"""Single-agent runners for home and contextual chat contexts."""

from __future__ import annotations

import json
import logging
import re
from datetime import date
from collections.abc import AsyncGenerator
from typing import Any

from langchain_core.messages import AIMessage, HumanMessage, SystemMessage, ToolMessage
from langchain_core.tools import tool

from app.agents.client_agent import CLIENT_TOOLS
from app.agents.note_agent import NOTE_TOOLS
from app.agents.project_agent import PROJECT_TOOLS
from app.agents.relations_agent import make_query_relations_tool
from app.agents.task_agent import TASK_TOOLS
from app.agents.timeline_agent import TIMELINE_TOOLS
from app.core.scout_session_buffer import session_buffer
from app.core.langfuse_client import compile_prompt, extract_usage, get_langfuse, get_prompt_or_fallback, langfuse_context
from app.core.llm import get_agent_llm, model_for_agent
from app.core.memory_middleware import MemoryMiddleware
from app.core.ws_context import clear_tool_result_collector, execute_on_client, set_tool_result_collector
from app.db import async_session

logger = logging.getLogger(__name__)

MAX_HISTORY_TURNS = 20

# Mapping of core-memory language values to natural-language names for prompts.
_LANGUAGE_NAMES: dict[str, str] = {
    "en": "English", "it": "Italian", "es": "Spanish",
    "fr": "French", "de": "German",
    "english": "English", "italian": "Italian", "italiano": "Italian",
    "spanish": "Spanish", "español": "Spanish",
    "french": "French", "français": "French",
    "german": "German", "deutsch": "German",
}


def _language_instruction(context: dict[str, Any]) -> str:
    """Return a system-prompt suffix that tells the LLM to respond in the user's language.

    Returns an empty string when the language is English or unknown — saves tokens.
    """
    core = context.get("core_memory") or {}
    raw = (core.get("language") or "").strip().lower()
    if not raw:
        return ""
    lang = _LANGUAGE_NAMES.get(raw, raw.title())  # best-effort capitalisation
    if lang.lower() == "english":
        return ""
    return (
        f"\n\nIMPORTANT: Always respond in {lang}. "
        f"All your output text must be written in {lang}."
    )

MANIFEST_TOKEN_BUDGET = 3000  # rough budget for <linked_folder> block


def format_folder_manifest(manifest: dict | None) -> str:
    """Format a folder manifest into the <linked_folder> block.

    Truncates by mtime DESC if estimated tokens exceed MANIFEST_TOKEN_BUDGET.
    Returns empty string if manifest is None or has no files.
    """
    if not manifest or not manifest.get("files"):
        return ""
    files = list(manifest["files"])
    files.sort(key=lambda f: f.get("mtimeMs", 0), reverse=True)

    header = (
        f"<linked_folder>\npath: {manifest.get('folderPath', '?')}  "
        f"({len(files)} files, scanned {manifest.get('lastScannedAt', '?')})\nfiles:\n"
    )
    footer_template = "… {} more files omitted, use read_project_folder_file to access by path\n</linked_folder>"

    char_budget = MANIFEST_TOKEN_BUDGET * 4  # ~4 chars/token
    body = ""
    included = 0
    for f in files:
        line = f"- /{f['relPath']}  [{f.get('kind','text')}]  {f.get('summary','')}\n"
        if len(header) + len(body) + len(line) + len(footer_template.format(0)) > char_budget:
            break
        body += line
        included += 1
    omitted = len(files) - included
    if omitted > 0:
        return header + body + footer_template.format(omitted)
    return header + body + "</linked_folder>"


async def _fetch_project_manifest(project_id: str) -> dict | None:
    """Fetch manifest from Electron via execute_on_client. Returns None if unlinked or error."""
    from app.core.ws_context import execute_on_client
    try:
        result = await execute_on_client(
            action="read_project_folder_manifest",
            data={"projectId": project_id},
        )
        if not result or not result.get("folderPath"):
            return None
        return result
    except Exception:
        return None


async def build_brief_multi_project_manifest() -> str:
    """Build a compact multi-project manifest for the daily brief agent.

    Calls execute_on_client('list_projects_with_folder_manifests') and keeps
    the top 5 most-recently-modified files per project.
    """
    try:
        result = await execute_on_client(
            action="list_projects_with_folder_manifests",
            data={},
        )
    except Exception:
        return ""
    projects = (result or {}).get("projects") or []
    if not projects:
        return ""
    blocks: list[str] = ["<linked_folders>"]
    any_entry = False
    for p in projects:
        all_files = p.get("files", []) or []
        files = sorted(all_files, key=lambda f: f.get("mtimeMs", 0), reverse=True)[:5]
        blocks.append(f"project: {p.get('projectName','?')} [{p.get('projectId','?')}]")
        blocks.append(f"  path: {p.get('folderPath','?')}  (scanned {p.get('lastScannedAt','?')})")
        if not all_files:
            blocks.append("  (no indexed files yet — folder is linked but empty or unscanned)")
        else:
            for f in files:
                blocks.append(f"  - /{f['relPath']}  [{f.get('kind','text')}]  {f.get('summary','')}")
            if len(all_files) > 5:
                blocks.append(f"  … {len(all_files) - 5} more files (use read_project_folder_file by relPath)")
        any_entry = True
    if not any_entry:
        return ""
    blocks.append("</linked_folders>")
    return "\n".join(blocks)


def _datetime_context_injection(context: dict[str, Any]) -> str:
    """Build a comprehensive DATE CONTEXT block with pre-computed ms-epoch boundaries for common ranges."""
    fp = context.get("format_prefs")
    if not fp or not isinstance(fp, dict):
        return ""
    try:
        from zoneinfo import ZoneInfo
        from datetime import datetime as _dt, timezone as _utc, timedelta as _td

        tz_name: str = str(fp.get("timezone") or "UTC")
        now_iso: str = str(fp.get("now_iso") or "")
        date_fmt: str = str(fp.get("date_format") or "dd/MM/yyyy")
        time_fmt: str = str(fp.get("time_format") or "24h")

        tz = ZoneInfo(tz_name)
        if now_iso:
            now_utc = _dt.fromisoformat(now_iso.replace("Z", "+00:00"))
        else:
            now_utc = _dt.now(_utc.utc)

