import asyncio
import logging
import pwd
from pathlib import Path
from typing import Coroutine

from defence360agent.contracts.config import (
    ANTIVIRUS_MODE,
    ConfigValidationError,
    SystemConfig,
    UserConfig,
)
from defence360agent.contracts.hook_events import HookEvent
from defence360agent.contracts.messages import MessageType
from defence360agent.contracts.plugins import (
    MessageSink,
    MessageSource,
    expect,
)
from defence360agent.subsys.panels import hosting_panel
from defence360agent.subsys.persistent_state import (
    load_state,
    register_lock_file,
    save_state,
)
from defence360agent.utils import Scope, recurring_check
from defence360agent.utils.check_lock import check_lock
from defence360agent.utils.common import DAY

from defence360agent.wordpress import plugin
from defence360agent.contracts.config import Wordpress
from defence360agent.model.wordpress import WPSite
from defence360agent.wordpress.site_repository import (
    get_sites_by_path,
    get_sites_for_user,
    get_installed_sites,
)
from defence360agent.wordpress.proxy_auth import (
    is_secret_expired,
    rotate_secret,
)
from defence360agent.wordpress import (
    ChangelogProcessor,
    IncidentCollector,
    IncidentSender,
)
from defence360agent.wordpress.plugin import update_disabled_rules_on_sites
from defence360agent.model.wordpress_incident import (
    delete_old_wordpress_incidents,
)


logger = logging.getLogger(__name__)

LOCK_FILE = register_lock_file("wp-gen-auth", Scope.AV_IM360)
SITE_PROCESSING_LOCK_FILE = register_lock_file(
    "wp-site-process", Scope.AV_IM360
)

CONFIG_DIR = Path("/etc/sysconfig/imunify360/imunify360.config.d")

FIRST_INSTALL_CONFIG_FILE = Path(
    "/opt/imunify360/venv/share/imunify360/11_on_first_install_wp_av.config"
)
FIRST_INSTALL_CONFIG_PATH = CONFIG_DIR / "11_on_first_install_wp_av.config"

FIRST_INSTALL_FLAG = CONFIG_DIR / ".11_on_first_install_wp_av.flag"


def _get_cleaned_malware_hits(started_timestamp: float) -> list:
    """
    Get malware hits cleaned since the given timestamp with lazy import fallback.

    Returns empty list if imav.malwarelib is not available.
    """
    try:
        from imav.malwarelib.model import MalwareHit

        return MalwareHit.cleaned_since(started_timestamp)
    except ImportError:
        logger.debug(
            "imav.malwarelib not available, returning empty cleaned hits"
        )
        return []


class ImunifySecurityPlugin(MessageSink, MessageSource):
    SCOPE = Scope.AV_IM360

    def __init__(self):
        self._loop = None
        self._sink = None
        state = load_state("ImunifySecurityPlugin")
        self.installation_completed = state.get("installed")
        # Explicit None check: a persisted False must win over the live
        # config value. Plain `or` would flip False → True via short-circuit.
        persisted_enabled = state.get("enabled")
        self.last_config_value = (
            persisted_enabled
            if persisted_enabled is not None
            else Wordpress.SECURITY_PLUGIN_ENABLED
        )
        try:
            self._last_waf_enabled = Wordpress.WAF_ENABLED
        except KeyError:
            self._last_waf_enabled = True
        self._last_user_waf_enabled: dict[str, bool | None] = {}
        self.installation_task: asyncio.Task | None = None
        self.deleting_task: asyncio.Task | None = None
        self.install_and_update_task: asyncio.Task | None = None
        self.freshly_installed_sites: set[WPSite] = set()

        # Incident collection and changelog processing components
        self.incident_collector = IncidentCollector()
        self.incident_sender = IncidentSender()
        self.changelog_processor = ChangelogProcessor()
        self._site_processing_task: asyncio.Task | None = None

    async def create_sink(self, loop):
        pass

    async def create_source(self, loop, sink):
        self._loop = loop
        self._sink = sink
        self._update_auth_task = self._loop.create_task(
            self.refresh_auth_files()
        )

        self._site_processing_task = self._loop.create_task(
            self.process_wordpress_sites()
        )

        if ANTIVIRUS_MODE:
            await self._apply_first_install_config()
        else:
            FIRST_INSTALL_FLAG.unlink(missing_ok=True)

        await self._recover_installation_on_startup()

    async def _recover_installation_on_startup(self):
        """
        Self-heal when the installation state was lost.

