package main

import (
	"context"
	"fmt"
	"io"
	"os"
	"runtime"
)

// runDwim implements the dwim subcommand: it runs what "sfdupes scan
// root" runs with no flags, then what "sfdupes trees" runs, and ends
// with a line on stderr saying how to print the report again. The dwim
// command passes "/" as root. It catches SIGINT and SIGTERM as scan
// does, but only during the scan. An error from the scan, an interrupt
// included, ends it before the report. During the report, a signal
// ends it at once, as it ends trees.
func runDwim(ctx context.Context, root string, stdout io.Writer) error {
	scanCtx, stop := interruptContext(ctx)
	err := runScan(scanCtx, []string{root}, runtime.NumCPU(), false, false)

	stop()

	if err != nil {
		return err
	}

	err = runTrees(ctx, stdout)
	if err != nil {
		return err
	}

	fmt.Fprintln(os.Stderr,
		`dwim: run "sfdupes trees" to print this report again`)

	return nil
}