call() -> Prompt:
            return await asyncio.to_thread(
                self._sync_crossover, parent_a, parent_b, task_description,
            )

        return await async_retry_with_backoff(
            _call,
            max_retries=self._max_retries,
            retry_delay_base=self._retry_delay_base,
        )

    def _sync_crossover(
        self,
        parent_a: Prompt,
        parent_b: Prompt,
        task_description: str,
    ) -> Prompt:
        with dspy.context(lm=self._lm):
            pred = self._crossover(
                parent_a=parent_a.text,
                parent_b=parent_b.text,
                task_description=task_description,
            )
        self.call_count += 1
        return Prompt(text=pred.child_instruction)