        If the feature is enabled but installation_completed is falsy (state
        file missing, earlier install interrupted, etc.), manage_plugin_installation
        can never recover: its True == True guard always returns early.
        Trigger install_everywhere once per restart to repopulate the
        wordpress_site table and flip the flag.
        """
        if (
            self.installation_completed
            or not Wordpress.SECURITY_PLUGIN_ENABLED
        ):
            return
        logger.info(
            "Installation state is missing while feature is enabled; "
            "triggering startup self-recovery"
        )
        # Sync last_config_value to the live config. If the persisted state
        # held a stale `enabled: False`, _mark_installation_done would bail
        # on `if not self.last_config_value` and installation_completed would
        # never flip — recovery would re-run on every restart.
        self.last_config_value = True
        await self.process_installation(
            plugin.install_everywhere(sink=self._sink)
        )
        if self.installation_task is not None:
            self.installation_task.add_done_callback(
                self._mark_installation_done
            )

    async def _apply_first_install_config(self):
        if not FIRST_INSTALL_FLAG.exists():
            return
        if await hosting_panel.HostingPanel().users_count() == 1:
            _ = FIRST_INSTALL_CONFIG_PATH.write_text(
                FIRST_INSTALL_CONFIG_FILE.read_text()
            )
            FIRST_INSTALL_CONFIG_PATH.chmod(0o600)
        FIRST_INSTALL_FLAG.unlink()

    async def shutdown(self):
        self._update_auth_task.cancel()
        # CancelledError is handled by @recurring_check():
        await self._update_auth_task

        # Cancel site processing (changelogs + incidents) task
        if self._site_processing_task:
            self._site_processing_task.cancel()
            await self._site_processing_task

    def _task_in_progress(self, task_attr_name):
        if not hasattr(self, task_attr_name):
            logger.error("Unknown task '%s'", task_attr_name)
            return False
        task = getattr(self, task_attr_name)

        return task is not None and not task.done() and not task.cancelled()

    def _save_installation_state(self):
        save_state(
            "ImunifySecurityPlugin",
            {
                "installed": self.installation_completed,
                "enabled": self.last_config_value,
            },
        )

    def _mark_installation_done(self, task: asyncio.Task):
        if task.cancelled():
            logger.info("Installation task was cancelled")
            return

        exc = task.exception()
        if exc is not None:
            logger.error("Installation task failed: %s", exc)
            return

        if not self.last_config_value:
            logger.info(
                "Feature was disabled during installation, "
                "skipping flag update"
            )
            return

        self.installation_completed = True
        self._save_installation_state()

    async def process_installation(self, coro: Coroutine, for_new_sites=False):
        if self._task_in_progress("deleting_task"):
            if for_new_sites:
                coro.close()
                return

            if self.deleting_task:
                self.deleting_task.cancel()
                try:
                    await self.deleting_task
                except asyncio.CancelledError:
                    pass

        if self._task_in_progress("installation_task"):
            logger.warning("Installation is already running")
            coro.close()
            return

        self.installation_task = asyncio.create_task(coro)

    async def process_deleting(self, coro):
        if self._task_in_progress("installation_task"):
            if self.installation_task:
                self.installation_task.cancel()
                try:
                    await self.installation_task
                except asyncio.CancelledError:
                    pass

        if self._task_in_progress("deleting_task"):
            logger.warning("Deleting is already running")
            return

        self.deleting_task = asyncio.create_task(coro)

    @recurring_check(
        check_lock,
        check_period_first=True,
        check_lock_period=DAY,
        lock_file=LOCK_FILE,
    )
    async def refresh_auth_files(self):
        if is_secret_expired():
            await rotate_secret()
        await plugin.update_auth_everywhere(sink=self._sink)

    @recurring_check(
        check_lock,
        check_period_first=True,
        check_lock_period=1 * 60,  # Run every 1 minute
        lock_file=SITE_PROCESSING_LOCK_FILE,
    )
    async def process_wordpress_sites(self):
        """
        Periodic task for WordPress site file processing.

