#!/usr/bin/env python3

"""HTTP handler and route wiring for ani-cli-web."""

import json
import mimetypes
import os
import shutil
import subprocess
import traceback
from base64 import b64decode
from binascii import Error as BinasciiError
from dataclasses import dataclass
from functools import lru_cache
from http import HTTPStatus
from http.cookies import SimpleCookie
from http.server import BaseHTTPRequestHandler
from html import escape as html_escape
from pathlib import Path
from urllib.parse import parse_qs, unquote, urlencode, urlparse, urlunparse

from app_support import (
    ANI_CLI,
    APP_NAME,
    CHANGELOG_FILE,
    CLIENT_DISCONNECT_ERRORS,
    MAX_JSON_BODY_BYTES,
    MODE_CHOICES,
    VERSION,
    client_address_is_local,
    configured_remote_path_roots,
    debug_enabled,
    debug_log,
    load_project_text_file,
    normalize_config,
    path_is_within_roots,
    remote_access_allowed,
    remote_access_credentials_configured,
    remote_access_credentials_match,
    remote_access_session_matches,
    remote_access_session_value,
    sanitize_public_config,
    send_discord_webhook_event,
    validate_discord_webhook_url,
)

@dataclass(frozen=True)
class HandlerContext:
    add_to_watchlist: object
    config_html: str
    download_watchlist_item: object
    ensure_runtime: object
    episode_list: object
    get_config_snapshot: object
    get_jellyfin_sync_status: object
    get_watchlist_homepage_summary: object
    get_watchlist: object
    get_watchlist_refresh_status: object
    http_error: object
    index_html: str
    queue_html: str
    remove_from_watchlist: object
    run_jellyfin_sync: object
    runtime_state: object
    save_runtime_config: object
    search_anime: object
    resolve_search_thumbnail: object
    start_jellyfin_sync: object
    test_discord_webhook_config: object
    thumbnail_file_path: object
    update_all_watchlist_statuses: object
    update_watchlist_auto_download: object
    update_watchlist_category: object
    update_watchlist_media_type: object
    update_watchlist_status: object
    upload_watchlist_thumbnail: object
    watchlist_html: str


def build_handler_class(context):
    class ConfiguredHandler(Handler):
        handler_context = context

    return ConfiguredHandler


def dependency_status():
    checks = ["curl", "sed", "grep", "openssl", "fzf", "aria2c", "ffmpeg", "yt-dlp"]
    result = {name: bool(shutil.which(name)) for name in checks}
    result["ani-cli"] = bool(shutil.which(ANI_CLI) or (Path(ANI_CLI).exists() and os.access(ANI_CLI, os.X_OK)))
    return result


def browse_filesystem(path_value="", mode="dir", allowed_roots=None):
    raw_mode = str(mode or "dir").strip().lower()
    browse_mode = raw_mode if raw_mode in {"dir", "file"} else "dir"
    raw_path = str(path_value or "").strip()
    if raw_path:
        base_path = Path(raw_path).expanduser()
    elif allowed_roots:
        base_path = allowed_roots[0]
    else:
        base_path = Path.home()
    try:
        resolved = base_path.resolve()
    except OSError as exc:
        raise ValueError(f"Could not access path: {exc}") from exc
    if not resolved.exists():
        raise ValueError("Selected path does not exist.")
    if resolved.is_file():
        resolved = resolved.parent
    if not resolved.is_dir():
        raise ValueError("Selected path is not a directory.")
    if allowed_roots and not path_is_within_roots(resolved, allowed_roots):
        raise PermissionError("That path is outside the allowed remote browse roots.")

    entries = []
    try:
        for child in resolved.iterdir():
            try:
                is_dir = child.is_dir()
            except OSError:
                continue
            if allowed_roots and not path_is_within_roots(child, allowed_roots):
                continue
            if browse_mode == "dir" and not is_dir:
                continue
            entries.append(
                {
                    "name": child.name,
                    "path": str(child),
                    "is_dir": is_dir,
                }
            )
    except OSError as exc:
        raise ValueError(f"Could not list directory: {exc}") from exc

    entries.sort(key=lambda item: (not item["is_dir"], item["name"].lower(), item["name"]))
    parent_path = str(resolved.parent if resolved.parent != resolved else resolved)
    if allowed_roots and not path_is_within_roots(parent_path, allowed_roots):
        parent_path = str(resolved)
    root_paths = [str(Path(root)) for root in (allowed_roots or [])]
    return {
        "path": str(resolved),
        "parent_path": parent_path,
        "home_path": str(allowed_roots[0] if allowed_roots else Path.home()),
        "root_paths": root_paths,
        "mode": browse_mode,
        "entries": entries,
    }


