// Copyright (c) 2012-2014 Jeremy Latt
// Copyright (c) 2016 Daniel Oaks <daniel@danieloaks.net>
// released under the MIT license

package irc

import (
	"fmt"
	"os"
	"runtime"
	"runtime/debug"
	"runtime/pprof"
	"time"

	"github.com/DanielOaks/girc-go/ircmsg"
)

// DEBUG GCSTATS/NUMGOROUTINE/etc
func debugHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
	if !client.flags[Operator] {
		return false
	}

	switch msg.Params[0] {
	case "GCSTATS":
		stats := debug.GCStats{
			Pause:          make([]time.Duration, 10),
			PauseQuantiles: make([]time.Duration, 5),
		}
		debug.ReadGCStats(&stats)

		client.Notice(fmt.Sprintf("last GC:     %s", stats.LastGC.Format(time.RFC1123)))
		client.Notice(fmt.Sprintf("num GC:      %d", stats.NumGC))
		client.Notice(fmt.Sprintf("pause total: %s", stats.PauseTotal))
		client.Notice(fmt.Sprintf("pause quantiles min%%: %s", stats.PauseQuantiles[0]))
		client.Notice(fmt.Sprintf("pause quantiles 25%%:  %s", stats.PauseQuantiles[1]))
		client.Notice(fmt.Sprintf("pause quantiles 50%%:  %s", stats.PauseQuantiles[2]))
		client.Notice(fmt.Sprintf("pause quantiles 75%%:  %s", stats.PauseQuantiles[3]))
		client.Notice(fmt.Sprintf("pause quantiles max%%: %s", stats.PauseQuantiles[4]))

	case "NUMGOROUTINE":
		count := runtime.NumGoroutine()
		client.Notice(fmt.Sprintf("num goroutines: %d", count))

	case "PROFILEHEAP":
		profFile := "ergonomadic.mprof"
		file, err := os.Create(profFile)
		if err != nil {
			client.Notice(fmt.Sprintf("error: %s", err))
			break
		}
		defer file.Close()
		pprof.Lookup("heap").WriteTo(file, 0)
		client.Notice(fmt.Sprintf("written to %s", profFile))

	case "STARTCPUPROFILE":
		profFile := "ergonomadic.prof"
		file, err := os.Create(profFile)
		if err != nil {
			client.Notice(fmt.Sprintf("error: %s", err))
			break
		}
		if err := pprof.StartCPUProfile(file); err != nil {
			defer file.Close()
			client.Notice(fmt.Sprintf("error: %s", err))
			break
		}

		client.Notice(fmt.Sprintf("CPU profile writing to %s", profFile))

	case "STOPCPUPROFILE":
		pprof.StopCPUProfile()
		client.Notice(fmt.Sprintf("CPU profiling stopped"))
	}
	return false
}