package tasks

import (
	"context"
	"database/sql"
	"fmt"
	"log/slog"
	"strconv"
	"strings"
	"sync"
	"sync/atomic"
	"time"
	"vctp/db"
	"vctp/db/queries"
	"vctp/internal/report"
	"vctp/internal/utils"
	"vctp/internal/vcenter"

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

type inventorySnapshotRow struct {
	InventoryId     sql.NullInt64
	Name            string
	Vcenter         string
	VmId            sql.NullString
	EventKey        sql.NullString
	CloudId         sql.NullString
	CreationTime    sql.NullInt64
	DeletionTime    sql.NullInt64
	ResourcePool    sql.NullString
	Datacenter      sql.NullString
	Cluster         sql.NullString
	Folder          sql.NullString
	ProvisionedDisk sql.NullFloat64
	VcpuCount       sql.NullInt64
	RamGB           sql.NullInt64
	IsTemplate      string
	PoweredOn       string
	SrmPlaceholder  string
	VmUuid          sql.NullString
	SnapshotTime    int64
	IsPresent       string
}

type snapshotTotals = db.SnapshotTotals

// RunVcenterSnapshotHourly records hourly inventory snapshots into a daily table.
func (c *CronTask) RunVcenterSnapshotHourly(ctx context.Context, logger *slog.Logger) (err error) {
	jobCtx := ctx
	jobTimeout := durationFromSeconds(c.Settings.Values.Settings.HourlyJobTimeoutSeconds, 20*time.Minute)
	if jobTimeout > 0 {
		var cancel context.CancelFunc
		jobCtx, cancel = context.WithTimeout(ctx, jobTimeout)
		defer cancel()
	}
	startedAt := time.Now()
	defer func() {
		logger.Info("Hourly snapshot job finished", "duration", time.Since(startedAt))
	}()
	tracker := NewCronTracker(c.Database)
	done, skip, err := tracker.Start(jobCtx, "hourly_snapshot")
	if err != nil {
		return err
	}
	if skip {
		logger.Warn("Hourly snapshot skipped because a previous run is still active")
		return nil
	}
	defer func() { done(err) }()

	ctx, cancel := context.WithCancel(jobCtx)
	defer cancel()
	startTime := time.Now()

	if err := db.CheckMigrationState(ctx, c.Database.DB()); err != nil {
		return err
	}

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

	if c.FirstHourlySnapshotCheck {
		if err := report.EnsureSnapshotRegistry(ctx, c.Database); err != nil {
			return err
		}
		lastSnapshot, err := report.LatestSnapshotTime(ctx, c.Database, "hourly")
		if err != nil {
			return err
		}
		minIntervalSeconds := intWithDefault(c.Settings.Values.Settings.VcenterInventorySnapshotSeconds, 3600)
		if !lastSnapshot.IsZero() && startTime.Sub(lastSnapshot) < time.Duration(minIntervalSeconds)*time.Second {
			c.Logger.Info("Skipping hourly snapshot, last snapshot too recent",
				"last_snapshot", lastSnapshot,
				"min_interval_seconds", minIntervalSeconds,
			)
			c.FirstHourlySnapshotCheck = false
			return nil
		}
		c.FirstHourlySnapshotCheck = false
	}

	tableName, err := hourlyInventoryTableName(startTime)
	if err != nil {
		return err
	}

	dbConn := c.Database.DB()
	db.ApplySQLiteTuning(ctx, dbConn)
	if err := ensureDailyInventoryTable(ctx, dbConn, tableName); err != nil {
		return err
	}

	var wg sync.WaitGroup
	var errCount int64
	concurrencyLimit := c.Settings.Values.Settings.HourlySnapshotConcurrency
	if override, ok := utils.EnvInt("VCTP_HOURLY_SNAPSHOT_CONCURRENCY"); ok && override >= 0 {
		concurrencyLimit = override
	}
	var sem chan struct{}
	if concurrencyLimit > 0 {
		sem = make(chan struct{}, concurrencyLimit)
	}
	c.Logger.Info("Starting hourly snapshots", "vcenter_count", len(c.Settings.Values.Settings.VcenterAddresses), "concurrency_limit", concurrencyLimit)
	for _, url := range c.Settings.Values.Settings.VcenterAddresses {
		wg.Add(1)
		go func(url string) {
			defer wg.Done()
			waitStarted := time.Now()
			vcStart := time.Now()
			if sem != nil {
				sem <- struct{}{}
				defer func() { <-sem }()
			}
			waitDuration := time.Since(waitStarted)

			timeout := durationFromSeconds(c.Settings.Values.Settings.HourlySnapshotTimeoutSeconds, 10*time.Minute)
			runCtx, cancel := context.WithTimeout(ctx, timeout)
			defer cancel()

			c.Logger.Info("Starting hourly snapshot for vcenter", "url", url)
			if err := c.captureHourlySnapshotForVcenter(runCtx, startTime, tableName, url); err != nil {
				atomic.AddInt64(&errCount, 1)
				c.Logger.Error("hourly snapshot failed", "error", err, "url", url)
			} else {
				c.Logger.Info("Finished hourly snapshot for vcenter",
					"url", url,
					"queue_wait", waitDuration,
					"duration", time.Since(vcStart),
					"timeout", timeout,
				)
			}
		}(url)
	}
	wg.Wait()
	if errCount > 0 {
		err = fmt.Errorf("hourly snapshot failed for %d vcenter(s)", errCount)
		return err
	}

	rowCount, err := db.TableRowCount(ctx, dbConn, tableName)
	if err != nil {
		c.Logger.Warn("unable to count hourly snapshot rows", "error", err, "table", tableName)
	}
	if err := report.RegisterSnapshot(ctx, c.Database, "hourly", tableName, startTime, rowCount); err != nil {
		c.Logger.Warn("failed to register hourly snapshot", "error", err, "table", tableName)
	}

	c.Logger.Debug("Finished hourly vcenter snapshot", "vcenter_count", len(c.Settings.Values.Settings.VcenterAddresses), "table", tableName, "row_count", rowCount)
	return nil
}