@lru_cache(maxsize=1)
def installed_ani_cli_version():
    try:
        completed = subprocess.run(
            [ANI_CLI, "--version"],
            check=True,
            capture_output=True,
            text=True,
            timeout=6,
        )
    except (OSError, subprocess.SubprocessError):
        return "Unavailable"
    version = str(completed.stdout or completed.stderr or "").strip()
    return version or "Unavailable"


class Handler(BaseHTTPRequestHandler):
    server_version = "AniCliWeb/1.0"
    remote_session_cookie_name = "ani_cli_web_session"
    remote_session_cookie_max_age_seconds = 30 * 24 * 60 * 60
    quiet_poll_paths = {"/api/queue", "/api/watchlist/refresh-status", "/api/config/jellyfin/sync-status"}

    def _context(self):
        context = getattr(self, "handler_context", None) or getattr(type(self), "handler_context", None)
        if context is None:
            raise RuntimeError("Handler context is not configured.")
        return context

    def _runtime(self):
        context = Handler._context(self)
        context.ensure_runtime(start_workers=True)
        return context.runtime_state()

    def _effective_client_host(self):
        peer_host = self.client_address[0] if self.client_address else ""
        if not client_address_is_local(peer_host):
            return peer_host
        forwarded = (
            self.headers.get("X-Forwarded-For")
            or self.headers.get("x-forwarded-for")
            or self.headers.get("X-Real-IP")
            or self.headers.get("x-real-ip")
            or ""
        )
        if forwarded:
            first = str(forwarded).split(",", 1)[0].strip().strip("[]")
            if first:
                return first
        forwarded_header = str(self.headers.get("Forwarded") or self.headers.get("forwarded") or "").strip()
        if forwarded_header:
            for part in forwarded_header.split(";"):
                key, _, value = part.partition("=")
                if key.strip().lower() != "for":
                    continue
                candidate = value.strip().strip('"')
                if candidate.startswith("[") and "]" in candidate:
                    candidate = candidate[1 : candidate.index("]")]
                elif ":" in candidate and candidate.count(":") == 1:
                    candidate = candidate.split(":", 1)[0]
                candidate = candidate.strip()
                if candidate:
                    return candidate
        return peer_host

    def _authorization_header(self):
        return str(self.headers.get("Authorization") or self.headers.get("authorization") or "").strip()

    def _host_header(self):
        host = str(self.headers.get("X-Forwarded-Host") or self.headers.get("x-forwarded-host") or "").strip()
        if host:
            return host.split(",", 1)[0].strip()
        return str(self.headers.get("Host") or self.headers.get("host") or "").strip()

    def _origin(self):
        return str(self.headers.get("Origin") or self.headers.get("origin") or "").strip()

    def _content_type(self):
        return str(self.headers.get("Content-Type") or self.headers.get("content-type") or "").strip()

    def _request_is_secure(self):
        forwarded_proto = str(self.headers.get("X-Forwarded-Proto") or self.headers.get("x-forwarded-proto") or "").strip()
        if forwarded_proto:
            return forwarded_proto.split(",", 1)[0].strip().lower() == "https"
        forwarded = str(self.headers.get("Forwarded") or self.headers.get("forwarded") or "").strip()
        if forwarded:
            for part in forwarded.split(";"):
                key, _, value = part.partition("=")
                if key.strip().lower() == "proto":
                    return value.strip().strip('"').lower() == "https"
        return False

    def _origin_matches_host(self):
        origin = Handler._origin(self)
        if not origin:
            return False
        parsed = urlparse(origin)
        if parsed.scheme not in {"http", "https"} or not parsed.netloc:
            return False
        return parsed.netloc.lower() == Handler._host_header(self).lower()

    def _basic_auth_credentials(self):
        header = Handler._authorization_header(self)
        if not header.startswith("Basic "):
            return ("", "")
        encoded = header[len("Basic ") :].strip()
        if not encoded:
            return ("", "")
        try:
            decoded = b64decode(encoded.encode("ascii"), validate=True).decode("utf-8")
        except (BinasciiError, UnicodeDecodeError, ValueError):
            return ("", "")
        username, separator, password = decoded.partition(":")
        if not separator:
            return ("", "")
        return (username.strip(), password.strip())

    def _bearer_token(self):
        header = str(self.headers.get("Authorization") or "").strip()
        if not header.startswith("Bearer "):
            return ""
        return header[len("Bearer ") :].strip()

