"""Stored-process MCP tools: reusable saved prompts (note_type='process').

A process is a Note whose body is a prompt the operator fires later
("run the X process"). Mirrors entities.py — the tools wrap notes_svc directly.
get_process is the fire mechanism: it returns the full prompt for Claude to run.
"""
from __future__ import annotations

from fabledassistant.mcp._context import current_user_id
from fabledassistant.services import knowledge as knowledge_svc
from fabledassistant.services import notes as notes_svc


async def list_processes(q: str = "", tag: str = "", limit: int = 50) -> dict:
    """List stored processes (reusable saved prompts).

    Args:
        q: Free-text search across title + body (optional).
        tag: Filter to a single tag (optional).
        limit: Max results (1-100).

    Returns {"processes": [{id, title, tags, preview}], "total": int}.
    """
    uid = current_user_id()
    items, total = await knowledge_svc.query_knowledge(
        user_id=uid, note_type="process", tags=[tag] if tag else [],
        sort="modified", q=q or None, limit=max(1, min(limit, 100)), offset=0,
    )
    procs = [{"id": it["id"], "title": it["title"], "tags": it.get("tags", []),
              "preview": it.get("snippet", "")} for it in items]
    return {"processes": procs, "total": total}


async def create_process(title: str, body: str, tags: list[str] | None = None) -> dict:
    """Create a stored process (a reusable saved prompt).

    Args:
        title: Process name, e.g. "Drift Audit" (required).
        body: The full prompt to run later (markdown). Required.
        tags: Plain-string tags, no # prefix.
    """
    if not (title or "").strip() or not (body or "").strip():
        raise ValueError("create_process requires a non-empty title and body")
    uid = current_user_id()
    note = await notes_svc.create_note(
        uid, title=title.strip(), body=body, note_type="process", tags=tags,
    )
    return note.to_dict()


async def get_process(name_or_id: str) -> dict:
    """Fetch a stored process by name or id and return its full prompt — the
    fire mechanism. The operator says "run the <name> process"; call this and
    follow the returned body (including any 'clarify first' steps it contains).

    Resolution: numeric id → exact (case-insensitive) title → substring. On an
    ambiguous substring match, the best (most-recent) match is returned with an
    `other_matches` list so you can disambiguate with the operator.
    """
    uid = current_user_id()
    note, candidates = await notes_svc.resolve_process(uid, name_or_id)
    if note is None:
        raise ValueError(f"process {name_or_id!r} not found")
    out = note.to_dict()
    if candidates:
        out["other_matches"] = candidates
    return out


async def update_process(process_id: int, title: str = "", body: str = "",
                         tags: list[str] | None = None) -> dict:
    """Update a stored process. Only provided fields change — empty title/body
    leave that field unchanged; pass tags to replace the tag set."""
    uid = current_user_id()
    note = await notes_svc.get_note(uid, process_id)
    if note is None or note.note_type != "process":
        raise ValueError(f"process {process_id} not found")
    fields: dict = {}
    if title.strip():
        fields["title"] = title.strip()
    if body.strip():
        fields["body"] = body
    if tags is not None:
        fields["tags"] = tags
    updated = await notes_svc.update_note(uid, process_id, **fields)
    return updated.to_dict()


def register(mcp) -> None:
    for fn in (list_processes, create_process, get_process, update_process):
        mcp.tool(name=fn.__name__)(fn)