from __future__ import annotations

import json
import logging
from pathlib import Path
from typing import Any

from PySide6.QtCore import QObject, QUrl, Signal, Slot
from PySide6.QtGui import QDesktopServices
from PySide6.QtWebChannel import QWebChannel
from PySide6.QtWebEngineCore import (
    QWebEngineDownloadRequest,
    QWebEnginePage,
    QWebEngineProfile,
    QWebEngineSettings,
    QWebEngineUrlRequestInterceptor,
)
from PySide6.QtWebEngineWidgets import QWebEngineView
from PySide6.QtWidgets import QMessageBox

from addons import AddonManager
from cdp import CDPClient
from config import (
    DEFAULT_SETTINGS,
    FEATURE_PERMISSION_MAP,
    START_URL,

)
from models import ProfileContext
from network import NetworkBackend

log = logging.getLogger(__name__)

CACHE_SIZE_BYTES = 512 * 1024 * 1024

BLOCKED_PROTOCOLS = {
    "file",
    "shell",
    "cmd",
    "powershell",
    "ms-settings",
}

PROMPT_PROTOCOLS = {
    "mailto",
    "discord",
    "spotify",
    "steam",
}

BLOCKED_EXTENSIONS = {
    ".bat",
    ".cmd",
    ".ps1",
    ".vbs",
    ".js",
    ".jse",
    ".wsf",
    ".scr",
    ".hta",
    ".lnk",
    ".reg",
    ".iso",
    ".img",
    ".cpl",
    ".msc",
    ".jar",
    ".msix",
    ".msixbundle",
    ".appinstaller",
}


WARN_EXTENSIONS = {
    ".exe",
    ".dll",
    ".msi",
    ".com",
}


class Bridge(QObject):
    messageReceived = Signal(str)
    pluginLogReceived = Signal(str)
    pluginErrorReceived = Signal(str)

    def __init__(
        self,
        db,
        context: ProfileContext,
    ):
        super().__init__()

        self.db = db
        self.context = context

    @Slot(str)
    def log(
        self,
        message: str,
    ) -> None:
        self.messageReceived.emit(
            message
        )

    @Slot(str)
    def plugin_log(
        self,
        message: str,
    ) -> None:
        self.pluginLogReceived.emit(
            message
        )

    @Slot(str)
    def plugin_error(
        self,
        message: str,
    ) -> None:
        self.pluginErrorReceived.emit(
            message
        )

    @Slot(result=str)
    def version(
        self,
    ) -> str:
        return "1.0.0"

    @Slot(result=str)
    def platform(
        self,
    ) -> str:
        return "PySide6"

    @Slot(result=str)
    def plugin_runtime(
        self,
    ) -> str:
        return "bdapi-lite"

    @Slot(str, str, result=str)
    def pluginLoad(
        self,
        plugin: str,
        key: str,
    ) -> str:
        value = (
            self.db.plugin_setting_get(
                self.context.name,
                plugin,
                key,
                None,
            )
        )

        return json.dumps(
            value,
            ensure_ascii=False,
        )

    @Slot(str, str, str)
    def pluginSave(
        self,
        plugin: str,
        key: str,
        value: str,
    ) -> None:
        try:
            value = json.loads(
                value
            )
        except Exception:
            pass

        self.db.plugin_setting_set(
            self.context.name,
            plugin,
            key,
            value,
        )

    @Slot(str, str, str)
    def pluginLog(
        self,
        plugin: str,
        level: str,
        message: str,
    ) -> None:
        self.db.plugin_log(
            self.context.name,
            plugin,
            level,
            message,
        )

    @Slot(str, str)
    def pluginCrash(
        self,
        plugin: str,
        error: str,
    ) -> None:
        self.db.plugin_crash(
            self.context.name,
            plugin,
            error,
        )