// RunVcenterDailyAggregate summarizes hourly snapshots into a daily summary table.
func (c *CronTask) RunVcenterDailyAggregate(ctx context.Context, logger *slog.Logger) (err error) {
	jobCtx := ctx
	jobTimeout := durationFromSeconds(c.Settings.Values.Settings.DailyJobTimeoutSeconds, 15*time.Minute)
	if jobTimeout > 0 {
		var cancel context.CancelFunc
		jobCtx, cancel = context.WithTimeout(ctx, jobTimeout)
		defer cancel()
	}
	tracker := NewCronTracker(c.Database)
	done, skip, err := tracker.Start(jobCtx, "daily_aggregate")
	if err != nil {
		return err
	}
	if skip {
		logger.Warn("Daily aggregate skipped because a previous run is still active")
		return nil
	}
	defer func() { done(err) }()

	if err := db.CheckMigrationState(jobCtx, c.Database.DB()); err != nil {
		return err
	}

	startedAt := time.Now()
	defer func() {
		logger.Info("Daily summary job finished", "duration", time.Since(startedAt))
	}()
	targetTime := time.Now().Add(-time.Minute)
	err = c.aggregateDailySummary(jobCtx, targetTime, false)
	return err
}

func (c *CronTask) AggregateDailySummary(ctx context.Context, date time.Time, force bool) error {
	return c.aggregateDailySummary(ctx, date, force)
}

func (c *CronTask) aggregateDailySummary(ctx context.Context, targetTime time.Time, force bool) error {
	dayStart := time.Date(targetTime.Year(), targetTime.Month(), targetTime.Day(), 0, 0, 0, 0, targetTime.Location())
	dayEnd := dayStart.AddDate(0, 0, 1)
	summaryTable, err := dailySummaryTableName(targetTime)
	if err != nil {
		return err
	}

	dbConn := c.Database.DB()
	if err := db.EnsureSummaryTable(ctx, dbConn, summaryTable); err != nil {
		return err
	}
	if err := report.EnsureSnapshotRegistry(ctx, c.Database); err != nil {
		return err
	}
	if rowsExist, err := db.TableHasRows(ctx, dbConn, summaryTable); err != nil {
		return err
	} else if rowsExist && !force {
		c.Logger.Debug("Daily summary already exists, skipping aggregation", "summary_table", summaryTable)
		return nil
	} else if rowsExist && force {
		if err := clearTable(ctx, dbConn, summaryTable); err != nil {
			return err
		}
	}

	hourlySnapshots, err := report.ListSnapshotsByRange(ctx, c.Database, "hourly", dayStart, dayEnd)
	if err != nil {
		return err
	}
	hourlySnapshots = filterSnapshotsWithRows(ctx, dbConn, hourlySnapshots)
	if len(hourlySnapshots) == 0 {
		return fmt.Errorf("no hourly snapshot tables found for %s", dayStart.Format("2006-01-02"))
	}

	hourlyTables := make([]string, 0, len(hourlySnapshots))
	for _, snapshot := range hourlySnapshots {
		hourlyTables = append(hourlyTables, snapshot.TableName)
	}
	unionQuery, err := buildUnionQuery(hourlyTables, summaryUnionColumns, templateExclusionFilter())
	if err != nil {
		return err
	}

	currentTotals, err := db.SnapshotTotalsForUnion(ctx, dbConn, unionQuery)
	if err != nil {
		c.Logger.Warn("unable to calculate daily totals", "error", err, "date", dayStart.Format("2006-01-02"))
	} else {
		c.Logger.Info("Daily snapshot totals",
			"date", dayStart.Format("2006-01-02"),
			"vm_count", currentTotals.VmCount,
			"vcpu_total", currentTotals.VcpuTotal,
			"ram_total_gb", currentTotals.RamTotal,
			"disk_total_gb", currentTotals.DiskTotal,
		)
	}

	prevStart := dayStart.AddDate(0, 0, -1)
	prevEnd := dayStart
	prevSnapshots, err := report.ListSnapshotsByRange(ctx, c.Database, "hourly", prevStart, prevEnd)
	if err == nil && len(prevSnapshots) > 0 {
		prevSnapshots = filterSnapshotsWithRows(ctx, dbConn, prevSnapshots)
		prevTables := make([]string, 0, len(prevSnapshots))
		for _, snapshot := range prevSnapshots {
			prevTables = append(prevTables, snapshot.TableName)
		}
		prevUnion, err := buildUnionQuery(prevTables, summaryUnionColumns, templateExclusionFilter())
		if err == nil {
			prevTotals, err := db.SnapshotTotalsForUnion(ctx, dbConn, prevUnion)
			if err != nil {
				c.Logger.Warn("unable to calculate previous day totals", "error", err, "date", prevStart.Format("2006-01-02"))
			} else {
				c.Logger.Info("Daily snapshot comparison",
					"current_date", dayStart.Format("2006-01-02"),
					"previous_date", prevStart.Format("2006-01-02"),
					"vm_delta", currentTotals.VmCount-prevTotals.VmCount,
					"vcpu_delta", currentTotals.VcpuTotal-prevTotals.VcpuTotal,
					"ram_delta_gb", currentTotals.RamTotal-prevTotals.RamTotal,
					"disk_delta_gb", currentTotals.DiskTotal-prevTotals.DiskTotal,
				)
			}
		} else {
			c.Logger.Warn("unable to build previous day union", "error", err)
		}
	}

