Initial commit

internal/moon/casChatAPI.go

@@ -0,0 +1,100 @@
+package moon
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/hjson/hjson-go"
+)
+
+// CasCheckID check given telegram user id vs CAS spammers base.
+// https://api.cas.chat/check?user_id=821871410
+func CasCheckID(id int64) (bool, error) {
+	var (
+		result bool
+		err    error
+		url    = fmt.Sprintf("https://api.cas.chat/check?user_id=%d", id)
+		c      = &http.Client{
+			Timeout: 15 * time.Second,
+		}
+		banned    CasTrue
+		notBanned CasFalse
+	)
+
+	resp, err := c.Get(url) //nolint: bodyclose, noctx
+
+	if err != nil {
+		return result, fmt.Errorf("unable to query api.cas.chat, %w", err)
+	}
+
+	// Looks like we should clse body as it it recommends in docs: https://pkg.go.dev/net/http .
+	defer func(Body io.ReadCloser) {
+		err := Body.Close()
+
+		if err != nil {
+			Log.Errorf("Unable to close response body for request to %s: %s", url, err)
+		}
+	}(resp.Body)
+
+	// Client should not return with http status code other than 200.
+	if resp.StatusCode > 200 {
+		return result, fmt.Errorf( //nolint: err113
+			"api.cas.chat returns non-200 http status code: %d %s",
+			resp.StatusCode, resp.Status)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+
+	if err != nil {
+		return result, fmt.Errorf("unable to read response from api.cas.chat, %w", err)
+	}
+
+	// looks like go native json decoder is pretty shitty, so we'll take hjson as less restrictive parser, parse json
+	// encode it back to struct, then parse struct as encode/json
+
+	var tmp map[string]any
+	err = hjson.Unmarshal(body, &tmp)
+
+	// Не удалось распарсить.
+	if err != nil {
+		return result, fmt.Errorf("unable to parse response from api.cas.chat via hjson: %w", err)
+	}
+
+	tmpjson, err := json.Marshal(tmp)
+
+	// Не удалось преобразовать map-ку в json.
+	if err != nil {
+		return result, fmt.Errorf(
+			"unable to parse back to json response from api.cas.chat parsed by hjson: %w", err)
+	}
+
+	if err := json.Unmarshal(tmpjson, &notBanned); err == nil {
+		// if ok field in json == false, then user is not in ban. (records about id not found)
+		if !notBanned.Ok {
+			return false, err
+		}
+	} // At this point we just ignore err != nil, because it *can be* other json type.
+
+	if err := json.Unmarshal(body, &banned); err == nil {
+		// if ok field in json == true, then user is banned. (records about id are found)
+		if banned.Ok {
+			Log.Debugf(
+				"api.cas.chat reported user with id=%d as banned: offences=%d ban_time=%s",
+				id,
+				banned.Result.Offenses,
+				banned.Result.TimeAdded,
+			)
+
+			return true, err
+		}
+
+		return result, fmt.Errorf("api.cas.chat returns strange structure: %s", string(body)) //nolint: err113
+	} // At this point we can't ignore err != nil because we do not know (yet?) other forms of json reply from cas api.
+
+	return result, fmt.Errorf("unable to parse response from api.cas.chat: %s", string(body)) //nolint: err113
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */