# [DEF:backend.src.api.routes.migration:Module]
# @TIER: STANDARD
# @SEMANTICS: api, migration, dashboards
# @PURPOSE:   API endpoints for migration operations.
# @LAYER:     API
# @RELATION:  DEPENDS_ON -> backend.src.dependencies
# @RELATION:  DEPENDS_ON -> backend.src.models.dashboard

from fastapi import APIRouter, Depends, HTTPException, Query
from typing import List, Dict, Any
from sqlalchemy.orm import Session
from ...dependencies import get_config_manager, get_task_manager, has_permission
from ...core.database import get_db
from ...models.dashboard import DashboardMetadata, DashboardSelection
from ...core.superset_client import SupersetClient
from ...core.logger import belief_scope
from ...core.mapping_service import IdMappingService
from ...models.mapping import ResourceMapping

router = APIRouter(prefix="/api", tags=["migration"])

# [DEF:get_dashboards:Function]
# @PURPOSE: Fetch all dashboards from the specified environment for the grid.
# @PRE:     Environment ID must be valid.
# @POST:    Returns a list of dashboard metadata.
# @PARAM:   env_id (str) - The ID of the environment to fetch from.
# @RETURN:  List[DashboardMetadata]
@router.get("/environments/{env_id}/dashboards", response_model=List[DashboardMetadata])
async def get_dashboards(
    env_id: str,
    config_manager=Depends(get_config_manager),
    _ = Depends(has_permission("plugin:migration", "EXECUTE"))
):
    with belief_scope("get_dashboards", f"env_id={env_id}"):
        environments = config_manager.get_environments()
    env = next((e for e in environments if e.id == env_id), None)
    if not env:
        raise HTTPException(status_code=404, detail="Environment not found")

    client = SupersetClient(env)
    dashboards = client.get_dashboards_summary()
    return dashboards
# [/DEF:get_dashboards:Function]

# [DEF:execute_migration:Function]
# @PURPOSE: Execute the migration of selected dashboards.
# @PRE:     Selection must be valid and environments must exist.
# @POST:    Starts the migration task and returns the task ID.
# @PARAM:   selection (DashboardSelection) - The dashboards to migrate.
# @RETURN:  Dict - {"task_id": str, "message": str}
@router.post("/execute")
async def execute_migration(
    selection: DashboardSelection,
    config_manager=Depends(get_config_manager),
    task_manager=Depends(get_task_manager),
    _ = Depends(has_permission("plugin:migration", "EXECUTE"))
):
    with belief_scope("execute_migration"):
        # Validate environments exist
        environments = config_manager.get_environments()
    env_ids = {e.id for e in environments}
    if selection.source_env_id not in env_ids or selection.target_env_id not in env_ids:
        raise HTTPException(status_code=400, detail="Invalid source or target environment")

    # Create migration task with debug logging
    from ...core.logger import logger
    
    # Include replace_db_config and fix_cross_filters in the task parameters
    task_params = selection.dict()
    task_params['replace_db_config'] = selection.replace_db_config
    task_params['fix_cross_filters'] = selection.fix_cross_filters
    
    logger.info(f"Creating migration task with params: {task_params}")
    logger.info(f"Available environments: {env_ids}")
    logger.info(f"Source env: {selection.source_env_id}, Target env: {selection.target_env_id}")
    
    try:
        task = await task_manager.create_task("superset-migration", task_params)
        logger.info(f"Task created successfully: {task.id}")
        return {"task_id": task.id, "message": "Migration initiated"}
    except Exception as e:
        logger.error(f"Task creation failed: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to create migration task: {str(e)}")
# [/DEF:execute_migration:Function]

# [DEF:get_migration_settings:Function]
# @PURPOSE: Get current migration Cron string explicitly.
@router.get("/settings", response_model=Dict[str, str])
async def get_migration_settings(
    config_manager=Depends(get_config_manager),
    _ = Depends(has_permission("plugin:migration", "READ"))
):
    with belief_scope("get_migration_settings"):
        # For simplicity in MVP, assuming cron expression is stored in config
        # default to a valid cron if not set.
        config = config_manager.get_config()
        cron = config.get("migration_sync_cron", "0 2 * * *")
        return {"cron": cron}
# [/DEF:get_migration_settings:Function]

# [DEF:update_migration_settings:Function]
# @PURPOSE: Update migration Cron string.
@router.put("/settings", response_model=Dict[str, str])
async def update_migration_settings(
    payload: Dict[str, str],
    config_manager=Depends(get_config_manager),
    _ = Depends(has_permission("plugin:migration", "WRITE"))
):
    with belief_scope("update_migration_settings"):
        if "cron" not in payload:
            raise HTTPException(status_code=400, detail="Missing 'cron' field in payload")
        
        cron_expr = payload["cron"]
        # Basic validation could go here
        
        # In a real system, you'd save this to config and restart the scheduler.
        # Here we just blindly patch the in-memory or file config for the MVP.
        current_cfg = config_manager.get_config()
        current_cfg["migration_sync_cron"] = cron_expr
        config_manager.save_config(current_cfg)
        
        return {"cron": cron_expr, "status": "updated"}
# [/DEF:update_migration_settings:Function]

# [DEF:get_resource_mappings:Function]
# @PURPOSE: Fetch all synchronized object mappings from the database.
@router.get("/mappings-data", response_model=List[Dict[str, Any]])
async def get_resource_mappings(
    skip: int = Query(0, ge=0),
    limit: int = Query(100, ge=1, le=1000),
    db: Session = Depends(get_db),
    _ = Depends(has_permission("plugin:migration", "READ"))
):
    with belief_scope("get_resource_mappings"):
        mappings = db.query(ResourceMapping).offset(skip).limit(limit).all()
        result = []
        for m in mappings:
            result.append({
                "id": m.id,
                "environment_id": m.environment_id,
                "resource_type": m.resource_type.value,
                "uuid": m.uuid,
                "remote_id": m.remote_integer_id,
                "resource_name": m.resource_name,
                "last_synced_at": m.last_synced_at.isoformat() if m.last_synced_at else None
            })
        return result
# [/DEF:get_resource_mappings:Function]

# [/DEF:backend.src.api.routes.migration:Module]