From 0dc94fc121352a8f5ea14e1b37d0db4bccc2c234 Mon Sep 17 00:00:00 2001
From: Aleksandr Zelenin <aleksandr@zelenin.me>
Date: Tue, 9 Oct 2018 06:46:15 +0300
Subject: [PATCH] add pullers

---
 client/puller/chat.go       | 46 ++++++++++++++++++++++++++++++
 client/puller/chats.go      | 56 +++++++++++++++++++++++++++++++++++++
 client/puller/error.go      |  7 +++++
 client/puller/supergroup.go | 48 +++++++++++++++++++++++++++++++
 4 files changed, 157 insertions(+)
 create mode 100644 client/puller/chat.go
 create mode 100644 client/puller/chats.go
 create mode 100644 client/puller/error.go
 create mode 100644 client/puller/supergroup.go

diff --git a/client/puller/chat.go b/client/puller/chat.go
new file mode 100644
index 0000000..2cac330
--- /dev/null
+++ b/client/puller/chat.go
@@ -0,0 +1,46 @@
+package puller
+
+import (
+    "github.com/zelenin/go-tdlib/client"
+)
+
+func ChatHistory(tdlibClient *client.Client, chatId int64) (chan *client.Message, chan error) {
+    messageChan := make(chan *client.Message, 10)
+    errChan := make(chan error, 1)
+
+    var fromMessageId int64 = 0
+    var offset int32 = 0
+    var limit int32 = 100
+
+    go chatHistory(tdlibClient, messageChan, errChan, chatId, fromMessageId, offset, limit, false)
+
+    return messageChan, errChan
+}
+
+func chatHistory(tdlibClient *client.Client, messageChan chan *client.Message, errChan chan error, chatId int64, fromMessageId int64, offset int32, limit int32, onlyLocal bool) {
+    defer func() {
+        close(messageChan)
+        close(errChan)
+    }()
+
+    for {
+        messages, err := tdlibClient.GetChatHistory(chatId, fromMessageId, offset, limit, onlyLocal)
+        if err != nil {
+            errChan <- err
+
+            return
+        }
+
+        if len(messages.Messages) == 0 {
+            errChan <- EOP
+
+            break
+        }
+
+        for _, message := range messages.Messages {
+            fromMessageId = message.Id
+
+            messageChan <- message
+        }
+    }
+}
diff --git a/client/puller/chats.go b/client/puller/chats.go
new file mode 100644
index 0000000..9011181
--- /dev/null
+++ b/client/puller/chats.go
@@ -0,0 +1,56 @@
+package puller
+
+import (
+    "math"
+
+    "github.com/zelenin/go-tdlib/client"
+)
+
+func Chats(tdlibClient *client.Client) (chan *client.Chat, chan error) {
+    chatChan := make(chan *client.Chat, 10)
+    errChan := make(chan error, 1)
+
+    var offsetOrder client.JsonInt64 = math.MaxInt64
+    var offsetChatId int64 = 0
+    var limit int32 = 100
+
+    go chats(tdlibClient, chatChan, errChan, offsetOrder, offsetChatId, limit)
+
+    return chatChan, errChan
+}
+
+func chats(tdlibClient *client.Client, chatChan chan *client.Chat, errChan chan error, offsetOrder client.JsonInt64, offsetChatId int64, limit int32) {
+    defer func() {
+        close(chatChan)
+        close(errChan)
+    }()
+
+    for {
+        chats, err := tdlibClient.GetChats(offsetOrder, offsetChatId, limit)
+        if err != nil {
+            errChan <- err
+
+            return
+        }
+
+        if len(chats.ChatIds) == 0 {
+            errChan <- EOP
+
+            break
+        }
+
+        for _, chatId := range chats.ChatIds {
+            chat, err := tdlibClient.GetChat(chatId)
+            if err != nil {
+                errChan <- err
+
+                return
+            }
+
+            offsetOrder = chat.Order
+            offsetChatId = chat.Id
+
+            chatChan <- chat
+        }
+    }
+}
diff --git a/client/puller/error.go b/client/puller/error.go
new file mode 100644
index 0000000..d40b6e4
--- /dev/null
+++ b/client/puller/error.go
@@ -0,0 +1,7 @@
+package puller
+
+import (
+    "errors"
+)
+
+var EOP = errors.New("end of pull")
diff --git a/client/puller/supergroup.go b/client/puller/supergroup.go
new file mode 100644
index 0000000..2ad9692
--- /dev/null
+++ b/client/puller/supergroup.go
@@ -0,0 +1,48 @@
+package puller
+
+import (
+    "github.com/zelenin/go-tdlib/client"
+)
+
+func SupergroupMembers(tdlibClient *client.Client, supergroupId int32) (chan *client.ChatMember, chan error) {
+    chatMemberChan := make(chan *client.ChatMember, 10)
+    errChan := make(chan error, 1)
+
+    var filter client.SupergroupMembersFilter = nil
+    var offset int32 = 0
+    var limit int32 = 200
+
+    go supergroupMembers(tdlibClient, chatMemberChan, errChan, supergroupId, filter, offset, limit)
+
+    return chatMemberChan, errChan
+}
+
+func supergroupMembers(tdlibClient *client.Client, chatMemberChan chan *client.ChatMember, errChan chan error, supergroupId int32, filter client.SupergroupMembersFilter, offset int32, limit int32) {
+    defer func() {
+        close(chatMemberChan)
+        close(errChan)
+    }()
+
+    var page int32 = 0
+
+    for {
+        chatMembers, err := tdlibClient.GetSupergroupMembers(supergroupId, filter, page*limit+offset, limit)
+        if err != nil {
+            errChan <- err
+
+            return
+        }
+
+        if len(chatMembers.Members) == 0 {
+            errChan <- EOP
+
+            break
+        }
+
+        for _, member := range chatMembers.Members {
+            chatMemberChan <- member
+        }
+
+        page++
+    }
+}