"""PlanningOrchestrator — multi-phase planning coordinator.

Sequences `/office-hours → /plan-ceo-review → /plan-eng-review →
/plan-design-review` (last only when description hints at UI scope), each in a
**fresh subprocess** (per W2 plan + spike findings). Phases coordinate via
disk artifacts (gstack convention: `~/.gstack/projects/<slug>/...`).

API used by router/adapters:

    PlanningOrchestrator.start(slug, description, channel_id, adapter)
        → (session, first_response_text)

    PlanningOrchestrator.respond(adapter, channel_id, message)
        → (session, response_text, phase_ready: bool)

    PlanningOrchestrator.advance(adapter, channel_id)
        → (session, first_response_text, completed: bool)
            # completed=True when no further phase remains; final-plan stub
            # written by the orchestrator if the planning agent didn't.

    PlanningOrchestrator.cancel(adapter, channel_id)
        → bool

    PlanningOrchestrator.has_ui_scope(description) → bool

The orchestrator writes the final-plan stub path even if planning agent did
not (so PRD generator always has something to read in W3).
"""

from __future__ import annotations

import logging
import re
from pathlib import Path
from typing import Callable

from src.planning_session import (
    GSTACK_PROJECTS_ROOT,
    PHASE_READY_MARKER,
    WORKSPACE_ROOT,
    PlanningSession,
    _load_planning_state,
    _save_planning_state,
    _channel_key,
    clear_planning_state,
    get_planning_state,
)

log = logging.getLogger(__name__)

# Ordered phase pipeline. The design phase is appended only when the
# description hints at UI scope (heuristic — see has_ui_scope).
BASE_PHASES = ["/office-hours", "/plan-ceo-review", "/plan-eng-review"]
DESIGN_PHASE = "/plan-design-review"

UI_HINT_PATTERN = re.compile(
    r"\b(ui|ux|frontend|design|button|page|css|html|interfa[țt]?[aăă]?|"
    r"layout|component|view|dashboard|modal|form|screen|"
    # Romanian variants
    r"pagin[ăa]|buton|ecran|formular)",
    re.IGNORECASE,
)


def has_ui_scope(description: str) -> bool:
    """Cheap heuristic — adds /plan-design-review when description mentions UI."""
    return bool(UI_HINT_PATTERN.search(description or ""))


def _phases_for(description: str) -> list[str]:
    phases = list(BASE_PHASES)
    if has_ui_scope(description):
        phases.append(DESIGN_PHASE)
    return phases


def _final_plan_path(slug: str) -> Path:
    return WORKSPACE_ROOT / slug / "scripts" / "ralph" / "final-plan.md"


def _ensure_final_plan_dir(slug: str) -> Path:
    target = _final_plan_path(slug)
    target.parent.mkdir(parents=True, exist_ok=True)
    return target


# ---------------------------------------------------------------------------
# Orchestrator
# ---------------------------------------------------------------------------


class PlanningOrchestrator:
    """Stateless coordinator — all state is in `sessions/planning.json`."""

    @staticmethod
    def start(
        slug: str,
        description: str,
        channel_id: str,
        adapter: str = "echo",
        on_text: Callable[[str], None] | None = None,
    ) -> tuple[PlanningSession, str]:
        """Begin planning at phase 0 (`/office-hours`). Persists state.

        Returns (PlanningSession, first_response_text).
        """
        phases = _phases_for(description)
        first_phase = phases[0]
        log.info(
            "planning.start slug=%s adapter=%s channel=%s phases=%s",
            slug, adapter, channel_id, phases,
        )
        # Wipe any prior state for this channel (start fresh).
        clear_planning_state(adapter, channel_id)

        session = PlanningSession.start(
            slug=slug,
            description=description,
            phase=first_phase,
            channel_id=channel_id,
            adapter=adapter,
            on_text=on_text,
        )
        # Stash phase plan into disk state so advance() knows the pipeline.
        data = _load_planning_state()
        key = _channel_key(adapter, channel_id)
        if key in data:
            data[key]["phases_planned"] = phases
            data[key]["phase_index"] = 0
            data[key]["phases_completed"] = []
            _save_planning_state(data)
        return session, session.last_response

    @staticmethod
    def respond(
        adapter: str,
        channel_id: str,
        message: str,
        on_text: Callable[[str], None] | None = None,
    ) -> tuple[PlanningSession | None, str, bool]:
        """Forward `message` into the active phase via `--resume`.

        Returns (session, response_text, phase_ready).
        `phase_ready=True` means the planning agent emitted PHASE_READY_MARKER
        — the adapter should surface a "Continuă faza" / "Finalizează" button.
        """
        session = PlanningSession.from_state(adapter, channel_id)
        if session is None:
            return None, "Nu există o sesiune de planning activă pe acest canal.", False
        text = session.respond(message, on_text=on_text)
        return session, text, session.is_phase_ready()

    @staticmethod
    def advance(
        adapter: str,
        channel_id: str,
        on_text: Callable[[str], None] | None = None,
    ) -> tuple[PlanningSession | None, str, bool]:
        """Move to the next phase (fresh subprocess). Returns (session, text, completed).

