# app/tasks/sync.py
"""
Issue synchronization tasks for Syndarix.

These tasks handle bidirectional issue synchronization:
- Incremental sync (polling for recent changes)
- Full reconciliation (daily comprehensive sync)
- Webhook event processing
- Pushing local changes to external trackers

Tasks are routed to the 'sync' queue for dedicated processing.
Per ADR-011, sync follows a master/replica model with configurable direction.
"""

import logging
from typing import Any

from app.celery_app import celery_app

logger = logging.getLogger(__name__)


@celery_app.task(bind=True, name="app.tasks.sync.sync_issues_incremental")
def sync_issues_incremental(self) -> dict[str, Any]:
    """
    Perform incremental issue synchronization across all projects.

    This periodic task (runs every 5 minutes):
    1. Query each project's external tracker for recent changes
    2. Compare with local issue cache
    3. Apply updates to local database
    4. Handle conflicts based on sync direction config

    Returns:
        dict with status and type
    """
    logger.info("Starting incremental issue sync across all projects")

    # TODO: Implement incremental sync
    # This will involve:
    # 1. Loading all active projects with sync enabled
    # 2. For each project, querying external tracker since last_sync_at
    # 3. Upserting issues into local database
    # 4. Updating last_sync_at timestamp

    return {
        "status": "pending",
        "type": "incremental",
    }


@celery_app.task(bind=True, name="app.tasks.sync.sync_issues_full")
def sync_issues_full(self) -> dict[str, Any]:
    """
    Perform full issue reconciliation across all projects.

    This periodic task (runs daily):
    1. Fetch all issues from external trackers
    2. Compare with local database
    3. Handle orphaned issues
    4. Resolve any drift between systems

    Returns:
        dict with status and type
    """
    logger.info("Starting full issue reconciliation across all projects")

    # TODO: Implement full sync
    # This will involve:
    # 1. Loading all active projects
    # 2. Fetching complete issue lists from external trackers
    # 3. Comparing with local database
    # 4. Handling deletes and orphans
    # 5. Resolving conflicts based on sync config

    return {
        "status": "pending",
        "type": "full",
    }


@celery_app.task(bind=True, name="app.tasks.sync.process_webhook_event")
def process_webhook_event(
    self,
    provider: str,
    event_type: str,
    payload: dict[str, Any],
) -> dict[str, Any]:
    """
    Process a webhook event from an external Git provider.

    This task handles real-time updates from:
    - Gitea: issue.created, issue.updated, pull_request.*, etc.
    - GitHub: issues, pull_request, push, etc.
    - GitLab: issue events, merge request events, etc.

    Args:
        provider: Git provider name (gitea, github, gitlab)
        event_type: Event type from provider
        payload: Raw webhook payload

    Returns:
        dict with status, provider, and event_type
    """
    logger.info(f"Processing webhook event from {provider}: {event_type}")

    # TODO: Implement webhook processing
    # This will involve:
    # 1. Validating webhook signature
    # 2. Parsing provider-specific payload
    # 3. Mapping to internal event format
    # 4. Updating local database
    # 5. Triggering any dependent workflows

    return {
        "status": "pending",
        "provider": provider,
        "event_type": event_type,
    }


@celery_app.task(bind=True, name="app.tasks.sync.sync_project_issues")
def sync_project_issues(
    self,
    project_id: str,
    full: bool = False,
) -> dict[str, Any]:
    """
    Synchronize issues for a specific project.

    This task can be triggered manually or by webhooks:
    1. Connect to project's external tracker
    2. Fetch issues (incremental or full)
    3. Update local database

    Args:
        project_id: UUID of the project
        full: Whether to do full sync or incremental

    Returns:
        dict with status and project_id
    """
    logger.info(
        f"Syncing issues for project {project_id} (full={full})"
    )

    # TODO: Implement project-specific sync
    # This will involve:
    # 1. Loading project configuration
    # 2. Connecting to external tracker
    # 3. Fetching issues based on full flag
    # 4. Upserting to database

    return {
        "status": "pending",
        "project_id": project_id,
    }


@celery_app.task(bind=True, name="app.tasks.sync.push_issue_to_external")
def push_issue_to_external(
    self,
    project_id: str,
    issue_id: str,
    operation: str,
) -> dict[str, Any]:
    """
    Push a local issue change to the external tracker.

    This task handles outbound sync when Syndarix is the master:
    - create: Create new issue in external tracker
    - update: Update existing issue
    - close: Close issue in external tracker

    Args:
        project_id: UUID of the project
        issue_id: UUID of the local issue
        operation: Operation type (create, update, close)

    Returns:
        dict with status, issue_id, and operation
    """
    logger.info(
        f"Pushing {operation} for issue {issue_id} in project {project_id}"
    )

    # TODO: Implement outbound sync
    # This will involve:
    # 1. Loading issue and project config
    # 2. Mapping to external tracker format
    # 3. Calling provider API
    # 4. Updating external_id mapping

    return {
        "status": "pending",
        "issue_id": issue_id,
        "operation": operation,
    }