    def _cookie_value(self, name):
        raw = str(self.headers.get("Cookie") or self.headers.get("cookie") or "").strip()
        if not raw:
            return ""
        try:
            cookie = SimpleCookie()
            cookie.load(raw)
        except Exception:
            return ""
        morsel = cookie.get(name)
        if not morsel:
            return ""
        return morsel.value.strip()

    def _session_cookie(self):
        return Handler._cookie_value(self, Handler.remote_session_cookie_name)

    def _remote_credentials_valid(self):
        session = Handler._session_cookie(self)
        if session and remote_access_session_matches(session):
            return True
        username, password = Handler._basic_auth_credentials(self)
        return remote_access_credentials_match(username, password)

    def _normalized_next_path(self, value):
        raw = str(value or "").strip()
        if not raw:
            return "/"
        parsed = urlparse(raw)
        if parsed.scheme or parsed.netloc:
            return "/"
        path = parsed.path or "/"
        if not path.startswith("/"):
            return "/"
        if path == "/auth/login":
            path = "/"
        query = parsed.query or ""
        return urlunparse(("", "", path, "", query, ""))

    def _current_path_without_auth_query(self, parsed):
        params = parse_qs(parsed.query, keep_blank_values=True)
        params.pop("token", None)
        params.pop("remote_token", None)
        query = urlencode(params, doseq=True)
        return urlunparse(("", "", parsed.path or "/", "", query, ""))

    def _remote_auth_cookie(self, session_value):
        attributes = (
            f"{Handler.remote_session_cookie_name}={session_value}; "
            f"Path=/; HttpOnly; SameSite=Lax; Max-Age={Handler.remote_session_cookie_max_age_seconds}"
        )
        if Handler._request_is_secure(self):
            attributes += "; Secure"
        return attributes

    def _clear_remote_auth_cookie(self):
        attributes = (
            f"{Handler.remote_session_cookie_name}=; "
            "Path=/; HttpOnly; SameSite=Lax; Max-Age=0"
        )
        if Handler._request_is_secure(self):
            attributes += "; Secure"
        return attributes

    def _set_remote_auth_cookie_and_redirect(self, session_value, location):
        Handler.write_response_bytes(
            self,
            b"",
            HTTPStatus.SEE_OTHER,
            {
                "Location": Handler._normalized_next_path(self, location),
                "Set-Cookie": Handler._remote_auth_cookie(self, session_value),
            },
        )

    def _is_browser_page_request(self, parsed):
        if getattr(self, "command", "") != "GET":
            return False
        return not str(parsed.path or "").startswith("/api/")

    def _render_remote_login_page(self, parsed, message=""):
        next_path = Handler._current_path_without_auth_query(self, parsed)
        error_html = ""
        if message:
            error_html = f'<p class="error">{html_escape(message)}</p>'
        html = f"""<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>{APP_NAME} sign in</title>
  <style>
    :root {{
      color-scheme: dark;
      --bg: #0b0813;
      --panel: rgba(25, 18, 41, 0.94);
      --line: rgba(255, 255, 255, 0.08);
      --text: #f6f2ff;
      --muted: #b8b0cf;
      --accent: #9d7bff;
      --error: #ffb4c2;
    }}
    * {{ box-sizing: border-box; }}
    body {{
      margin: 0;
      min-height: 100vh;
      display: grid;
      place-items: center;
      padding: 24px;
      background:
        radial-gradient(circle at top left, rgba(157, 123, 255, 0.18), transparent 28%),
        linear-gradient(180deg, #120c1d 0%, #0b0813 56%, #07050d 100%);
      color: var(--text);
      font: 15px/1.5 "Segoe UI", Inter, system-ui, sans-serif;
    }}
    .panel {{
      width: min(100%, 420px);
      display: grid;
      gap: 14px;
      padding: 22px;
      border: 1px solid var(--line);
      border-radius: 22px;
      background: var(--panel);
    }}
    h1, p {{ margin: 0; }}
    h1 {{ font-size: 28px; line-height: 1.05; }}
    .muted {{ color: var(--muted); }}
    .error {{
      color: var(--error);
      padding: 10px 12px;
      border-radius: 14px;
      background: rgba(255, 144, 164, 0.12);
      border: 1px solid rgba(255, 144, 164, 0.18);
    }}
    form {{
      display: grid;
      gap: 12px;
    }}
    label {{
      display: grid;
      gap: 8px;
      color: var(--muted);
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.08em;
    }}
    input {{
      width: 100%;
      min-height: 44px;
      border-radius: 14px;
      border: 1px solid var(--line);
      background: rgba(10, 7, 18, 0.82);
      color: var(--text);
      padding: 0 13px;
    }}
    button {{
      min-height: 42px;
      border: 0;
      border-radius: 14px;
      background: linear-gradient(135deg, var(--accent), #7b5cff);
      color: #fcfaff;
      font: inherit;
      font-weight: 700;
      cursor: pointer;
    }}
    code {{
      font-size: 13px;
      color: var(--text);
    }}
  </style>
</head>
<body>
  <section class="panel">
    <div>
      <h1>{APP_NAME}</h1>
      <p class="muted">Sign in with the configured username and password. After that, this browser keeps a persistent auth session cookie.</p>
    </div>
    {error_html}
    <form method="post" action="/auth/login">
      <input type="hidden" name="next" value="{html_escape(next_path, quote=True)}">
      <label>Username
        <input name="username" type="text" autocomplete="username" autofocus required>
      </label>
      <label>Password
        <input name="password" type="password" autocomplete="current-password" required>
      </label>
      <button type="submit">Sign in</button>
    </form>
    <p class="muted">API clients can also use <code>Authorization: Basic &lt;base64(username:password)&gt;</code>.</p>
  </section>
</body>
</html>
"""
        Handler.write_response_bytes(
            self,
            html.encode("utf-8"),
            HTTPStatus.UNAUTHORIZED,
            {"Content-Type": "text/html; charset=utf-8"},
        )
        return True

