new: readme updated

Author: Matrix86

README.md

@@ -1,2 +1,122 @@
-# cloudwatcher
-File system notification for Cloud platforms in Golang.
+# Cloudwatcher
+![License](https://img.shields.io/github/license/Matrix86/cloudwatcher) ![GitHub go.mod Go version](https://img.shields.io/github/go-mod/go-version/Matrix86/cloudwatcher) ![GitHub Workflow Status (branch)](https://img.shields.io/github/workflow/status/Matrix86/cloudwatcher/Build%20and%20Test/main) ![GitHub release (latest by date)](https://img.shields.io/github/v/release/Matrix86/cloudwatcher?color=red) 
+
+File system notification for Cloud platforms (and not) in Golang.
+
+cloudwatcher is a file system notification library for cloud platforms (and not) in Go. 
+Currently it implements the watchers for the following services:
+- Amazon S3
+- Google Drive
+- Dropbox
+- local filesystem (fsnotify/polling)
+
+It is possible specify the directory to monitor and the polling time (how much often the watcher should check that directory), 
+and every time a new file is added, removed or changed, an event is generated and sent to the `Events` channel.
+
+## Usage
+
+```go
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/Matrix86/cloudwatcher"
+)
+
+func main() {
+	s, err := cloudwatcher.New("local", "/home/user/tests", time.Second)
+	if err != nil {
+		fmt.Printf("ERROR: %s", err)
+		return
+	}
+
+	config := map[string]string{
+		"disable_fsnotify": "false",
+	}
+
+	err = s.SetConfig(config)
+	if err != nil {
+		fmt.Printf("ERROR: %s", err)
+		return
+	}
+
+	err = s.Start()
+	defer s.Close()
+	for {
+		select {
+		case v := <-s.GetEvents():
+			fmt.Printf("EVENT: %s %s\n", v.Key, v.TypeString())
+
+		case e := <-s.GetErrors():
+			fmt.Printf("ERROR: %s\n", e)
+		}
+	}
+}
+```
+
+The channel returned by `GetEvents()` function, will return an [Event](event.go) struct that contains the event type, the Key
+with the name of the file that generates the event and the object itself.
+
+> :warning: check the Event.Object field before use it...in some cases it could be nil (FileDelete event with fsnotify)  
+
+## Amazon S3
+
+The config of the S3 watcher is the following:
+
+```go
+config := map[string]string{
+    "bucket_name": "storage",
+    "endpoint":   "s3-us-west-2.amazonaws.com",
+    "access_key":  "user",
+    "secret_key":  "secret",
+    "token":      "",
+    "region":     "us-west-2",
+    "ssl_enabled": "true",
+}
+```
+
+An example can be found [here](examples/s3/s3.go).
+
+> :gem: [minio](https://docs.min.io/docs/minio-quickstart-guide.html) can be used for testing purposes
+
+## Google Drive
+
+In order to use it you need to enable the drive API from [here](https://developers.google.com/drive/api/v3/enable-drive-api) .
+After that you can specify the `client-id` and the `client-secret` on the config file. 
+The logic to retrieve the token has to be handled outside the library and the `token` field should contain the json. 
+
+You can find an example in the [examples directory](examples/gdrive/gdrive.go). 
+
+```go
+config := map[string]string{
+    "debug":         "true",
+    "token":         Token,
+    "client_id":     ClientId,
+    "client_secret": ClientSecret,
+}
+```
+
+## Dropbox
+
+First, you need to register a new app from the [developer console](https://www.dropbox.com/developers/).
+Use the `client-id` and the `client-secret` to retrieve the user token and use it on the `token` field of the config.
+
+You can find an example in the [examples directory](examples/dropbox/dropbox.go). 
+
+```go
+config := map[string]string{
+    "debug": "true",
+    "token": Token,
+}
+```
+
+## Local filesystem
+
+It is based on [fsnotify](https://github.com/fsnotify/fsnotify) library, so it is cross platform: Windows, Linux, BSD and macOS.
+It is not mandatory to call the `SetConfig()` function, and the polling time argument of `cloudwatcher.New` is not used.
+
+Setting `disable_fsnotify` parameter on config to "true" the watcher doesn't use fsnotify and use the listing approach instead.
+
+> :warning: not set `disable_fsnotify` to "true" if you plan to use it on a big directory!!! It could increase the I/O on disk