from __future__ import annotations
from typing import ClassVar
from .base import BaseAgent, AgentInput, AgentOutput

_DOW_NAMES = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]


class TimeOfDayAgent(BaseAgent):
    """Frames the current moment relative to the user's productive peak."""
    agent_id: ClassVar[str] = "time-of-day"
    ttl_seconds: ClassVar[int] = 900  # 15m — must stay current-hour accurate
    version: ClassVar[str] = "1.0.0"

    def compute(self, inp: AgentInput) -> AgentOutput:
        hour = inp.now.hour
        dow = inp.now.weekday()  # 0=Monday … 6=Sunday
        preferred = inp.profile.get("preferred_hour")
        is_weekend = dow >= 5

        parts = [f"It is {hour:02d}:00 on {_DOW_NAMES[dow]} ({self._label(hour)})."]

        if is_weekend:
            parts.append("Weekend context — prefer personal or reflective tips over work tasks.")

        if preferred is not None:
            ph = int(preferred)
            delta = min(abs(hour - ph), 24 - abs(hour - ph))  # circular distance
            if delta == 0:
                parts.append(
                    f"This is the user's peak productivity hour ({ph:02d}:00) — "
                    f"a high-impact tip is appropriate."
                )
            elif delta <= 2:
                parts.append(f"Approaching the user's peak productivity window ({ph:02d}:00).")
        else:
            parts.append("No preferred-hour data yet.")

        prompt = " ".join(parts)
        snapshot = {"hour": hour, "day_of_week": dow, "preferred_hour": preferred}
        return self._make_output(inp, prompt, snapshot)

    @staticmethod
    def _label(hour: int) -> str:
        if 5 <= hour < 12:
            return "morning"
        if 12 <= hour < 17:
            return "afternoon"
        if 17 <= hour < 21:
            return "evening"
        return "night"