"""Typed proposals emitted by Commit before either memory backend is mutated."""

from __future__ import annotations

import hashlib
import re
from datetime import datetime, timezone
from typing import Literal

from pydantic import BaseModel, ConfigDict, Field


class MemoryCandidate(BaseModel):
    model_config = ConfigDict(strict=True, extra="forbid")
    candidate_id: str
    destination: Literal["project", "student"]
    project_id: str
    kind: str
    statement: str
    attribution: Literal[
        "explicit_student",
        "idea_observer_interaction",
        "idea_observer_profile_proposal",
    ]
    confidence: float = Field(ge=0.0, le=1.0)
    evidence_ids: list[str] = Field(default_factory=list)
    interaction_ids: list[str] = Field(default_factory=list)
    observed_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))

    @property
    def recurrence_key(self) -> str:
        normalized = re.sub(r"\s+", " ", self.statement.casefold()).strip()
        return hashlib.sha256(f"{self.kind}\0{normalized}".encode("utf-8")).hexdigest()


def make_candidate_id(
    destination: str,
    project_id: str,
    kind: str,
    statement: str,
) -> str:
    normalized = re.sub(r"\s+", " ", statement.casefold()).strip()
    digest = hashlib.sha256(
        f"{destination}\0{project_id}\0{kind}\0{normalized}".encode("utf-8")
    ).hexdigest()
    return f"mc_{digest}"


def interaction_ref(value: str) -> str:
    return "ji_" + hashlib.sha256(value.strip().encode("utf-8")).hexdigest()[:24]