	insertQuery, err := db.BuildDailySummaryInsert(summaryTable, unionQuery)
	if err != nil {
		return err
	}

	if _, err := dbConn.ExecContext(ctx, insertQuery); err != nil {
		c.Logger.Error("failed to aggregate daily inventory", "error", err, "date", dayStart.Format("2006-01-02"))
		return err
	}
	rowCount, err := db.TableRowCount(ctx, dbConn, summaryTable)
	if err != nil {
		c.Logger.Warn("unable to count daily summary rows", "error", err, "table", summaryTable)
	}
	if err := report.RegisterSnapshot(ctx, c.Database, "daily", summaryTable, dayStart, rowCount); err != nil {
		c.Logger.Warn("failed to register daily snapshot", "error", err, "table", summaryTable)
	}

	c.Logger.Debug("Finished daily inventory aggregation", "summary_table", summaryTable)
	return nil
}

// RunVcenterMonthlyAggregate summarizes the previous month's daily snapshots.
func (c *CronTask) RunVcenterMonthlyAggregate(ctx context.Context, logger *slog.Logger) (err error) {
	jobCtx := ctx
	jobTimeout := durationFromSeconds(c.Settings.Values.Settings.MonthlyJobTimeoutSeconds, 20*time.Minute)
	if jobTimeout > 0 {
		var cancel context.CancelFunc
		jobCtx, cancel = context.WithTimeout(ctx, jobTimeout)
		defer cancel()
	}
	tracker := NewCronTracker(c.Database)
	done, skip, err := tracker.Start(jobCtx, "monthly_aggregate")
	if err != nil {
		return err
	}
	if skip {
		logger.Warn("Monthly aggregate skipped because a previous run is still active")
		return nil
	}
	defer func() { done(err) }()

	if err := db.CheckMigrationState(jobCtx, c.Database.DB()); err != nil {
		return err
	}

	startedAt := time.Now()
	defer func() {
		logger.Info("Monthly summary job finished", "duration", time.Since(startedAt))
	}()
	now := time.Now()
	firstOfThisMonth := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
	targetMonth := firstOfThisMonth.AddDate(0, -1, 0)
	err = c.aggregateMonthlySummary(jobCtx, targetMonth, false)
	return err
}

func (c *CronTask) AggregateMonthlySummary(ctx context.Context, month time.Time, force bool) error {
	return c.aggregateMonthlySummary(ctx, month, force)
}

func (c *CronTask) aggregateMonthlySummary(ctx context.Context, targetMonth time.Time, force bool) error {
	if err := report.EnsureSnapshotRegistry(ctx, c.Database); err != nil {
		return err
	}

	monthStart := time.Date(targetMonth.Year(), targetMonth.Month(), 1, 0, 0, 0, 0, targetMonth.Location())
	monthEnd := monthStart.AddDate(0, 1, 0)
	dailySnapshots, err := report.ListSnapshotsByRange(ctx, c.Database, "hourly", monthStart, monthEnd)
	if err != nil {
		return err
	}

	dbConn := c.Database.DB()
	dailySnapshots = filterSnapshotsWithRows(ctx, dbConn, dailySnapshots)
	if len(dailySnapshots) == 0 {
		return fmt.Errorf("no hourly snapshot tables found for %s", targetMonth.Format("2006-01"))
	}

	monthlyTable, err := monthlySummaryTableName(targetMonth)
	if err != nil {
		return err
	}

	if err := db.EnsureSummaryTable(ctx, dbConn, monthlyTable); err != nil {
		return err
	}
	if rowsExist, err := db.TableHasRows(ctx, dbConn, monthlyTable); err != nil {
		return err
	} else if rowsExist && !force {
		c.Logger.Debug("Monthly summary already exists, skipping aggregation", "summary_table", monthlyTable)
		return nil
	} else if rowsExist && force {
		if err := clearTable(ctx, dbConn, monthlyTable); err != nil {
			return err
		}
	}

	dailyTables := make([]string, 0, len(dailySnapshots))
	for _, snapshot := range dailySnapshots {
		dailyTables = append(dailyTables, snapshot.TableName)
	}
	unionQuery, err := buildUnionQuery(dailyTables, summaryUnionColumns, templateExclusionFilter())
	if err != nil {
		return err
	}

	monthlyTotals, err := db.SnapshotTotalsForUnion(ctx, dbConn, unionQuery)
	if err != nil {
		c.Logger.Warn("unable to calculate monthly totals", "error", err, "month", targetMonth.Format("2006-01"))
	} else {
		c.Logger.Info("Monthly snapshot totals",
			"month", targetMonth.Format("2006-01"),
			"vm_count", monthlyTotals.VmCount,
			"vcpu_total", monthlyTotals.VcpuTotal,
			"ram_total_gb", monthlyTotals.RamTotal,
			"disk_total_gb", monthlyTotals.DiskTotal,
		)
	}

