"""Optional retrieval directions and skills attached to a report structure.

检索方向 (``retrieval_directions``): when listed, material collection **splits
search terms along those facets** instead of treating the labels as queries.
检索来源 (``retrieval_skills``): when listed, collection calls those skills
instead of the collector's default web_search / Q&A research-skill stack.
Empty lists are no-ops: runners and the chat collector keep today's behaviour.
"""

from __future__ import annotations

from typing import Any

from deerflow.persistence.report_structures.directions import (
    MAX_DIRECTION_CHARS,
    MAX_RETRIEVAL_DIRECTIONS,
    normalize_retrieval_directions,
)
from deerflow.persistence.report_structures.skills import (
    MAX_RETRIEVAL_SKILLS,
    MAX_SKILL_NAME_CHARS,
    normalize_retrieval_skills,
)

# Must match the built-in collector agent id (seed + frontend). Extra skills
# from a report structure are only merged onto this agent so other custom
# agents cannot widen their whitelist via run context.
COLLECTOR_AGENT_ID = "deep-research-collector"

# Keep in sync with frontend ``COLLECTOR_DIRECTION_INTRO``.
_COLLECTOR_DIRECTION_INTRO = (
    "请按以下检索方向拆分检索词（这是拆词约束，不是检索词本身）："
    "每个方向拆成若干具体、可检索的检索词（含课题中的专名、时间、地点、同义/中英对照等），"
    "不要直接把方向名称拿去搜索——方向标签往往搜不到结果。"
    "覆盖列出的每一个方向；未列出的方面不必主动扩展。"
    "某个检索词没有结果时，换更具体或更短的词再试，仍不要改用未列出的方向。"
)

_COLLECTOR_SKILL_INTRO = (
    "请严格按照以下技能收集素材：先用 read_file 读取每个技能的 SKILL.md，"
    "再按其说明调用工具检索。不要改用未列出的技能，也不要自行改成纯 web_search"
    "（除非技能说明要求联网）。每个技能至少使用一轮。"
)

__all__ = [
    "COLLECTOR_AGENT_ID",
    "MAX_DIRECTION_CHARS",
    "MAX_RETRIEVAL_DIRECTIONS",
    "MAX_RETRIEVAL_SKILLS",
    "MAX_SKILL_NAME_CHARS",
    "format_collector_direction_block",
    "format_collector_skill_block",
    "format_direction_lines",
    "merge_collector_skill_allowlist",
    "normalize_retrieval_directions",
    "normalize_retrieval_skills",
    "queries_from_retrieval_directions",
    "runtime_extra_skills",
]


def format_direction_lines(directions: Any) -> str:
    """Numbered direction list, or ``""`` when empty."""
    dirs = normalize_retrieval_directions(directions)
    return "\n".join(f"{i}. {item}" for i, item in enumerate(dirs, 1))


def queries_from_retrieval_directions(topic: str, directions: Any) -> list[str]:
    """Last-resort search strings when directed query-planning fails.

    Prefer LLM/collector splitting: direction labels concatenated with the
    topic are often not retrievable. Empty directions → ``[]``.
    """
    topic_text = " ".join((topic or "").split()).strip()
    dirs = normalize_retrieval_directions(directions)
    if not dirs:
        return []

    seen: set[str] = set()
    queries: list[str] = []
    for direction in dirs:
        if topic_text and topic_text not in direction:
            query = f"{topic_text} {direction}".strip()
        else:
            query = direction
        key = query.casefold()
        if not query or key in seen:
            continue
        seen.add(key)
        queries.append(query)
    return queries


def format_collector_direction_block(directions: Any) -> str:
    """XML block appended to the collector's first user message, or ``""``."""
    lines = format_direction_lines(directions)
    if not lines:
        return ""
    return f"<retrieval-directions>\n{_COLLECTOR_DIRECTION_INTRO}\n{lines}\n</retrieval-directions>"


def format_collector_skill_block(skills: Any) -> str:
    """XML block appended to the collector's first user message, or ``""``."""
    names = normalize_retrieval_skills(skills)
    if not names:
        return ""
    lines = "\n".join(f"{i}. {item}" for i, item in enumerate(names, 1))
    return f"<retrieval-skills>\n{_COLLECTOR_SKILL_INTRO}\n{lines}\n</retrieval-skills>"


def runtime_extra_skills(cfg: Any) -> list[str]:
    """Read extra skill names from a LangGraph run config / context dict."""
    if not isinstance(cfg, dict):
        return []
    return normalize_retrieval_skills(cfg.get("extra_skills") or cfg.get("retrieval_skills"))


def merge_collector_skill_allowlist(
    agent_id: str | None,
    base: list[str] | None,
    extra: Any,
) -> list[str] | None:
    """Widen the collector agent's skill allowlist for one run.

    Other agents are unchanged. Empty extras are a no-op. ``None`` base means
    "all skills" (default lead agent) and is left alone.
    """
    extras = normalize_retrieval_skills(extra)
    if not extras or agent_id != COLLECTOR_AGENT_ID:
        return list(base) if base is not None else None
    seen: set[str] = set()
    out: list[str] = []
    for name in [*(base or []), *extras]:
        if not name or name in seen:
            continue
        seen.add(name)
        out.append(name)
    return out