        Runs every minute to:
        1. Process changelog.php files written by the WordPress plugin (rule disable/enable from WP admin)
        2. Collect incident files written by the WordPress plugin
        """
        logger.debug(
            "Processing rule disable changelogs"
            " and collecting WordPress CVE protection incidents"
        )
        try:
            sites = get_installed_sites()
            if not sites:
                logger.debug(
                    "No WordPress sites found for periodic processing"
                )
                return

            # Process changelogs (rule disable/enable from WordPress admin)
            affected_sites = (
                await self.changelog_processor.process_changelogs_for_sites(
                    sites, self._sink
                )
            )
            if affected_sites:
                await update_disabled_rules_on_sites(
                    domains=[s.domain for s in affected_sites],
                    sink=self._sink,
                )

            # Collect incidents
            incidents = (
                await self.incident_collector.collect_incidents_for_sites(
                    sites,
                    delete_after_processing=True,
                )
            )

            await self.incident_sender.send_incidents(self._sink, incidents)

            delete_old_wordpress_incidents(days=30)

        except Exception as e:
            logger.error("Error in WordPress periodic processing: %s", e)

    async def _install_on_new_sites(self):
        """Install plugin on new WordPress sites."""
        # Clear any previously tracked sites
        self.freshly_installed_sites.clear()

        async def install_and_track():
            installed_sites = await plugin.install_everywhere(sink=self._sink)
            if installed_sites:
                self.freshly_installed_sites.update(installed_sites)
            return installed_sites

        await self.process_installation(
            install_and_track(),
            for_new_sites=True,
        )

    async def _tidy_up(self):
        """Tidy up sites from which the WordPress plugin was deleted manually."""
        await plugin.tidy_up_manually_deleted(
            sink=self._sink,
            freshly_installed_sites=self.freshly_installed_sites,
        )
        await plugin.fix_data_file_permissions_everywhere(sink=self._sink)

        if not Wordpress.SECURITY_PLUGIN_ENABLED:
            await self.process_deleting(
                plugin.remove_all_installed(sink=self._sink)
            )
            self.installation_completed = False
            self.last_config_value = False
            self._save_installation_state()

    async def _adopt_found_sites(self):
        """Adopt sites where plugin is installed but not tracked in our database."""
        adopted_sites = await plugin.adopt_found_sites(sink=self._sink)
        # Add adopted sites to freshly_installed_sites to prevent them from being
        # marked as manually deleted by tidy_up (AVD database may not be updated yet)
        if adopted_sites:
            self.freshly_installed_sites.update(adopted_sites)

    async def _update_existing(self):
        """Update plugin on all sites where it is installed."""
        await plugin.update_everywhere(sink=self._sink)

    async def _run_install_and_update(self):
        """
        Combined operation: install on new sites, adopt found sites, tidy up,
        and update existing plugins.
        This runs all operations sequentially to avoid race conditions.
        """
        # Install plugin on new sites.
        await self._install_on_new_sites()
        # Wait for installation to complete before proceeding.
        if self.installation_task:
            await self.installation_task

        # Adopt sites where plugin is installed but not in our database.
        await self._adopt_found_sites()

        # Tidy up and update.
        await self._tidy_up()
        await self._update_existing()

    @expect(MessageType.WordpressPluginAction)
    async def manage_plugin_action(self, message):
        logger.info(
            "ImunifySecurityPlugin received message action: %s method: %s",
            message.action,
            message.method,
        )

