from __future__ import annotations

import os
import shutil
import subprocess
from dataclasses import dataclass
from pathlib import Path
from typing import Callable, Mapping, MutableMapping, Optional

from dotenv import set_key

AUTOSTART_ENV_KEY = "AIFORECAST_START_WITH_WINDOWS"
AUTOSTART_REGISTRY_VALUE_NAME = "SuperAIForecastRunBat"
AUTOSTART_STARTUP_FILE_NAME = "SuperAIForecastRunBat.cmd"
BROWSER_PATH_ENV_KEY = "AIFORECAST_BROWSER_PATH"
WINDOWS_RUN_KEY_PATH = r"Software\Microsoft\Windows\CurrentVersion\Run"
DEFAULT_BROWSER_PREFERENCE = "opera"


@dataclass(frozen=True)
class BrowserLaunchStatus:
    preferred: str
    available: bool
    executable: Optional[str]

    def to_payload(self) -> dict[str, object]:
        return {
            "preferred": self.preferred,
            "available": self.available,
            "executable": self.executable,
        }


@dataclass(frozen=True)
class StartupPreferenceStatus:
    supported: bool
    enabled: bool
    registered: bool
    command: Optional[str]
    env_key: str
    registry_value_name: str
    browser: BrowserLaunchStatus
    message: str

    def to_payload(self) -> dict[str, object]:
        return {
            "supported": self.supported,
            "enabled": self.enabled,
            "registered": self.registered,
            "command": self.command,
            "env_key": self.env_key,
            "registry_value_name": self.registry_value_name,
            "browser": self.browser.to_payload(),
            "message": self.message,
        }


def _read_bool_env_value(value: Optional[str], *, default: bool) -> bool:
    if value is None:
        return default
    normalized = value.strip().lower()
    if not normalized:
        return default
    if normalized in {"1", "true", "yes", "on"}:
        return True
    if normalized in {"0", "false", "no", "off"}:
        return False
    return default


def resolve_start_with_windows_enabled(
    env: Mapping[str, str] | None = None,
    *,
    default: bool = True,
) -> bool:
    runtime_env = os.environ if env is None else env
    return _read_bool_env_value(runtime_env.get(AUTOSTART_ENV_KEY), default=default)


def resolve_windows_startup_folder(env: Mapping[str, str] | None = None) -> Path:
    runtime_env = os.environ if env is None else env
    app_data = runtime_env.get("APPDATA", "").strip()
    if app_data:
        return Path(app_data) / "Microsoft" / "Windows" / "Start Menu" / "Programs" / "Startup"
    return (
        Path.home()
        / "AppData"
        / "Roaming"
        / "Microsoft"
        / "Windows"
        / "Start Menu"
        / "Programs"
        / "Startup"
    )


def build_windows_startup_launcher_path(
    project_root: Path,
    env: Mapping[str, str] | None = None,
) -> Path:
    del project_root
    return resolve_windows_startup_folder(env) / AUTOSTART_STARTUP_FILE_NAME


def build_windows_startup_launcher_contents(project_root: Path) -> str:
    resolved_project_root = Path(project_root).resolve()
    run_bat_path = resolved_project_root / "run.bat"
    return "\n".join(
        [
            "@echo off",
            f'start "" /d "{resolved_project_root}" "{run_bat_path}"',
            "",
        ],
    )


def _read_text_file(path: Path) -> Optional[str]:
    try:
        return path.read_text(encoding="utf-8")
    except FileNotFoundError:
        return None


def _write_text_file(path: Path, content: str) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(content, encoding="utf-8")


def _delete_file(path: Path) -> None:
    try:
        path.unlink()
    except FileNotFoundError:
        return


def _normalize_text_lines(value: Optional[str]) -> Optional[str]:
    if value is None:
        return None
    return value.replace("\r\n", "\n").replace("\r", "\n")


def iter_preferred_browser_candidates(env: Mapping[str, str] | None = None) -> list[str]:
    runtime_env = os.environ if env is None else env
    candidates: list[str] = []
    custom_browser_path = runtime_env.get(BROWSER_PATH_ENV_KEY, "").strip()
    if custom_browser_path:
        candidates.append(custom_browser_path)

