"""Cairn's phone pushes, through ntfy (Jacob's phone already runs the ntfy app for the printers).

What is pushed, and when (server.py runs check() every 30 s; `cairn tick` calls back_on_list()):
- 07:00: what's due today and what's late, one push, or none when nothing is. Sent once a day, up to noon if the
  server was down at seven.
- At a card's due time (a due: with a time): its title, with a Done button. Up to 2 h late if the server was down.
- When a Later card's day comes: "Back on the list".

⚠ An ntfy.sh topic can be read by anyone who knows its name, so the name is long and random and lives only in
notify.env (gitignored, mode 600). A #client card's title never goes in a push, the same rule as bambu-p1s'
NTFY_DISCREET. With no notify.env, nothing is sent and nothing fails.
"""
import datetime as dt, json, os, urllib.request
from pathlib import Path

import board as B

ROOT = Path(__file__).resolve().parent
ENV = ROOT / "notify.env"
STATE = B.BOARD / ".pushed.json"              # what was already sent: gitignored
APP_URL = "https://board.your-tailnet.ts.net:8443"
DIGEST_AT, DIGEST_UNTIL = dt.time(7, 0), dt.time(12, 0)
LATE_LIMIT = dt.timedelta(hours=2)


def config():
    out = {}
    if ENV.exists():
        for line in ENV.read_text().splitlines():
            key, eq, value = line.partition("=")
            if eq and not key.strip().startswith("#"):
                out[key.strip()] = value.strip().strip('"')
    return out


def send(title, body, priority=3, tags=(), click=None, actions=None):
    cfg = config()
    if not cfg.get("NTFY_TOPIC"):
        return False
    msg = {"topic": cfg["NTFY_TOPIC"], "title": title, "message": body, "priority": priority, "tags": list(tags)}
    if click:
        msg["click"] = click
    if actions:
        msg["actions"] = actions
    req = urllib.request.Request(cfg.get("NTFY_SERVER", "https://ntfy.sh"), data=json.dumps(msg).encode(),
                                 headers={"Content-Type": "application/json"})
    with urllib.request.urlopen(req, timeout=15):
        return True


def shown(card):
    """A card's title as a push may show it."""
    return "Client task" if card.cat == "client" else card.title


def done_button(card):
    """ntfy's http action: the phone itself POSTs the op to the board over the tailnet. The opid is fixed per card and
    due time, so a second tap changes nothing."""
    body = {"ops": [{"opid": f"push-done-{card.id}-{card.due}", "op": "done", "id": card.id}], "who": "push"}
    return {"action": "http", "label": "Done", "url": f"{APP_URL}/api/sync", "method": "POST",
            "headers": {"Content-Type": "application/json"}, "body": json.dumps(body), "clear": True}


def open_cards(board):
    return board.columns["Doing"] + board.columns["Todo"]


def digest(board, today):
    """(title, body) for the morning push, or None when nothing is due or late."""
    day = today.isoformat()
    late = [c for c in open_cards(board) if c.due and c.due[:10] < day]
    due = [c for c in open_cards(board) if c.due and c.due[:10] == day]
    if not late and not due:
        return None
    lines = [f"late {c.due[5:10]} · {shown(c)}" for c in sorted(late, key=lambda c: c.due)]
    lines += [f"{c.due[11:] or 'today'} · {shown(c)}" for c in sorted(due, key=lambda c: c.due)]
    if len(lines) > 8:
        lines = lines[:7] + [f"… {len(lines) - 7} more"]
    doing = len(board.columns["Doing"])
    if doing:
        lines.append(f"{doing} in hand")
    title = ", ".join(p for p in (f"{len(due)} due today" if due else "", f"{len(late)} late" if late else "") if p)
    return title, "\n".join(lines)


def timed_due(board, now):
    """Cards whose due time has come in the last LATE_LIMIT."""
    out = []
    for c in open_cards(board):
        if len(c.due) > 10:
            at = dt.datetime.fromisoformat(c.due)
            if at <= now < at + LATE_LIMIT:
                out.append(c)
    return out


def check(now=None):
    """The server's 30-second check: the morning digest, then any due time that has come. Never raises."""
    now = now or dt.datetime.now().replace(second=0, microsecond=0)
    try:
        state = json.loads(STATE.read_text()) if STATE.exists() else {}
    except ValueError:
        state = {}
    sent = set(state.get("due", []))
    try:
        board = B.load()
        if DIGEST_AT <= now.time() < DIGEST_UNTIL and state.get("digest") != now.date().isoformat():
            d = digest(board, now.date())
            if not d or send(d[0], d[1], 3, ["spiral_calendar"], APP_URL):
                state["digest"] = now.date().isoformat()
        for c in timed_due(board, now):
            key = f"{c.id}@{c.due}"
            if key not in sent and send(shown(c), f"due {c.due[11:]}", 4, ["alarm_clock"],
                                        f"{APP_URL}/#{c.id}", [done_button(c)]):
                sent.add(key)
    except Exception as e:                 # a failed push must never take the server down; it tries again in 30 s
        print(f"notify: {e}", flush=True)
    state["due"] = sorted(sent)[-500:]
    tmp = STATE.with_suffix(".part")
    tmp.write_text(json.dumps(state))
    tmp.replace(STATE)


def back_on_list(cards):
    for c in cards:
        try:
            send("Back on the list", shown(c), 3, ["leftwards_arrow_with_hook"], f"{APP_URL}/#{c.id}")
        except Exception as e:
            print(f"notify: {e}", flush=True)