        now_ms = int(now_utc.timestamp() * 1000)
        now_local = now_utc.astimezone(tz)
        now_local_str = now_local.strftime("%Y-%m-%d %H:%M")
        weekday_str = now_local.strftime("%A")
        y, m, d = now_local.year, now_local.month, now_local.day

        def _day(year: int, month: int, day: int) -> tuple[int, int]:
            s = _dt(year, month, day, tzinfo=tz)
            e = s + _td(days=1)
            return int(s.timestamp() * 1000), int(e.timestamp() * 1000) - 1

        def _between(start: "_dt", end_excl: "_dt") -> tuple[int, int]:
            return int(start.timestamp() * 1000), int(end_excl.timestamp() * 1000) - 1

        today_s, today_e = _day(y, m, d)
        yd = now_local - _td(days=1)
        yesterday_s, yesterday_e = _day(yd.year, yd.month, yd.day)
        tm = now_local + _td(days=1)
        tomorrow_s, tomorrow_e = _day(tm.year, tm.month, tm.day)

        # ISO week (Mon–Sun)
        monday = _dt(y, m, d, tzinfo=tz) - _td(days=now_local.weekday())
        last_monday = monday - _td(weeks=1)
        next_monday = monday + _td(weeks=1)
        this_week_s, this_week_e = _between(monday, next_monday)
        last_week_s, last_week_e = _between(last_monday, monday)
        next_week_s, next_week_e = _between(next_monday, next_monday + _td(weeks=1))

        # Calendar months
        this_m_start = _dt(y, m, 1, tzinfo=tz)
        next_m_start = _dt(y + (m // 12), m % 12 + 1, 1, tzinfo=tz)
        last_m_start = _dt(y - (1 if m == 1 else 0), 12 if m == 1 else m - 1, 1, tzinfo=tz)
        next2_m = next_m_start.month % 12 + 1
        next2_y = next_m_start.year + (1 if next_m_start.month == 12 else 0)
        next2_m_start = _dt(next2_y, next2_m, 1, tzinfo=tz)
        this_month_s, this_month_e = _between(this_m_start, next_m_start)
        last_month_s, last_month_e = _between(last_m_start, this_m_start)
        next_month_s, next_month_e = _between(next_m_start, next2_m_start)

        # Calendar years
        this_yr_s, this_yr_e = _between(_dt(y, 1, 1, tzinfo=tz), _dt(y + 1, 1, 1, tzinfo=tz))
        last_yr_s, last_yr_e = _between(_dt(y - 1, 1, 1, tzinfo=tz), _dt(y, 1, 1, tzinfo=tz))

        sunday = monday + _td(days=6)
        last_sunday = last_monday + _td(days=6)
        next_sunday = next_monday + _td(days=6)

        return (
            f"\n\nDATE CONTEXT (timezone: {tz_name}, dateFormat: {date_fmt}, timeFormat: {time_fmt})\n"
            f"now_local: {now_local_str} ({weekday_str})\n"
            f"now_ms:    {now_ms}\n\n"
            f"today      [{today_s}, {today_e}]   {y:04d}-{m:02d}-{d:02d}\n"
            f"tomorrow   [{tomorrow_s}, {tomorrow_e}]   {tm.strftime('%Y-%m-%d')}\n"
            f"yesterday  [{yesterday_s}, {yesterday_e}]   {yd.strftime('%Y-%m-%d')}\n"
            f"this_week  [{this_week_s}, {this_week_e}]   {monday.strftime('%Y-%m-%d')} → {sunday.strftime('%Y-%m-%d')} (Mon–Sun)\n"
            f"last_week  [{last_week_s}, {last_week_e}]   {last_monday.strftime('%Y-%m-%d')} → {last_sunday.strftime('%Y-%m-%d')}\n"
            f"next_week  [{next_week_s}, {next_week_e}]   {next_monday.strftime('%Y-%m-%d')} → {next_sunday.strftime('%Y-%m-%d')}\n"
            f"this_month [{this_month_s}, {this_month_e}]   {y:04d}-{m:02d}\n"
            f"last_month [{last_month_s}, {last_month_e}]   {last_m_start.strftime('%Y-%m')}\n"
            f"next_month [{next_month_s}, {next_month_e}]   {next_m_start.strftime('%Y-%m')}\n"
            f"this_year  [{this_yr_s}, {this_yr_e}]   {y:04d}\n"
            f"last_year  [{last_yr_s}, {last_yr_e}]   {y - 1:04d}\n\n"
            f"When calling list_tasks_due_today or list_timelines_today, always pass user_timezone=\"{tz_name}\".\n"
            f"When presenting dates, format using dateFormat={date_fmt} and timeFormat={time_fmt}."
        )
    except Exception:
        return ""


def _proactive_hints_injection(context: dict[str, Any]) -> str:
    """Return a system-prompt paragraph listing proactive behavioral hints.

    Returns empty string when no hints or confidence below threshold.
    Capped at 600 chars.
    """
    hints: list[str] = context.get("proactive_hints") or []
    if not hints:
        return ""
    body = "\n".join(f"- {h}" for h in hints)
    section = f"\n\nI noticed (behavioral patterns):\n{body}"
    if len(section) > 600:
        section = section[:597] + "..."
    return section


def _relational_memory_injection(context: dict[str, Any]) -> str:
    """Return a system-prompt paragraph listing known people/projects from relational memory.

    Returns empty string when no relational rows or tier is Free.
    Capped at 800 chars to control token spend.
    """
    relations: list[str] = context.get("relational_memory") or []
    if not relations:
        return ""
    body = "\n".join(f"- {r}" for r in relations)
    section = f"\n\nKnown people & projects:\n{body}"
    if len(section) > 800:
        section = section[:797] + "..."
    return section


_IDENTITY_KEYS = ("user_name", "job_role", "industry", "primary_use_case", "tone_preference")


def _user_identity_injection(context: dict[str, Any]) -> str:
    """Return a compact user-profile block from core memory onboarding fields.

