// Copyright 2015 Light Code Labs, LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// +build !windows,!plan9,!nacl

package caddy

import (
	"log"
	"os"
	"os/signal"
	"syscall"
)

// trapSignalsPosix captures POSIX-only signals.
func trapSignalsPosix() {
	signalToString := map[os.Signal]string{syscall.SIGHUP: "SIGHUP", syscall.SIGUSR1: "SIGUSR1"}

	go func() {
		sigchan := make(chan os.Signal, 1)
		signal.Notify(sigchan, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGUSR1, syscall.SIGUSR2)

		for sig := range sigchan {
			switch sig {
			case syscall.SIGQUIT:
				log.Println("[INFO] SIGQUIT: Terminating process")
				if PidFile != "" {
					os.Remove(PidFile)
				}
				os.Exit(0)

			case syscall.SIGTERM:
				log.Println("[INFO] SIGTERM: Shutting down")
				exitCode := executeShutdownCallbacks(signalToString[sig])
				err := Stop()
				if err != nil {
					log.Printf("[ERROR] SIGTERM stop: %v", err)
					exitCode = 3
				}
				if PidFile != "" {
					os.Remove(PidFile)
				}
				os.Exit(exitCode)

			case syscall.SIGUSR1, syscall.SIGHUP:
				log.Printf("[INFO] %s: Reloading", signalToString[sig])

				// Start with the existing Caddyfile
				caddyfileToUse, inst, err := getCurrentCaddyfile()
				if err != nil {
					log.Printf("[ERROR] %s: %v", signalToString[sig], err)
					continue
				}
				if loaderUsed.loader == nil {
					// This also should never happen
					log.Printf("[ERROR] %s: no Caddyfile loader with which to reload Caddyfile", signalToString[sig])
					continue
				}

				// Load the updated Caddyfile
				newCaddyfile, err := loaderUsed.loader.Load(inst.serverType)
				if err != nil {
					log.Printf("[ERROR] %s: loading updated Caddyfile: %v", signalToString[sig], err)
					continue
				}
				if newCaddyfile != nil {
					caddyfileToUse = newCaddyfile
				}

				// Kick off the restart; our work is done
				_, err = inst.Restart(caddyfileToUse)
				if err != nil {
					log.Printf("[ERROR] %s: %v", signalToString[sig], err)
				}

			case syscall.SIGUSR2:
				log.Println("[INFO] SIGUSR2: Upgrading")
				if err := Upgrade(); err != nil {
					log.Printf("[ERROR] SIGUSR2: upgrading: %v", err)
				}
			}
		}
	}()
}