Rewrite for extensibility & compactness

-This is a break from previous versions unfortunately
-Connecting is now a promise
-Chats, contacts & previously unread messages are supplied on connection
-Groups!
-Message confirmations are more reliable
-Timeout queries & connections

example/ConversationExtract.js

@@ -0,0 +1,97 @@
+const WhatsAppWeb = require("../WhatsAppWeb")
+const fs = require("fs")
+
+/** 
+ * Extract all your WhatsApp conversations & save them to a file
+ * produceAnonData => should the Id of the chat be recorded
+ * */ 
+function extractChats (authCreds, outputFile, produceAnonData=false, offset=null) {
+    let client = new WhatsAppWeb() // instantiate an instance
+    // internal extract function
+    const extract = function () {
+        let rows = 0
+        let chats = Object.keys(client.chats)
+        let encounteredOffset
+        if (offset) {
+            encounteredOffset = false
+        } else {
+            encounteredOffset = true
+            fs.writeFileSync(outputFile, "chat,input,output\n") // write header to file
+        }
+
+        const extractChat = function (index) {
+            const id = chats[index]
+            if (id.includes("g.us") || !encounteredOffset) { // skip groups
+                if (id === offset) {
+                    encounteredOffset = true
+                }
+                if (index+1 < chats.length) {
+                    return extractChat(index+1)
+                }
+                return
+            }
+            console.log("extracting for " + id + "...")
+
+            var curInput = ""
+            var curOutput = ""
+            var lastMessage
+            return client.loadEntireConversation (id, m => {
+                var text
+                if (!m.message) { // if message not present, return
+                    return
+                } else if (m.message.conversation) { // if its a plain text message
+                    text = m.message.conversation
+                } else if (m.message.extendedTextMessage && m.message.extendedTextMessage.contextInfo) { // if its a reply to a previous message
+                    const mText = m.message.extendedTextMessage.text
+                    const quotedMessage = m.message.extendedTextMessage.contextInfo.quotedMessage 
+                    // if it's like a '.' and the quoted message has no text, then just forget it
+                    if (mText.length <= 2 && !quotedMessage.conversation) {
+                        return
+                    }
+                    // if somebody sent like a '.', then the text should be the quoted message
+                    if (mText.length <= 2) {
+                        text = quotedMessage.conversation
+                    } else { // otherwise just use this text
+                        text = mText
+                    }
+                } else {
+                    return
+                }
+                // if the person who sent the message has switched, flush the row
+                if (lastMessage && !m.key.fromMe && lastMessage.key.fromMe) {
+
+                    let row = "" + (produceAnonData ? "" : id) + ",\"" + curInput + "\",\"" + curOutput + "\"\n"
+                    fs.appendFileSync (outputFile, row)
+                    rows += 1
+                    curInput = ""
+                    curOutput = ""
+                }
+
+                if (m.key.fromMe) {
+                    curOutput += curOutput === "" ? text : ("\n"+text)
+                } else {
+                    curInput += curInput === "" ? text : ("\n"+text)
+                }
+
+                lastMessage = m
+            }, 50, false) // load from the start, in chunks of 50
+            .then (() => console.log("finished extraction for " + id))
+            .then (() => {
+                if (index+1 < chats.length) {
+                    return extractChat(index+1)
+                }
+            })
+        }
+
+        extractChat(0)
+        .then (() => {
+            console.log("extracted all; total " + rows + " rows")
+            client.logout ()
+        })
+    }
+    client.connect (authCreds)
+    .then (() => extract())
+    .catch (err => console.log("got error: " + error))
+}
+let creds = null//JSON.parse(fs.readFileSync("auth_info.json"))
+extractChats(creds, "output.csv")