package tasks

import (
	"context"
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
	"log/slog"
	"runtime"
	"strings"
	"time"
	"vctp/db/queries"
	"vctp/internal/utils"
	"vctp/internal/vcenter"

	"github.com/vmware/govmomi/vim25/mo"
	"github.com/vmware/govmomi/vim25/types"
)

// use gocron to check vcenters for VMs or updates we don't know about
func (c *CronTask) RunVcenterPoll(ctx context.Context, logger *slog.Logger) error {
	var matchFound bool

	// reload settings in case vcenter list has changed
	c.Settings.ReadYMLSettings()

	for _, url := range c.Settings.Values.Settings.VcenterAddresses {
		c.Logger.Debug("connecting to vcenter", "url", url)
		vc := vcenter.New(c.Logger, c.VcCreds)
		vc.Login(url)

		// Get list of VMs from vcenter
		vms, err := vc.GetAllVmReferences()

		// Get list of VMs from inventory table
		c.Logger.Debug("Querying inventory table")
		results, err := c.Database.Queries().GetInventoryByVcenter(ctx, url)
		if err != nil {
			c.Logger.Error("Unable to query inventory table", "error", err)
			return err
		}

		if len(results) == 0 {
			c.Logger.Error("Empty inventory results")
			return fmt.Errorf("Empty inventory results")
		}

		// Iterate VMs from vcenter and see if they were in the database
		for _, vm := range vms {
			matchFound = false

			// Skip any vCLS VMs
			if strings.HasPrefix(vm.Name(), "vCLS-") {
				c.Logger.Debug("Skipping internal VM", "vm_name", vm.Name())
				continue
			}

			// TODO - should we compare the UUID as well?
			for _, dbvm := range results {
				if dbvm.VmId.String == vm.Reference().Value {
					c.Logger.Debug("Found match for VM", "vm_name", dbvm.Name, "id", dbvm.VmId.String)
					matchFound = true
					break
				}
			}

			if !matchFound {
				c.Logger.Debug("Need to add VM to inventory table", "MoRef", vm.Reference())
				vmObj, err := vc.ConvertObjToMoVM(vm)
				if err != nil {
					c.Logger.Error("Received error getting vm maangedobject", "error", err)
					continue
				}

				// retrieve VM properties and insert into inventory
				err = c.AddVmToInventory(vmObj, vc, ctx)
				if err != nil {
					c.Logger.Error("Received error with VM add", "error", err)
					continue
				}

				// add sleep to slow down mass VM additions
				utils.SleepWithContext(ctx, (10 * time.Millisecond))
			}
		}
		c.Logger.Debug("Finished checking vcenter", "url", url)
		vc.Logout()
	}

	c.Logger.Debug("Finished polling vcenters")

	return nil
}

func (c *CronTask) AddVmToInventory(vmObject *mo.VirtualMachine, vc *vcenter.Vcenter, ctx context.Context) error {
	var (
		numVcpus       int32
		numRam         int32
		totalDiskGB    float64
		creationTS     int64
		srmPlaceholder string
		foundVmConfig  bool
		isTemplate     string
		poweredOn      string
		folderPath     string
		clusterName    string
		err            error
	)

	if vmObject == nil {
		return errors.New("can't process empty vm object")
	}

	c.Logger.Debug("found VM")

	if vmObject.Name == "DBRaaS_testVMTemplate" {
		c.Logger.Debug("Found problematic VM")
		//prettyPrint(vmObject)
	}

	srmPlaceholder = "FALSE" // Default assumption
	//prettyPrint(vmObject)

	// calculate VM properties we want to store
	if vmObject.Config != nil {
		if vmObject.Config.Template {
			c.Logger.Debug("Not adding templates to inventory")
			return nil
		} else {
			isTemplate = "FALSE"
		}

		numRam = vmObject.Config.Hardware.MemoryMB
		numVcpus = vmObject.Config.Hardware.NumCPU

		// Calculate creation date
		if vmObject.Config.CreateDate.IsZero() {
			c.Logger.Debug("Creation date not available for this VM")
		} else {
			creationTS = vmObject.Config.CreateDate.Unix()
		}

		// Calculate disk size
		var totalDiskBytes int64

		// Calculate the total disk allocated in GB
		for _, device := range vmObject.Config.Hardware.Device {
			if disk, ok := device.(*types.VirtualDisk); ok {

				// Print the filename of the backing device
				if backing, ok := disk.Backing.(*types.VirtualDiskFlatVer2BackingInfo); ok {
					c.Logger.Debug("Adding disk", "size_bytes", disk.CapacityInBytes, "backing_file", backing.FileName)
				} else {
					c.Logger.Debug("Adding disk, unknown backing type", "size_bytes", disk.CapacityInBytes)
				}

				totalDiskBytes += disk.CapacityInBytes
				//totalDiskGB += float64(disk.CapacityInBytes / 1024 / 1024 / 1024) // Convert from bytes to GB
			}
		}
		totalDiskGB = float64(totalDiskBytes / 1024 / 1024 / 1024)
		c.Logger.Debug("Converted total disk size", "bytes", totalDiskBytes, "GB", totalDiskGB)

