"""Round 75 — a link that is a playlist says so before it downloads.

trav pasted a song from a YouTube Mix (``watch?v=…&list=RD…``). yt-dlp's
default is to take the whole list, so LinTunes started importing song after
song from a list of over 900, with nothing on screen saying why. Now:

- only a plain song link skips the listing (``link_kind``);
- anything else is listed first (``PlaylistProbe``). One song goes straight
  through, and several become a checklist: a song-in-a-list link ticks only
  its song, a playlist link ticks them all;
- the chosen songs are downloaded by their own pages, never the list link;
- an import of several songs gets a per-song progress window.

yt-dlp itself is never run. A fake on PATH speaks the same marker lines.
"""
import os
import stat
import sys
import time

import pytest
from PyQt6.QtCore import Qt

from lintunes import url_import
from lintunes.gui.url_import_dialog import (
    UrlImportDialog, format_duration, linked_song_id,
)
from lintunes.gui.url_import_progress import (
    IMPORTED, NOT_DOWNLOADED, SKIPPED, WAITING, UrlImportProgress,
)
from lintunes.library_manager import LibraryManager
from lintunes.models import Library
from lintunes.preferences import Preferences
from lintunes.url_import import (
    PlaylistProbe, UrlImportWorker, error_item, link_kind,
)

MIX = "https://www.youtube.com/watch?app=desktop&v=bbb&list=RDbbb&start_radio=1"

# Lists $FAKE_ENTRIES songs (aaa, bbb, ccc, …) for --flat-playlist; downloads
# each URL it's given otherwise, failing any whose id starts with "bad".
# Every run appends its argv to $FAKE_YTDLP_LOG.
FAKE_YTDLP = '''#!/usr/bin/env python3
import os, sys
args = sys.argv[1:]
with open(os.environ["FAKE_YTDLP_LOG"], "a") as log:
    log.write("\\x1f".join(args) + "\\n")
urls = args[args.index("--") + 1:]
if "--flat-playlist" in args:
    n = int(os.environ.get("FAKE_ENTRIES", "3"))
    loops = int(os.environ.get("FAKE_LOOPS", "1"))
    for i in list(range(n)) * loops:
        vid = chr(ord("a") + i) * 3
        print(f"LTENTRY {vid}\\t{60 * (i + 1)}.0\\t"
              f"https://www.youtube.com/watch?v={vid}\\tSong {vid}", flush=True)
    if n == 0:
        print("ERROR: [generic] Unsupported URL: " + urls[0], file=sys.stderr,
              flush=True)
        sys.exit(1)
    sys.exit(0)
dest = args[args.index("-P") + 1]
for url in urls:
    vid = url.rsplit("=", 1)[-1]
    if vid.startswith("bad"):
        print(f"ERROR: [youtube] {vid}: Video unavailable", file=sys.stderr,
              flush=True)
        continue
    print(f"LTSTART 1\\t1\\t{vid}\\tSong {vid}", flush=True)
    print("LTPROG  50.0%", flush=True)
    path = os.path.join(dest, f"Song {vid} [{vid}].mp3")
    src = os.environ.get("FAKE_YTDLP_AUDIO")
    with open(path, "wb") as f:
        f.write(open(src, "rb").read() if src else b"ID3fake")
    print(f"LTFILE {path}", flush=True)
'''


@pytest.fixture
def fake(tmp_path, monkeypatch):
    bin_dir = tmp_path / "bin"
    bin_dir.mkdir()
    script = bin_dir / "yt-dlp"
    script.write_text(FAKE_YTDLP.replace("/usr/bin/env python3",
                                         sys.executable))
    script.chmod(script.stat().st_mode | stat.S_IEXEC)
    log = tmp_path / "argv.log"
    monkeypatch.setenv("PATH", f"{bin_dir}{os.pathsep}{os.environ['PATH']}")
    monkeypatch.setenv("FAKE_YTDLP_LOG", str(log))
    monkeypatch.setenv("XDG_CONFIG_HOME", str(tmp_path / "config"))
    return lambda: ([line.split("\x1f") for line in
                     log.read_text().splitlines()] if log.exists() else [])


def _pump(qapp, until, timeout=10.0):
    deadline = time.monotonic() + timeout
    while not until() and time.monotonic() < deadline:
        qapp.processEvents()
        time.sleep(0.01)
    assert until(), "timed out waiting"


