package main

import (
	"runtime"

	profilerconfig "git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-node/config/profiler"
	httputil "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/http"
)

func initProfilerService(c *cfg) {
	tuneProfilers(c)

	pprof, _ := pprofComponent(c)
	pprof.init(c)
}

func pprofComponent(c *cfg) (*httpComponent, bool) {
	var updated bool
	// check if it has been inited before
	if c.dynamicConfiguration.pprof == nil {
		c.dynamicConfiguration.pprof = new(httpComponent)
		c.dynamicConfiguration.pprof.cfg = c
		c.dynamicConfiguration.pprof.name = "pprof"
		c.dynamicConfiguration.pprof.handler = httputil.Handler()
		c.dynamicConfiguration.pprof.preReload = tuneProfilers
		updated = true
	}

	// (re)init read configuration
	enabled := profilerconfig.Enabled(c.appCfg)
	if enabled != c.dynamicConfiguration.pprof.enabled {
		c.dynamicConfiguration.pprof.enabled = enabled
		updated = true
	}
	address := profilerconfig.Address(c.appCfg)
	if address != c.dynamicConfiguration.pprof.address {
		c.dynamicConfiguration.pprof.address = address
		updated = true
	}
	dur := profilerconfig.ShutdownTimeout(c.appCfg)
	if dur != c.dynamicConfiguration.pprof.shutdownDur {
		c.dynamicConfiguration.pprof.shutdownDur = dur
		updated = true
	}

	return c.dynamicConfiguration.pprof, updated
}

func tuneProfilers(c *cfg) {
	// Disabled by default, see documentation for
	// runtime.SetBlockProfileRate() and runtime.SetMutexProfileFraction().
	blockRate := 0
	mutexRate := 0

	if profilerconfig.Enabled(c.appCfg) {
		blockRate = profilerconfig.BlockRate(c.appCfg)
		mutexRate = profilerconfig.MutexRate(c.appCfg)
	}

	runtime.SetBlockProfileRate(blockRate)
	runtime.SetMutexProfileFraction(mutexRate)
}