add debug function

Author: siongui

Diff for: debug.go

@@ -3,9 +3,24 @@ package instago
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"strings"
+	"time"
 )
 
+var saveRawJsonByte = false
+
+// If set to true, the JSON data returned by API endpoint will be saved. For
+// development purpose. default is false.
+func SetSaveRawJsonByte(b bool) {
+	saveRawJsonByte = b
+}
+
+func SaveRawJsonByte(prefix string, b []byte) (err error) {
+	filename := prefix + time.Now().Format(time.RFC3339) + ".json"
+	return ioutil.WriteFile(filename, b, 0644)
+}
+
 func jsonPrettyPrint(v interface{}) {
 	b, err := json.MarshalIndent(v, "", "  ")
 	if err != nil {

Diff for: follow.go

@@ -59,7 +59,11 @@ func (m *IGApiManager) getFollowResponse(url string) (rf rawFollow, err error) {
 		return
 	}
 
-	//println(string(b))
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("follow-", b)
+	}
+
 	err = json.Unmarshal(b, &rf)
 	return
 }

Diff for: media.go

@@ -26,7 +26,11 @@ func (m *IGApiManager) GetMediaInfo(id string) (item IGItem, err error) {
 		return
 	}
 
-	//println(string(b))
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("media-"+id+"-info-", b)
+	}
+
 	mpp := mediaPostResp{}
 	err = json.Unmarshal(b, &mpp)
 	if err != nil {

Diff for: post.go

@@ -29,6 +29,11 @@ func (m *IGApiManager) GetPostInfo(code string) (em IGMedia, err error) {
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("post-"+code+"-with-login-", b)
+	}
+
 	pi := postInfo{}
 	err = json.Unmarshal(b, &pi)
 	if err != nil {
@@ -46,6 +51,11 @@ func GetPostInfoNoLogin(code string) (em IGMedia, err error) {
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("post-"+code+"-no-login-", b)
+	}
+
 	pi := postInfo{}
 	err = json.Unmarshal(b, &pi)
 	if err != nil {

Diff for: reelsmedia.go

@@ -24,6 +24,11 @@ func (m *IGApiManager) GetHighlightsReelsMedia(id string) (tray IGStoryHighlight
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("reels_media-", b)
+	}
+
 	// The name of json field is the id of the highlight tray, which is only
 	// known in run-time, not compile-time. So we need to replace the id of
 	// the highlight tray with *reels_media*, which can be decoded by Go

Diff for: reelstray.go

@@ -65,7 +65,11 @@ func (m *IGApiManager) GetReelsTray() (r reelsTray, err error) {
 		return
 	}
 
-	//println(string(b))
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("reels_tray-", b)
+	}
+
 	err = json.Unmarshal(b, &r)
 	return
 }

Diff for: saved.go

@@ -47,6 +47,11 @@ func (m *IGApiManager) GetSavedPosts(numOfItem int) (items []IGItem, err error)
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("saved-", b)
+	}
+
 	spp := savedPostsResp{}
 	err = json.Unmarshal(b, &spp)
 	if err != nil {
@@ -90,6 +95,11 @@ func (m *IGApiManager) GetSavedCollection(id string) (items []IGItem, err error)
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte(id+"-collection-", b)
+	}
+
 	spp := savedPostsResp{}
 	err = json.Unmarshal(b, &spp)
 	if err != nil {
@@ -109,6 +119,11 @@ func (m *IGApiManager) GetSavedCollectionList() (c []Collection, err error) {
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("collections-list-", b)
+	}
+
 	cl := collectionsList{}
 	err = json.Unmarshal(b, &cl)
 	if err != nil {

Diff for: timeline.go

@@ -23,7 +23,11 @@ func (m *IGApiManager) GetTimeline() (tl IGTimeline, err error) {
 		return
 	}
 
-	//println(string(b))
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte("timeline-", b)
+	}
+
 	err = json.Unmarshal(b, &tl)
 	return
 }

Diff for: userreelmedia.go

@@ -23,6 +23,11 @@ func (m *IGApiManager) GetUserReelMedia(userid string) (ut userTray, err error)
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte(userid+"-story-", b)
+	}
+
 	err = json.Unmarshal(b, &ut)
 	return
 }

Diff for: userstory.go

@@ -17,6 +17,11 @@ func (m *IGApiManager) GetUserStory(id string) (tray IGReelTray, err error) {
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte(id+"-reel_media-", b)
+	}
+
 	err = json.Unmarshal(b, &tray)
 	return
 }

Diff for: userstoryhighlight.go

@@ -66,6 +66,11 @@ func (m *IGApiManager) GetUserStoryHighlights(id string) (trays []IGStoryHighlig
 		return
 	}
 
+	// for development purpose
+	if saveRawJsonByte {
+		SaveRawJsonByte(id+"-highlights_tray-", b)
+	}
+
 	t := rawHighlightsTray{}
 	err = json.Unmarshal(b, &t)
 	if err != nil {