// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package otelcol // import "go.opentelemetry.io/collector/otelcol"

import (
	"errors"
	"flag"

	"github.com/spf13/cobra"

	"go.opentelemetry.io/collector/featuregate"
)

// NewCommand constructs a new cobra.Command using the given CollectorSettings.
// Any URIs specified in CollectorSettings.ConfigProviderSettings.ResolverSettings.URIs
// are considered defaults and will be overwritten by config flags passed as
// command-line arguments to the executable.
func NewCommand(set CollectorSettings) *cobra.Command {
	flagSet := flags(featuregate.GlobalRegistry())
	rootCmd := &cobra.Command{
		Use:          set.BuildInfo.Command,
		Version:      set.BuildInfo.Version,
		SilenceUsage: true,
		RunE: func(cmd *cobra.Command, _ []string) error {
			err := updateSettingsUsingFlags(&set, flagSet)
			if err != nil {
				return err
			}

			col, err := NewCollector(set)
			if err != nil {
				return err
			}
			return col.Run(cmd.Context())
		},
	}
	rootCmd.AddCommand(newComponentsCommand(set))
	rootCmd.AddCommand(newValidateSubCommand(set, flagSet))
	rootCmd.Flags().AddGoFlagSet(flagSet)
	return rootCmd
}

func updateSettingsUsingFlags(set *CollectorSettings, flags *flag.FlagSet) error {
	if set.ConfigProvider == nil {
		resolverSet := &set.ConfigProviderSettings.ResolverSettings
		configFlags := getConfigFlag(flags)

		if len(configFlags) > 0 {
			resolverSet.URIs = configFlags
		}
		if len(resolverSet.URIs) == 0 {
			return errors.New("at least one config flag must be provided")
		}
		// Provide a default set of providers and converters if none have been specified.
		// TODO: Remove this after CollectorSettings.ConfigProvider is removed and instead
		// do it in the builder.
		if len(resolverSet.Providers) == 0 && len(resolverSet.Converters) == 0 {
			set.ConfigProviderSettings = newDefaultConfigProviderSettings(resolverSet.URIs)
		}
	}
	return nil
}