	insertQuery, err := db.BuildMonthlySummaryInsert(monthlyTable, unionQuery)
	if err != nil {
		return err
	}

	if _, err := dbConn.ExecContext(ctx, insertQuery); err != nil {
		c.Logger.Error("failed to aggregate monthly inventory", "error", err, "month", targetMonth.Format("2006-01"))
		return err
	}
	rowCount, err := db.TableRowCount(ctx, dbConn, monthlyTable)
	if err != nil {
		c.Logger.Warn("unable to count monthly summary rows", "error", err, "table", monthlyTable)
	}
	if err := report.RegisterSnapshot(ctx, c.Database, "monthly", monthlyTable, targetMonth, rowCount); err != nil {
		c.Logger.Warn("failed to register monthly snapshot", "error", err, "table", monthlyTable)
	}

	c.Logger.Debug("Finished monthly inventory aggregation", "summary_table", monthlyTable)
	return nil
}

// RunSnapshotCleanup drops hourly and daily snapshot tables older than retention.
func (c *CronTask) RunSnapshotCleanup(ctx context.Context, logger *slog.Logger) (err error) {
	jobCtx := ctx
	jobTimeout := durationFromSeconds(c.Settings.Values.Settings.CleanupJobTimeoutSeconds, 10*time.Minute)
	if jobTimeout > 0 {
		var cancel context.CancelFunc
		jobCtx, cancel = context.WithTimeout(ctx, jobTimeout)
		defer cancel()
	}
	tracker := NewCronTracker(c.Database)
	done, skip, err := tracker.Start(jobCtx, "snapshot_cleanup")
	if err != nil {
		return err
	}
	if skip {
		logger.Warn("Snapshot cleanup skipped because a previous run is still active")
		return nil
	}
	defer func() { done(err) }()

	if err := db.CheckMigrationState(jobCtx, c.Database.DB()); err != nil {
		return err
	}

	startedAt := time.Now()
	defer func() {
		logger.Info("Snapshot cleanup job finished", "duration", time.Since(startedAt))
	}()
	now := time.Now()
	hourlyMaxDays := intWithDefault(c.Settings.Values.Settings.HourlySnapshotMaxAgeDays, 60)
	dailyMaxMonths := intWithDefault(c.Settings.Values.Settings.DailySnapshotMaxAgeMonths, 12)

	hourlyCutoff := now.AddDate(0, 0, -hourlyMaxDays)
	dailyCutoff := now.AddDate(0, -dailyMaxMonths, 0)

	dbConn := c.Database.DB()

	hourlyTables, err := report.ListTablesByPrefix(ctx, c.Database, "inventory_hourly_")
	if err != nil {
		return err
	}

	removedHourly := 0
	for _, table := range hourlyTables {
		if strings.HasPrefix(table, "inventory_daily_summary_") {
			continue
		}
		tableDate, ok := parseSnapshotDate(table, "inventory_hourly_", "epoch")
		if !ok {
			continue
		}
		if tableDate.Before(truncateDate(hourlyCutoff)) {
			if err := dropSnapshotTable(ctx, dbConn, table); err != nil {
				c.Logger.Error("failed to drop hourly snapshot table", "error", err, "table", table)
			} else {
				removedHourly++
				if err := report.DeleteSnapshotRecord(ctx, c.Database, table); err != nil {
					c.Logger.Warn("failed to remove hourly snapshot registry entry", "error", err, "table", table)
				}
			}
		}
	}

	dailyTables, err := report.ListTablesByPrefix(ctx, c.Database, "inventory_daily_summary_")
	if err != nil {
		return err
	}
	removedDaily := 0
	for _, table := range dailyTables {
		tableDate, ok := parseSnapshotDate(table, "inventory_daily_summary_", "20060102")
		if !ok {
			continue
		}
		if tableDate.Before(truncateDate(dailyCutoff)) {
			if err := dropSnapshotTable(ctx, dbConn, table); err != nil {
				c.Logger.Error("failed to drop daily snapshot table", "error", err, "table", table)
			} else {
				removedDaily++
				if err := report.DeleteSnapshotRecord(ctx, c.Database, table); err != nil {
					c.Logger.Warn("failed to remove daily snapshot registry entry", "error", err, "table", table)
				}
			}
		}
	}

	c.Logger.Info("Finished snapshot cleanup",
		"removed_hourly_tables", removedHourly,
		"removed_daily_tables", removedDaily,
		"hourly_max_age_days", hourlyMaxDays,
		"daily_max_age_months", dailyMaxMonths,
	)
	return nil
}

func hourlyInventoryTableName(t time.Time) (string, error) {
	return db.SafeTableName(fmt.Sprintf("inventory_hourly_%d", t.Unix()))
}

func dailySummaryTableName(t time.Time) (string, error) {
	return db.SafeTableName(fmt.Sprintf("inventory_daily_summary_%s", t.Format("20060102")))
}

func monthlySummaryTableName(t time.Time) (string, error) {
	return db.SafeTableName(fmt.Sprintf("inventory_monthly_summary_%s", t.Format("200601")))
}

func ensureDailyInventoryTable(ctx context.Context, dbConn *sqlx.DB, tableName string) error {
	if err := db.EnsureSnapshotTable(ctx, dbConn, tableName); err != nil {
		return err
	}
	if err := ensureSnapshotRowID(ctx, dbConn, tableName); err != nil {
		return err
	}