    Returns empty string when no onboarding keys are present.
    """
    core = context.get("core_memory") or {}
    parts: list[str] = []
    for key in _IDENTITY_KEYS:
        val = (core.get(key) or "").strip()
        if val:
            parts.append(f"- {key}: {val}")
    if not parts:
        return ""
    return "\n\nUser profile:\n" + "\n".join(parts)


def _request_context_block(context: dict[str, Any]) -> str:
    """Return a small block with per-request scope and resolved project context."""
    parts: list[str] = []
    scope = context.get("scope")
    if scope and isinstance(scope, dict):
        parts.append(f"scope: {json.dumps(scope, ensure_ascii=True)}")
    resolved = context.get("resolved_project_id")
    if resolved and isinstance(resolved, str):
        parts.append(f"resolved_project_id: {resolved}")
    return "\n".join(parts)


_HOME_SYSTEM_PROMPT = """\
You are adiuvAI's home executive assistant.{user_identity}
You are not a chatbot — you are a proactive partner who runs ahead of the user, anticipates what they need next, and closes every reply with a concrete next step or a clarifying question.

# How you work
- Use tools before answering anything factual. Never guess counts, dates, or status.
- Prefer parallel tool calls when the questions are independent (e.g. counts per status). Chain calls when one result feeds the next.
- After delivering the answer, propose the next useful action: a follow-up task to draft, a deadline at risk, a project to triage, a person to remind. Use what you know about the user (job role, industry, primary use case) to make the suggestion relevant.
- Match the user's tone preference. Default to warm-but-direct; stay concise.
- When the user asks to remember, forget, or update something, use memory tools.

# Filter discipline
- Never set the `assignee` filter on list_tasks/count_tasks unless the user explicitly names a person ("Marco's tasks") or refers to themselves ("my tasks", "assigned to me", "mine").
- The user's own name in the User profile block is for context only — it is NOT a default filter.
- When in doubt, omit `assignee` and return the global result.

# Output format
Return markdown. Reference entities with these tags exactly — one id per tag, each tag on its own line, no prefix/suffix text on the same line:
  <project>id</project>  <task>id</task>  <note>id</note>  <timeline>id</timeline>

When the answer contains a list of entities (any of the tags above), structure the reply as three blocks separated by blank lines:
  1. One short intro line stating what is coming (count + scope, e.g. "Ecco i tuoi 18 task ad alta priorità:"). Match the user's language.
  2. All entity tags, one per line, consecutive, no prose interleaved. Do NOT put titles, dates, priorities, or any descriptive text on the same line as a tag or between tags.
  3. One short closing recap (1–2 sentences) that points out a pattern, risk, or insight noticed in the list, and ends with a concrete next step or clarifying question.

For single-entity answers skip blocks 1 and 3 if they would be redundant; just emit the tag.

For analytical answers (status overviews, breakdowns by category/priority/project, comparisons, trends, "resoconto", "panoramica") consider returning a chart block when it communicates the answer faster than prose. The decision is yours — skip charts for trivial single-number answers. Schema:
  <chart>{{"chartType":"pie|bar|line|area|radar|radial","title":"...","data":[{{"name":"...","value":N}},...], "config":{{"value":{{"label":"...","color":"var(--chart-1)"}} }} }}</chart>
- pie for share-of-total breakdowns; bar for category comparisons; line/area for time series; radar for multi-dimension.
- data rows must include a "name" field; numeric series keys must match config keys.
- Use var(--chart-1) through var(--chart-5) for colors, cycling 1-5 in series order. Do NOT wrap in hsl() or oklch() — these are complete CSS values already.

For upcoming-timeline questions ("prossimi eventi"), include only future items in the current month unless the user asks otherwise.

# Date filtering
{date_context}

When filtering tasks/timelines/notes by date, take dueDateFrom / dueDateTo (ms epoch UTC) verbatim from the DATE CONTEXT boundary table above. Do NOT compute boundaries from now_ms yourself.
For specific dates not listed, compute local-midnight in the user timezone and convert to UTC ms.
For "today" / "tomorrow" queries, prefer list_tasks_due_today / list_timelines_today with user_timezone from DATE CONTEXT.

# Language
{language_instruction}

# Known people & projects
{relational_memory}

# Behavioral hints
{proactive_hints}

# Request context
{request_context}\
"""

_CONTEXTUAL_SYSTEM_PROMPT = """You are adiuvAI's contextual assistant. The user is working inside the app and has opened a side chat anchored to a specific view ("current view"). Help them act on that view: recap, plan, create entities, answer questions.

Rules:
1. Base context (current view summary) is provided every turn. Treat it as ground truth for ids and names; never invent them.
2. ALL reads go through `get_page_details`. The legacy tools `list_projects`, `get_project`, `list_tasks`, `get_task`, `list_notes`, `get_note` are NOT available in this channel — do not attempt to call them. To find an entity by name, call `get_page_details({entityType: 'projects_all' | 'tasks_all' | 'timeline_all'})` to list, then `get_page_details({entityType: '<type>', entityId})` for the full snapshot.
3. When the user requests an action that creates or updates an entity:
   - If the current view is a project and no project is specified, use the current project automatically.
   - If the current view is the global Tasks / Projects / Timeline list and no project is specified, ASK before attaching to any project. Don't silently create orphan entities.
4. The current view can change mid-conversation (user navigates). When you see a system message "User navigated to ...", treat the new view as the active context. Prior turns remain visible but the active scope shifts.
5. Notes: you can read note bodies via `get_page_details({entityType:'note'})`. You CANNOT edit, summarize-to-replace, or append. Tell the user "note editing is coming in a later release" if asked.
6. Be concise. Default to 1-3 short paragraphs. Bullet lists fine. Don't restate the user's request.
7. Never expose ids in prose. Use names. Ids only travel through tool calls.

# Date context
{date_context}

# Language
{language_instruction}
"""

_TASK_BRIEF_RESEARCH_SYSTEM_PROMPT = """\
You are an executive assistant preparing a briefing dossier for your principal before they act on a specific task.
Your job: gather all relevant context, synthesize it into a tight actionable dossier, and — if the task requires writing (email, message, document) — produce a ready-to-use draft.{user_identity}

# Research workflow
Follow these steps in order, using tools:
1. Read the task fully (title, description, due date, priority, status, project, comments).
2. Fetch the parent project (`get_project`) to understand scope, aiSummary, and any linked client.
3. If the project has a clientId: call `get_client(id)` to retrieve full client details.
4. Call `query_relations` (subject_label=client_name or task subject) to find cross-project connections — e.g. the same client appearing in multiple projects.
5. Search associative memory (`search_associative`) and archival memory (`archival_memory_search`) using the task title + client name as query phrases to surface relevant past interactions.
6. Read core memory blocks for tone preference, language, and user style: `memory_get("tone_preference")`, `memory_get("language")`.
7. Determine task kind: is this a writing task (email reply, message, follow-up, proposal)? If yes, draft a ready-to-send piece.