# --------------------------------------------------------------------------
# A. what a link names, from the URL alone


@pytest.mark.parametrize("url, kind", [
    ("https://www.youtube.com/watch?v=abc", "song"),
    ("https://m.youtube.com/watch?v=abc&t=30", "song"),
    ("https://music.youtube.com/watch?v=abc", "song"),
    ("https://youtu.be/abc", "song"),
    ("https://youtu.be/abc?list=PL1", "song_in_list"),
    ("https://www.youtube.com/shorts/abc", "song"),
    (MIX, "song_in_list"),
    ("https://www.youtube.com/watch?v=abc&list=PLxyz&index=4", "song_in_list"),
    ("https://www.youtube.com/playlist?list=PLxyz", "list"),
    ("https://soundcloud.com/someone/sets/an-album", "unknown"),
    ("https://soundcloud.com/someone/a-song", "unknown"),
    ("https://www.youtube.com/@channel", "unknown"),
    ("not a url", "unknown"),
])
def test_link_kind(url, kind):
    assert link_kind(url) == kind


def test_linked_song_id():
    assert linked_song_id(MIX) == "bbb"
    assert linked_song_id("https://youtu.be/xyz?list=PL") == "xyz"
    assert linked_song_id("https://soundcloud.com/a/b") == ""


def test_format_duration():
    assert format_duration(None) == ""
    assert format_duration(65) == "1:05"
    assert format_duration(3725) == "1:02:05"


def test_entry_and_error_lines():
    assert url_import.parse_line(
        "LTENTRY abc\t195.0\thttps://y.test/watch?v=abc\tA: Song\tX\n") == (
        "entry", {"id": "abc", "duration": 195,
                  "url": "https://y.test/watch?v=abc", "title": "A: Song\tX"})
    assert url_import.parse_line("LTENTRY abc\tNA\thttps://y/v\tT\n")[1][
        "duration"] is None
    # no page to download it from: not an entry we can use
    assert url_import.parse_line("LTENTRY abc\t1\t\tT\n") is None
    assert error_item("[youtube] -5o7lcpMDqs: Video unavailable") == (
        "-5o7lcpMDqs", "Video unavailable")
    assert error_item("Unable to download webpage") is None


def test_several_urls_all_follow_the_double_dash(tmp_path):
    cmd = url_import.build_command(["https://a/1", "https://a/2"], tmp_path)
    assert cmd[cmd.index("--"):] == ["--", "https://a/1", "https://a/2"]
    probe = url_import.build_probe_command(MIX, "firefox")
    assert "--flat-playlist" in probe and probe[-2:] == ["--", MIX]
    assert probe[probe.index("--cookies-from-browser") + 1] == "firefox"
    assert "--extract-audio" not in probe     # listing downloads nothing


# --------------------------------------------------------------------------
# B. the probe and the worker


def test_probe_streams_entries_in_order(fake):
    probe = PlaylistProbe(MIX)
    got = []
    probe.entry.connect(lambda e: got.append(e["id"]))
    probe.finished.connect(lambda n: got.append(("finished", n)))
    probe._run()
    assert got == ["aaa", "bbb", "ccc", ("finished", 3)]
    assert not probe.busy()


def test_a_probe_that_finds_nothing_fails(fake, monkeypatch):
    monkeypatch.setenv("FAKE_ENTRIES", "0")
    probe = PlaylistProbe("https://x.test/nothing")
    got = []
    probe.failed.connect(got.append)
    probe._run()
    assert got == ["[generic] Unsupported URL: https://x.test/nothing"]


def test_worker_counts_across_urls_and_names_failures(fake, tmp_path):
    worker = UrlImportWorker(["https://y/watch?v=aaa",
                              "https://y/watch?v=badone",
                              "https://y/watch?v=ccc"])
    worker.temp_dir = tmp_path / "dl"
    worker.temp_dir.mkdir()
    events = []
    worker.item_started.connect(
        lambda i, n, vid, t: events.append(("start", i, n, vid)))
    worker.item_failed.connect(lambda vid, why: events.append(("bad", vid)))
    worker.downloaded.connect(lambda p: events.append(("file",)))
    worker.finished.connect(lambda d: events.append(("done", d["downloaded"])))
    worker._run()
    assert events == [("start", 1, 3, "aaa"), ("file",), ("bad", "badone"),
                      ("start", 2, 3, "ccc"), ("file",), ("done", 2)]