        # Check if install_and_update is running - it blocks all other actions
        if self._task_in_progress("install_and_update_task"):
            logger.warning(
                "Install-and-update is still running, skipping action %s",
                message.action,
            )
            return

        if message.action == "install_on_new_sites":
            if not self.installation_completed:
                # The installation is not completed yet. We cannot know reliably which sites are new.
                return

            await self._install_on_new_sites()
            return

        if self._task_in_progress("installation_task"):
            logger.warning(
                "Installation is still running, skipping action %s",
                message.action,
            )
            return

        if self._task_in_progress("deleting_task"):
            logger.warning(
                "Uninstallation is already running, skipping action %s",
                message.action,
            )
            return

        if message.action == "update_existing":
            await self._update_existing()
            return

        if message.action == "tidy_up":
            await self._tidy_up()
            return

        if message.action == "install_and_update":
            if not self.installation_completed:
                # The installation is not completed yet. We cannot know reliably which sites are new.
                logger.warning(
                    "Installation is not completed yet, skipping"
                    " install_and_update"
                )
                return

            # Run install_and_update as a background task to prevent blocking.
            # Note: No need to check if already running - the check at the top of this function
            # (line 182) already handles that case.
            self.install_and_update_task = asyncio.create_task(
                self._run_install_and_update()
            )

    @expect(MessageType.ConfigUpdate)
    async def manage_plugin_installation(self, message):
        if not isinstance(message["conf"], SystemConfig):
            return

        current_config_value = Wordpress.SECURITY_PLUGIN_ENABLED
        if current_config_value == self.last_config_value:
            return

        # Update last config value immediately to prevent multiple installations
        self.last_config_value = current_config_value

        if current_config_value and not self.installation_completed:
            # Reset waf_enabled to True when the plugin is re-enabled so that
            # any stale "False" from before the plugin was disabled is cleared.
            # This keeps the config and actual deployment state in sync.
            try:
                SystemConfig().dict_to_config(
                    {"WORDPRESS": {"waf_enabled": True}}
                )
                self._last_waf_enabled = True
            except ConfigValidationError:
                logger.debug(
                    "waf_enabled config reset skipped, field not in schema yet"
                )
            await self.process_installation(
                plugin.install_everywhere(sink=self._sink)
            )
            if self.installation_task is not None:
                self.installation_task.add_done_callback(
                    self._mark_installation_done
                )

        elif not current_config_value and (
            self.installation_completed
            or self._task_in_progress("installation_task")
        ):
            await self.process_deleting(
                plugin.remove_all_installed(sink=self._sink)
            )
            self.installation_completed = False
            self._save_installation_state()

    @expect(MessageType.ConfigUpdate)
    async def manage_waf_config(self, message):
        if not Wordpress.SECURITY_PLUGIN_ENABLED:
            return
        conf = message["conf"]
        config_dict = conf.config_to_dict()
        waf_value = config_dict.get("WORDPRESS", {}).get("waf_enabled")
        if isinstance(conf, UserConfig):
            if waf_value is None:
                # waf_enabled reset to None means "revert to global default".
                # If the user previously had WAF disabled, redeploy their rules.
                prev = self._last_user_waf_enabled.pop(conf.username, None)
                if prev is False and plugin._get_global_waf_enabled():
                    await plugin.redeploy_wp_rules_for_user(conf.username)
                return
            if waf_value == self._last_user_waf_enabled.get(conf.username):
                return
            self._last_user_waf_enabled[conf.username] = waf_value
            if not waf_value or not plugin._get_global_waf_enabled():
                await plugin.remove_waf_rules_for_user(conf.username)
            else:
                await plugin.redeploy_wp_rules_for_user(conf.username)
        elif isinstance(conf, SystemConfig):
            if waf_value is None:
                return
            try:
                current = Wordpress.WAF_ENABLED
            except KeyError:
                return
            if current == self._last_waf_enabled:
                return
            self._last_waf_enabled = current
            if not current:
                await plugin.remove_waf_rules_for_all_sites()
            else:
                await plugin.redeploy_wp_rules()

