"""Plugin service layer — business logic for plugin lifecycle operations."""

from __future__ import annotations

import logging
import uuid
from typing import Any

from sqlalchemy.ext.asyncio import AsyncSession

from app.core.audit import log_audit
from app.plugins.registry import PluginRegistry, get_registry
from app.plugins.migration_runner import MigrationValidationError

logger = logging.getLogger(__name__)


class PluginService:
    """Service layer for plugin lifecycle management.

    Wraps the PluginRegistry with audit logging and error handling.
    """

    def __init__(self, registry: PluginRegistry | None = None) -> None:
        self._registry = registry or get_registry()

    @property
    def registry(self) -> PluginRegistry:
        return self._registry

    async def list_plugins(self, db: AsyncSession) -> list[dict[str, Any]]:
        """List all discovered and installed plugins with their status."""
        return await self._registry.list_plugins(db)

    async def install_plugin(
        self,
        db: AsyncSession,
        name: str,
        tenant_id: uuid.UUID | None = None,
        user_id: uuid.UUID | None = None,
    ) -> dict[str, Any]:
        """Install a plugin by name.

        Runs migrations, calls on_install hook, creates DB record.
        Idempotent: returns existing record if already installed.
        """
        try:
            record = await self._registry.install(db, name)
            if tenant_id and user_id:
                await log_audit(
                    db, tenant_id, user_id,
                    action="plugin.install",
                    entity_type="plugin",
                    entity_id=getattr(record, "id", None),
                    changes={"name": name, "version": record.version},
                )
            return {
                "name": record.name,
                "display_name": record.display_name,
                "version": record.version,
                "status": record.status,
                "installed": record.installed,
                "active": record.active,
                "message": "Plugin installed successfully",
            }
        except ValueError as exc:
            raise ValueError(str(exc))
        except MigrationValidationError as exc:
            raise MigrationValidationError(str(exc))

    async def activate_plugin(
        self,
        db: AsyncSession,
        name: str,
        tenant_id: uuid.UUID | None = None,
        user_id: uuid.UUID | None = None,
    ) -> dict[str, Any]:
        """Activate a plugin by name.

        Registers event listeners and routes. Idempotent.
        """
        try:
            record = await self._registry.activate(db, name)
            was_already_active = record.active and record.status == "active"
            if tenant_id and user_id:
                await log_audit(
                    db, tenant_id, user_id,
                    action="plugin.activate",
                    entity_type="plugin",
                    entity_id=getattr(record, "id", None),
                    changes={"name": name, "was_already_active": was_already_active},
                )
            return {
                "name": record.name,
                "display_name": record.display_name,
                "version": record.version,
                "status": record.status,
                "installed": record.installed,
                "active": record.active,
                "message": "Plugin is already active" if was_already_active else "Plugin activated successfully",
            }
        except ValueError as exc:
            raise ValueError(str(exc))

    async def deactivate_plugin(
        self,
        db: AsyncSession,
        name: str,
        tenant_id: uuid.UUID | None = None,
        user_id: uuid.UUID | None = None,
    ) -> dict[str, Any]:
        """Deactivate a plugin by name.

        Unregisters event listeners and routes. Idempotent.
        """
        try:
            record = await self._registry.deactivate(db, name)
            was_already_inactive = not record.active and record.status == "inactive"
            if tenant_id and user_id:
                await log_audit(
                    db, tenant_id, user_id,
                    action="plugin.deactivate",
                    entity_type="plugin",
                    entity_id=getattr(record, "id", None),
                    changes={"name": name, "was_already_inactive": was_already_inactive},
                )
            return {
                "name": record.name,
                "display_name": record.display_name,
                "version": record.version,
                "status": record.status,
                "installed": record.installed,
                "active": record.active,
                "message": "Plugin is already inactive" if was_already_inactive else "Plugin deactivated successfully",
            }
        except ValueError as exc:
            raise ValueError(str(exc))

    async def uninstall_plugin(
        self,
        db: AsyncSession,
        name: str,
        remove_data: bool = False,
        tenant_id: uuid.UUID | None = None,
        user_id: uuid.UUID | None = None,
    ) -> dict[str, Any]:
        """Uninstall a plugin by name.

        Deactivates, calls on_uninstall hook, optionally drops tables, removes DB record.
        """
        try:
            record = await self._registry.uninstall(db, name, remove_data=remove_data)
            dropped_tables = getattr(record, "dropped_tables", [])
            if tenant_id and user_id:
                await log_audit(
                    db, tenant_id, user_id,
                    action="plugin.uninstall",
                    entity_type="plugin",
                    changes={"name": name, "remove_data": remove_data, "dropped_tables": dropped_tables},
                )
            return {
                "name": name,
                "display_name": record.display_name,
                "version": record.version,
                "status": "uninstalled",
                "installed": False,
                "active": False,
                "dropped_tables": dropped_tables,
                "message": f"Plugin uninstalled{' and data tables dropped' if remove_data else ''}",
            }
        except ValueError as exc:
            raise ValueError(str(exc))

    def get_manifest_schema(self) -> dict[str, Any]:
        """Return the manifest schema documentation."""
        from app.plugins.manifest import MANIFEST_SCHEMA_DOC
        return MANIFEST_SCHEMA_DOC.model_dump()


# Global service instance
_service: PluginService | None = None


def get_plugin_service() -> PluginService:
    """Get the global plugin service instance."""
    global _service
    if _service is None:
        _service = PluginService()
    return _service


def reset_plugin_service_for_testing(registry: PluginRegistry | None = None) -> PluginService:
    """Create a fresh plugin service for testing."""
    global _service
    _service = PluginService(registry=registry)
    return _service