package opsservice

import (
	"context"
	"fmt"
	"time"

	"github.com/google/uuid"
	"github.com/tidbcloud/observability/pkg/common/message"
)

// VMClusterService provides operations for managing VM clusters via HelmRelease CRs
type VMClusterService struct {
}

// CreateVMCluster creates a new VM cluster by creating a HelmRelease CR
func (s *VMClusterService) CreateVMCluster(ctx context.Context, req message.CreateVMClusterReq) (message.CreateVMClusterResp, error) {
	// Generate unique ID for the cluster
	clusterID := uuid.New().String()

	// TODO: Implement actual HelmRelease CR creation
	// 1. Create HelmRelease CR with the provided values
	// 2. Set up monitoring for the deployment status
	// 3. Return initial response with deployment status

	// For now, return a mock response following the design pattern
	resp := message.CreateVMClusterResp{
		Name:      fmt.Sprintf("vmclusters/%s", req.Name),
		ID:        clusterID,
		Status:    message.VMClusterStatusDeploying,
		Endpoints: map[string]string{
			// Will be populated once deployment is complete
		},
		Values: req.Values,
		HelmReleaseInfo: message.HelmReleaseInfo{
			ReleaseName:      req.Name,
			ReleaseNamespace: "observability",
			Chart:            "victoria-metrics/victoria-metrics-cluster",
			Version:          "0.0.1", // Should come from configuration
		},
		CreateTime: time.Now(),
	}

	return resp, nil
}

// GetVMCluster retrieves details of a specific VM cluster
func (s *VMClusterService) GetVMCluster(ctx context.Context, req message.GetVMClusterReq) (message.GetVMClusterResp, error) {
	// TODO: Implement actual HelmRelease CR retrieval
	// 1. Get HelmRelease CR by ID
	// 2. Check deployment status
	// 3. Retrieve service endpoints
	// 4. Return cluster details

	// Mock response for now
	resp := message.GetVMClusterResp{
		Name:   fmt.Sprintf("vmclusters/cluster-%s", req.ID),
		ID:     req.ID,
		Status: message.VMClusterStatusRunning,
		Endpoints: map[string]string{
			"prometheus": fmt.Sprintf("http://cluster-%s-vmselect:8481/prometheus", req.ID),
			"grafana":    fmt.Sprintf("http://cluster-%s-grafana", req.ID),
		},
		Values: map[string]interface{}{
			"ha-mode": true,
			"vmstorage": map[string]interface{}{
				"resources": map[string]interface{}{
					"limits": map[string]interface{}{
						"cpu":    "500m",
						"memory": "2Gi",
					},
				},
			},
		},
		HelmReleaseInfo: message.HelmReleaseInfo{
			ReleaseName:      fmt.Sprintf("cluster-%s", req.ID),
			ReleaseNamespace: "observability",
			Chart:            "victoria-metrics/victoria-metrics-cluster",
			Version:          "0.0.1",
		},
		CreateTime: time.Now().Add(-24 * time.Hour), // Mock create time
		UpdateTime: time.Now().Add(-1 * time.Hour),  // Mock update time
	}

	return resp, nil
}

// ListVMClusters lists all deployed VM clusters
func (s *VMClusterService) ListVMClusters(ctx context.Context, req message.ListVMClustersReq) (message.ListVMClustersResp, error) {
	// TODO: Implement actual HelmRelease CR listing
	// 1. List all HelmRelease CRs with VM cluster label
	// 2. Filter based on pagination parameters
	// 3. Return summarized cluster information

	// Mock response with sample clusters
	clusters := []message.VMClusterSummary{
		{
			Name:   "vmclusters/my-cluster-1",
			ID:     "cluster-1-id",
			Status: message.VMClusterStatusRunning,
			Endpoints: map[string]string{
				"prometheus": "http://my-cluster-1-vmselect:8481/prometheus",
			},
			CreateTime: time.Now().Add(-48 * time.Hour),
			UpdateTime: time.Now().Add(-2 * time.Hour),
		},
		{
			Name:      "vmclusters/another-vm",
			ID:        "cluster-2-id",
			Status:    message.VMClusterStatusUpdating,
			Endpoints: map[string]string{
				// Endpoints might be unavailable during update
			},
			CreateTime: time.Now().Add(-24 * time.Hour),
			UpdateTime: time.Now().Add(-30 * time.Minute),
		},
	}

	resp := message.ListVMClustersResp{
		VMClusters:       clusters,
		ContinueResponse: message.ContinueResponse{
			// Add pagination token if needed
		},
	}

	return resp, nil
}

// UpdateVMCluster updates an existing VM cluster configuration
func (s *VMClusterService) UpdateVMCluster(ctx context.Context, req message.UpdateVMClusterReq) (message.UpdateVMClusterResp, error) {
	// TODO: Implement actual HelmRelease CR update
	// 1. Get existing HelmRelease CR
	// 2. Update the values with new configuration
	// 3. Trigger Helm upgrade via controller
	// 4. Monitor update progress

	resp := message.UpdateVMClusterResp{
		Name:      fmt.Sprintf("vmclusters/cluster-%s", req.ID),
		ID:        req.ID,
		Status:    message.VMClusterStatusUpdating,
		Endpoints: map[string]string{
			// Endpoints might be temporarily unavailable during update
		},
		Values: req.Values,
		HelmReleaseInfo: message.HelmReleaseInfo{
			ReleaseName:      fmt.Sprintf("cluster-%s", req.ID),
			ReleaseNamespace: "observability",
			Chart:            "victoria-metrics/victoria-metrics-cluster",
			Version:          "0.0.1",
		},
		UpdateTime: time.Now(),
	}

	return resp, nil
}

// DeleteVMCluster deletes a VM cluster by removing the HelmRelease CR
func (s *VMClusterService) DeleteVMCluster(ctx context.Context, req message.DeleteVMClusterReq) (message.DeleteVMClusterResp, error) {
	// TODO: Implement actual HelmRelease CR deletion
	// 1. Get HelmRelease CR by ID
	// 2. Delete the CR (which triggers Helm uninstall)
	// 3. Monitor deletion progress
	// 4. Clean up associated resources

	resp := message.DeleteVMClusterResp{
		Message: fmt.Sprintf("VM cluster %s deletion initiated", req.ID),
	}

	return resp, nil
}

// GetVMClusterService returns the singleton VM cluster service instance
func GetVMClusterService() *VMClusterService {
	// TODO: Initialize with proper dependencies (K8s client, Helm controller)
	return &VMClusterService{}
}