    @expect(HookEvent.MalwareCleanupFinished)
    async def handle_malware_cleanup_finished(self, message):
        """
        INFO    [2025-02-24 12:00:20,384] imav.plugins.wordpress: Malware cleanup finished:
        HookEvent.MalwareCleanupFinished(
            {
                'cleanup_id': 'fa4fe7e48dbf45588f53b24366cd8893',
                'started': 1740398411.786418,
                'error': None,
                'total_files': 3,
                'total_cleaned': 3,
                'status': 'ok'
            }
        )
        """
        # Skip if plugin is disabled
        if not self.last_config_value:
            return

        # Leave early if status is not ok or the started time is missing.
        if message.get("status") != "ok" or not message.get("started"):
            return

        # load all malware hits cleaned since the cleanup started
        hits = _get_cleaned_malware_hits(message["started"])

        site_paths = set()

        # Collect all site paths that need to be updated.
        for hit in hits:
            if hit.resource_type == "file":
                try:
                    user_info = pwd.getpwnam(hit.user)
                    user_sites = get_sites_for_user(user_info)
                    uid = (  # In None cases there also no user_sites, so it wouldn't be used
                        user_info.pw_uid if user_info else None
                    )
                    for site_path in user_sites:
                        if hit.orig_file.startswith(site_path):
                            site_paths.add((site_path, uid))
                            break

                except KeyError:
                    pass

        if not site_paths:
            logger.debug("Cleanup finished => no sites found for cleaned hits")
            return

        logger.info(
            "Cleanup finished => %s site(s) need to be updated",
            len(site_paths),
        )

        # Convert paths to WPSite objects with empty domain and update data on the sites that need to be updated.
        # We need to work with paths here because sometimes the domain is not set, see https://cloudlinux.atlassian.net/browse/DEF-32238.
        wordpress_sites = [
            WPSite(docroot=site_path, domain="", uid=uid)
            for site_path, uid in site_paths
        ]

        await plugin.update_data_on_sites(self._sink, wordpress_sites)

        logger.info("%s site(s) updated after a cleanup", len(wordpress_sites))

    @expect(HookEvent.MalwareScanningFinished)
    async def handle_malware_scan_finished(self, message):
        """
        INFO    [2025-02-24 11:57:17,968] imav.plugins.wordpress: Malware scan finished:
        HookEvent.MalwareScanningFinished(
            {
                'scan_id': 'b9bd136aff0a4d87a248c859cfe41c47',
                'scan_type': 'user',
                'path': '/home/user1'
            }
        )
        INFO    [2025-02-24 12:00:10,740] imav.plugins.wordpress: Malware scan finished:
        HookEvent.MalwareScanningFinished(
            {
                'scan_id': 'a74271d2cdd04e0c9bd49ef6de23e0d8',
                'scan_type': 'user',
                'path': '/home/user4',
                'started': 1740398383,
                'total_files': 39229,
                'total_malicious': 3,
                'error': None,
                'status': 'ok',
                'scan_params': {'intensity_cpu': 2, 'intensity_io': 2, 'intensity_ram': 2048, 'initiator': None, 'file_patterns': None, 'exclude_patterns': None, 'follow_symlinks': False, 'detect_elf': True},
                'stats': {'scan_time': 27, 'mem_peak': 28217344, 'smart_time_hs': 0.004, 'scan_time_hs': 1.1751, 'smart_time_preg': 0, 'scan_time_preg': 2.7391, 'finder_time': 13.5896, 'cas_time': 0.7562, 'deobfuscate_time': 0.8998, 'total_files': 39229}
            }
        )
        """
        # Skip if plugin is disabled
        if not self.last_config_value:
            return

        # Leave early if status is not ok or path or stats are missing.
        if (
            message.get("status") != "ok"
            or not message.get("path")
            or not message.get("stats")
        ):
            return

        # Malware scan is finished, figure out what sites need to be updated based on the path.
        path = message["path"]
        sites = get_sites_by_path(path)
        if not sites:
            logger.debug("Scan finished => no sites found for path=%s", path)
            return

        # Update data on the sites that need to be updated.
        logger.info(
            "Scan finished => %s site(s) need to be updated", len(sites)
        )

        await plugin.update_data_on_sites(self._sink, sites)

        logger.info("%s site(s) updated after a scan", len(sites))
