package main

import (
	"context"
	"fmt"
	"path/filepath"

	"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
	awsconfig "github.com/aws/aws-sdk-go-v2/config"
	"github.com/glebarez/sqlite"
	"github.com/tidbcloud/metering/pkg/common/constants"
	"github.com/tidbcloud/metering/pkg/common/models"
	"github.com/tidbcloud/metering/pkg/common/utils"
	"github.com/tidbcloud/metering/pkg/common/utils/storage"
	awsobj "github.com/tidbcloud/metering/pkg/common/utils/storage/aws"
	azblob "github.com/tidbcloud/metering/pkg/common/utils/storage/azure"
	gcpobj "github.com/tidbcloud/metering/pkg/common/utils/storage/gcp"
	"gorm.io/gorm"
)

const (
	objectcachepath = "data"
)

// BillingRepoterLoader load billing repoter from object
type BillingRepoterObjectStorage struct {
	conf      *SupplementaryConfig
	objcli    storage.StorageProvider
	cachepath string
	perfix    string
}

func NewBillingRepoterObjectStorage(conf *SupplementaryConfig) *BillingRepoterObjectStorage {
	return &BillingRepoterObjectStorage{
		conf: conf,
	}
}

func (b *BillingRepoterObjectStorage) Init() (*BillingRepoterObjectStorage, error) {
	abspath, err := utils.EnsureCache(objectcachepath, objectcachepath)
	if err != nil {
		return b, err
	}
	b.cachepath = abspath
	switch b.conf.Vendor {
	case constants.VendorAzure:
		{
			err := b.ensureAzureClient()
			if err != nil {
				return b, err
			}
		}
	case constants.VendorAWS:
		{
			err := b.ensureAWSClient()
			if err != nil {
				return b, err
			}
		}
	case constants.VendorGCP:
		{
			err := b.ensureGCPClient()
			if err != nil {
				return b, err
			}
		}
	default:
		return b, fmt.Errorf("invalid vendor: %s", b.conf.Vendor)
	}

	return b, nil
}
func (b *BillingRepoterObjectStorage) ensureAzureClient() error {
	cred, err := azidentity.NewDefaultAzureCredential(nil)
	if err != nil {
		return err
	}
	b.objcli, err = azblob.NewAzureProviderBlob(cred, b.conf.SourceObject.Azure.StorageAccountName, b.conf.SourceObject.Azure.ContainerName)
	if err != nil {
		return err
	}
	b.perfix = b.conf.SourceObject.Azure.Perfix
	return nil
}

func (b *BillingRepoterObjectStorage) ensureAWSClient() error {
	cfg, err := awsconfig.LoadDefaultConfig(context.TODO())
	if err != nil {
		return fmt.Errorf("unable to get aws config: %v", err)
	}
	cfg.Region = b.conf.SourceObject.AWS.Region
	if b.conf.SourceObject.AWS.RoleArn != "" {
		b.objcli = awsobj.NewAwsProviderS3(cfg, b.conf.SourceObject.AWS.BucketName).AssumeRole(context.TODO(), b.conf.SourceObject.AWS.RoleArn)

	} else {
		b.objcli = awsobj.NewAwsProviderS3(cfg, b.conf.SourceObject.AWS.BucketName)
	}
	b.perfix = b.conf.SourceObject.AWS.Perfix
	return nil
}

func (b *BillingRepoterObjectStorage) ensureGCPClient() error {
	b.objcli = gcpobj.NewGcpProviderGcs(b.conf.SourceObject.GCP.ProjectId, b.conf.SourceObject.GCP.BucketName)
	b.perfix = b.conf.SourceObject.GCP.Perfix
	return nil
}

// LoadNetworkRepoterWithTs load network  billing repoter sqlite from object blob
func (b *BillingRepoterObjectStorage) LoadNetworkRepoterWithTs(ctx context.Context, timestemp int64) ([]*models.BillingReport, []*models.BillingReportV2, error) {
	daaytime := utils.GenerateDailyDate(timestemp)
	destfilename := fmt.Sprintf("%s/%s/%s.db", b.perfix, daaytime, daaytime)
	blobs, err := b.objcli.ListObjectByName(ctx, destfilename)
	if err != nil {
		return nil, nil, err
	}
	if len(blobs) == 0 {
		return nil, nil, fmt.Errorf("no file found in object storage")
	}
	if len(blobs) > 1 {
		return nil, nil, fmt.Errorf("more than one file found in object storage")
	}
	//download blob to cache
	destFile := filepath.Join(b.cachepath, filepath.Base(destfilename))
	err = b.objcli.DownloadObjects(ctx, blobs, b.cachepath)
	if err != nil {
		return nil, nil, err
	}
	//load file
	db, err := ensureSQLite(destFile)
	if err != nil {
		return nil, nil, err
	}
	// load repoter from sqlite
	res, resv2, err := loadRepoterFromSQLite(db)
	if err != nil {
		return nil, nil, err
	}
	return res, resv2, nil
}

func (b *BillingRepoterObjectStorage) LoadInstanceRepoterWithTs(ctx context.Context, timestemp int64) ([]*models.BillingReport, []*models.BillingReportV2, error) {
	destfilename := fmt.Sprintf("%s/%d.sqlite", b.perfix, timestemp)
	blobs, err := b.objcli.ListObjectByName(ctx, destfilename)
	if err != nil {
		return nil, nil, err
	}
	if len(blobs) == 0 {
		return nil, nil, fmt.Errorf("no file found in object storage")
	}
	if len(blobs) > 1 {
		return nil, nil, fmt.Errorf("more than one file found in object storage")
	}
	//download blob to cache
	destFile := filepath.Join(b.cachepath, filepath.Base(destfilename))
	err = b.objcli.DownloadObjects(ctx, blobs, b.cachepath)
	if err != nil {
		return nil, nil, err
	}
	//load file
	db, err := ensureSQLite(destFile)
	if err != nil {
		return nil, nil, err
	}
	// load repoter from sqlite
	res, resv2, err := loadRepoterFromSQLite(db)
	if err != nil {
		return nil, nil, err
	}
	return res, resv2, nil
}
func ensureSQLite(dbfile string) (*gorm.DB, error) {
	db, err := gorm.Open(sqlite.Open(dbfile), &gorm.Config{})
	if err != nil {
		return nil, err
	}
	err = db.AutoMigrate(&models.BillingReportV2{}, &models.BillingReport{})
	return db, err
}

func loadRepoterFromSQLite(db *gorm.DB) ([]*models.BillingReport, []*models.BillingReportV2, error) {
	var res []*models.BillingReport
	err := db.Find(&res).Error
	if err != nil {
		return nil, nil, err
	}
	var resv2 []*models.BillingReportV2
	err = db.Find(&resv2).Error
	if err != nil {
		return nil, nil, err
	}

	return res, resv2, nil
}