Global code ovehaul - remove CAS and other, add 15 minute greet check

- Remove CAS, as it no longer works for us
- Remove other checks
- Implement 15 minute greet timeout check
- Fix chat logos
- Ditch thirdparty logger, use stdlib log facility wrapper for logging

internal/moon/types.go

@@ -1,40 +1,82 @@
 package moon
 
 import (
-	"os"
-	"time"
+	"github.com/NicoNex/echotron/v3"
+	"github.com/akyoto/cache"
 )
 
 // MyConfig describes bot config file format.
 type MyConfig struct {
-	Name     string `json:"name,omitempty"`
 	Token    string `json:"token,omitempty"`
 	LogLevel string `json:"loglevel,omitempty"`
 	LogFile  string `json:"logfile,omitempty"`
-	LogChats bool   `json:"logchats,omitempty"`
-	CSign    string `json:"csign,omitempty"`
-	DataDir  string `json:"datadir,omitempty"`
+
+	// ChatLogs is the directory for per-chat, per-day chat event logs. Empty
+	// disables chat logging. If set, the directory must already exist: a path
+	// that does not is a typo, and silently logging nowhere is the worst
+	// possible response to one.
+	ChatLogs string `json:"chat_logs,omitempty"`
 }
 
-// CasFalse describes response from api.cas.chat when user is not blacklisted.
-type CasFalse struct {
-	Ok          bool   `json:"ok"`
-	Description string `json:"description"`
+// tgClient is the subset of the Telegram API that bunny-bot actually calls.
+// It exists so tests can substitute a fake; echotron.API satisfies it.
+type tgClient interface {
+	SendMessage(text string, chatID int64, opts *echotron.MessageOptions) (echotron.APIResponseMessage, error)
+	BanChatMember(chatID int64, userID int64, opts *echotron.BanOptions) (echotron.APIResponseBool, error)
+	DeleteMessage(chatID int64, messageID int) (echotron.APIResponseBase, error)
 }
 
-// CasFalse describes response from api.cas.chat when user is blacklisted.
-type CasTrue struct {
-	Ok     bool `json:"ok"`
-	Result struct {
-		Reasons   []int     `json:"reasons"`
-		Offenses  int       `json:"offenses"`
-		TimeAdded time.Time `json:"time_added"`
-	} `json:"result"`
+// chatUser identifies a user's membership of one specific chat. The same user is
+// a different identity in every chat: being silent in one says nothing about
+// another, and answering in one must not rescue them in another.
+type chatUser struct {
+	chatID int64
+	userID int64
 }
 
-type Chatlog struct {
-	LogFilePath string
-	File        *os.File
+// banOutcome is what a squash attempt actually did. The three cases are distinct
+// on purpose: a duplicate ban is a success, not a failure, and reporting it as
+// one makes a working ban look broken in the logs.
+type banOutcome int
+
+// eventCache is a typed wrapper over akyoto/cache.Cache that stores values of
+// type T keyed by a Unix timestamp in microseconds. It hides the underlying
+// sync.Map so callers never deal with interface{} keys/values or per-access type
+// conversions.
+type eventCache[T any] struct {
+	cache *cache.Cache
 }
 
+// joinRef is one stale join, kept together with everything the verdict and the
+// retraction need so neither has to look anything up.
+type joinRef struct {
+	micros int64
+
+	// chat and user come from the join event itself, so a ban can be logged with
+	// the newcomer's real name and the chat's real title instead of a cache
+	// lookup that may have expired or never been populated.
+	chat echotron.Chat
+	user *echotron.User
+
+	// greetingID is the question we asked them, deleted once they are banned for
+	// never answering it. Zero means we never managed to ask.
+	greetingID int
+}
+
+// pendingGreeting is one recorded join: the message that announced it, and the
+// id of the greeting we sent in reply.
+//
+// The greeting id lives here rather than in a second cache, so that recording,
+// forgetting and retracting are all one lookup on one key. A zero greeting id
+// means "no greeting was ever delivered for this join" — never a failure.
+type pendingGreeting struct {
+	join       *echotron.Message
+	greetingID int
+}
+
+// retractOutcome is what a retraction pass actually achieved. The three cases are
+// distinct because "nothing to delete" and "tried and failed" call for different
+// log lines, and only the second is worth an operator's attention.
+type retractOutcome int
+
 /* vim: set ft=go noet ai ts=4 sw=4 sts=4: */