public static async Task <string> InflateURLAsync(string urlshort)
{
//url short has form something like this:
//aros057.azurewebsites.net/api/FunctionRedirect?UrlShort=Y
//the last bit is the token to look in the DB.
urlshort = urlshort.Substring(urlshort.LastIndexOf("=") + 1);
//prepare tables
CloudTable tableUrl = Common.CreateTable(Common.tableNameURL);
string partitionKey = urlshort.Substring(0, 1);
TableOperation retrieveOperation = TableOperation.Retrieve <UrlEntity>(partitionKey, urlshort);
TableResult result = await tableUrl.ExecuteAsync(retrieveOperation);
UrlEntity entity = result.Result as UrlEntity;
if (entity == null || string.IsNullOrEmpty(entity.UrlFull))
{
throw new Exception("Bad link");
}
else
{
return(entity.UrlFull);
}
}
public static async Task <IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
ILogger log)
{
log.LogInformation("C# HTTP trigger function processed a request.");
//string UrlFull = req.Query["UrlFull"]; //cant use this inbuild function because there might be an & symbol, terminating the parameter
string UrlFull = null;
string qry = req.QueryString.Value;
string param = "UrlFull=";
int start = qry.IndexOf(param);
if (start >= 0)
{
UrlFull = qry.Substring(start + param.Length); //manually search for the full URL
//append 'http' protocol if none is specified
if (!UrlFull.Contains("://"))
{
UrlFull = "http://" + UrlFull;
}
}
if (string.IsNullOrEmpty(UrlFull))
{
return(new BadRequestObjectResult("No input full URL"));
}
try
{
//prepare tables
CloudTable tableUrl = Common.CreateTable(Common.tableNameURL);
//index
CloudTable tableIndex = Common.CreateTable(Common.tableNameIndex);
IndexEntity IERetrieved = await Common.RetrieveEntityUsingPointQueryAsync(tableIndex, "0", "index");
ulong index;
if (IERetrieved == null)
{
//not yet initialised
index = 0;
}
else
{
// use stored value
index = Convert.ToUInt64(IERetrieved.Index);
}
string UrlShort = Common.uLongToBase62(index);
index++;
//now save index to the table. Ensure this does not fail, same index can't possibly be used again in case of an exception
IndexEntity IE = new IndexEntity(index.ToString());
var IndexRes = await Common.InsertOrMergeEntityAsync(tableIndex, IE);
//insert URL pair to the DB
UrlEntity UrlMap = new UrlEntity(UrlShort, UrlFull);
UrlMap = (UrlEntity)await Common.InsertOrMergeEntityAsync(tableUrl, UrlMap);
string result = req.Host.Value + "/api/FunctionRedirect?UrlShort=" + UrlShort;
return(new OkObjectResult(result));
}
catch
{
return(new StatusCodeResult(500));
}
}