    def ensure_client_access(self):
        client_host = Handler._effective_client_host(self)
        if client_address_is_local(client_host):
            return
        if not remote_access_allowed():
            raise PermissionError(
                "Remote access is disabled. Set ANI_CLI_WEB_ALLOW_REMOTE=1 to allow non-local clients."
            )
        if not remote_access_credentials_configured():
            raise PermissionError(
                "Remote access requires ANI_CLI_WEB_AUTH_USERNAME and ANI_CLI_WEB_AUTH_PASSWORD for non-local clients."
            )
        if not Handler._remote_credentials_valid(self):
            raise PermissionError("Remote username or password missing or invalid.")

    def enforce_same_origin(self):
        origin = Handler._origin(self)
        if not origin:
            if Handler._session_cookie(self):
                raise PermissionError("Browser API requests must include a same-origin Origin header.")
            return
        if not Handler._origin_matches_host(self):
            raise PermissionError("Cross-origin browser requests are not allowed.")

    def _remote_path_roots(self):
        return configured_remote_path_roots(Handler._context(self).get_config_snapshot())

    def validate_remote_path(self, path_value, label):
        client_host = Handler._effective_client_host(self)
        if client_address_is_local(client_host):
            return
        roots = Handler._remote_path_roots(self)
        if not roots:
            raise PermissionError(f"Remote {label} changes are disabled until a server-side path root is configured.")
        if not path_is_within_roots(path_value, roots):
            raise PermissionError(f"Remote {label} must stay inside the configured remote path roots.")