    local_app_data = runtime_env.get("LOCALAPPDATA", "").strip()
    program_files = runtime_env.get("ProgramFiles", "").strip()
    program_files_x86 = runtime_env.get("ProgramFiles(x86)", "").strip()

    common_candidates = [
        Path(local_app_data) / "Programs" / "Opera" / "opera.exe",
        Path(local_app_data) / "Programs" / "Opera" / "launcher.exe",
        Path(program_files) / "Opera" / "opera.exe",
        Path(program_files) / "Opera" / "launcher.exe",
        Path(program_files_x86) / "Opera" / "opera.exe",
        Path(program_files_x86) / "Opera" / "launcher.exe",
        Path(local_app_data) / "Programs" / "Opera GX" / "opera.exe",
        Path(local_app_data) / "Programs" / "Opera GX" / "launcher.exe",
    ]
    candidates.extend(str(path) for path in common_candidates if str(path).strip())

    for binary_name in ("opera.exe", "opera", "launcher.exe"):
        binary_path = shutil.which(binary_name)
        if binary_path:
            candidates.append(binary_path)

    deduped: list[str] = []
    seen: set[str] = set()
    for candidate in candidates:
        normalized = str(candidate).strip()
        if not normalized:
            continue
        lowered = normalized.lower()
        if lowered in seen:
            continue
        seen.add(lowered)
        deduped.append(normalized)
    return deduped


def get_browser_launch_status(
    env: Mapping[str, str] | None = None,
    *,
    path_exists: Callable[[Path], bool] | None = None,
) -> BrowserLaunchStatus:
    exists = path_exists or Path.exists
    for candidate in iter_preferred_browser_candidates(env):
        candidate_path = Path(candidate)
        if exists(candidate_path):
            return BrowserLaunchStatus(
                preferred=DEFAULT_BROWSER_PREFERENCE,
                available=True,
                executable=str(candidate_path),
            )
    return BrowserLaunchStatus(
        preferred=DEFAULT_BROWSER_PREFERENCE,
        available=False,
        executable=None,
    )


def open_url_with_preferred_browser(
    url: str,
    *,
    env: Mapping[str, str] | None = None,
    path_exists: Callable[[Path], bool] | None = None,
    popen: Callable[..., object] = subprocess.Popen,
) -> bool:
    browser_status = get_browser_launch_status(env, path_exists=path_exists)
    if not browser_status.available or not browser_status.executable:
        return False
    try:
        popen(
            [browser_status.executable, url],
            stdout=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL,
        )
        return True
    except OSError:
        return False


def _read_windows_run_value(
    value_name: str,
    *,
    key_path: str = WINDOWS_RUN_KEY_PATH,
) -> Optional[str]:
    import winreg

    try:
        with winreg.OpenKey(winreg.HKEY_CURRENT_USER, key_path, 0, winreg.KEY_READ) as key:
            value, _ = winreg.QueryValueEx(key, value_name)
            return str(value)
    except FileNotFoundError:
        return None


def _delete_windows_run_value(
    value_name: str,
    *,
    key_path: str = WINDOWS_RUN_KEY_PATH,
) -> None:
    import winreg

    try:
        with winreg.OpenKey(winreg.HKEY_CURRENT_USER, key_path, 0, winreg.KEY_SET_VALUE) as key:
            winreg.DeleteValue(key, value_name)
    except FileNotFoundError:
        return


def get_startup_preference_status(
    project_root: Path,
    *,
    env: Mapping[str, str] | None = None,
    os_name: Optional[str] = None,
    registry_reader: Callable[[str], Optional[str]] = _read_windows_run_value,
    path_exists: Callable[[Path], bool] | None = None,
    startup_file_reader: Callable[[Path], Optional[str]] = _read_text_file,
) -> StartupPreferenceStatus:
    resolved_os_name = os.name if os_name is None else os_name
    runtime_env = os.environ if env is None else env
    supported = resolved_os_name == "nt"
    enabled = resolve_start_with_windows_enabled(runtime_env, default=True)
    launcher_path = build_windows_startup_launcher_path(project_root, runtime_env)
    launcher_contents = _normalize_text_lines(build_windows_startup_launcher_contents(project_root))
    command = str((Path(project_root).resolve() / "run.bat"))
    registered_launcher = bool(
        supported
        and _normalize_text_lines(startup_file_reader(launcher_path)) == launcher_contents
    )
    legacy_registered_command = registry_reader(AUTOSTART_REGISTRY_VALUE_NAME) if supported else None
    legacy_registered = bool(supported and legacy_registered_command)
    registered = bool(supported and registered_launcher and not legacy_registered)
    browser = get_browser_launch_status(runtime_env, path_exists=path_exists)

