C# - Automatic downloader with web API

C# Project: - Needs to run as a windows service (Should automatically start if it exits for any reason) - Automatically download files from a list of URLs and download paths in a json file ([login to view URL] - Example below) - There should be a config with a default download path ([login to view URL]) - The downloads should be downloaded to the path in the "[login to view URL]" and if a path is not defined then it should use the default path in the [login to view URL] - Automatically write/append a log which is named as the current date ([login to view URL]) - Log entries should contain download progress in Percentage, Download Speed, and total MB/GB downloaded - Log should report when a download is complete and when a new one is started - Log should report any failed downloads with a reason for the failure - If a download fails then it should mark it as failed in the [login to view URL] by adding "failed" key - After a failure, it should retry downloading it - Each time the download fails it should incrememnt the failed number in the [login to view URL] - If the download fails more than 3 times then it should not retry - Once a download is complete, the file should be checked to make sure it downloaded entirely to prevent false positives - Once a download is complete and verified then a status should be added to the link in the [login to view URL] - Needs an API over a built in web server with following features: -- API must respond with JSON response -- Response must contain success or error (error must have a description with reason) -- All API requests require a security hash which is calculated based on a secret string, a secret number and all GET data hashed with MD5, I will provide an example of how this is achieved in PHP. -- /addlink endpoint - Adds a link into a file --- Option to give directory of where the file should be downloaded to -- /deletelink endpoint - Removes a link from the file -- /movefile endpoint - Move a file from one path to another path -- /deletefile endpoint - Delete a file from the system for the given path -- /renamefile endpoint - Rename a file at the given path to the given name -- /downloadfile endpoint - Delivers a downloads of the file from the given path to the browser -- /downloadstatus endpoint - Check status of download by filename -- All endpoints should have a callback URL option to POST the result to another web server along with a hash generated using the same method as the checkHash function below (For example, when a download completes or fails, it should POST the result to a web server if a callback URL is provided to the API) - Web server must have a JSON config with the following options: -- Enable/Disable Web Server -- Web Server Port -- Enable/Disable SSL on Web Server -- SSL Certificate must be in its own files ([login to view URL] and [login to view URL]) -- Secret String -- Secret Number -- Enable/Disable IP Whitelist (When Whitelist is disabled, anyone can use the web server API) -- IP Whitelist (Array) - Empty array means nobody can use the web server except localhost -- IP Blacklist (Array) - This should always be enforced, even if the whitelist is disabled (Empty array means no IPs are blacklisted) Example Download Links File: [{"url":"[login to view URL]","path":"C:\\somepath","failed":0},{"url":"[login to view URL]","path":"C:\\somepath123","failed":0},{"url":"[login to view URL]","path":"C:\\Downloads","failed":3}] PHP examples: function escapeURL($s) { $s=str_replace( array(" ","+","-",".","_"), array("%20","%20","%2D","%2E","%5F"), urlencode($s)); return $s; } function checkHash($secstring,$secnum,$APIData) { $hash=$_GET["hash"]; $body=""; $cpt=0; foreach ($APIData as $name => $value) { if ($name == "hash") continue; if ($cpt++ > 0) $body .="&"; $body .= escapeURL($name)."=".escapeURL($value); } $calcHash=md5($body.$secstring.":".$secnum); if ($hash!=$calcHash) return false; return true; }