temp: broken push to laptop

PcgsApi/PcgsClient.cs

@@ -0,0 +1,127 @@
+using System.Net.Http.Headers;
+using System.Text.Json;
+using ReactiveUI;
+using ReactiveUI.SourceGenerators;
+
+namespace PcgsApi;
+
+public partial class PcgsClient : ReactiveObject {
+    public enum ErrorType {
+        None,
+        NoCoinFound,
+        InvalidRequestFormat,
+        ApiKeyInvalid
+    }
+
+    protected readonly string _apiKey;
+
+    protected readonly string _apiUri = "https://api.pcgs.com/publicapi";
+
+    /// <summary>
+    ///     Creates a new instance of the PcgsClient class.
+    ///     Although this is a constructor, it's meant to be called only from the CreateClient method.
+    /// </summary>
+    private PcgsClient(string apiKey) {
+        _apiKey = apiKey;
+    }
+
+    [Reactive] private int _numApiRequests;
+
+    /// <summary>
+    ///     Creates a new instance of the PcgsClient class.
+    /// </summary>
+    /// <param name="apiKey">The api key to use for requests.</param>
+    /// <returns>A new instance of the PcgsClient class, or null if the key is invalid.</returns>
+    public static async Task<PcgsClient?> CreateClient(string apiKey) {
+        // Check if the api key is valid.
+        var testClient = new PcgsClient(apiKey);
+        var validCreds = await testClient.VerifyCredentials();
+        if (!validCreds) return null;
+        return testClient;
+    }
+
+    /// <summary>
+    ///     Sends a request to the API to verify the credentials.
+    /// </summary>
+    /// <returns>A boolean indicating whether or not the credentials are valid.</returns>
+    public async Task<bool> VerifyCredentials() {
+        // Create a way to check if the api key given is valid
+        // I think the best way to do this is to make a request to the api and see if it returns the expected response.
+        var result =
+            await GetCoinFactsByGrade(1,
+                "AG-03"); // This is a known invalid coin id - this is because the api is very fast with invalid requests.
+        if (result.Item1 == ErrorType.ApiKeyInvalid) return false;
+        return true;
+    }
+
+    /// <summary>
+    ///     Gets the coin information for a given PCGS number and grade.
+    /// </summary>
+    /// <param name="pcgsNumber">The PCGS number of the coin.</param>
+    /// <param name="grade">The grade of the coin.</param>
+    /// <param name="plusGrade">Whether or not the coin is a plus grade.</param>
+    /// <returns>A tuple containing the error type and the coin information.</returns>
+    public async Task<(ErrorType, PcgsCoin?)>
+        GetCoinFactsByGrade(int pcgsNumber, string grade, bool plusGrade = false) {
+        using (var client = new HttpClient()) {
+            var gradeParam = GetGradeFromString(grade);
+
+            var requestUri =
+                $"{_apiUri}/coindetail/GetCoinFactsByGrade/?PCGSNo={pcgsNumber}&GradeNo={gradeParam}&PlusGrade={plusGrade}";
+            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", _apiKey);
+            Console.WriteLine($"Sending request to {requestUri}");
+            var response = await client.GetAsync(requestUri);
+            Console.WriteLine("Got response.");
+
+            if (response.IsSuccessStatusCode) {
+                // Check response for errors.
+                var jsonResponse = await response.Content.ReadAsStringAsync();
+                var parsedResponse = ParseJsonResponse(jsonResponse);
+                return parsedResponse;
+            }
+        }
+
+        return (ErrorType.ApiKeyInvalid, null);
+    }
+
+    /// <summary>
+    ///     Utility function to parse the grade number from the grade string passed from the front end.
+    /// </summary>
+    /// <param name="grade">The grade string.</param>
+    /// <returns>The grade number.</returns>
+    private int GetGradeFromString(string grade) {
+        var actualGrade =
+            int.Parse(grade.Substring(grade.Length - 2)); // Throws an exception if the grade doesn't exist.
+        Console.WriteLine($"Grade is {actualGrade}");
+        return actualGrade;
+    }
+
+    /// <summary>
+    ///     Parses the json response from the api.
+    /// </summary>
+    /// <param name="json">The json response.</param>
+    /// <returns>A tuple containing an error type and the coin information.</returns>
+    private (ErrorType, PcgsCoin?) ParseJsonResponse(string json) {
+        Console.WriteLine(json);
+        // Check for errors in the response
+        if (json.Contains("\"ServerMessage\":\"No data found\"")) return (ErrorType.NoCoinFound, null);
+        if (json.Contains("\"IsValidRequest\":false")) return (ErrorType.InvalidRequestFormat, null);
+
+        var newCoin = JsonSerializer.Deserialize<PcgsCoin>(json);
+        return (ErrorType.None, newCoin);
+    }
+}
+
+// Exception for invalid request format
+internal class InvalidRequestFormatException : Exception {
+    public InvalidRequestFormatException() { }
+    public InvalidRequestFormatException(string message) : base(message) { }
+    public InvalidRequestFormatException(string message, Exception inner) : base(message, inner) { }
+}
+
+// Exception for no coin found
+internal class CoinNotFoundException : Exception {
+    public CoinNotFoundException() { }
+    public CoinNotFoundException(string message) : base(message) { }
+    public CoinNotFoundException(string message, Exception inner) : base(message, inner) { }
+}