package sequel

import (
	"database/sql"
	"flag"
	"fmt"

	"github.com/peterbourgon/ff/v3"

	"edge-infra.dev/pkg/edge/controllers/sequel/dbctl"
	"edge-infra.dev/pkg/lib/gcp/cloudsql"
)

// config is the controllers application config
type config struct {
	host           string
	connectionName string
	name           string
	user           string
	password       string
	port           string
	db             *dbctl.DB
	namespace      string
	projectID      string
	concurrency    int
}

// newConfig creates the controller config, reading initial values via flags and
// environment variables via ff
func newConfig(args []string) (*config, error) {
	fs := flag.NewFlagSet("sequel", flag.ExitOnError)

	cfg := &config{}
	cfg.bindFlags(fs)

	if err := ff.Parse(fs, args, ff.WithEnvVarNoPrefix()); err != nil {
		return nil, fmt.Errorf("failed to parse configuration: %w", err)
	}
	if err := cfg.validate(); err != nil {
		return nil, fmt.Errorf("invalid configuration: %w", err)
	}

	return cfg, nil
}

// afterParse computes additional values after flags have been parsed
func (c *config) afterParse() error {
	if c.db == nil {
		conn, err := c.connectDatabase()
		if err != nil {
			return err
		}
		c.db = dbctl.New(conn)
	}

	return nil
}

func (c *config) validate() error {
	if c.name == "" {
		return fmt.Errorf("--name is required")
	}

	if c.user == "" {
		return fmt.Errorf("--user is required")
	}

	if c.projectID == "" {
		return fmt.Errorf("--project-id is required")
	}

	return nil
}

func (c *config) connectDatabase() (*sql.DB, error) {
	edgeDB := &cloudsql.EdgePostgres{}
	switch {
	case c.connectionName != "":
		edgeDB = cloudsql.GCPPostgresConnection(c.connectionName)
	case c.connectionName == "":
		edgeDB = cloudsql.PostgresConnection(c.host, c.port).Password(c.password)
	}
	dbConnection, err := edgeDB.
		DBName(c.name).
		Username(c.user).
		NewConnection()
	if err != nil {
		return nil, err
	}
	if err := dbConnection.Ping(); err != nil {
		return nil, err
	}
	return dbConnection, nil
}

// bindFlags binds the controller's configuration to command line flags.
func (c *config) bindFlags(fs *flag.FlagSet) {
	fs.StringVar(&c.connectionName, "connection-name", "",
		"CloudSQL postgres database connection name")
	fs.StringVar(&c.host, "host", "",
		"CloudSQL postgres database host")
	fs.StringVar(&c.port, "port", "",
		"CloudSQL postgres database port")
	fs.StringVar(&c.name, "name", "",
		"CloudSQL postgres database name")
	fs.StringVar(&c.user, "user", "",
		"CloudSQL postgres database user")
	fs.StringVar(&c.password, "password", "",
		"CloudSQL postgres database password")
	fs.StringVar(&c.namespace, "namespace", "",
		"K8s namespace the controller is deployed to")
	fs.StringVar(&c.projectID, "project-id", "",
		"GCP project id to store database password secret")
	fs.IntVar(&c.concurrency, "concurrency", 8,
		"amount of database users to reconcile at a time")
}