package vacuum

import (
	"fmt"
	"time"

	"github.com/seaweedfs/seaweedfs/weed/worker/tasks/base"
	"github.com/seaweedfs/seaweedfs/weed/worker/types"
)

// Detection implements the detection logic for vacuum tasks
func Detection(metrics []*types.VolumeHealthMetrics, clusterInfo *types.ClusterInfo, config base.TaskConfig) ([]*types.TaskDetectionResult, error) {
	if !config.IsEnabled() {
		return nil, nil
	}

	vacuumConfig := config.(*Config)
	var results []*types.TaskDetectionResult
	minVolumeAge := time.Duration(vacuumConfig.MinVolumeAgeSeconds) * time.Second

	for _, metric := range metrics {
		// Check if volume needs vacuum
		if metric.GarbageRatio >= vacuumConfig.GarbageThreshold && metric.Age >= minVolumeAge {
			priority := types.TaskPriorityNormal
			if metric.GarbageRatio > 0.6 {
				priority = types.TaskPriorityHigh
			}

			result := &types.TaskDetectionResult{
				TaskType:   types.TaskTypeVacuum,
				VolumeID:   metric.VolumeID,
				Server:     metric.Server,
				Collection: metric.Collection,
				Priority:   priority,
				Reason:     "Volume has excessive garbage requiring vacuum",
				Parameters: map[string]interface{}{
					"garbage_ratio": metric.GarbageRatio,
					"volume_age":    metric.Age.String(),
				},
				ScheduleAt: time.Now(),
			}
			results = append(results, result)
		}
	}

	return results, nil
}

// Scheduling implements the scheduling logic for vacuum tasks
func Scheduling(task *types.Task, runningTasks []*types.Task, availableWorkers []*types.Worker, config base.TaskConfig) bool {
	vacuumConfig := config.(*Config)

	// Count running vacuum tasks
	runningVacuumCount := 0
	for _, runningTask := range runningTasks {
		if runningTask.Type == types.TaskTypeVacuum {
			runningVacuumCount++
		}
	}

	// Check concurrency limit
	if runningVacuumCount >= vacuumConfig.MaxConcurrent {
		return false
	}

	// Check for available workers with vacuum capability
	for _, worker := range availableWorkers {
		if worker.CurrentLoad < worker.MaxConcurrent {
			for _, capability := range worker.Capabilities {
				if capability == types.TaskTypeVacuum {
					return true
				}
			}
		}
	}

	return false
}

// CreateTask creates a new vacuum task instance
func CreateTask(params types.TaskParams) (types.TaskInterface, error) {
	// Extract configuration from params
	var config *Config
	if configData, ok := params.Parameters["config"]; ok {
		if configMap, ok := configData.(map[string]interface{}); ok {
			config = &Config{}
			if err := config.FromMap(configMap); err != nil {
				return nil, fmt.Errorf("failed to parse vacuum config: %v", err)
			}
		}
	}

	if config == nil {
		config = NewDefaultConfig()
	}

	// Create and return the vacuum task using existing Task type
	return NewTask(params.Server, params.VolumeID), nil
}