"""Deterministic rules: Misc evaluation, match calculation, description markdown.

Replicates SKILL.md Schritt 3b/4/5. No LLM here — the numbers written to the
CRM must never be hallucinated.
"""
from __future__ import annotations

import datetime as dt
import json
import urllib.parse
import urllib.request
from math import asin, cos, radians, sin, sqrt

SAUERLACH = (47.9721357, 11.6528398)
NOMINATIM_UA = "projekt-matching/1.0 (Thomas.Langer@destengs.com)"

YES, NO, UNKNOWN = "yes", "no", "unknown"
SYMBOL = {YES: "✅", NO: "❌", UNKNOWN: "❔"}
RATING_VALUE = {YES: 100, UNKNOWN: 25, NO: 0}
KAT_ORDER = {"Must": 0, "Nice": 1, "Misc": 2}


def geocode(place: str):
    """Nominatim lookup -> (lat, lon) or None. Policy: max 1 request/s."""
    url = "https://nominatim.openstreetmap.org/search?" + urllib.parse.urlencode(
        {"q": place, "format": "json", "countrycodes": "de", "limit": 1})
    req = urllib.request.Request(url, headers={"User-Agent": NOMINATIM_UA})
    data = json.load(urllib.request.urlopen(req, timeout=20))
    return (float(data[0]["lat"]), float(data[0]["lon"])) if data else None


def distance_to_sauerlach_km(place: str, geocode_fn=geocode):
    """Haversine distance; None on geocoding failure/ambiguity."""
    try:
        pos = geocode_fn(place)
    except Exception:
        return None
    if pos is None:
        return None
    dlat = radians(pos[0] - SAUERLACH[0])
    dlon = radians(pos[1] - SAUERLACH[1])
    h = (sin(dlat / 2) ** 2
         + cos(radians(SAUERLACH[0])) * cos(radians(pos[0])) * sin(dlon / 2) ** 2)
    return 2 * 6371 * asin(sqrt(h))


def eval_misc(item: dict, today: dt.date, geocode_fn=geocode) -> str:
    kind = item.get("miscType") or "other"
    if kind == "security":
        return NO                          # K.-o.-Kriterium (SÜ dauert >= 3 Monate)
    if kind == "start":
        iso = item.get("startDate")
        if not iso:
            return UNKNOWN
        try:
            start = dt.date.fromisoformat(iso)
        except ValueError:
            return UNKNOWN
        return YES if start <= today + dt.timedelta(days=56) else NO
    if kind == "workload":
        pct = item.get("workloadPercent")
        if pct is None:
            return UNKNOWN
        return YES if 75 <= pct <= 100 else UNKNOWN
    if kind == "duration":
        return YES
    if kind == "location":
        if item.get("remotePercent") == 100:
            return YES
        place = item.get("onsiteLocation")
        if not place:
            return NO                      # Einsatzort/Remote-Anteil unklar
        km = distance_to_sauerlach_km(place, geocode_fn)
        if km is None:
            return UNKNOWN
        if km <= 50:
            return YES
        if km <= 60:
            return UNKNOWN
        return NO
    return UNKNOWN


def calc_match(rows: list, kat: str):
    vals = [RATING_VALUE[r["rating"]] for r in rows if r["kat"] == kat]
    if not vals:
        return None
    return int(sum(vals) / len(vals) + 0.5)    # half-up, not banker's rounding


def fmt_match(value):
    return "–" if value is None else f"{value} %"


def order_rows(rows: list) -> list:
    return sorted(rows, key=lambda r: KAT_ORDER[r["kat"]])   # stable sort


def build_description(rows: list) -> str:
    """rows already ordered Must -> Nice -> Misc (use order_rows)."""
    must, nice = calc_match(rows, "Must"), calc_match(rows, "Nice")
    lines = [f"Must-have-Match: {fmt_match(must)} · Nice-to-have-Match: {fmt_match(nice)}",
             "", "| Nr. | Kat. | ❔ | Anforderung |", "|---|---|---|---|"]
    for i, r in enumerate(rows, 1):
        lines.append(f"| {i} | {r['kat']} | {SYMBOL[r['rating']]} | {r['text']} |")
    return "\n".join(lines)