    def do_GET(self):
        parsed = urlparse(self.path)
        try:
            if parsed.path == "/auth/login":
                if Handler._session_cookie(self) and remote_access_session_matches(Handler._session_cookie(self)):
                    params = parse_qs(parsed.query, keep_blank_values=True)
                    next_path = (params.get("next") or ["/"])[0]
                    Handler._set_remote_auth_cookie_and_redirect(self, Handler._session_cookie(self), next_path)
                    return
                if remote_access_allowed() and remote_access_credentials_configured():
                    Handler._render_remote_login_page(self, parsed)
                    return
            self.ensure_client_access()
            if parsed.path == "/":
                self.html(Handler._context(self).index_html)
            elif parsed.path == "/queue":
                self.html(Handler._context(self).queue_html)
            elif parsed.path == "/config":
                self.html(Handler._context(self).config_html)
            elif parsed.path == "/watchlist":
                self.html(Handler._context(self).watchlist_html)
            elif parsed.path == "/api/config":
                self.json(sanitize_public_config(Handler._context(self).get_config_snapshot()))
            elif parsed.path == "/api/version":
                self.json({"name": APP_NAME, "version": VERSION, "ani_cli_version": installed_ani_cli_version()})
            elif parsed.path == "/api/changelog":
                self.json({"content": load_project_text_file(CHANGELOG_FILE, default="Changelog unavailable.")})
            elif parsed.path == "/api/dependencies":
                self.json(dependency_status())
            elif parsed.path == "/api/fs/browse":
                params = parse_qs(parsed.query)
                client_host = Handler._effective_client_host(self)
                allowed_roots = None if client_address_is_local(client_host) else Handler._remote_path_roots(self)
                self.json(
                    browse_filesystem(
                        (params.get("path") or [""])[0],
                        (params.get("mode") or ["dir"])[0],
                        allowed_roots=allowed_roots,
                    )
                )
            elif parsed.path == "/api/search":
                runtime = Handler._runtime(self)
                config = runtime["config"]
                params = parse_qs(parsed.query)
                query = (params.get("q") or [""])[0].strip()
                mode = (params.get("mode") or [config["mode"]])[0].lower()
                if not query:
                    raise ValueError("Search query is required")
                if mode not in MODE_CHOICES:
                    raise ValueError("Mode must be sub or dub")
                self.json({"results": Handler._context(self).search_anime(query, mode)})
            elif parsed.path == "/api/search/thumb":
                Handler._runtime(self)
                params = parse_qs(parsed.query)
                title = (params.get("title") or [""])[0].strip()
                if not title:
                    raise ValueError("Title is required")
                path = Handler._context(self).resolve_search_thumbnail(title)
                self.file(path)
            elif parsed.path.startswith("/api/anime/") and parsed.path.endswith("/episodes"):
                runtime = Handler._runtime(self)
                config = runtime["config"]
                show_id = unquote(parsed.path[len("/api/anime/") : -len("/episodes")])
                params = parse_qs(parsed.query)
                mode = (params.get("mode") or [config["mode"]])[0].lower()
                if mode not in MODE_CHOICES:
                    raise ValueError("Mode must be sub or dub")
                self.json({"episodes": Handler._context(self).episode_list(show_id, mode)})
            elif parsed.path == "/api/queue":
                runtime = Handler._runtime(self)
                params = parse_qs(parsed.query)
                page = (params.get("page") or ["1"])[0]
                per_page = (params.get("per_page") or ["10"])[0]
                self.json(runtime["download_queue"].list(page=page, per_page=per_page))
            elif parsed.path.startswith("/api/queue/"):
                runtime = Handler._runtime(self)
                parts = parsed.path.strip("/").split("/")
                if len(parts) != 3:
                    self.error(HTTPStatus.NOT_FOUND, "Not found")
                    return
                _, _, job_id = parts
                self.json(runtime["download_queue"].get(job_id))
            elif parsed.path.startswith("/api/watchlist/thumb/"):
                runtime = Handler._runtime(self)
                show_id = unquote(parsed.path[len("/api/watchlist/thumb/") :]).strip()
                debug_log("thumbnail.route.request", show_id=show_id, path=parsed.path, query=parsed.query)
                item = runtime["watchlist"].get(show_id)
                path = Handler._context(self).thumbnail_file_path(item.get("thumbnail_path"))
                if not path or not path.exists():
                    debug_log("thumbnail.route.miss", show_id=show_id, resolved_path=path)
                    self.error(HTTPStatus.NOT_FOUND, "Thumbnail not found")
                    return
                debug_log("thumbnail.route.hit", show_id=show_id, resolved_path=path)
                self.file(path)
            elif parsed.path == "/api/watchlist/homepage":
                Handler._runtime(self)
                self.json(Handler._context(self).get_watchlist_homepage_summary())
            elif parsed.path in {"/api/watchlist", "/api/watchlist/get"}:
                Handler._runtime(self)
                params = parse_qs(parsed.query)
                page = (params.get("page") or ["1"])[0]
                per_page = (params.get("per_page") or ["30"])[0]
                category = (params.get("category") or [""])[0].strip().lower() or None
                self.json(Handler._context(self).get_watchlist(page=page, per_page=per_page, category=category))
            elif parsed.path == "/api/watchlist/refresh-status":
                Handler._runtime(self)
                self.json(Handler._context(self).get_watchlist_refresh_status())
            elif parsed.path == "/api/config/jellyfin/sync-status":
                Handler._runtime(self)
                self.json(Handler._context(self).get_jellyfin_sync_status())
            else:
                self.error(HTTPStatus.NOT_FOUND, "Not found")
        except Exception as exc:
            self.exception(exc)