    if not supported:
        message = "Tu dong khoi dong file .bat chi duoc ho tro tren Windows."
    elif enabled and registered_launcher and legacy_registered:
        message = "Phat hien logic khoi dong cu trong Windows Run. Launcher se xoa no va giu Startup folder cho run.bat."
    elif enabled and registered:
        message = "run.bat dang duoc dang ky trong Startup folder cua Windows."
    elif enabled:
        message = "Da bat tu dong khoi dong. Launcher se tao file Startup mo run.bat."
    else:
        message = "run.bat se khong khoi dong cung Windows."

    return StartupPreferenceStatus(
        supported=supported,
        enabled=enabled,
        registered=registered,
        command=command,
        env_key=AUTOSTART_ENV_KEY,
        registry_value_name=AUTOSTART_REGISTRY_VALUE_NAME,
        browser=browser,
        message=message,
    )


def sync_startup_preference(
    project_root: Path,
    *,
    env: MutableMapping[str, str] | None = None,
    os_name: Optional[str] = None,
    registry_reader: Callable[[str], Optional[str]] = _read_windows_run_value,
    registry_deleter: Callable[[str], None] = _delete_windows_run_value,
    path_exists: Callable[[Path], bool] | None = None,
    startup_file_reader: Callable[[Path], Optional[str]] = _read_text_file,
    startup_file_writer: Callable[[Path, str], None] = _write_text_file,
    startup_file_deleter: Callable[[Path], None] = _delete_file,
) -> StartupPreferenceStatus:
    runtime_env = os.environ if env is None else env
    status = get_startup_preference_status(
        project_root,
        env=runtime_env,
        os_name=os_name,
        registry_reader=registry_reader,
        path_exists=path_exists,
        startup_file_reader=startup_file_reader,
    )
    if status.supported:
        launcher_path = build_windows_startup_launcher_path(project_root, runtime_env)
        launcher_contents = build_windows_startup_launcher_contents(project_root)
        registry_deleter(status.registry_value_name)
        if status.enabled:
            startup_file_writer(launcher_path, launcher_contents)
        else:
            startup_file_deleter(launcher_path)
    return get_startup_preference_status(
        project_root,
        env=runtime_env,
        os_name=os_name,
        registry_reader=registry_reader,
        path_exists=path_exists,
        startup_file_reader=startup_file_reader,
    )


def update_startup_preference(
    project_root: Path,
    env_file: Path,
    *,
    enabled: bool,
    env: MutableMapping[str, str] | None = None,
    os_name: Optional[str] = None,
    env_writer: Callable[..., tuple[Optional[bool], str, str]] = set_key,
    registry_reader: Callable[[str], Optional[str]] = _read_windows_run_value,
    registry_deleter: Callable[[str], None] = _delete_windows_run_value,
    path_exists: Callable[[Path], bool] | None = None,
    startup_file_reader: Callable[[Path], Optional[str]] = _read_text_file,
    startup_file_writer: Callable[[Path, str], None] = _write_text_file,
    startup_file_deleter: Callable[[Path], None] = _delete_file,
) -> StartupPreferenceStatus:
    runtime_env = os.environ if env is None else env
    runtime_env[AUTOSTART_ENV_KEY] = "1" if enabled else "0"
    env_file.parent.mkdir(parents=True, exist_ok=True)
    env_writer(str(env_file), AUTOSTART_ENV_KEY, runtime_env[AUTOSTART_ENV_KEY], quote_mode="never")
    return sync_startup_preference(
        project_root,
        env=runtime_env,
        os_name=os_name,
        registry_reader=registry_reader,
        registry_deleter=registry_deleter,
        path_exists=path_exists,
        startup_file_reader=startup_file_reader,
        startup_file_writer=startup_file_writer,
        startup_file_deleter=startup_file_deleter,
    )