	return db.EnsureColumns(ctx, dbConn, tableName, []db.ColumnDef{
		{Name: "VcpuCount", Type: "BIGINT"},
		{Name: "RamGB", Type: "BIGINT"},
	})
}
func buildUnionQuery(tables []string, columns []string, whereClause string) (string, error) {
	if len(tables) == 0 {
		return "", fmt.Errorf("no tables provided for union")
	}
	if len(columns) == 0 {
		return "", fmt.Errorf("no columns provided for union")
	}

	queries := make([]string, 0, len(tables))
	columnList := strings.Join(columns, ", ")
	for _, table := range tables {
		safeName, err := db.SafeTableName(table)
		if err != nil {
			return "", err
		}
		query := fmt.Sprintf("SELECT %s FROM %s", columnList, safeName)
		if whereClause != "" {
			query = fmt.Sprintf("%s WHERE %s", query, whereClause)
		}
		queries = append(queries, query)
	}
	if len(queries) == 0 {
		return "", fmt.Errorf("no valid tables provided for union")
	}
	return strings.Join(queries, "\nUNION ALL\n"), nil
}

func templateExclusionFilter() string {
	return `COALESCE(CAST("IsTemplate" AS TEXT), '') NOT IN ('TRUE', 'true', '1')`
}

func parseSnapshotDate(table string, prefix string, layout string) (time.Time, bool) {
	if !strings.HasPrefix(table, prefix) {
		return time.Time{}, false
	}
	suffix := strings.TrimPrefix(table, prefix)
	if layout == "epoch" {
		epoch, err := strconv.ParseInt(suffix, 10, 64)
		if err != nil {
			return time.Time{}, false
		}
		return time.Unix(epoch, 0), true
	}
	parsed, err := time.Parse(layout, suffix)
	if err != nil {
		return time.Time{}, false
	}
	return parsed, true
}

func truncateDate(t time.Time) time.Time {
	return time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, t.Location())
}

func dropSnapshotTable(ctx context.Context, dbConn *sqlx.DB, table string) error {
	if _, err := db.SafeTableName(table); err != nil {
		return err
	}
	_, err := dbConn.ExecContext(ctx, fmt.Sprintf("DROP TABLE IF EXISTS %s", table))
	return err
}

func clearTable(ctx context.Context, dbConn *sqlx.DB, table string) error {
	if _, err := db.SafeTableName(table); err != nil {
		return err
	}
	_, err := dbConn.ExecContext(ctx, fmt.Sprintf("DELETE FROM %s", table))
	if err != nil {
		return fmt.Errorf("failed to clear table %s: %w", table, err)
	}
	return nil
}

func filterSnapshotsWithRows(ctx context.Context, dbConn *sqlx.DB, snapshots []report.SnapshotRecord) []report.SnapshotRecord {
	filtered := snapshots[:0]
	for _, snapshot := range snapshots {
		if rowsExist, err := db.TableHasRows(ctx, dbConn, snapshot.TableName); err == nil && rowsExist {
			filtered = append(filtered, snapshot)
		}
	}
	return filtered
}

type columnDef struct {
	Name string
	Type string
}

var summaryUnionColumns = []string{
	`"InventoryId"`, `"Name"`, `"Vcenter"`, `"VmId"`, `"EventKey"`, `"CloudId"`, `"CreationTime"`,
	`"DeletionTime"`, `"ResourcePool"`, `"Datacenter"`, `"Cluster"`, `"Folder"`,
	`"ProvisionedDisk"`, `"VcpuCount"`, `"RamGB"`, `"IsTemplate"`, `"PoweredOn"`,
	`"SrmPlaceholder"`, `"VmUuid"`, `"SnapshotTime"`, `"IsPresent"`,
}

func ensureSnapshotRowID(ctx context.Context, dbConn *sqlx.DB, tableName string) error {
	driver := strings.ToLower(dbConn.DriverName())
	switch driver {
	case "pgx", "postgres":
		hasColumn, err := db.ColumnExists(ctx, dbConn, tableName, "RowId")
		if err != nil {
			return err
		}
		if !hasColumn {
			if err := db.AddColumnIfMissing(ctx, dbConn, tableName, db.ColumnDef{Name: "RowId", Type: "BIGSERIAL"}); err != nil {
				return err
			}
		}
		if err := db.BackfillSerialColumn(ctx, dbConn, tableName, "RowId"); err != nil {
			return err
		}
	case "sqlite":
		return nil
	}
	return nil
}

func nullInt64ToInt(value sql.NullInt64) int64 {
	if value.Valid {
		return value.Int64
	}
	return 0
}

func nullFloat64ToFloat(value sql.NullFloat64) float64 {
	if value.Valid {
		return value.Float64
	}
	return 0
}

func intWithDefault(value int, fallback int) int {
	if value <= 0 {
		return fallback
	}
	return value
}

func durationFromSeconds(seconds int, fallback time.Duration) time.Duration {
	if seconds > 0 {
		return time.Duration(seconds) * time.Second
	}
	return fallback
}

