"""Windows notifications from the Harbor server, so the human hears about questions and urgent messages even with the
chat page closed. Off by default; switched on from the board (stored per project in the database)."""
import base64
import os
import subprocess
import sys
from xml.sax.saxutils import escape

APP_ID = r"{1AC14E77-02E7-4E5D-B744-2EB1AE5198B7}\WindowsPowerShell\v1.0\powershell.exe"


def toast_script(title, body):
    xml = ('<toast><visual><binding template="ToastGeneric"><text>' + escape(str(title)[:80]) + "</text><text>"
           + escape(str(body)[:300]) + "</text></binding></visual></toast>")
    xml = xml.replace("'", "''")                              # inside a PowerShell single-quoted string
    return ("[Windows.UI.Notifications.ToastNotificationManager, Windows.UI.Notifications, ContentType = WindowsRuntime] "
            "| Out-Null\n"
            "[Windows.Data.Xml.Dom.XmlDocument, Windows.Data.Xml.Dom.XmlDocument, ContentType = WindowsRuntime] | Out-Null\n"
            "$xml = New-Object Windows.Data.Xml.Dom.XmlDocument\n"
            f"$xml.LoadXml('{xml}')\n"
            "$toast = [Windows.UI.Notifications.ToastNotification]::new($xml)\n"
            f"[Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier('{APP_ID}').Show($toast)\n")


def toast(title, body):
    """Show a Windows notification; returns True when PowerShell accepted it."""
    if sys.platform != "win32" or os.environ.get("HARBOR_NO_TOASTS"):
        return False
    encoded = base64.b64encode(toast_script(title, body).encode("utf-16-le")).decode("ascii")
    try:
        r = subprocess.run(["powershell", "-NoProfile", "-NonInteractive", "-EncodedCommand", encoded],
                           capture_output=True, timeout=20, creationflags=getattr(subprocess, "CREATE_NO_WINDOW", 0))
        return r.returncode == 0
    except (OSError, subprocess.SubprocessError):
        return False


def pending_for_human(h, limit=3):
    """Messages to the human that deserve a notification and were not notified yet (questions, urgent, direct)."""
    row = h.conn.execute("SELECT value FROM meta WHERE key='toast_last'").fetchone()
    last = int(row["value"]) if row else 0
    rows = [h._message_dict(r) for r in h.conn.execute(
        h.MESSAGE_SELECT + " JOIN deliveries d ON d.message_id=m.id AND d.agent=? WHERE d.read_at IS NULL AND m.id>? "
        "ORDER BY m.id LIMIT 200", (h.human, last))]
    worth = sorted((m for m in rows if m["recipients"] != ["All"] or m["importance"] == "urgent"
                    or m["kind"] == "question"), key=lambda m: m["id"])
    top = max([m["id"] for m in rows], default=last)
    return worth[-limit:], top


def enabled(h):
    row = h.conn.execute("SELECT value FROM meta WHERE key='toasts'").fetchone()
    return bool(row and row["value"] == "on")


def set_enabled(h, on):
    top = h.conn.execute("SELECT COALESCE(MAX(id), 0) FROM messages").fetchone()[0]

    def do(c):
        c.execute("INSERT INTO meta(key, value) VALUES ('toasts', ?) ON CONFLICT(key) DO UPDATE SET value=excluded.value",
                  ("on" if on else "off",))
        c.execute("INSERT INTO meta(key, value) VALUES ('toast_last', ?) ON CONFLICT(key) DO UPDATE SET "
                  "value=excluded.value", (str(top),))           # never notify the backlog
    h._write(do)


def mark(h, top):
    h._write(lambda c: c.execute("INSERT INTO meta(key, value) VALUES ('toast_last', ?) ON CONFLICT(key) DO UPDATE "
                                 "SET value=excluded.value", (str(top),)))