feat: analysis gen qrcode

pkg/wechat/qrcode/wxacode.go

@@ -0,0 +1,75 @@
+package qrcode
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+
+	"lone-services/pkg/utils"
+	"lone-services/pkg/wechat/auth"
+)
+
+// 小程序码（有数量限制）：https://developers.weixin.qq.com/miniprogram/dev/OpenApiDoc/qrcode-link/qr-code/getQRCode.html
+const wxaCodeURL = "https://api.weixin.qq.com/wxa/getwxacode"
+
+// BuildPath 拼小程序 path，如 pagesB/userLogin/index?session_id=xxx
+func BuildPath(page string, params map[string]string) string {
+	if len(params) == 0 {
+		return page
+	}
+	query := url.Values{}
+	for k, v := range params {
+		query.Add(k, v)
+	}
+	return page + "?" + query.Encode()
+}
+
+// GetWxaCode 使用已有 access_token 生成有限小程序码，成功返回图片二进制。
+func (c *Client) GetWxaCode(accessToken string, req *WxaCodeRequest) ([]byte, error) {
+	if accessToken == utils.StringEmpty {
+		return nil, fmt.Errorf("wechat access_token empty")
+	}
+	if req == nil || req.Path == utils.StringEmpty {
+		return nil, fmt.Errorf("wechat qrcode path empty")
+	}
+
+	payload, err := json.Marshal(req)
+	if err != nil {
+		return nil, err
+	}
+
+	apiURL := fmt.Sprintf("%s?access_token=%s", wxaCodeURL, accessToken)
+	httpClient := &http.Client{Timeout: 15 * time.Second}
+	resp, err := httpClient.Post(apiURL, "application/json", bytes.NewReader(payload))
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("wechat qrcode http status %d", resp.StatusCode)
+	}
+
+	if err := parseImageOrError(body); err != nil {
+		return nil, err
+	}
+	return body, nil
+}
+
+// CreateWxaCode 通过 auth 拉取 access_token 后生成有限小程序码。
+func (c *Client) CreateWxaCode(ctx context.Context, req *WxaCodeRequest) ([]byte, error) {
+	token, err := auth.NewClient(c.AppID, c.Secret).AccessToken(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return c.GetWxaCode(token.AccessToken, req)
+}