package gojs

import (
	"github.com/ssgo/log"
	"github.com/ssgo/u"
	"runtime"
	"sync"
)

type LB struct {
	args   []any
	pool   []*Runtime
	logger *log.Logger
	debug  bool
	lock   sync.RWMutex
	num    int
}

type LBConfig struct {
	Num   uint
	Args  []any
	Debug bool
}

func (p *LB) Get() *Runtime {
	p.lock.RLock()
	i := u.GlobalRand1.Intn(p.num)
	rt := p.pool[i]
	p.lock.RUnlock()
	return rt
}

func NewLB(plg *Program, opt LBConfig, logger *log.Logger) *LB {
	if opt.Num == 0 {
		opt.Num = uint(runtime.NumCPU())
	}
	if opt.Num > uint(runtime.NumCPU())*2 {
		opt.Num = uint(runtime.NumCPU()) * 2
	}
	p := &LB{
		pool:   make([]*Runtime, opt.Num),
		args:   opt.Args,
		logger: logger,
		debug:  opt.Debug,
		num:    int(opt.Num),
	}
	p.lock.Lock()
	for i := 0; i < int(opt.Num); i++ {
		rt := New()
		err := rt.StartFromProgram(plg)
		if err == nil {
			_, err = rt.RunMain(p.args...)
		}
		if err != nil {
			p.logger.Error(err.Error())
		}
		p.pool[i] = rt
	}
	p.lock.Unlock()
	return p
}

func NewLBByFile(file string, opt LBConfig, logger *log.Logger) *LB {
	if plg, err := CompileFile(file); err == nil {
		return NewLB(plg, opt, logger)
	} else {
		return nil
	}
}

func NewLBByCode(code, refFile string, opt LBConfig, logger *log.Logger) *LB {
	if plg, err := CompileCode(code, refFile); err == nil {
		return NewLB(plg, opt, logger)
	} else {
		return nil
	}
}