# --------------------------------------------------------------------------
# C. the dialog


def _dialog(qapp, url):
    qapp.clipboard().setText(url)
    dialog = UrlImportDialog("Adds to the end of “Chill”")
    assert dialog.url() == url
    return dialog


def test_a_plain_song_link_is_never_listed(qapp, fake):
    dialog = _dialog(qapp, "https://www.youtube.com/watch?v=abc")
    dialog._on_import()
    assert dialog.result() == dialog.DialogCode.Accepted
    assert dialog.chosen_entries() == []
    assert fake() == []                 # yt-dlp was never run


def test_a_mix_ticks_only_the_linked_song(qapp, fake):
    dialog = _dialog(qapp, MIX)
    dialog._on_import()
    assert not dialog._ok.isEnabled()   # nothing to import while checking
    _pump(qapp, lambda: dialog._probe is None)
    assert dialog.result() != dialog.DialogCode.Accepted
    assert dialog._list.count() == 3
    assert dialog._ok.text() == "Import 1 Song"
    assert [e["id"] for e in dialog.chosen_entries()] == ["bbb"]
    assert "3 songs" in dialog._status.text()

    dialog._list.item(2).setCheckState(Qt.CheckState.Checked)
    assert dialog._ok.text() == "Import 2 Songs"
    dialog._check_all(False)
    assert not dialog._ok.isEnabled()
    dialog._check_all(True)
    assert dialog._ok.text() == "Import 3 Songs"
    dialog._on_import()
    assert dialog.result() == dialog.DialogCode.Accepted
    assert [e["url"] for e in dialog.chosen_entries()] == [
        "https://www.youtube.com/watch?v=aaa",
        "https://www.youtube.com/watch?v=bbb",
        "https://www.youtube.com/watch?v=ccc"]


def test_a_looping_mix_lists_each_song_once(qapp, fake, monkeypatch):
    monkeypatch.setenv("FAKE_LOOPS", "3")
    dialog = _dialog(qapp, MIX)
    dialog._on_import()
    _pump(qapp, lambda: dialog._probe is None)
    assert dialog._list.count() == 3
    assert [e["id"] for e in dialog.chosen_entries()] == ["bbb"]


def test_just_this_song_never_waits_for_the_list(qapp, fake):
    dialog = _dialog(qapp, MIX)
    dialog._on_import()
    assert dialog._just.isVisibleTo(dialog)
    dialog._just.click()                 # before a single row has arrived
    assert dialog.result() == dialog.DialogCode.Accepted
    assert dialog._probe is None
    assert dialog.chosen_entries() == []
    assert dialog.download_urls() == ["https://www.youtube.com/watch?v=bbb"]


def test_download_urls(qapp, fake):
    song = _dialog(qapp, "https://www.youtube.com/watch?v=abc")
    song._on_import()
    assert song.download_urls() == ["https://www.youtube.com/watch?v=abc"]
    playlist = _dialog(qapp, "https://www.youtube.com/playlist?list=PLx")
    playlist._on_import()
    assert not playlist._just.isVisibleTo(playlist)   # no song to pick
    _pump(qapp, lambda: playlist._probe is None)
    assert len(playlist.download_urls()) == 3


def test_a_playlist_link_ticks_everything(qapp, fake):
    dialog = _dialog(qapp, "https://www.youtube.com/playlist?list=PLx")
    dialog._on_import()
    _pump(qapp, lambda: dialog._probe is None)
    assert len(dialog.chosen_entries()) == 3


def test_a_one_song_listing_goes_straight_through(qapp, fake, monkeypatch):
    monkeypatch.setenv("FAKE_ENTRIES", "1")
    dialog = _dialog(qapp, "https://soundcloud.com/someone/a-song")
    dialog._on_import()
    _pump(qapp, lambda: dialog.result() == dialog.DialogCode.Accepted)
    assert dialog.chosen_entries() == []   # the link itself downloads


def test_a_failed_listing_stays_open_and_says_why(qapp, fake, monkeypatch):
    monkeypatch.setenv("FAKE_ENTRIES", "0")
    dialog = _dialog(qapp, "https://x.test/nothing")
    dialog._on_import()
    _pump(qapp, lambda: dialog._probe is None)
    assert dialog.result() != dialog.DialogCode.Accepted
    assert "Unsupported URL" in dialog._status.text()
    assert dialog._ok.isEnabled() and dialog._url.isEnabled()