    def do_POST(self):
        parsed = urlparse(self.path)
        try:
            if parsed.path == "/auth/login":
                if not remote_access_allowed() or not remote_access_credentials_configured():
                    raise PermissionError("Remote access sign-in is not available.")
                payload = Handler.body_form(self)
                username = str(payload.get("username") or "").strip()
                password = str(payload.get("password") or "").strip()
                next_path = payload.get("next") or "/"
                if not remote_access_credentials_match(username, password):
                    Handler._render_remote_login_page(
                        self,
                        urlparse(Handler._normalized_next_path(self, next_path)),
                        "Username or password missing or invalid.",
                    )
                    return
                Handler._set_remote_auth_cookie_and_redirect(self, remote_access_session_value(), next_path)
                return
            self.ensure_client_access()
            Handler.enforce_same_origin(self)
            if parsed.path == "/api/config":
                Handler.update_config(self, Handler.require_json_object(self, self.body_json()))
            elif parsed.path == "/api/config/jellyfin/sync":
                payload = Handler.require_json_object(self, self.body_json())
                current = Handler._context(self).get_config_snapshot()
                merged = dict(current)
                merged.update(payload)
                for key, label in (
                    ("download_dir", "download directory"),
                    ("jellyfin_tv_dir", "Jellyfin TV directory"),
                    ("jellyfin_movie_dir", "Jellyfin movie directory"),
                ):
                    if str(merged.get(key) or "").strip():
                        Handler.validate_remote_path(self, merged[key], label)
                self.json(Handler._context(self).start_jellyfin_sync(merged), HTTPStatus.ACCEPTED)
            elif parsed.path == "/api/config/webhook/test":
                payload = Handler.require_json_object(self, self.body_json())
                validate_discord_webhook_url(payload.get("discord_webhook_url"))
                self.json(Handler._context(self).test_discord_webhook_config(payload))
            elif parsed.path == "/api/queue":
                runtime = Handler._runtime(self)
                payload = Handler.require_json_object(self, self.body_json())
                if str(payload.get("download_dir") or "").strip():
                    Handler.validate_remote_path(self, payload["download_dir"], "download directory")
                self.json(runtime["download_queue"].add(payload), HTTPStatus.CREATED)
            elif parsed.path == "/api/queue/retry-failed":
                runtime = Handler._runtime(self)
                self.json(runtime["download_queue"].retry_all_failed())
            elif parsed.path == "/api/queue/clear-finished":
                runtime = Handler._runtime(self)
                self.json(runtime["download_queue"].clear_finished())
            elif parsed.path.startswith("/api/queue/"):
                runtime = Handler._runtime(self)
                parts = parsed.path.strip("/").split("/")
                if len(parts) != 4:
                    self.error(HTTPStatus.NOT_FOUND, "Not found")
                    return
                _, _, job_id, action = parts
                actions = {
                    "retry": runtime["download_queue"].retry,
                    "cancel": runtime["download_queue"].cancel,
                    "remove": runtime["download_queue"].remove,
                }
                if action not in actions:
                    self.error(HTTPStatus.NOT_FOUND, "Not found")
                    return
                self.json(actions[action](job_id))
            elif parsed.path in {"/api/watchlist", "/api/watchlist/add"}:
                Handler._runtime(self)
                result = Handler._context(self).add_to_watchlist(Handler.require_json_object(self, self.body_json()))
                status = HTTPStatus.CREATED if result.get("created") else HTTPStatus.OK
                self.json(result, status)
            elif parsed.path == "/api/watchlist/ensure-thumbnails":
                runtime = Handler._runtime(self)
                payload = Handler.require_json_object(self, self.body_json())
                self.json(
                    runtime["watchlist"].ensure_thumbnails(
                        Handler.optional_list_field(self, payload, "show_ids") or [],
                        limit=payload.get("limit", 6),
                        force=Handler.optional_bool_field(self, payload, "force", default=False),
                    )
                )
            elif parsed.path == "/api/watchlist/update-status":
                Handler._runtime(self)
                payload = Handler.require_fields(self, self.body_json(), "show_id")
                self.json(Handler._context(self).update_watchlist_status(payload["show_id"], payload.get("mode")))
            elif parsed.path == "/api/watchlist/download-all":
                Handler._runtime(self)
                payload = Handler.require_fields(self, self.body_json(), "show_id", "mode")
                self.json(Handler._context(self).download_watchlist_item(payload["show_id"], payload["mode"]), HTTPStatus.CREATED)
            elif parsed.path == "/api/watchlist/update-category":
                Handler._runtime(self)
                payload = Handler.require_fields(self, self.body_json(), "show_id")
                self.json(Handler._context(self).update_watchlist_category(payload["show_id"], payload.get("category")))
            elif parsed.path == "/api/watchlist/update-media-type":
                Handler._runtime(self)
                payload = Handler.require_fields(self, self.body_json(), "show_id")
                self.json(Handler._context(self).update_watchlist_media_type(payload["show_id"], payload.get("media_type")))
            elif parsed.path == "/api/watchlist/update-auto-download":
                Handler._runtime(self)
                payload = Handler.require_fields(self, self.body_json(), "show_id")
                self.json(
                    Handler._context(self).update_watchlist_auto_download(
                        payload["show_id"],
                        payload.get("mode"),
                        payload.get("quality"),
                        payload.get("name"),
                        payload.get("source_name"),
                        payload.get("series"),
                        payload.get("episode_offset"),
                    )
                )
            elif parsed.path == "/api/watchlist/update-all":
                Handler._runtime(self)
                result = Handler._context(self).update_all_watchlist_statuses()
                status = HTTPStatus.ACCEPTED if result.get("created") else HTTPStatus.OK
                self.json(result, status)
            elif parsed.path == "/api/watchlist/remove":
                Handler._runtime(self)
                payload = Handler.require_fields(self, self.body_json(), "show_id")
                self.json(Handler._context(self).remove_from_watchlist(payload["show_id"]))
            elif parsed.path == "/api/watchlist/upload-thumbnail":
                Handler._runtime(self)
                payload = Handler.require_fields(self, self.body_json(), "show_id", "data_url")
                self.json(Handler._context(self).upload_watchlist_thumbnail(payload))
            else:
                self.error(HTTPStatus.NOT_FOUND, "Not found")
        except Exception as exc:
            self.exception(exc)

