perf(chat): 分页客服会话并拆分统计查询

backend/migrations/000057_chat_attention_rules.sql

@@ -0,0 +1,37 @@
+-- +goose Up
+-- +goose StatementBegin
+
+ALTER TABLE chat_messages
+  ADD COLUMN admin_attention_type VARCHAR(32) NOT NULL DEFAULT '' COMMENT '客服关注类型: user_inquiry用户咨询, order_paid支付成功' AFTER attachment_urls,
+  ADD KEY idx_chat_messages_attention (conversation_id, admin_attention_type, id);
+
+UPDATE chat_messages
+SET admin_attention_type = 'user_inquiry'
+WHERE sender_type = 'user' AND admin_attention_type = '';
+
+INSERT INTO chat_admin_conversation_states (
+  conversation_id, admin_user_id, remark, last_read_message_id, last_read_at
+)
+SELECT c.id, au.id, '', COALESCE(c.last_message_id, 0), c.last_message_at
+FROM chat_conversations c
+JOIN admin_users au ON au.status = 'active'
+JOIN admin_user_roles aur ON aur.admin_user_id = au.id
+JOIN roles r ON r.id = aur.role_id AND r.code = 'cs'
+LEFT JOIN chat_admin_conversation_states cas
+  ON cas.conversation_id = c.id AND cas.admin_user_id = au.id
+WHERE cas.id IS NULL;
+
+UPDATE chat_admin_conversation_states cas
+JOIN chat_conversations c ON c.id = cas.conversation_id
+SET cas.last_read_message_id = COALESCE(c.last_message_id, 0),
+    cas.last_read_at = c.last_message_at
+WHERE cas.last_read_message_id = 0;
+
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+ALTER TABLE chat_messages
+  DROP KEY idx_chat_messages_attention,
+  DROP COLUMN admin_attention_type;
+-- +goose StatementEnd