# v3
class RequestInterceptor(QWebEngineUrlRequestInterceptor):
    def __init__(
        self,
        network: NetworkBackend,
    ):
        super().__init__()
        self.network = network

    def interceptRequest(
        self,
        info,
    ) -> None:

        host = (
            info.requestUrl()
            .host()
            .lower()
        )

        request = {
            "url": info.requestUrl().toString(),
            "host": host,
            "headers": {},
        }

        try:
            _, blocked = (
                self.network.process_request(
                    request
                )
            )

            if blocked:
                info.block(True)

        except Exception:
            log.exception(
                "request interception failed"
            )
class BrowserPage(QWebEnginePage):
    consoleMessage = Signal(str)

    def __init__(
        self,
        profile: QWebEngineProfile,
        permissions: dict[str, Any],
        parent=None,
    ):
        super().__init__(
            profile,
            parent,
        )

        self.permissions = permissions or {}

        self.featurePermissionRequested.connect(
            self._handle_permission_request
        )

    def javaScriptConsoleMessage(
        self,
        level,
        message: str,
        line: int,
        source: str,
    ) -> None:
        self.consoleMessage.emit(
            f"{source}:{line} {message}"
        )

    def acceptNavigationRequest(
        self,
        url,
        nav_type,
        is_main_frame,
    ) -> bool:
        scheme = (
            url.scheme()
            .lower()
            .strip()
        )

        if scheme in {
            "javascript",
            "data",
        }:
            return False

        if scheme in BLOCKED_PROTOCOLS:
            return False

        if scheme in PROMPT_PROTOCOLS:
            result = QMessageBox.question(
                self.view(),
                "External Link",
                (
                    "Open external application?\n\n"
                    f"{url.toString()}"
                ),
            )

            if (
                result
                == QMessageBox.StandardButton.Yes
            ):
                QDesktopServices.openUrl(
                    url
                )

            return False

        return super().acceptNavigationRequest(
            url,
            nav_type,
            is_main_frame,
        )

    def _handle_permission_request(
        self,
        origin,
        feature,
    ) -> None:
        feature_name = str(
            feature
        )

        allowed = False

        for (
            key,
            permission,
        ) in FEATURE_PERMISSION_MAP.items():
            if key in feature_name:
                allowed = bool(
                    self.permissions.get(
                        permission,
                        False,
                    )
                )
                break

        self.setFeaturePermission(
            origin,
            feature,
            (
                QWebEnginePage.PermissionPolicy.PermissionGrantedByUser
                if allowed
                else QWebEnginePage.PermissionPolicy.PermissionDeniedByUser
            ),
        )


class BrowserView(QWebEngineView):
    downloadProgress = Signal(
        str,
        int,
        int,
    )

    pluginDiagnostics = Signal(
        dict
    )

    def __init__(
        self,
        db,
        context: ProfileContext,
        settings: dict[str, Any] | None,
        parent=None,
    ):
        super().__init__(parent)

        self.db = db
        self.context = context

        self._settings_data = (
            settings
            or dict(
                DEFAULT_SETTINGS
            )
        )

        self.db.ensure_profile(
            self.context.name
        )

        self.network = (
            NetworkBackend(
                self.db,
                self._settings_data,
            )
        )

        self.profile = (
            self._create_profile()
        )

        self.interceptor = (
            RequestInterceptor(
                self.network
            )
        )

        self.profile.setUrlRequestInterceptor(
            self.interceptor
        )

        self.page_ = BrowserPage(
            self.profile,
            self._settings_data.get(
                "permissions",
                {},
            ),
            self,
        )

        self.setPage(
            self.page_
        )

        self.bridge = None
        self.channel = None
        self.addons = None
        self.cdp = None
        self._devtools_page = None
        self._devtools_view = None

        self._configure_web_settings()
        self._initialize_bridge()
        self._initialize_downloads()
        self._load_addons()

    def _create_profile(
        self,
    ) -> QWebEngineProfile:
        storage_path = (
            self.context.storage_path
        )

        cache_path = (
            self.context.cache_path
        )

        profile = (
            QWebEngineProfile(
                self.context.name,
                self,
            )
        )

        profile.setPersistentStoragePath(
            str(storage_path)
        )

        profile.setCachePath(
            str(cache_path)
        )

        profile.setHttpCacheMaximumSize(
            CACHE_SIZE_BYTES
        )

        profile.setPersistentCookiesPolicy(
            QWebEngineProfile.PersistentCookiesPolicy.ForcePersistentCookies
        )

        return profile

    def _configure_web_settings(
        self,
    ) -> None:
        settings = self.settings()

