package lifecycle

import (
	"time"

	"git.apinb.com/bsm-sdk/core/utils"
	"git.apinb.com/ops/files/internal/models"
	"gorm.io/gorm"
)

const (
	deletionLeaseDuration  = 5 * time.Minute
	DeleteOperationTimeout = 30 * time.Second
)

type DeletionLease struct {
	Token      string
	LeaseUntil time.Time
}

func ClaimDeletion(db *gorm.DB, id uint, allowedStatuses []models.FileStatus, now time.Time) (DeletionLease, bool, error) {
	query := db.Model(&models.FileObject{}).
		Where("id = ? AND status IN ?", id, allowedStatuses)
	return claimDeletion(query, now)
}

func ClaimExpiredPendingDeletion(db *gorm.DB, id uint, now time.Time) (DeletionLease, bool, error) {
	query := db.Model(&models.FileObject{}).
		Where("id = ? AND status = ? AND expires_at <= ?", id, models.FileStatusPending, now)
	return claimDeletion(query, now)
}

func ClaimDeletionRetry(db *gorm.DB, id uint, now time.Time) (DeletionLease, bool, error) {
	query := db.Model(&models.FileObject{}).
		Where("id = ? AND status = ?", id, models.FileStatusDeleting).
		Where("delete_lease_until IS NULL OR delete_lease_until <= ?", now)
	return claimDeletion(query, now)
}

func FinalizeDeletion(db *gorm.DB, id uint, token string) error {
	if token == "" {
		return gorm.ErrRecordNotFound
	}

	return db.Transaction(func(tx *gorm.DB) error {
		result := tx.Model(&models.FileObject{}).
			Where("id = ? AND status = ? AND delete_token = ?", id, models.FileStatusDeleting, token).
			Updates(map[string]any{
				"status":             models.FileStatusExpired,
				"delete_token":       "",
				"delete_lease_until": nil,
			})
		if result.Error != nil {
			return result.Error
		}
		if result.RowsAffected != 1 {
			return gorm.ErrRecordNotFound
		}

		result = tx.Where("id = ? AND status = ?", id, models.FileStatusExpired).
			Delete(&models.FileObject{})
		if result.Error != nil {
			return result.Error
		}
		if result.RowsAffected != 1 {
			return gorm.ErrRecordNotFound
		}
		return nil
	})
}

func claimDeletion(query *gorm.DB, now time.Time) (DeletionLease, bool, error) {
	lease := DeletionLease{
		Token:      utils.ULID(),
		LeaseUntil: now.Add(deletionLeaseDuration),
	}
	result := query.Updates(map[string]any{
		"status":             models.FileStatusDeleting,
		"delete_token":       lease.Token,
		"delete_lease_until": lease.LeaseUntil,
	})
	if result.Error != nil {
		return DeletionLease{}, false, result.Error
	}
	if result.RowsAffected != 1 {
		return DeletionLease{}, false, nil
	}
	return lease, true, nil
}