"""Deterministic execution planner for ExProve."""

from __future__ import annotations

import hashlib
from typing import Any, Dict

from .contracts import LocalExecutionTask, SharedMarketContext, PlanDelta


def _deterministic_delta(task: LocalExecutionTask, ctx: SharedMarketContext) -> Dict[str, Any]:
    seed_input = f"{task.task_id}:{task.instrument}:{task.venue}:{ctx.version}:{ctx.contract_id}"
    digest = hashlib.sha256(seed_input.encode("utf-8")).hexdigest()
    return {
        "route": [task.venue],
        "size_adjustment": int(digest[:6], 16) % 1000,
        "timestamp": 0.0,
        "hash_seed": digest,
    }


def compute_plan_delta(task: LocalExecutionTask, ctx: SharedMarketContext, *, author: str) -> PlanDelta:
    return PlanDelta(
        delta=_deterministic_delta(task, ctx),
        timestamp=0.0,
        author=author,
        contract_id=ctx.contract_id,
        privacy_budget=None,
    )