        for attribute in (
            QWebEngineSettings.WebAttribute.JavascriptEnabled,
            QWebEngineSettings.WebAttribute.LocalStorageEnabled,
            QWebEngineSettings.WebAttribute.FullScreenSupportEnabled,
            QWebEngineSettings.WebAttribute.ScrollAnimatorEnabled,
            QWebEngineSettings.WebAttribute.WebGLEnabled,
            QWebEngineSettings.WebAttribute.Accelerated2dCanvasEnabled,
        ):
            settings.setAttribute(
                attribute,
                True,
            )

        settings.setAttribute(
            QWebEngineSettings.WebAttribute.AllowRunningInsecureContent,
            False,
        )

    def _initialize_bridge(
        self,
    ) -> None:
        self.bridge = Bridge(
            self.db,
            self.context,
        )

        self.channel = (
            QWebChannel()
        )

        self.channel.registerObject(
            "bridge",
            self.bridge,
        )

        self.page_.setWebChannel(
            self.channel
        )

    def _initialize_downloads(
        self,
    ) -> None:
        self.profile.downloadRequested.connect(
            self._handle_download
        )

    def _load_addons(
        self,
    ) -> None:
        self.addons = AddonManager(
            self.context.name,
            self.db,
        )

        self.addons.install(
            self.profile
        )

    def plugin_inventory(
        self,
    ) -> list[dict]:
        if not self.addons:
            return []

        rows = []

        for plugin in (
            self.addons.plugins.discover()
        ):
            try:
                rows.append(
                    self.addons.plugins.metadata(
                        plugin
                    )
                )
            except Exception:
                log.exception(
                    "plugin metadata"
                )

        return rows

    def install_plugin_file(
        self,
        source: str | Path,
    ) -> Path:
        installed = (
            self.addons.plugins.install_file(
                Path(source)
            )
        )

        self.reload_addons()

        return installed

    def plugin_diagnostics(
        self,
    ) -> None:
        self.page().runJavaScript(
            """
(() => {
    if (!window.PluginRuntime)
        return {};

    return {
        loaded:Object.keys(
            PluginRuntime.plugins || {}
        ),
        failed:Object.keys(
            PluginRuntime.failed || {}
        ),
        failures:
            PluginRuntime.failed || {}
    };
})();
""",
            self.pluginDiagnostics.emit,
        )

    def initialize_cdp(
        self,
        websocket_url: str,
    ) -> None:
        if not self._settings_data.get(
            "enable_cdp",
            False,
        ):
            return

        if self.cdp:
            return

        try:
            self.cdp = CDPClient(
                db=self.db,
                websocket_url=websocket_url,
                capture_bodies=False,
                backend=self.network,
            )

            self.cdp.start()

        except Exception:
            log.exception(
                "cdp startup failed"
            )

    # v2
    def _download_directory(
        self,
    ) -> Path:

        directory = (
            self.context
            .downloads_path
        )

        directory.mkdir(
            parents=True,
            exist_ok=True,
        )

        return directory

    def _handle_download(
        self,
        download: QWebEngineDownloadRequest,
    ) -> None:
        filename = (
            download.downloadFileName()
        )

        extension = (
            Path(filename)
            .suffix
            .lower()
        )

        if extension in BLOCKED_EXTENSIONS:
            download.cancel()

            QMessageBox.warning(
                self,
                "Download Blocked",
                filename,
            )

            return

        if extension in WARN_EXTENSIONS:
            result = QMessageBox.warning(
                self,
                "Executable Download",
                filename,
                QMessageBox.StandardButton.Yes
                | QMessageBox.StandardButton.No,
            )

            if (
                result
                != QMessageBox.StandardButton.Yes
            ):
                download.cancel()
                return

        download.setDownloadDirectory(
            str(
                self._download_directory()
            )
        )

        download.accept()

        download.receivedBytesChanged.connect(
            lambda d=download:
            self._emit_download_progress(
                d
            )
        )

    def _emit_download_progress(
        self,
        download: QWebEngineDownloadRequest,
    ) -> None:
        self.downloadProgress.emit(
            download.downloadFileName(),
            download.receivedBytes(),
            download.totalBytes(),
        )

    def reload_addons(
        self,
    ) -> None:
        self.profile.scripts().clear()
        self._load_addons()
        self.reload()