# Output structure
Write the briefing in the user's language. Use this exact structure:

**What needs to be done**
(1–2 sentences, concrete and specific — what action the user must take)

**Context you should know**
(bullet points covering: client background, related projects, prior interactions, tone/style notes, any relevant deadlines or dependencies)

**Suggested first step**
(one specific, immediately actionable instruction)

If this is a writing task, append a canvas block at the very end:
<canvas kind="email|document|message">
...ready-to-use draft here...
</canvas>

Do NOT include the canvas block for non-writing tasks.
Do NOT repeat verbatim task fields the user already sees in the UI.
Be concrete — no vague advice. Every bullet should be a fact that changes what the user does.

# Date context
{date_context}

# Language
{language_instruction}

# Known people & projects
{relational_memory}

# Request context
{request_context}\
"""

_TASK_BRIEF_FOLLOWUP_SYSTEM_PROMPT = """\
You are an executive assistant continuing a conversation with your principal.
You have already prepared and delivered a research briefing for the active task. The user has read it.{user_identity}

Your briefing:
---
{briefing_context}
---

Continue from here. Do NOT repeat the briefing. Refer to it when relevant.
Help the user execute: edit drafts, refine wording, look up additional details, plan next steps.
Stay terse — your principal is a busy executive.

# Date context
{date_context}

# Language
{language_instruction}

# Known people & projects
{relational_memory}

# Request context
{request_context}\
"""

def _as_text(content: Any) -> str:
    if content is None:
        return ""
    if isinstance(content, str):
        return content
    if isinstance(content, list):
        parts: list[str] = []
        for item in content:
            if isinstance(item, str):
                parts.append(item)
            elif isinstance(item, dict):
                text = item.get("text")
                if isinstance(text, str):
                    parts.append(text)
        return "".join(parts)
    return str(content)


def _candidate_tokens(message: str) -> list[str]:
    tokens = re.findall(r"[a-zA-Z0-9_-]+", message.lower())
    return [token for token in tokens if len(token) >= 3]


async def _resolve_project_id_from_message(message: str) -> str | None:
    """Resolve likely project UUID from user message using client project list."""
    try:
        result = await execute_on_client(action="select", table="projects")
    except Exception as exc:
        logger.warning("deep_agent: project resolve select failed: %s", exc)
        return None

    rows = result.get("rows", [])
    if not isinstance(rows, list) or not rows:
        return None

    tokens = _candidate_tokens(message)
    scored: list[tuple[int, dict[str, Any]]] = []
    for row in rows:
        if not isinstance(row, dict):
            continue
        name = str(row.get("name", "")).lower()
        score = sum(1 for token in tokens if token in name)
        if score > 0:
            scored.append((score, row))

    if not scored:
        return None

    scored.sort(key=lambda item: item[0], reverse=True)
    top_score = scored[0][0]
    top_rows = [row for score, row in scored if score == top_score]
    if len(top_rows) != 1:
        return None

    project_id = top_rows[0].get("id")
    return project_id if isinstance(project_id, str) else None


def _needs_project_resolution(message: str) -> bool:
    lowered = message.lower()
    return any(keyword in lowered for keyword in ["project", "progetto", "progetti", "whitelist"])


async def _prepare_context(message: str, context: dict[str, Any]) -> dict[str, Any]:
    prepared = dict(context)
    if _needs_project_resolution(message):
        resolved_project_id = await _resolve_project_id_from_message(message)
        if resolved_project_id:
            prepared["resolved_project_id"] = resolved_project_id
            logger.info("deep_agent: resolved_project_id=%s", resolved_project_id)
    return prepared


def _all_tools() -> list[Any]:
    return [*TASK_TOOLS, *PROJECT_TOOLS, *NOTE_TOOLS, *TIMELINE_TOOLS]


# ── Contextual sidebar tools ──────────────────────────────────────────


@tool
async def get_page_details(
    entity_type: str = "",
    entity_id: str = "",
) -> str:
    """Fetch full details for the entity currently in view.

    entity_type: one of 'project' | 'task' | 'note' | 'timeline_event' |
                 'tasks_all' | 'projects_all' | 'timeline_all'.
    entity_id: UUID of the entity for singular entity views.  Omit for list views.

    The Electron drizzle-executor fulfils this op against local SQLite and
    returns the row(s) as a JSON tool result.
    """
    result = await execute_on_client(
        action="get_page_details",
        table=entity_type or "unknown",
        data={"entityId": entity_id or None},
    )
    if not result:
        return "No details found."
    return str(result)


def _contextual_tools(user_id: str, trace_id: str | None) -> list[Any]:
    """Return the tool palette for the contextual sidebar agent.

    Read ops go through get_page_details only — legacy list_*/get_* tools
    return shallow snapshots and cause the agent to under-answer (see
    smoke trace 0b46841484ba7d024ed9f8d5ac8b1df0). Writes are limited
    to entity creation + task update; note edits are next-sprint.
    """
    from app.agents.note_agent import create_note  # noqa: PLC0415
    from app.agents.task_agent import create_task, update_task  # noqa: PLC0415
    from app.agents.timeline_agent import create_timeline  # noqa: PLC0415

    return [
        get_page_details,
        create_task,
        update_task,
        create_note,
        create_timeline,
        *_memory_tools(user_id, trace_id),
    ]


def _trace_id_from_context(context: dict[str, Any]) -> str | None:
    debug = context.get("_debug")
    if isinstance(debug, dict):
        request_id = debug.get("request_id")
        if isinstance(request_id, str) and request_id:
            return request_id
    return None


def _session_id_from_context(context: dict[str, Any]) -> str | None:
    debug = context.get("_debug")
    if isinstance(debug, dict):
        session_id = debug.get("session_id")
        if isinstance(session_id, str) and session_id:
            return session_id
    return None


def _build_system_prompt(name: str, fallback: str, context: dict[str, Any]) -> tuple[str, Any]:
    """Fetch Langfuse template and compile all per-request slots into one system prompt."""
    template, prompt_obj = get_prompt_or_fallback(name, fallback)
    text = compile_prompt(
        template, prompt_obj,
        date_context=_datetime_context_injection(context).strip(),
        language_instruction=_language_instruction(context).strip(),
        user_identity=_user_identity_injection(context).strip(),
        relational_memory=_relational_memory_injection(context).strip(),
        proactive_hints=_proactive_hints_injection(context).strip(),
        request_context=_request_context_block(context),
    )
    return text, prompt_obj