# --------------------------------------------------------------------------
# D. the progress window


def test_progress_rows_follow_the_download(qapp):
    window = UrlImportProgress([{"id": "a", "title": "A"},
                                {"id": "b", "title": "B"},
                                {"id": "c", "title": "C"},
                                {"id": "d", "title": "D"}])
    assert window.status("a") == WAITING
    window.started("a")
    window.progress(43)
    assert window.status("a") == "Downloading 43%"
    window.landed(True)
    assert window.status("a") == IMPORTED
    window.failed("b", "Video unavailable")
    assert window.status("b") == "Couldn't download: Video unavailable"
    window.started("c")
    window.finish(cancelled=True)
    assert window.status("c") == SKIPPED and window.status("d") == SKIPPED
    assert window._summary.text().startswith("Done: 1 of 4 songs imported")
    assert not window._stop.isEnabled()

    quiet = UrlImportProgress([{"id": "x", "title": "X"}])
    quiet.finish(cancelled=False)
    assert quiet.status("x") == NOT_DOWNLOADED


# --------------------------------------------------------------------------
# E. through the window


@pytest.fixture
def window(qapp, tmp_path, fake, monkeypatch):
    from lintunes.gui.main_window import MainWindow
    library = Library(music_folder=str(tmp_path / "media"))
    (tmp_path / "media").mkdir()
    manager = LibraryManager(library, tmp_path / "data")
    win = MainWindow(manager, Preferences(tmp_path / "data"))
    monkeypatch.setattr(win, "_enqueue_identify", lambda tracks: None)
    yield win
    win.close()


def test_only_the_chosen_songs_download(window, qapp, fake, mp3_file,
                                        monkeypatch):
    from lintunes.gui import main_window as mw
    monkeypatch.setenv("FAKE_YTDLP_AUDIO", str(mp3_file))
    chosen = [{"id": "aaa", "title": "Song aaa",
               "url": "https://www.youtube.com/watch?v=aaa"},
              {"id": "ccc", "title": "Song ccc",
               "url": "https://www.youtube.com/watch?v=ccc"}]

    class _Dialog:
        cookies_used = None
        def __init__(self, description, parent=None, **_kw):
            pass
        def exec(self):
            return True
        def url(self):
            return MIX
        def add_to_playlist(self):
            return False
        def chosen_entries(self):
            return chosen
        def spotify_tracks(self):
            return []
        def download_urls(self):
            return [c["url"] for c in chosen]
    monkeypatch.setattr(mw, "UrlImportDialog", _Dialog)

    window._import_from_url()
    worker = window._url_worker
    _pump(qapp, lambda: worker.temp_dir is None)

    [argv] = fake()
    assert argv[argv.index("--") + 1:] == [c["url"] for c in chosen]
    assert MIX not in argv              # never the whole list
    progress = window._url_progress
    assert progress is not None and progress.isVisible()
    assert progress.status("aaa") == IMPORTED
    assert progress.status("ccc") == IMPORTED
    assert len(window._manager.library.tracks) == 2

    # Hidden, it comes back from the status bar only while downloading.
    progress.close()
    window._sync_label.clicked.emit()
    assert not progress.isVisible()      # done downloading: stays hidden
    worker._busy = True                  # as if still going
    window._sync_label.clicked.emit()
    assert progress.isVisible()
    worker._busy = False


def test_one_song_gets_no_progress_window(window, qapp, fake, mp3_file,
                                          monkeypatch):
    from lintunes.gui import main_window as mw
    monkeypatch.setenv("FAKE_YTDLP_AUDIO", str(mp3_file))

    class _Dialog:
        cookies_used = None
        def __init__(self, *a, **kw):
            pass
        def exec(self):
            return True
        def url(self):
            return "https://www.youtube.com/watch?v=aaa"
        def add_to_playlist(self):
            return False
        def chosen_entries(self):
            return []
        def spotify_tracks(self):
            return []
        def download_urls(self):
            return [self.url()]
    monkeypatch.setattr(mw, "UrlImportDialog", _Dialog)
    window._import_from_url()
    worker = window._url_worker
    _pump(qapp, lambda: worker.temp_dir is None)
    assert window._url_progress is None
    assert len(window._manager.library.tracks) == 1