        If no more phases remain, writes a final-plan.md stub (if the agent
        didn't) and returns (last_session, summary_text, completed=True).
        """
        state = get_planning_state(adapter, channel_id)
        if not state:
            return None, "Nu există o sesiune de planning activă.", False

        phases = state.get("phases_planned") or _phases_for(state.get("description", ""))
        completed = list(state.get("phases_completed") or [])
        current_phase = state.get("phase")
        if current_phase and current_phase not in completed:
            completed.append(current_phase)

        # Find next phase
        try:
            cur_idx = phases.index(current_phase) if current_phase in phases else -1
        except ValueError:
            cur_idx = -1
        next_idx = cur_idx + 1

        slug = state["slug"]
        description = state.get("description", "")

        if next_idx >= len(phases):
            # Pipeline complete — ensure final-plan.md exists, return summary.
            target = _ensure_final_plan_dir(slug)
            if not target.exists():
                stub = _build_final_plan_stub(slug, description, completed, state)
                target.write_text(stub, encoding="utf-8")
                log.info("planning.advance wrote final-plan stub: %s", target)
            # Persist completion marker but keep state so adapter can show
            # "Dau drumul tonight?" buttons.
            data = _load_planning_state()
            key = _channel_key(adapter, channel_id)
            if key in data:
                data[key]["phases_completed"] = completed
                data[key]["phase"] = "__complete__"
                data[key]["final_plan_path"] = str(target)
                _save_planning_state(data)
            session = PlanningSession.from_state(adapter, channel_id)
            summary = _summary_text(slug, completed, target)
            return session, summary, True

        next_phase = phases[next_idx]
        log.info(
            "planning.advance slug=%s adapter=%s channel=%s %s → %s",
            slug, adapter, channel_id, current_phase, next_phase,
        )
        # Fresh subprocess for the next phase. Phase coordinates with prior
        # phase via gstack disk artifacts (~/.gstack/projects/<slug>/).
        session = PlanningSession.start(
            slug=slug,
            description=description,
            phase=next_phase,
            channel_id=channel_id,
            adapter=adapter,
            on_text=on_text,
        )
        data = _load_planning_state()
        key = _channel_key(adapter, channel_id)
        if key in data:
            data[key]["phases_completed"] = completed
            data[key]["phase_index"] = next_idx
            data[key]["phases_planned"] = phases
            _save_planning_state(data)
        return session, session.last_response, False

    @staticmethod
    def cancel(adapter: str, channel_id: str) -> bool:
        """Drop planning state. Returns True if anything was cleared."""
        return clear_planning_state(adapter, channel_id)

    @staticmethod
    def final_plan_path(slug: str) -> Path:
        return _final_plan_path(slug)

    # Re-exported for convenience.
    has_ui_scope = staticmethod(has_ui_scope)


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


def _summary_text(slug: str, completed_phases: list[str], plan_path: Path) -> str:
    phases_str = " → ".join(completed_phases) if completed_phases else "(nicio fază)"
    return (
        f"✅ **Plan gata pentru `{slug}`**\n\n"
        f"Faze rulate: {phases_str}\n"
        f"Plan salvat: `{plan_path}`\n\n"
        "Apasă **Dau drumul tonight** ca Ralph să-l implementeze la 23:00, "
        "sau **Anulează** dacă vrei să mai gândim."
    )


def _build_final_plan_stub(
    slug: str, description: str, completed_phases: list[str], state: dict
) -> str:
    """Emit a minimal final-plan.md when the planning agent didn't write one.

    Captures what we know so PRD generator (W3) has something concrete to read.
    """
    phases_lines = "\n".join(f"- `{p}`" for p in completed_phases) or "- (none)"
    last_excerpt = (state.get("last_text_excerpt") or "").strip()
    last_block = (
        f"\n\n## Last agent output excerpt\n\n```\n{last_excerpt[:2000]}\n```"
        if last_excerpt
        else ""
    )
    return f"""# Final plan — {slug}

## Context

{description}

## Phases completed

{phases_lines}

## Architecture overview

(To be filled by planning agent. Stub written by PlanningOrchestrator because the
agent didn't write its own `final-plan.md` before pipeline completion.)

## User stories preliminare

(Stub. Ralph PRD generator will infer concrete stories from this plan + repo state.)

## Implementation hints

(Stub.)

## Verification approach

- typecheck + lint + tests pe modulele atinse
- smart gates Ralph pe tags inferred per story
{last_block}
"""