_TAG_LINE_RE = re.compile(r"<(task|timeline)>\[[^\]]+\]</\1>")
_TIMELINE_DMY_RE = re.compile(r"(?P<d>\d{2})/(?P<m>\d{2})/(?P<y>\d{4})")


def _is_upcoming_timeline_query(message: str) -> bool:
    lowered = message.lower()
    has_upcoming = "prossim" in lowered or "upcoming" in lowered or "next" in lowered
    has_timeline_topic = any(
        token in lowered
        for token in ("event", "evento", "eventi", "timeline", "milestone", "scaden")
    )
    return has_upcoming and has_timeline_topic


def _timeline_date_in_current_month_or_future(dmy: str) -> bool:
    match = _TIMELINE_DMY_RE.search(dmy)
    if not match:
        return True
    try:
        parsed = date(
            int(match.group("y")),
            int(match.group("m")),
            int(match.group("d")),
        )
    except ValueError:
        return True

    today = date.today()
    return parsed >= today and parsed.year == today.year and parsed.month == today.month


def _normalize_tagged_list_lines(text: str, message: str) -> str:
    if not text:
        return text

    upcoming_timeline_only = _is_upcoming_timeline_query(message)
    output_lines: list[str] = []

    for line in text.splitlines():
        matches = list(_TAG_LINE_RE.finditer(line))
        if not matches:
            output_lines.append(line)
            continue

        had_non_tag_text = _TAG_LINE_RE.sub("", line).strip(" -\t0123456789.*:)")
        if not had_non_tag_text and len(matches) == 1:
            tag_text = matches[0].group(0)
            if (
                upcoming_timeline_only
                and "<timeline>" in tag_text
                and not _timeline_date_in_current_month_or_future(line)
            ):
                continue
            output_lines.append(tag_text)
            continue

        for match in matches:
            tag_text = match.group(0)
            if (
                upcoming_timeline_only
                and "<timeline>" in tag_text
                and not _timeline_date_in_current_month_or_future(line)
            ):
                continue
            output_lines.append(tag_text)

    return "\n".join(output_lines)


def _normalize_memory_label(path_or_label: str) -> str:
    value = path_or_label.strip()
    if value.startswith("/memories/"):
        value = value[len("/memories/"):]
    value = value.strip("/")
    return value


def _memory_tools(user_id: str, trace_id: str | None) -> list[Any]:
    @tool
    async def memory_list_blocks() -> str:
        """List all core memory blocks currently stored for the user."""
        logger.info("deep_agent: memory_list_blocks trace=%s user=%s", trace_id or "-", user_id)
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            blocks = await memory.list_core_blocks(user_id)
        if not blocks:
            return "No memory blocks found."
        lines = [f"- {b['label']}: {b['value']}" for b in blocks]
        return "Memory blocks:\n" + "\n".join(lines)

    @tool
    async def memory_get(path_or_label: str) -> str:
        """Get one memory block by label or /memories/<label> path."""
        label = _normalize_memory_label(path_or_label)
        logger.info("deep_agent: memory_get trace=%s user=%s label=%s", trace_id or "-", user_id, label)
        if not label:
            return "Invalid memory label."
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            value = await memory.get_core_block(user_id, label)
        if value is None:
            return f"Memory block '{label}' not found."
        return f"Memory block '{label}':\n{value}"

    @tool
    async def memory_create(path_or_label: str, value: str) -> str:
        """Create or overwrite a memory block value by label or /memories/<label> path."""
        label = _normalize_memory_label(path_or_label)
        logger.info("deep_agent: memory_create trace=%s user=%s label=%s", trace_id or "-", user_id, label)
        if not label:
            return "Invalid memory label."
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            await memory.update_core(user_id, label, value, trace_id=trace_id)
        return f"Memory block '{label}' saved."

    @tool
    async def memory_append(path_or_label: str, content: str) -> str:
        """Append content to a memory block, creating it if missing."""
        label = _normalize_memory_label(path_or_label)
        logger.info("deep_agent: memory_append trace=%s user=%s label=%s", trace_id or "-", user_id, label)
        if not label:
            return "Invalid memory label."
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            await memory.append_core(user_id, label, content)
        return f"Memory block '{label}' appended."

    @tool
    async def memory_replace(path_or_label: str, old_string: str, new_string: str) -> str:
        """Replace one exact string in a memory block."""
        label = _normalize_memory_label(path_or_label)
        logger.info("deep_agent: memory_replace trace=%s user=%s label=%s", trace_id or "-", user_id, label)
        if not label:
            return "Invalid memory label."
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            changed = await memory.replace_core(user_id, label, old_string, new_string)
        if not changed:
            return f"No replacement made in '{label}' (old string not found)."
        return f"Memory block '{label}' updated."

    @tool
    async def memory_delete(path_or_label: str) -> str:
        """Delete a memory block by label or /memories/<label> path."""
        label = _normalize_memory_label(path_or_label)
        logger.info("deep_agent: memory_delete trace=%s user=%s label=%s", trace_id or "-", user_id, label)
        if not label:
            return "Invalid memory label."
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            deleted = await memory.delete_core(user_id, label)
        if not deleted:
            return f"Memory block '{label}' not found."
        return f"Memory block '{label}' deleted."

    @tool
    async def archival_memory_insert(content: str) -> str:
        """Insert a long-term archival memory entry."""
        logger.info("deep_agent: archival_memory_insert trace=%s user=%s", trace_id or "-", user_id)
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            await memory.insert_archival(user_id, content, source="assistant")
        return "Archival memory saved."

