package remotewrite

import (
	"context"
	"flag"
	"fmt"
	"time"

	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmalert/utils"
)

var (
	addr = flag.String("remoteWrite.url", "", "Optional URL to VictoriaMetrics or vminsert where to persist alerts state "+
		"and recording rules results in form of timeseries. For example, if -remoteWrite.url=http://127.0.0.1:8428 is specified, "+
		"then the alerts state will be written to http://127.0.0.1:8428/api/v1/write . See also -remoteWrite.disablePathAppend")

	headers = flag.String("remoteWrite.headers", "", "Optional HTTP headers to send with each request to the corresponding -remoteWrite.url. "+
		"For example, -remoteWrite.headers='My-Auth:foobar' would send 'My-Auth: foobar' HTTP header with every request to the corresponding -remoteWrite.url. "+
		"Multiple headers must be delimited by '^^': -remoteWrite.headers='header1:value1^^header2:value2'")

	basicAuthUsername     = flag.String("remoteWrite.basicAuth.username", "", "Optional basic auth username for -remoteWrite.url")
	basicAuthPassword     = flag.String("remoteWrite.basicAuth.password", "", "Optional basic auth password for -remoteWrite.url")
	basicAuthPasswordFile = flag.String("remoteWrite.basicAuth.passwordFile", "", "Optional path to basic auth password to use for -remoteWrite.url")

	bearerToken     = flag.String("remoteWrite.bearerToken", "", "Optional bearer auth token to use for -remoteWrite.url.")
	bearerTokenFile = flag.String("remoteWrite.bearerTokenFile", "", "Optional path to bearer token file to use for -remoteWrite.url.")

	maxQueueSize  = flag.Int("remoteWrite.maxQueueSize", 1e5, "Defines the max number of pending datapoints to remote write endpoint")
	maxBatchSize  = flag.Int("remoteWrite.maxBatchSize", 1e3, "Defines defines max number of timeseries to be flushed at once")
	concurrency   = flag.Int("remoteWrite.concurrency", 1, "Defines number of writers for concurrent writing into remote querier")
	flushInterval = flag.Duration("remoteWrite.flushInterval", 5*time.Second, "Defines interval of flushes to remote write endpoint")

	tlsInsecureSkipVerify = flag.Bool("remoteWrite.tlsInsecureSkipVerify", false, "Whether to skip tls verification when connecting to -remoteWrite.url")
	tlsCertFile           = flag.String("remoteWrite.tlsCertFile", "", "Optional path to client-side TLS certificate file to use when connecting to -remoteWrite.url")
	tlsKeyFile            = flag.String("remoteWrite.tlsKeyFile", "", "Optional path to client-side TLS certificate key to use when connecting to -remoteWrite.url")
	tlsCAFile             = flag.String("remoteWrite.tlsCAFile", "", "Optional path to TLS CA file to use for verifying connections to -remoteWrite.url. "+
		"By default system CA is used")
	tlsServerName = flag.String("remoteWrite.tlsServerName", "", "Optional TLS server name to use for connections to -remoteWrite.url. "+
		"By default the server name from -remoteWrite.url is used")

	oauth2ClientID         = flag.String("remoteWrite.oauth2.clientID", "", "Optional OAuth2 clientID to use for -remoteWrite.url.")
	oauth2ClientSecret     = flag.String("remoteWrite.oauth2.clientSecret", "", "Optional OAuth2 clientSecret to use for -remoteWrite.url.")
	oauth2ClientSecretFile = flag.String("remoteWrite.oauth2.clientSecretFile", "", "Optional OAuth2 clientSecretFile to use for -remoteWrite.url.")
	oauth2TokenURL         = flag.String("remoteWrite.oauth2.tokenUrl", "", "Optional OAuth2 tokenURL to use for -notifier.url.")
	oauth2Scopes           = flag.String("remoteWrite.oauth2.scopes", "", "Optional OAuth2 scopes to use for -notifier.url. Scopes must be delimited by ';'.")
)

// Init creates Client object from given flags.
// Returns nil if addr flag wasn't set.
func Init(ctx context.Context) (*Client, error) {
	if *addr == "" {
		return nil, nil
	}

	t, err := utils.Transport(*addr, *tlsCertFile, *tlsKeyFile, *tlsCAFile, *tlsServerName, *tlsInsecureSkipVerify)
	if err != nil {
		return nil, fmt.Errorf("failed to create transport: %w", err)
	}

	authCfg, err := utils.AuthConfig(
		utils.WithBasicAuth(*basicAuthUsername, *basicAuthPassword, *basicAuthPasswordFile),
		utils.WithBearer(*bearerToken, *bearerTokenFile),
		utils.WithOAuth(*oauth2ClientID, *oauth2ClientSecret, *oauth2ClientSecretFile, *oauth2TokenURL, *oauth2Scopes),
		utils.WithHeaders(*headers))
	if err != nil {
		return nil, fmt.Errorf("failed to configure auth: %w", err)
	}

	return NewClient(ctx, Config{
		Addr:              *addr,
		AuthCfg:           authCfg,
		Concurrency:       *concurrency,
		MaxQueueSize:      *maxQueueSize,
		MaxBatchSize:      *maxBatchSize,
		FlushInterval:     *flushInterval,
		DisablePathAppend: *disablePathAppend,
		Transport:         t,
	})
}