go-api-pkg/api/http.go

package api

import (
	"bytes"
	"context"
	"encoding/json"
	"math/rand"
	"net/http"

	"github.com/go-redis/redis/v8"
)

type HttpClient struct {
	ua    string
	redis *redis.Client
}

func NewHttpClient(ua string, redis *redis.Client) *HttpClient {
	return &HttpClient{ua, redis}
}

func (c *HttpClient) SendGet(api, url string, data, out any) error {
	res, err := c.sendRequest(api, url, http.MethodGet, data)
	if err != nil {
		return err
	}

	decoder := json.NewDecoder(res.Body)
	err = decoder.Decode(&out)
	if err != nil {
		return err
	}

	return nil
}

func (c *HttpClient) SendPost(api, url string, data, out any) (any, error) {
	res, err := c.sendRequest(api, url, http.MethodPost, data)
	if err != nil {
		return nil, err
	}

	decoder := json.NewDecoder(res.Body)
	err = decoder.Decode(out)
	if err != nil {
		return nil, err
	}

	return out, nil
}

func (c *HttpClient) sendRequest(api, url, method string, data any) (*http.Response, error) {
	apiUrl := c.getApiUrl(api) + url
	client := &http.Client{}

	json, err := json.Marshal(&data)
	if err != nil {
		return nil, err
	}

	req, err := http.NewRequest(method, apiUrl, bytes.NewBuffer(json))
	if err != nil {
		return nil, err
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("User-Agent", c.ua)
	res, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	// defer res.Body.Close()

	return res, nil
}

func (c *HttpClient) getApiUrl(api string) string {
	ctx, key, apiAddr := context.Background(), "internal__"+api+"__ips", api
	// FIXME: key name ^^
	cmd := c.redis.LLen(ctx, key)
	if cmd.Err() == nil {
		len := int(cmd.Val())
		if len == 0 {
			apiAddr = c.redis.LIndex(ctx, key, 0).Val()
		} else {
			apiAddr = c.redis.LIndex(ctx, key, int64(rand.Intn(len-0)+0)).Val()
		}
	}

	if apiAddr == "" {
		apiAddr = api // default api run on 80 int port
	}

	return "https://" + apiAddr
}