    @tool
    async def archival_memory_search(query: str, top_k: int = 5) -> str:
        """Search long-term archival memory by semantic fallback (keyword currently)."""
        logger.info("deep_agent: archival_memory_search trace=%s user=%s query=%s", trace_id or "-", user_id, query[:80])
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            results = await memory.search_archival(user_id, query, top_k=top_k)
        if not results:
            return "No archival memory results found."
        lines = [f"- {item}" for item in results]
        return "Archival memory results:\n" + "\n".join(lines)

    @tool
    async def conversation_search(query: str, top_k: int = 5) -> str:
        """Search recall memory from prior episodic conversation summaries."""
        logger.info("deep_agent: conversation_search trace=%s user=%s query=%s", trace_id or "-", user_id, query[:80])
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            results = await memory.search_recall(user_id, query, top_k=top_k)
        if not results:
            return "No recall memory results found."
        lines = [f"- {item}" for item in results]
        return "Recall memory results:\n" + "\n".join(lines)

    @tool
    async def search_associative(query: str, limit: int = 5) -> str:
        """Semantic search across associative (archival) memory for a given query.

        Use this to surface long-term memories related to a topic, client, or task
        that may not appear in recent episodes.

        query: natural-language search phrase.
        limit: max results (default 5).
        """
        logger.info("deep_agent: search_associative trace=%s user=%s query=%s", trace_id or "-", user_id, query[:80])
        async with async_session() as db:
            memory = MemoryMiddleware(db)
            results = await memory.search_archival(user_id, query, top_k=limit)
        if not results:
            return "No associative memory results found."
        lines = [f"- {item}" for item in results]
        return "Associative memory results:\n" + "\n".join(lines)

    return [
        memory_list_blocks,
        memory_get,
        memory_create,
        memory_append,
        memory_replace,
        memory_delete,
        archival_memory_insert,
        archival_memory_search,
        conversation_search,
        search_associative,
    ]


def _read_only_memory_tools(user_id: str, trace_id: str | None) -> list[Any]:
    """Return memory tools that only read — safe for the read-only brief-agent subset."""
    all_mem = _memory_tools(user_id, trace_id)
    _read_names = {
        "memory_list_blocks", "memory_get", "archival_memory_search",
        "conversation_search", "search_associative",
    }
    return [t for t in all_mem if t.name in _read_names]


def _brief_research_tools(user_id: str, trace_id: str | None) -> list[Any]:
    """Return the full tool palette for Stage-1 task brief research (read-only)."""
    return [
        *TASK_TOOLS,
        *PROJECT_TOOLS,
        *NOTE_TOOLS,
        *TIMELINE_TOOLS,
        *CLIENT_TOOLS,
        *_read_only_memory_tools(user_id, trace_id),
        make_query_relations_tool(user_id, trace_id),
    ]


def _all_tools_for_user(user_id: str, trace_id: str | None) -> list[Any]:
    return [*_all_tools(), *_memory_tools(user_id, trace_id)]


def _history_to_messages(history: list[dict[str, str]] | None) -> list[Any]:
    if not history:
        return []
    turns = history[-MAX_HISTORY_TURNS:]
    result: list[Any] = []
    for turn in turns:
        role = turn.get("role", "")
        content = turn.get("content", "")
        if not content:
            continue
        if role == "user":
            result.append(HumanMessage(content=content))
        elif role == "assistant":
            result.append(AIMessage(content=content))
    return result


async def _run_single_agent(
    *,
    user_id: str,
    system_prompt: str,
    message: str,
    context: dict[str, Any],
    max_steps: int = 6,
    langfuse_prompt: Any = None,
    agent_name: str = "agent",
    conversation_history: list[dict[str, str]] | None = None,
) -> str:
    trace_id = _trace_id_from_context(context)
    session_id = _session_id_from_context(context)
    lf = get_langfuse()
    llm = get_agent_llm(agent_name)
    tools = _all_tools_for_user(user_id, trace_id)
    logger.info("deep_agent: run_single_agent_start trace=%s user=%s", trace_id or "-", user_id)
    llm_with_tools = llm.bind_tools(tools)
    _buffered = session_buffer.get(user_id, session_id) if session_id else None
    history_messages = _buffered if _buffered is not None else _history_to_messages(conversation_history)
    messages: list[Any] = [
        SystemMessage(content=system_prompt),
        *history_messages,
        HumanMessage(content=message),
    ]

    tool_calls_count = 0
    collected: list[dict[str, Any]] = []
    set_tool_result_collector(collected)

    _lf_ctx = langfuse_context(user_id=user_id, session_id=session_id)
    _lf_ctx.__enter__()

    _span_ctx = (
        lf.start_as_current_observation(
            as_type="agent",
            name=agent_name,
            metadata={"user_id": user_id, "session_id": trace_id},
            input=message,
        )
        if lf else None
    )
    _span = _span_ctx.__enter__() if _span_ctx else None
    _messages_to_save: list[Any] | None = None

    try:
        for _ in range(max_steps):
            _gen_ctx = (
                lf.start_as_current_observation(
                    as_type="generation",
                    name=f"{agent_name}-llm",
                    model=model_for_agent(agent_name),
                    prompt=langfuse_prompt,
                    input=messages,
                )
                if lf else None
            )
            _gen = _gen_ctx.__enter__() if _gen_ctx else None
            response: AIMessage = await llm_with_tools.ainvoke(messages)
            if _gen_ctx:
                _gen.update(output=_as_text(response.content), usage_details=extract_usage(response))
                _gen_ctx.__exit__(None, None, None)

            messages.append(response)

            if not response.tool_calls:
                final_text = _as_text(response.content)
                logger.info(
                    "deep_agent: run_single_agent_end trace=%s user=%s tool_calls=%d response_chars=%d",
                    trace_id or "-",
                    user_id,
                    tool_calls_count,
                    len(final_text),
                )
                if _span:
                    _span.update(output=final_text)
                _messages_to_save = messages[1:]  # strip SystemMessage; save full tool history
                return final_text

            tool_map = {tool_def.name: tool_def for tool_def in tools}
            for call in response.tool_calls:
                tool_calls_count += 1
                call_id = str(call.get("id", ""))
                call_name = str(call.get("name", ""))
                call_args = call.get("args", {})
                logger.info(
                    "deep_agent: AI->Tool tool_call_id=%s tool=%s args=%s",
                    call_id,
                    call_name,
                    json.dumps(call_args, ensure_ascii=True)[:800],
                )

