package api

import (
	. "context"
	"sync"
	"time"

	"github.com/qiniu/x/rpc.v7"
)

const DefaultApiHost string = "http://uc.qbox.me"

var (
	bucketMu    sync.RWMutex
	bucketCache = make(map[string]BucketInfo)
)

type Client struct {
	*rpc.Client
	host   string
	scheme string
}

func NewClient(host string, scheme string) *Client {
	if host == "" {
		host = DefaultApiHost
	}
	client := rpc.DefaultClient
	return &Client{&client, host, scheme}
}

type BucketInfo struct {
	UpHosts []string `json:"up"`
	IoHost  string   `json:"io"`
	Expire  int64    `json:"expire"` // expire == 0 means no expire
}

func (p *Client) GetBucketInfo(ak, bucketName string) (ret BucketInfo, err error) {
	key := ak + ":" + bucketName + ":" + p.scheme
	bucketMu.RLock()
	bucketInfo, ok := bucketCache[key]
	bucketMu.RUnlock()
	if ok && (bucketInfo.Expire == 0 || bucketInfo.Expire > time.Now().Unix()) {
		ret = bucketInfo
		return
	}
	hostInfo, err := p.bucketHosts(ak, bucketName)
	if err != nil {
		return
	}
	ret.Expire = time.Now().Unix() + hostInfo.Ttl
	if p.scheme == "https" {
		ret.UpHosts = hostInfo.Https["up"]
		if iohosts, ok := hostInfo.Https["io"]; ok && len(iohosts) != 0 {
			ret.IoHost = iohosts[0]
		}
	} else {
		ret.UpHosts = hostInfo.Http["up"]
		if iohosts, ok := hostInfo.Http["io"]; ok && len(iohosts) != 0 {
			ret.IoHost = iohosts[0]
		}
	}
	bucketMu.Lock()
	bucketCache[key] = ret
	bucketMu.Unlock()
	return
}

type HostsInfo struct {
	Ttl   int64               `json:"ttl"`
	Http  map[string][]string `json:"http"`
	Https map[string][]string `json:"https"`
}

/*
请求包：
	GET /v1/query?ak=<ak>&&bucket=<bucket>
返回包：
	200 OK {
	  "ttl": <ttl>,              // 有效时间
	  "http": {
	    "up": [],
	    "io": [],                // 当bucket为global时，我们不需要iohost, io缺省
	  },
	  "https": {
	    "up": [],
	    "io": [],                // 当bucket为global时，我们不需要iohost, io缺省
	  }
	}
*/

func (p *Client) bucketHosts(ak, bucket string) (info HostsInfo, err error) {
	ctx := Background()
	err = p.CallWithForm(ctx, &info, "GET", p.host+"/v1/query", map[string][]string{
		"ak":     []string{ak},
		"bucket": []string{bucket},
	})
	return
}