    def update_config(self, payload):
        payload = Handler.require_json_object(self, payload)
        current = Handler._context(self).get_config_snapshot()
        merged = dict(current)
        merged.update(payload)
        config = normalize_config(merged)
        for key, label in (
            ("download_dir", "download directory"),
            ("jellyfin_tv_dir", "Jellyfin TV directory"),
            ("jellyfin_movie_dir", "Jellyfin movie directory"),
        ):
            if str(config.get(key) or "").strip():
                Handler.validate_remote_path(self, config[key], label)
        if "discord_webhook_url" in payload and str(config.get("discord_webhook_url") or "").strip():
            validate_discord_webhook_url(config["discord_webhook_url"])
        Path(config["download_dir"]).expanduser().mkdir(parents=True, exist_ok=True)
        context = Handler._context(self)
        context.save_runtime_config(payload)
        self.json(sanitize_public_config(context.get_config_snapshot()))

    def require_fields(self, payload, *names):
        payload = Handler.require_json_object(self, payload)
        missing = [name for name in names if not str(payload.get(name) or "").strip()]
        if missing:
            if len(missing) == 1:
                raise ValueError(f"Missing required field: {missing[0]}")
            raise ValueError(f"Missing required fields: {', '.join(missing)}")
        return payload

    def require_json_object(self, payload):
        if not isinstance(payload, dict):
            raise ValueError("Expected a JSON object")
        return payload

    def optional_list_field(self, payload, name):
        payload = Handler.require_json_object(self, payload)
        if name not in payload or payload.get(name) is None:
            return None
        value = payload.get(name)
        if not isinstance(value, list):
            raise ValueError(f"Field '{name}' must be a JSON array")
        return value

    def optional_bool_field(self, payload, name, default=False):
        payload = Handler.require_json_object(self, payload)
        if name not in payload or payload.get(name) is None:
            return default
        value = payload.get(name)
        if isinstance(value, bool):
            return value
        if isinstance(value, str):
            normalized = value.strip().lower()
            if normalized in {"1", "true", "yes", "on"}:
                return True
            if normalized in {"0", "false", "no", "off"}:
                return False
        raise ValueError(f"Field '{name}' must be a boolean")

    def body_json(self):
        content_type = Handler._content_type(self).split(";", 1)[0].strip().lower()
        if content_type != "application/json":
            raise ValueError("Request body must use Content-Type: application/json.")
        try:
            length = int(self.headers.get("Content-Length", "0") or "0")
        except ValueError as exc:
            raise ValueError("Invalid Content-Length header") from exc
        if length < 0:
            raise ValueError("Invalid Content-Length header")
        if length > MAX_JSON_BODY_BYTES:
            raise Handler._context(self).http_error(HTTPStatus.REQUEST_ENTITY_TOO_LARGE, "Request body too large.")
        raw_bytes = self.rfile.read(length) if length else b"{}"
        if len(raw_bytes) > MAX_JSON_BODY_BYTES:
            raise Handler._context(self).http_error(HTTPStatus.REQUEST_ENTITY_TOO_LARGE, "Request body too large.")
        try:
            raw = raw_bytes.decode("utf-8")
        except UnicodeDecodeError as exc:
            raise ValueError("Request body must be valid UTF-8 JSON.") from exc
        try:
            return json.loads(raw)
        except json.JSONDecodeError as exc:
            raise ValueError("Invalid JSON body") from exc