                tool_fn = tool_map.get(call_name)
                if tool_fn is None:
                    tool_output = f"Unknown tool: {call_name}"
                elif lf:
                    with lf.start_as_current_observation(
                        as_type="tool",
                        name=call_name,
                        input=call_args,
                    ) as tool_obs:
                        tool_output = await tool_fn.ainvoke(call_args)
                        tool_obs.update(output=str(tool_output)[:8000])
                else:
                    tool_output = await tool_fn.ainvoke(call_args)

                logger.info(
                    "deep_agent: Tool->AI tool_call_id=%s tool=%s output=%s",
                    call_id,
                    call_name,
                    str(tool_output)[:1200],
                )

                messages.append(ToolMessage(content=str(tool_output), tool_call_id=call["id"]))

        final = await llm.ainvoke(messages)
        final_text = _as_text(final.content)
        messages.append(AIMessage(content=final_text))
        logger.info(
            "deep_agent: run_single_agent_end trace=%s user=%s tool_calls=%d response_chars=%d fallback=1",
            trace_id or "-",
            user_id,
            tool_calls_count,
            len(final_text),
        )
        if _span:
            _span.update(output=final_text)
        _messages_to_save = messages[1:]
        return final_text
    finally:
        if session_id and _messages_to_save is not None:
            session_buffer.set(user_id, session_id, _messages_to_save)
        clear_tool_result_collector()
        if _span_ctx:
            _span_ctx.__exit__(None, None, None)
        _lf_ctx.__exit__(None, None, None)
        if lf:
            lf.flush()


async def _run_single_agent_stream(
    *,
    user_id: str,
    system_prompt: str,
    message: str,
    context: dict[str, Any],
    max_steps: int = 6,
    langfuse_prompt: Any = None,
    agent_name: str = "agent",
    tools: list[Any] | None = None,
    conversation_history: list[dict[str, str]] | None = None,
) -> AsyncGenerator[tuple[str, Any], None]:
    trace_id = _trace_id_from_context(context)
    session_id = _session_id_from_context(context)
    lf = get_langfuse()
    llm = get_agent_llm(agent_name)
    if tools is None:
        tools = _all_tools_for_user(user_id, trace_id)
    logger.info("deep_agent: run_single_agent_stream_start trace=%s user=%s", trace_id or "-", user_id)
    llm_with_tools = llm.bind_tools(tools)
    _buffered = session_buffer.get(user_id, session_id) if session_id else None
    history_messages = _buffered if _buffered is not None else _history_to_messages(conversation_history)
    messages: list[Any] = [
        SystemMessage(content=system_prompt),
        *history_messages,
        HumanMessage(content=message),
    ]

    tool_calls_count = 0
    streamed_chars = 0
    collected: list[dict[str, Any]] = []
    set_tool_result_collector(collected)

    _lf_ctx = langfuse_context(user_id=user_id, session_id=session_id)
    _lf_ctx.__enter__()

    _span_ctx = (
        lf.start_as_current_observation(
            as_type="agent",
            name=f"{agent_name}-stream",
            metadata={"user_id": user_id, "session_id": trace_id},
            input=message,
        )
        if lf else None
    )
    _span = _span_ctx.__enter__() if _span_ctx else None
    streamed_text: list[str] = []
    _messages_to_save: list[Any] | None = None

    try:
        for _ in range(max_steps):
            _gen_ctx = (
                lf.start_as_current_observation(
                    as_type="generation",
                    name=f"{agent_name}-llm",
                    model=model_for_agent(agent_name),
                    prompt=langfuse_prompt,
                    input=messages,
                )
                if lf else None
            )
            _gen = _gen_ctx.__enter__() if _gen_ctx else None
            response: AIMessage = await llm_with_tools.ainvoke(messages)
            if _gen_ctx:
                _gen.update(output=_as_text(response.content), usage_details=extract_usage(response))
                _gen_ctx.__exit__(None, None, None)

            if not response.tool_calls:
                # Yield the content from the ainvoke response directly — no second LLM call.
                # Previously, messages.append(response) was called first, so the re-stream
                # received [System, Human, AI] and regenerated a response without tools bound.
                final_text = _as_text(response.content)
                if final_text:
                    streamed_chars += len(final_text)
                    streamed_text.append(final_text)
                    yield "token", final_text
                logger.info(
                    "deep_agent: run_single_agent_stream_end trace=%s user=%s tool_calls=%d response_chars=%d",
                    trace_id or "-",
                    user_id,
                    tool_calls_count,
                    streamed_chars,
                )
                if _span:
                    _span.update(output="".join(streamed_text))
                messages.append(response)
                _messages_to_save = messages[1:]  # strip SystemMessage
                return

            messages.append(response)
            tool_map = {tool_def.name: tool_def for tool_def in tools}
            for call in response.tool_calls:
                tool_calls_count += 1
                call_id = str(call.get("id", ""))
                call_name = str(call.get("name", ""))
                call_args = call.get("args", {})
                logger.info(
                    "deep_agent: AI->Tool tool_call_id=%s tool=%s args=%s",
                    call_id,
                    call_name,
                    json.dumps(call_args, ensure_ascii=True)[:800],
                )

                tool_fn = tool_map.get(call_name)
                if tool_fn is None:
                    tool_output = f"Unknown tool: {call_name}"
                elif lf:
                    with lf.start_as_current_observation(
                        as_type="tool",
                        name=call_name,
                        input=call_args,
                    ) as tool_obs:
                        tool_output = await tool_fn.ainvoke(call_args)
                        tool_obs.update(output=str(tool_output)[:8000])
                else:
                    tool_output = await tool_fn.ainvoke(call_args)

                logger.info(
                    "deep_agent: Tool->AI tool_call_id=%s tool=%s output=%s",
                    call_id,
                    call_name,
                    str(tool_output)[:1200],
                )

                messages.append(ToolMessage(content=str(tool_output), tool_call_id=call["id"]))

        fallback_chunks: list[str] = []
        async for chunk in llm.astream(messages):
            token = _as_text(getattr(chunk, "content", ""))
            if token:
                streamed_chars += len(token)
                streamed_text.append(token)
                fallback_chunks.append(token)
                yield "token", token
        messages.append(AIMessage(content="".join(fallback_chunks)))
        _messages_to_save = messages[1:]
        logger.info(
            "deep_agent: run_single_agent_stream_end trace=%s user=%s tool_calls=%d response_chars=%d fallback=1",
            trace_id or "-",
            user_id,
            tool_calls_count,
            streamed_chars,
        )
        if _span:
            _span.update(output="".join(streamed_text))
    finally:
        if session_id and _messages_to_save is not None:
            session_buffer.set(user_id, session_id, _messages_to_save)
        clear_tool_result_collector()
        if _span_ctx:
            _span_ctx.__exit__(None, None, None)
        _lf_ctx.__exit__(None, None, None)
        if lf:
            lf.flush()