    def open(
        self,
        url: str = START_URL,
    ) -> None:
        self.load(
            QUrl(url)
        )

    def open_devtools(
        self,
    ) -> None:
        if self._devtools_page is None:
            self._devtools_page = (
                QWebEnginePage(
                    self.profile,
                    self,
                )
            )

            self.page_.setDevToolsPage(
                self._devtools_page
            )

        if self._devtools_view is None:
            self._devtools_view = (
                QWebEngineView()
            )

            self._devtools_view.setPage(
                self._devtools_page
            )

            self._devtools_view.resize(
                1400,
                900,
            )

        self._devtools_view.show()

    def switch_profile(
        self,
        profile_name: str,
    ) -> None:
        raise RuntimeError(
            "profile switching requires browser recreation"
        )

        # v3
    def install_plugin_url(
        self,
        url: str,
    ) -> Path:
        import tempfile

        from urllib.parse import (
            urlparse,
        )
        from urllib.request import (
            urlopen,
        )

        parsed = urlparse(
            url
        )

        if (
            parsed.scheme
            not in {
                "https"
            }
        ):
            raise ValueError(
                "https required"
            )

        with urlopen(
            url,
            timeout=30,
        ) as response:

            content_length = (
                response.headers.get(
                    "Content-Length"
                )
            )

            if content_length:
                if (
                    int(content_length)
                    > PLUGIN_MAX_SIZE
                ):
                    raise ValueError(
                        "plugin exceeds size limit"
                    )

            content_type = (
                response.headers.get(
                    "Content-Type",
                    "",
                )
                .split(";")[0]
                .strip()
                .lower()
            )

            allowed_types = {
                "application/javascript",
                "text/javascript",
                "application/x-javascript",
                "text/plain",
            }

            if (
                content_type
                and content_type
                not in allowed_types
            ):
                raise ValueError(
                    f"unsupported content type: "
                    f"{content_type}"
                )

            data = bytearray()

            while True:
                chunk = response.read(
                    65536
                )

                if not chunk:
                    break

                data.extend(
                    chunk
                )

                if (
                    len(data)
                    > PLUGIN_MAX_SIZE
                ):
                    raise ValueError(
                        "plugin exceeds size limit"
                    )

        with tempfile.NamedTemporaryFile(
            suffix=".plugin.js",
            delete=False,
        ) as handle:
            handle.write(data)

            path = Path(
                handle.name
            )

        try:
            installed = (
                self.install_plugin_file(
                    path
                )
            )

            return installed

        finally:
            path.unlink(
                missing_ok=True
            )

    def remove_plugin(
        self,
        plugin_name: str,
    ) -> bool:
        removed = (
            self.addons.uninstall_plugin(
                plugin_name
            )
        )

        if removed:
            self.reload_addons()

        return removed

    def set_plugin_enabled(
        self,
        plugin_name: str,
        enabled: bool,
    ) -> None:
        if enabled:
            self.addons.enable_plugin(
                plugin_name
            )
        else:
            self.addons.disable_plugin(
                plugin_name
            )

        self.reload_addons()

    # v2
    def shutdown(
        self,
    ) -> None:

        if self.cdp:
            try:
                self.cdp.stop()
            except Exception:
                log.exception(
                    "cdp stop failed"
                )

            self.cdp = None

        try:
            self.setPage(None)
        except Exception:
            pass

        if self.page_:
            self.page_.deleteLater()
            self.page_ = None

        if self.channel:
            self.channel.deleteLater()
            self.channel = None

        if self.bridge:
            self.bridge.deleteLater()
            self.bridge = None

        if self.profile:
            self.profile.deleteLater()
            self.profile = None
        if (
            self.profile
            and self.interceptor
        ):
            try:
                self.profile.setUrlRequestInterceptor(
                    None
                )
            except Exception:
                pass
        if self.interceptor:
            self.interceptor.deleteLater()
            self.interceptor = None
        if self.page_:
            try:
                self.page_.triggerAction(
                    QWebEnginePage.WebAction.Stop
                )
            except Exception:
                pass
        if self._devtools_page:
            self._devtools_page.deleteLater()
            self._devtools_page = None

        if self._devtools_view:
            self._devtools_view.close()
            self._devtools_view.deleteLater()
            self._devtools_view = None