package platformapi

import (
	"sync"
	"time"

	"github.com/juju/ratelimit"
)

type LimiterConfig struct {
	MaxAccessCount     int
	TimeGapMilliSecond int
}

type Limiter struct {
	limitConfig   map[string]*ratelimit.Bucket
	defaultConfig *LimiterConfig
	sync.RWMutex
}

func New(config map[string]*LimiterConfig, defaultConfig ...*LimiterConfig) *Limiter {
	limiter := &Limiter{
		limitConfig: make(map[string]*ratelimit.Bucket),
	}
	for k, v := range config {
		limiter.limitConfig[k] = ratelimit.NewBucketWithQuantum(time.Duration(v.TimeGapMilliSecond)*time.Millisecond, int64(v.MaxAccessCount), int64(v.MaxAccessCount))
	}
	if len(defaultConfig) > 0 {
		limiter.defaultConfig = defaultConfig[0]
	}
	return limiter
}

func (l *Limiter) AccessAPI(apiName string) {
	l.RLock()
	bucket := l.limitConfig[apiName]
	l.RUnlock()

	if bucket == nil && l.defaultConfig != nil {
		l.Lock()
		if bucket = l.limitConfig[apiName]; bucket == nil {
			v := l.defaultConfig
			bucket = ratelimit.NewBucketWithQuantum(time.Duration(v.TimeGapMilliSecond)*time.Millisecond, int64(v.MaxAccessCount), int64(v.MaxAccessCount))
			l.limitConfig[apiName] = bucket
		}
		l.Unlock()
	}
	if bucket != nil {
		bucket.Wait(1)
	}
}