async def run_home(user_id: str, message: str, context: dict[str, Any]) -> str:
    prepared_context = await _prepare_context(message, context)
    system_prompt, langfuse_prompt = _build_system_prompt("home_system", _HOME_SYSTEM_PROMPT, prepared_context)
    response = await _run_single_agent(
        user_id=user_id,
        system_prompt=system_prompt,
        message=message,
        context=prepared_context,
        langfuse_prompt=langfuse_prompt,
        agent_name="home-agent",
        conversation_history=context.get("conversation_history"),
    )
    return _normalize_tagged_list_lines(response, message)


async def run_home_stream(
    user_id: str,
    message: str,
    context: dict[str, Any],
    project_id: str | None = None,
) -> AsyncGenerator[tuple[str, Any], None]:
    from app.agents.folder_agent import FOLDER_TOOLS

    prepared_context = await _prepare_context(message, context)
    system_prompt, langfuse_prompt = _build_system_prompt("home_system", _HOME_SYSTEM_PROMPT, prepared_context)

    manifest_block = ""
    if project_id:
        manifest = await _fetch_project_manifest(project_id)
        manifest_block = format_folder_manifest(manifest)
    if not manifest_block:
        # No specific project context — surface all linked folders so the agent
        # can answer questions like "tell me about project X" using its files.
        manifest_block = await build_brief_multi_project_manifest()
    system_prompt = system_prompt + ("\n\n" + manifest_block if manifest_block else "")

    trace_id = _trace_id_from_context(prepared_context)
    tools = [*_all_tools_for_user(user_id, trace_id), *FOLDER_TOOLS]

    text_chunks: list[str] = []
    async for event in _run_single_agent_stream(
        user_id=user_id,
        system_prompt=system_prompt,
        message=message,
        context=prepared_context,
        langfuse_prompt=langfuse_prompt,
        agent_name="home-agent",
        tools=tools,
        conversation_history=context.get("conversation_history"),
    ):
        event_type, data = event
        if event_type != "token":
            yield event
            continue
        text_chunks.append(str(data or ""))

    normalized = _normalize_tagged_list_lines("".join(text_chunks), message)
    if normalized:
        yield "token", normalized


async def run_contextual_stream(
    user_id: str,
    message: str,
    context: dict[str, Any],
    scope: "ContextualScope",  # type: ignore[name-defined]
) -> AsyncGenerator[tuple[str, Any], None]:
    """Run the contextual agent for a single user turn.

    Injects the rendered scope block into the system prompt and exposes
    the contextual tool set.
    Note-edit tools (propose_note_edit) are intentionally excluded.

    *context contract*: callers MUST include ``context["_debug"]["session_id"]``
    (a non-empty str) so that ``_session_id_from_context`` can extract it for
    tracing and episode storage downstream.  The WS handler in device_ws.py
    satisfies this by always populating ``_debug`` before calling this function.
    """
    from app.schemas.contextual import ContextualScope, render_scope_block  # noqa: PLC0415

    prepared_context = await _prepare_context(message, context)
    trace_id = _trace_id_from_context(prepared_context)

    system_prompt, langfuse_prompt = _build_system_prompt(
        "contextual_system", _CONTEXTUAL_SYSTEM_PROMPT, prepared_context,
    )
    scope_block = render_scope_block(scope)
    system_prompt = system_prompt + f"\n\n## Current view\n{scope_block}"

    tools = _contextual_tools(user_id, trace_id)

    async for event in _run_single_agent_stream(
        user_id=user_id,
        system_prompt=system_prompt,
        message=message,
        context=prepared_context,
        langfuse_prompt=langfuse_prompt,
        agent_name="contextual-agent",
        tools=tools,
        conversation_history=context.get("conversation_history"),
    ):
        yield event


async def run_task_brief_research_stream(
    user_id: str,
    task_id: str,
    context: dict[str, Any],
    project_id: str | None = None,
) -> AsyncGenerator[tuple[str, Any], None]:
    """Stage-1 executive assistant: deep research for one task.

    Yields ``("token", chunk)`` events like other stream runners.
    The final concatenated text may contain a ``<canvas kind="...">...</canvas>`` block
    which the WS handler strips and emits as a ``canvas_draft`` mutation.
    """
    from app.agents.folder_agent import FOLDER_TOOLS

    prepared_context = await _prepare_context(f"task:{task_id}", context)
    tools = [*_brief_research_tools(user_id, _trace_id_from_context(prepared_context)), *FOLDER_TOOLS]

    # Inject task_id so the agent knows what to look up first.
    research_message = (
        f"Prepare a briefing dossier for task ID: {task_id}\n"
        "Follow the research workflow: read the task, then project, then client, "
        "then cross-project relations, then relevant memory. "
        "End with a concrete suggested first step. "
        "If this is a writing task, include a <canvas kind=\"...\"> draft."
    )

    system_prompt, langfuse_prompt = _build_system_prompt(
        "task_brief_research_system",
        _TASK_BRIEF_RESEARCH_SYSTEM_PROMPT,
        prepared_context,
    )

    manifest_block = ""
    if project_id:
        manifest = await _fetch_project_manifest(project_id)
        manifest_block = format_folder_manifest(manifest)
    system_prompt = system_prompt + ("\n\n" + manifest_block if manifest_block else "")

    async for event in _run_single_agent_stream(
        user_id=user_id,
        system_prompt=system_prompt,
        message=research_message,
        context=prepared_context,
        max_steps=12,
        langfuse_prompt=langfuse_prompt,
        agent_name="task-brief-agent",
        tools=tools,
        conversation_history=None,
    ):
        yield event


async def update_core_memory(user_id: str, key: str, value: str) -> None:
    """Compatibility helper kept for callers that expect explicit memory update API."""
    async with async_session() as db:
        memory = MemoryMiddleware(db)
        await memory.update_core(user_id, key, value)