    def body_form(self):
        try:
            length = int(self.headers.get("Content-Length", "0") or "0")
        except ValueError as exc:
            raise ValueError("Invalid Content-Length header") from exc
        if length < 0:
            raise ValueError("Invalid Content-Length header")
        if length > MAX_JSON_BODY_BYTES:
            raise Handler._context(self).http_error(HTTPStatus.REQUEST_ENTITY_TOO_LARGE, "Request body too large.")
        raw_bytes = self.rfile.read(length) if length else b""
        try:
            raw = raw_bytes.decode("utf-8")
        except UnicodeDecodeError as exc:
            raise ValueError("Request body must be valid UTF-8 form data.") from exc
        params = parse_qs(raw, keep_blank_values=True)
        return {key: values[-1] if values else "" for key, values in params.items()}

    def html(self, content):
        data = content.encode("utf-8")
        self.write_response_bytes(data, HTTPStatus.OK, {"Content-Type": "text/html; charset=utf-8"})

    def file(self, path):
        payload = Path(path).read_bytes()
        content_type = mimetypes.guess_type(str(path))[0] or "application/octet-stream"
        debug_log("file.serve", path=path, content_type=content_type, bytes=len(payload))
        self.write_response_bytes(
            payload,
            HTTPStatus.OK,
            {
                "Content-Type": content_type,
                "Cache-Control": "public, max-age=86400",
            },
        )

    def json(self, payload, status=HTTPStatus.OK):
        data = json.dumps(payload).encode("utf-8")
        self.write_response_bytes(data, status, {"Content-Type": "application/json"})

    def write_response_bytes(self, payload, status, headers):
        try:
            self.send_response(status)
            for key, value in headers.items():
                self.send_header(key, value)
            self.send_header("Content-Length", str(len(payload)))
            self.end_headers()
            self.wfile.write(payload)
        except CLIENT_DISCONNECT_ERRORS:
            return

    def error(self, status, message):
        try:
            self.json({"error": message}, status)
        except CLIENT_DISCONNECT_ERRORS:
            return

    def exception(self, exc):
        if isinstance(exc, CLIENT_DISCONNECT_ERRORS):
            return
        if isinstance(exc, Handler._context(self).http_error):
            self.error(exc.status, exc.message)
        elif isinstance(exc, KeyError):
            self.error(HTTPStatus.NOT_FOUND, str(exc).strip("'"))
        elif isinstance(exc, PermissionError):
            parsed = urlparse(getattr(self, "path", "") or "/")
            if remote_access_allowed() and remote_access_credentials_configured() and Handler._is_browser_page_request(self, parsed):
                Handler._render_remote_login_page(self, parsed, str(exc))
            else:
                self.error(HTTPStatus.FORBIDDEN, str(exc))
        elif isinstance(exc, ValueError):
            self.error(HTTPStatus.BAD_REQUEST, str(exc))
        else:
            if debug_enabled():
                debug_log("handler.exception", path=getattr(self, "path", ""), error=exc)
                traceback.print_exc()
            else:
                debug_log("handler.exception", path=getattr(self, "path", ""), error=exc)
            try:
                send_discord_webhook_event(
                    Handler._context(self).get_config_snapshot(),
                    "runtime_error",
                    {
                        "source": "http_handler",
                        "error": str(exc),
                        "details": f"path={getattr(self, 'path', '')}",
                    },
                )
            except Exception as notify_exc:
                debug_log("discord_webhook.runtime_error_failed", source="http_handler", error=notify_exc)
            self.error(HTTPStatus.INTERNAL_SERVER_ERROR, "Internal server error.")

    def log_message(self, fmt, *args):
        parsed = urlparse(getattr(self, "path", "") or "")
        if self.command == "GET" and parsed.path in Handler.quiet_poll_paths:
            return
        print(f"{self.address_string()} - {fmt % args}")


def server_host():
    return os.environ.get("ANI_CLI_WEB_HOST", "127.0.0.1").strip() or "127.0.0.1"


def server_port():
    raw = str(os.environ.get("ANI_CLI_WEB_PORT", "8421")).strip() or "8421"
    try:
        port = int(raw, 10)
    except ValueError as exc:
        raise ValueError("ANI_CLI_WEB_PORT must be a valid integer") from exc
    if not 1 <= port <= 65535:
        raise ValueError("ANI_CLI_WEB_PORT must be between 1 and 65535")
    return port