"""Evidence selection for skill learning."""

from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any

from beaver.engine.session.manager import SessionManager
from beaver.memory.runs.store import RunMemoryStore


@dataclass(slots=True)
class EvidencePacket:
    run_ids: list[str]
    session_ids: list[str]
    task_summaries: list[str]
    session_excerpts: list[str]
    metadata: dict[str, Any] = field(default_factory=dict)


class EvidenceSelector:
    def __init__(self, run_store: RunMemoryStore, session_manager: SessionManager | None = None) -> None:
        self.run_store = run_store
        self.session_manager = session_manager

    def select_runs_for_revision(self, skill_name: str, version: str, limit: int = 5) -> list[str]:
        runs = self.run_store.list_runs_by_skill(skill_name, version=version, limit=limit)
        return [record.run_id for record in runs]

    def select_runs_for_new_skill(self, theme: str, limit: int = 5) -> list[str]:
        lowered = theme.lower().strip()
        matches = []
        for record in self.run_store.list_runs():
            if lowered and lowered not in record.task_text.lower():
                continue
            matches.append(record.run_id)
        return matches[-limit:]

    def build_evidence_packet(self, run_ids: list[str], session_ids: list[str] | None = None) -> EvidencePacket:
        runs_by_id = {record.run_id: record for record in self.run_store.list_runs()}
        resolved_run_ids: list[str] = []
        resolved_session_ids: list[str] = list(dict.fromkeys(session_ids or []))
        task_summaries: list[str] = []
        session_excerpts: list[str] = []
        for run_id in run_ids:
            record = runs_by_id.get(run_id)
            if record is None:
                continue
            resolved_run_ids.append(run_id)
            if record.session_id not in resolved_session_ids:
                resolved_session_ids.append(record.session_id)
            summary = record.task_text.strip()
            if summary:
                task_summaries.append(summary[:400])
            if self.session_manager is not None:
                excerpt = self._session_excerpt(record.session_id, run_id)
                if excerpt:
                    session_excerpts.append(excerpt)
        return EvidencePacket(
            run_ids=resolved_run_ids,
            session_ids=resolved_session_ids,
            task_summaries=task_summaries[:8],
            session_excerpts=session_excerpts[:6],
            metadata={"bounded": True},
        )

    def _session_excerpt(self, session_id: str, run_id: str) -> str:
        if self.session_manager is None:
            return ""
        events = self.session_manager.get_run_event_records(session_id, run_id)
        visible: list[str] = []
        for event in events:
            if not event.context_visible or not event.content:
                continue
            visible.append(f"{event.role}: {event.content.strip()}")
        return "\n".join(visible[:12])[:2000]