		// Determine if the VM is a normal VM or an SRM placeholder
		if vmObject.Config.ManagedBy != nil && vmObject.Config.ManagedBy.Type == "com.vmware.vcDr" {
			c.Logger.Debug("VM ManagedBy indicates managed by SRM")
			srmPlaceholder = "TRUE"
		}

		// Retrieve the full folder path of the VM
		folderPath, err = vc.GetVMFolderPath(*vmObject)
		if err != nil {
			c.Logger.Error("failed to get vm folder path", "error", err)
			folderPath = ""
		} else {
			c.Logger.Debug("Found vm folder path", "folder_path", folderPath)
		}

		foundVmConfig = true
	} else {
		c.Logger.Error("Empty VM config")
	}

	c.Logger.Debug("VM has runtime data", "power_state", vmObject.Runtime.PowerState)
	if vmObject.Runtime.PowerState == "poweredOff" {
		poweredOn = "FALSE"
	} else {
		poweredOn = "TRUE"
	}

	rpName, err := vc.GetVmResourcePool(*vmObject)

	// Get VM's host and use that to determine cluster
	//c.Logger.Debug("Checking for VM host by runtime data", "runtime", vmObject.Runtime)
	clusterName, err = vc.GetClusterFromHost(vmObject.Runtime.Host)
	if err != nil {
		c.Logger.Error("Unable to determine cluster name", "error", err)
	} else {
		c.Logger.Debug("cluster", "name", clusterName)
	}

	dcName, err := vc.GetDatacenterForVM(*vmObject)
	if err != nil {
		c.Logger.Error("Unable to determine datacenter name", "error", err)
	} else {
		c.Logger.Debug("dc", "name", dcName)
	}

	if foundVmConfig {
		c.Logger.Debug("Adding to Inventory table", "vm_name", vmObject.Name, "vcpus", numVcpus, "ram", numRam)

		params := queries.CreateInventoryParams{
			Name:            vmObject.Name,
			Vcenter:         vc.Vurl,
			VmId:            sql.NullString{String: vmObject.Reference().Value, Valid: vmObject.Reference().Value != ""},
			Datacenter:      sql.NullString{String: dcName, Valid: dcName != ""},
			Cluster:         sql.NullString{String: clusterName, Valid: clusterName != ""},
			CreationTime:    sql.NullInt64{Int64: creationTS, Valid: creationTS > 0},
			InitialVcpus:    sql.NullInt64{Int64: int64(numVcpus), Valid: numVcpus > 0},
			InitialRam:      sql.NullInt64{Int64: int64(numRam), Valid: numRam > 0},
			ProvisionedDisk: sql.NullFloat64{Float64: totalDiskGB, Valid: totalDiskGB > 0},
			Folder:          sql.NullString{String: folderPath, Valid: folderPath != ""},
			ResourcePool:    sql.NullString{String: rpName, Valid: rpName != ""},
			VmUuid:          sql.NullString{String: vmObject.Config.Uuid, Valid: vmObject.Config.Uuid != ""},
			SrmPlaceholder:  srmPlaceholder,
			IsTemplate:      isTemplate,
			PoweredOn:       poweredOn,
		}

		c.Logger.Debug("database params", "params", params)
		// Insert the new inventory record into the database
		result, err := c.Database.Queries().CreateInventory(ctx, params)
		if err != nil {
			c.Logger.Error("unable to perform database insert", "error", err)
		} else {
			c.Logger.Debug("created database record", "insert_result", result)
		}
	} else {
		c.Logger.Debug("Not adding to Inventory due to missing vcenter config property", "vm_name", vmObject.Name)
	}

	return nil

}

// prettyPrint comes from https://gist.github.com/sfate/9d45f6c5405dc4c9bf63bf95fe6d1a7c
func prettyPrint(args ...interface{}) {
	var caller string

	timeNow := time.Now().Format("01-02-2006 15:04:05")
	prefix := fmt.Sprintf("[%s] %s -- ", "PrettyPrint", timeNow)
	_, fileName, fileLine, ok := runtime.Caller(1)

	if ok {
		caller = fmt.Sprintf("%s:%d", fileName, fileLine)
	} else {
		caller = ""
	}

	fmt.Printf("\n%s%s\n", prefix, caller)

	if len(args) == 2 {
		label := args[0]
		value := args[1]

		s, _ := json.MarshalIndent(value, "", "\t")
		fmt.Printf("%s%s: %s\n", prefix, label, string(s))
	} else {
		s, _ := json.MarshalIndent(args, "", "\t")
		fmt.Printf("%s%s\n", prefix, string(s))
	}
}