func normalizeResourcePool(value string) string {
	trimmed := strings.TrimSpace(value)
	if trimmed == "" {
		return ""
	}
	switch {
	case strings.EqualFold(trimmed, "tin"):
		return "Tin"
	case strings.EqualFold(trimmed, "bronze"):
		return "Bronze"
	case strings.EqualFold(trimmed, "silver"):
		return "Silver"
	case strings.EqualFold(trimmed, "gold"):
		return "Gold"
	default:
		return trimmed
	}
}

func snapshotFromVM(vmObject *mo.VirtualMachine, vc *vcenter.Vcenter, snapshotTime time.Time, inv *queries.Inventory, hostLookup map[string]vcenter.HostLookup, folderLookup vcenter.FolderLookup, rpLookup map[string]string) (inventorySnapshotRow, error) {
	if vmObject == nil {
		return inventorySnapshotRow{}, fmt.Errorf("missing VM object")
	}

	row := inventorySnapshotRow{
		Name:         vmObject.Name,
		Vcenter:      vc.Vurl,
		VmId:         sql.NullString{String: vmObject.Reference().Value, Valid: vmObject.Reference().Value != ""},
		SnapshotTime: snapshotTime.Unix(),
	}

	if inv != nil {
		row.InventoryId = sql.NullInt64{Int64: inv.Iid, Valid: inv.Iid > 0}
		row.EventKey = inv.EventKey
		row.CloudId = inv.CloudId
		row.DeletionTime = inv.DeletionTime
	}

	if vmObject.Config != nil {
		row.VmUuid = sql.NullString{String: vmObject.Config.Uuid, Valid: vmObject.Config.Uuid != ""}
		if !vmObject.Config.CreateDate.IsZero() {
			row.CreationTime = sql.NullInt64{Int64: vmObject.Config.CreateDate.Unix(), Valid: true}
		}
		row.VcpuCount = sql.NullInt64{Int64: int64(vmObject.Config.Hardware.NumCPU), Valid: vmObject.Config.Hardware.NumCPU > 0}
		row.RamGB = sql.NullInt64{Int64: int64(vmObject.Config.Hardware.MemoryMB) / 1024, Valid: vmObject.Config.Hardware.MemoryMB > 0}

		totalDiskBytes := int64(0)
		for _, device := range vmObject.Config.Hardware.Device {
			if disk, ok := device.(*types.VirtualDisk); ok {
				totalDiskBytes += disk.CapacityInBytes
			}
		}
		if totalDiskBytes > 0 {
			row.ProvisionedDisk = sql.NullFloat64{Float64: float64(totalDiskBytes / 1024 / 1024 / 1024), Valid: true}
		}

		if vmObject.Config.ManagedBy != nil && vmObject.Config.ManagedBy.ExtensionKey == "com.vmware.vcDr" && vmObject.Config.ManagedBy.Type == "placeholderVm" {
			row.SrmPlaceholder = "TRUE"
		} else {
			row.SrmPlaceholder = "FALSE"
		}

		if vmObject.Config.Template {
			row.IsTemplate = "TRUE"
		} else {
			row.IsTemplate = "FALSE"
		}
	}

	if vmObject.Runtime.PowerState == "poweredOff" {
		row.PoweredOn = "FALSE"
	} else {
		row.PoweredOn = "TRUE"
	}

	if inv != nil {
		if inv.ResourcePool.Valid {
			row.ResourcePool = sql.NullString{String: normalizeResourcePool(inv.ResourcePool.String), Valid: true}
		}
		row.Datacenter = inv.Datacenter
		row.Cluster = inv.Cluster
		row.Folder = inv.Folder
		if !row.CreationTime.Valid {
			row.CreationTime = inv.CreationTime
		}
		if !row.ProvisionedDisk.Valid {
			row.ProvisionedDisk = inv.ProvisionedDisk
		}
		if !row.VcpuCount.Valid {
			row.VcpuCount = inv.InitialVcpus
		}
		if !row.RamGB.Valid && inv.InitialRam.Valid {
			row.RamGB = sql.NullInt64{Int64: inv.InitialRam.Int64 / 1024, Valid: inv.InitialRam.Int64 > 0}
		}
		if row.IsTemplate == "" {
			row.IsTemplate = boolStringFromInterface(inv.IsTemplate)
		}
		if row.PoweredOn == "" {
			row.PoweredOn = boolStringFromInterface(inv.PoweredOn)
		}
		if row.SrmPlaceholder == "" {
			row.SrmPlaceholder = boolStringFromInterface(inv.SrmPlaceholder)
		}
		if !row.VmUuid.Valid {
			row.VmUuid = inv.VmUuid
		}
	}

	if row.ResourcePool.String == "" && vmObject.ResourcePool != nil {
		if rpLookup != nil {
			if rpName, ok := rpLookup[vmObject.ResourcePool.Value]; ok {
				row.ResourcePool = sql.NullString{String: normalizeResourcePool(rpName), Valid: rpName != ""}
			}
		}
		if !row.ResourcePool.Valid {
			if rpName, err := vc.GetVmResourcePool(*vmObject); err == nil {
				row.ResourcePool = sql.NullString{String: normalizeResourcePool(rpName), Valid: rpName != ""}
			}
		}
	}

	if row.Folder.String == "" {
		if folderPath, ok := vc.GetVMFolderPathFromLookup(*vmObject, folderLookup); ok {
			row.Folder = sql.NullString{String: folderPath, Valid: folderPath != ""}
		} else if folderPath, err := vc.GetVMFolderPath(*vmObject); err == nil {
			row.Folder = sql.NullString{String: folderPath, Valid: folderPath != ""}
		}
	}

