// MsgSyncReq: run commands on the remote host

// Copyright (C) 2021  Simon Ruderich
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package sync

import (
	"fmt"
	"os"
	"os/exec"
	"strings"

	"ruderich.org/simon/safcm"
	"ruderich.org/simon/safcm/cmd/safcm-remote/run"
)

func (s *Sync) syncCommands() error {
	// Run triggered commands first
	for _, path := range s.triggers {
		for _, x := range s.req.Files[path].TriggerCommands {
			err := s.syncCommand(x, "", path)
			if err != nil {
				return err
			}
		}
	}
	// Regular commands afterwards so they can react on triggers if
	// necessary
	for _, x := range s.req.Commands {
		err := s.syncCommand(x.Cmd, x.OrigGroup, "")
		if err != nil {
			return err
		}
	}
	return nil
}

func (s *Sync) syncCommand(command, group, trigger string) error {
	s.resp.CommandChanges = append(s.resp.CommandChanges,
		safcm.CommandChange{
			Command: command,
			Trigger: trigger,
		})
	if s.req.DryRun {
		return nil
	}
	change := &s.resp.CommandChanges[len(s.resp.CommandChanges)-1]

	var info string
	if trigger != "" {
		info = fmt.Sprintf("%q", trigger)
	} else if group != "" {
		info = group
	}

	cmd := exec.Command("/bin/sh", "-c", command)
	cmd.Env = safcmEnviroment(s.req.Groups)
	// Cannot use cmd.CombinedOutputCmd() because we need another log
	// level (here the command is the actual change and not a side effect)
	// and different error handling.
	s.log.Verbosef("commands: running %s (%s)",
		run.QuoteForDebug(cmd), info)
	out, err := s.cmd.Runner.CombinedOutput(cmd)
	if len(out) > 0 {
		s.log.Debug2f("commands: command output:\n%s", out)
	}
	change.Output = string(out)
	if err != nil {
		change.Error = err.Error()
		return fmt.Errorf("%q failed: %v", command, err)
	}

	return nil
}

func safcmEnviroment(groups []string) []string {
	exe, err := os.Executable()
	if err != nil {
		panic(err) // should not happen on supported systems
	}

	env := os.Environ()
	// Provide additional environment variables
	env = append(env,
		fmt.Sprintf("SAFCM_HELPER=%s", exe),
		fmt.Sprintf("SAFCM_GROUPS=%s", strings.Join(groups, " ")))
	for _, x := range groups {
		env = append(env, fmt.Sprintf("SAFCM_GROUP_%s=%s", x, x))
	}
	return env
}