"""diora-tui: terminal EPUB reader for diora, syncing books + reading position
against a diora server (see project README)."""

from __future__ import annotations

import argparse
import asyncio
from pathlib import Path

from textual.app import App

from . import config as config_mod
from . import login as login_mod, remote
from .library_screen import LibraryScreen

DEFAULT_LIBRARY = Path.home() / "Books"


class DioraTuiApp(App):
    CSS_PATH = "app.tcss"
    TITLE = "diora-tui"

    def __init__(self, library_dir: Path) -> None:
        super().__init__()
        self.library_dir = library_dir

    def on_mount(self) -> None:
        self.push_screen(LibraryScreen(self.library_dir))

    async def action_quit(self) -> None:
        cfg = config_mod.load()
        if cfg is not None:
            try:
                # Sends what is queued, then pulls: nothing read stays only here.
                await asyncio.to_thread(remote.sync_library, self.library_dir, cfg)
            except remote.SyncError:
                pass  # best-effort — don't block quitting on a sync failure
        self.exit()


def run_login(server: str | None, *, paste_key: bool) -> None:
    try:
        cfg = login_mod.login(server, paste_key=paste_key)
    except login_mod.LoginError as e:
        raise SystemExit(f"Fehler: {e}")
    config_mod.save(cfg)
    print("Gespeichert (Token und Schlüssel geschützt). Weiter mit  diora-tui  oder  diora-tui sync.")


def run_sync(library_dir: Path) -> None:
    cfg = config_mod.load()
    if cfg is None:
        raise SystemExit("Nicht angemeldet: erst  diora-tui login")
    print(f"Verbinde zu {cfg.server_url} …")
    try:
        result = remote.sync_library(library_dir, cfg)
    except remote.SyncError as e:
        raise SystemExit(f"Fehler: {e}")

    print(f"{result.books} EPUB(s) auf dem Server (geladen wird beim Öffnen)." )
    if result.pushed:
        print(f"Lesestand von {result.pushed} Buch/Bücher an den Server geschickt.")
    for title in result.new_titles:
        print(f"  + {title}")
    if result.skipped_pdf:
        print(f"{len(result.skipped_pdf)} PDF(s) übersprungen (TUI liest nur EPUB): {', '.join(result.skipped_pdf)}")
    if result.failed:
        print(f"{len(result.failed)} Buch/Bücher nicht entschlüsselbar (falscher Schlüssel?): {', '.join(result.failed)}")


def main() -> None:
    parser = argparse.ArgumentParser(description="diora-tui — EPUB-Reader im Terminal, synct mit diora")
    parser.add_argument(
        "--library",
        type=Path,
        default=DEFAULT_LIBRARY,
        help=f"Verzeichnis mit EPUB-Dateien (Standard: {DEFAULT_LIBRARY})",
    )
    subparsers = parser.add_subparsers(dest="command")
    login_parser = subparsers.add_parser("login", help="Einmal anmelden (Token + Schlüssel, geschützt gespeichert)")
    login_parser.add_argument("--server", help=f"Server-URL (Standard: {login_mod.DEFAULT_SERVER})")
    login_parser.add_argument("--paste-key", action="store_true", help="Buchschlüssel einfügen statt aus dem Passwort ableiten")
    subparsers.add_parser("logout", help="Gespeicherte Zugangsdaten löschen")
    subparsers.add_parser("sync", help="Bücherliste und Lesestand abgleichen (ohne die Oberfläche)")

    args = parser.parse_args()
    library_dir = args.library.expanduser()

    if args.command == "login":
        run_login(args.server, paste_key=args.paste_key)
        return
    if args.command == "logout":
        print("Zugangsdaten gelöscht." if config_mod.forget() else "Keine Zugangsdaten gespeichert.")
        return
    if args.command == "sync":
        run_sync(library_dir)
        return

    DioraTuiApp(library_dir).run()


if __name__ == "__main__":
    main()