	if vmObject.Runtime.Host != nil && hostLookup != nil {
		if lookup, ok := hostLookup[vmObject.Runtime.Host.Value]; ok {
			if row.Cluster.String == "" && lookup.Cluster != "" {
				row.Cluster = sql.NullString{String: lookup.Cluster, Valid: true}
			}
			if row.Datacenter.String == "" && lookup.Datacenter != "" {
				row.Datacenter = sql.NullString{String: lookup.Datacenter, Valid: true}
			}
		}
	}

	if row.Cluster.String == "" {
		if clusterName, err := vc.GetClusterFromHost(vmObject.Runtime.Host); err == nil {
			row.Cluster = sql.NullString{String: clusterName, Valid: clusterName != ""}
		}
	}

	if row.Datacenter.String == "" {
		if dcName, err := vc.GetDatacenterForVM(*vmObject); err == nil {
			row.Datacenter = sql.NullString{String: dcName, Valid: dcName != ""}
		}
	}

	return row, nil
}

func snapshotFromInventory(inv queries.Inventory, snapshotTime time.Time) inventorySnapshotRow {
	return inventorySnapshotRow{
		InventoryId:     sql.NullInt64{Int64: inv.Iid, Valid: inv.Iid > 0},
		Name:            inv.Name,
		Vcenter:         inv.Vcenter,
		VmId:            inv.VmId,
		EventKey:        inv.EventKey,
		CloudId:         inv.CloudId,
		CreationTime:    inv.CreationTime,
		DeletionTime:    inv.DeletionTime,
		ResourcePool:    sql.NullString{String: normalizeResourcePool(inv.ResourcePool.String), Valid: inv.ResourcePool.Valid},
		Datacenter:      inv.Datacenter,
		Cluster:         inv.Cluster,
		Folder:          inv.Folder,
		ProvisionedDisk: inv.ProvisionedDisk,
		VcpuCount:       inv.InitialVcpus,
		RamGB:           sql.NullInt64{Int64: inv.InitialRam.Int64 / 1024, Valid: inv.InitialRam.Valid && inv.InitialRam.Int64 > 0},
		IsTemplate:      boolStringFromInterface(inv.IsTemplate),
		PoweredOn:       boolStringFromInterface(inv.PoweredOn),
		SrmPlaceholder:  boolStringFromInterface(inv.SrmPlaceholder),
		VmUuid:          inv.VmUuid,
		SnapshotTime:    snapshotTime.Unix(),
	}
}

func insertDailyInventoryRow(ctx context.Context, dbConn *sqlx.DB, tableName string, row inventorySnapshotRow) error {
	query := fmt.Sprintf(`
INSERT INTO %s (
  "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
  "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
  "RamGB", "IsTemplate", "PoweredOn", "SrmPlaceholder", "VmUuid", "SnapshotTime", "IsPresent"
)
VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);
`, tableName)

	query = sqlx.Rebind(sqlx.BindType(dbConn.DriverName()), query)

	_, err := dbConn.ExecContext(ctx, query,
		row.InventoryId,
		row.Name,
		row.Vcenter,
		row.VmId,
		row.EventKey,
		row.CloudId,
		row.CreationTime,
		row.DeletionTime,
		row.ResourcePool,
		row.Datacenter,
		row.Cluster,
		row.Folder,
		row.ProvisionedDisk,
		row.VcpuCount,
		row.RamGB,
		row.IsTemplate,
		row.PoweredOn,
		row.SrmPlaceholder,
		row.VmUuid,
		row.SnapshotTime,
		row.IsPresent,
	)
	return err
}

func insertHourlyBatch(ctx context.Context, dbConn *sqlx.DB, tableName string, rows []inventorySnapshotRow) error {
	if len(rows) == 0 {
		return nil
	}
	tx, err := dbConn.BeginTxx(ctx, nil)
	if err != nil {
		return err
	}
	stmt, err := tx.PreparexContext(ctx, sqlx.Rebind(sqlx.BindType(dbConn.DriverName()), fmt.Sprintf(`
INSERT INTO %s (
  "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
  "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
  "RamGB", "IsTemplate", "PoweredOn", "SrmPlaceholder", "VmUuid", "SnapshotTime", "IsPresent"
) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
`, tableName)))
	if err != nil {
		tx.Rollback()
		return err
	}
	defer stmt.Close()

	for _, row := range rows {
		if _, err := stmt.ExecContext(ctx,
			row.InventoryId,
			row.Name,
			row.Vcenter,
			row.VmId,
			row.EventKey,
			row.CloudId,
			row.CreationTime,
			row.DeletionTime,
			row.ResourcePool,
			row.Datacenter,
			row.Cluster,
			row.Folder,
			row.ProvisionedDisk,
			row.VcpuCount,
			row.RamGB,
			row.IsTemplate,
			row.PoweredOn,
			row.SrmPlaceholder,
			row.VmUuid,
			row.SnapshotTime,
			row.IsPresent,
		); err != nil {
			tx.Rollback()
			return err
		}
	}
	return tx.Commit()
}

func (c *CronTask) captureHourlySnapshotForVcenter(ctx context.Context, startTime time.Time, tableName string, url string) error {
	c.Logger.Debug("connecting to vcenter for hourly snapshot", "url", url)
	vc := vcenter.New(c.Logger, c.VcCreds)
	if err := vc.Login(url); err != nil {
		return fmt.Errorf("unable to connect to vcenter: %w", err)
	}
	defer func() {
		if err := vc.Logout(); err != nil {
			c.Logger.Warn("vcenter logout failed", "url", url, "error", err)
		}
	}()

