# [DEF:SchedulerModule:Module]
# @SEMANTICS: scheduler, apscheduler, cron, backup
# @PURPOSE: Manages scheduled tasks using APScheduler.
# @LAYER: Core
# @RELATION: Uses TaskManager to run scheduled backups.

# [SECTION: IMPORTS]
from apscheduler.schedulers.background import BackgroundScheduler
from apscheduler.triggers.cron import CronTrigger
from .logger import logger, belief_scope
from .config_manager import ConfigManager
from typing import Optional
import asyncio
# [/SECTION]

# [DEF:SchedulerService:Class]
# @SEMANTICS: scheduler, service, apscheduler
# @PURPOSE: Provides a service to manage scheduled backup tasks.
class SchedulerService:
    def __init__(self, task_manager, config_manager: ConfigManager):
        with belief_scope("SchedulerService.__init__"):
            self.task_manager = task_manager
            self.config_manager = config_manager
            self.scheduler = BackgroundScheduler()
            self.loop = asyncio.get_event_loop()

    # [DEF:SchedulerService.start:Function]
    # @PURPOSE: Starts the background scheduler and loads initial schedules.
    def start(self):
        with belief_scope("SchedulerService.start"):
            if not self.scheduler.running:
                self.scheduler.start()
                logger.info("Scheduler started.")
                self.load_schedules()
    # [/DEF:SchedulerService.start:Function]

    # [DEF:SchedulerService.stop:Function]
    # @PURPOSE: Stops the background scheduler.
    def stop(self):
        with belief_scope("SchedulerService.stop"):
            if self.scheduler.running:
                self.scheduler.shutdown()
                logger.info("Scheduler stopped.")
    # [/DEF:SchedulerService.stop:Function]

    # [DEF:SchedulerService.load_schedules:Function]
    # @PURPOSE: Loads backup schedules from configuration and registers them.
    def load_schedules(self):
        with belief_scope("SchedulerService.load_schedules"):
            # Clear existing jobs
            self.scheduler.remove_all_jobs()
            
            config = self.config_manager.get_config()
            for env in config.environments:
                if env.backup_schedule and env.backup_schedule.enabled:
                    self.add_backup_job(env.id, env.backup_schedule.cron_expression)
    # [/DEF:SchedulerService.load_schedules:Function]

    # [DEF:SchedulerService.add_backup_job:Function]
    # @PURPOSE: Adds a scheduled backup job for an environment.
    # @PARAM:   env_id (str) - The ID of the environment.
    # @PARAM:   cron_expression (str) - The cron expression for the schedule.
    def add_backup_job(self, env_id: str, cron_expression: str):
        with belief_scope("SchedulerService.add_backup_job", f"env_id={env_id}, cron={cron_expression}"):
            job_id = f"backup_{env_id}"
            try:
                self.scheduler.add_job(
                    self._trigger_backup,
                    CronTrigger.from_crontab(cron_expression),
                    id=job_id,
                    args=[env_id],
                    replace_existing=True
                )
                logger.info(f"Scheduled backup job added for environment {env_id}: {cron_expression}")
            except Exception as e:
                logger.error(f"Failed to add backup job for environment {env_id}: {e}")
    # [/DEF:SchedulerService.add_backup_job:Function]

    # [DEF:SchedulerService._trigger_backup:Function]
    # @PURPOSE: Triggered by the scheduler to start a backup task.
    # @PARAM:   env_id (str) - The ID of the environment.
    def _trigger_backup(self, env_id: str):
        with belief_scope("SchedulerService._trigger_backup", f"env_id={env_id}"):
            logger.info(f"Triggering scheduled backup for environment {env_id}")
            
            # Check if a backup is already running for this environment
            active_tasks = self.task_manager.get_tasks(limit=100)
            for task in active_tasks:
                if (task.plugin_id == "superset-backup" and
                    task.status in ["PENDING", "RUNNING"] and
                    task.params.get("environment_id") == env_id):
                    logger.warning(f"Backup already running for environment {env_id}. Skipping scheduled run.")
                    return

            # Run the backup task
            # We need to run this in the event loop since create_task is async
            asyncio.run_coroutine_threadsafe(
                self.task_manager.create_task("superset-backup", {"environment_id": env_id}),
                self.loop
            )
    # [/DEF:SchedulerService._trigger_backup:Function]

# [/DEF:SchedulerService:Class]
# [/DEF:SchedulerModule:Module]