	vcVms, err := vc.GetAllVMsWithProps()
	if err != nil {
		return fmt.Errorf("unable to get VMs from vcenter: %w", err)
	}
	canDetectMissing := len(vcVms) > 0
	if !canDetectMissing {
		c.Logger.Warn("no VMs returned from vcenter; skipping missing VM detection", "url", url)
	}
	hostLookup, err := vc.BuildHostLookup()
	if err != nil {
		c.Logger.Warn("failed to build host lookup", "url", url, "error", err)
		hostLookup = nil
	} else {
		c.Logger.Debug("built host lookup", "url", url, "hosts", len(hostLookup))
	}
	folderLookup, err := vc.BuildFolderPathLookup()
	if err != nil {
		c.Logger.Warn("failed to build folder lookup", "url", url, "error", err)
		folderLookup = nil
	} else {
		c.Logger.Debug("built folder lookup", "url", url, "folders", len(folderLookup))
	}
	rpLookup, err := vc.BuildResourcePoolLookup()
	if err != nil {
		c.Logger.Warn("failed to build resource pool lookup", "url", url, "error", err)
		rpLookup = nil
	} else {
		c.Logger.Debug("built resource pool lookup", "url", url, "pools", len(rpLookup))
	}

	inventoryRows, err := c.Database.Queries().GetInventoryByVcenter(ctx, url)
	if err != nil {
		return fmt.Errorf("unable to query inventory table: %w", err)
	}

	inventoryByVmID := make(map[string]queries.Inventory, len(inventoryRows))
	for _, inv := range inventoryRows {
		if inv.VmId.Valid {
			inventoryByVmID[inv.VmId.String] = inv
		}
	}

	dbConn := c.Database.DB()
	presentSnapshots := make(map[string]inventorySnapshotRow, len(vcVms))
	totals := snapshotTotals{}
	for _, vm := range vcVms {
		if strings.HasPrefix(vm.Name, "vCLS-") {
			continue
		}

		if vm.Config != nil && vm.Config.Template {
			continue
		}

		var inv *queries.Inventory
		if existing, ok := inventoryByVmID[vm.Reference().Value]; ok {
			existingCopy := existing
			inv = &existingCopy
		}

		row, err := snapshotFromVM(&vm, vc, startTime, inv, hostLookup, folderLookup, rpLookup)
		if err != nil {
			c.Logger.Error("unable to build snapshot for VM", "vm_id", vm.Reference().Value, "error", err)
			continue
		}
		row.IsPresent = "TRUE"
		presentSnapshots[vm.Reference().Value] = row

		totals.VmCount++
		totals.VcpuTotal += nullInt64ToInt(row.VcpuCount)
		totals.RamTotal += nullInt64ToInt(row.RamGB)
		totals.DiskTotal += nullFloat64ToFloat(row.ProvisionedDisk)
	}

	batch := make([]inventorySnapshotRow, 0, len(presentSnapshots)+len(inventoryRows))
	for _, row := range presentSnapshots {
		batch = append(batch, row)
	}

	if !canDetectMissing {
		c.Logger.Info("Hourly snapshot summary",
			"vcenter", url,
			"vm_count", totals.VmCount,
			"vcpu_total", totals.VcpuTotal,
			"ram_total_gb", totals.RamTotal,
			"disk_total_gb", totals.DiskTotal,
		)
		return nil
	}

	for _, inv := range inventoryRows {
		if strings.HasPrefix(inv.Name, "vCLS-") {
			continue
		}
		vmID := inv.VmId.String
		if vmID != "" {
			if _, ok := presentSnapshots[vmID]; ok {
				continue
			}
		}

		row := snapshotFromInventory(inv, startTime)
		row.IsPresent = "FALSE"
		if !row.DeletionTime.Valid {
			deletionTime := startTime.Unix()
			row.DeletionTime = sql.NullInt64{Int64: deletionTime, Valid: true}
			if err := c.Database.Queries().InventoryMarkDeleted(ctx, queries.InventoryMarkDeletedParams{
				DeletionTime:   row.DeletionTime,
				VmId:           inv.VmId,
				DatacenterName: inv.Datacenter,
			}); err != nil {
				c.Logger.Warn("failed to mark inventory record deleted", "error", err, "vm_id", row.VmId.String)
			}
		}
		batch = append(batch, row)
	}

	if err := insertHourlyBatch(ctx, dbConn, tableName, batch); err != nil {
		return err
	}

	c.Logger.Info("Hourly snapshot summary",
		"vcenter", url,
		"vm_count", totals.VmCount,
		"vcpu_total", totals.VcpuTotal,
		"ram_total_gb", totals.RamTotal,
		"disk_total_gb", totals.DiskTotal,
	)
	return nil
}

func boolStringFromInterface(value interface{}) string {
	switch v := value.(type) {
	case nil:
		return ""
	case string:
		return v
	case []byte:
		return string(v)
	case bool:
		if v {
			return "TRUE"
		}
		return "FALSE"
	case int:
		if v != 0 {
			return "TRUE"
		}
		return "FALSE"
	case int64:
		if v != 0 {
			return "TRUE"
		}
		return "FALSE"
	default:
		return fmt.Sprint(v)
	}
}