F# API (#18)

- API is now F# / Giraffe / EF Core
- Snoozed requests are complete #17
- Updated doc links in preparation for transfer to Bit Badger Solutions organization's repository

src/api/MyPrayerJournal.Api/Handlers.fs

@@ -0,0 +1,261 @@
+/// HTTP handlers for the myPrayerJournal API
+[<RequireQualifiedAccess>]
+module MyPrayerJournal.Api.Handlers
+
+open Giraffe
+open MyPrayerJournal
+open System
+
+module Error =
+
+  open Microsoft.Extensions.Logging
+
+  /// Handle errors
+  let error (ex : Exception) (log : ILogger) =
+    log.LogError (EventId(), ex, "An unhandled exception has occurred while executing the request.")
+    clearResponse >=> setStatusCode 500 >=> json ex.Message
+
+  /// Handle 404s from the API, sending known URL paths to the Vue app so that they can be handled there
+  let notFound : HttpHandler =
+    fun next ctx ->
+      [ "/answered"; "/journal"; "/snoozed"; "/user" ]
+      |> List.filter ctx.Request.Path.Value.StartsWith
+      |> List.length
+      |> function
+      | 0 -> (setStatusCode 404 >=> json ([ "error", "not found" ] |> dict)) next ctx
+      | _ -> htmlFile "wwwroot/index.html" next ctx
+
+
+/// Handler helpers
+[<AutoOpen>]
+module private Helpers =
+  
+  open Microsoft.AspNetCore.Http
+  open System.Threading.Tasks
+  open System.Security.Claims
+
+  /// Get the database context from DI
+  let db (ctx : HttpContext) =
+    ctx.GetService<AppDbContext> ()
+
+  /// Get the user's "sub" claim
+  let user (ctx : HttpContext) =
+    ctx.User.Claims |> Seq.tryFind (fun u -> u.Type = ClaimTypes.NameIdentifier)
+
+  /// Get the current user's ID
+  //  NOTE: this may raise if you don't run the request through the authorize handler first
+  let userId ctx =
+    ((user >> Option.get) ctx).Value
+
+  /// Return a 201 CREATED response
+  let created next ctx =
+    setStatusCode 201 next ctx
+
+  /// The "now" time in JavaScript
+  let jsNow () =
+    DateTime.UtcNow.Subtract(DateTime (1970, 1, 1, 0, 0, 0)).TotalSeconds |> int64 |> (*) 1000L
+  
+  /// Handler to return a 403 Not Authorized reponse
+  let notAuthorized : HttpHandler =
+    setStatusCode 403 >=> fun _ _ -> Task.FromResult<HttpContext option> None
+
+  /// Handler to require authorization
+  let authorize : HttpHandler =
+    fun next ctx -> match user ctx with Some _ -> next ctx | None -> notAuthorized next ctx
+  
+  /// Flip JSON result so we can pipe into it
+  let asJson<'T> next ctx (o : 'T) =
+    json o next ctx
+
+
+/// Strongly-typed models for post requests
+module Models =
+  
+  /// A history entry addition (AKA request update)
+  [<CLIMutable>]
+  type HistoryEntry =
+    { /// The status of the history update
+      status     : string
+      /// The text of the update
+      updateText : string
+      }
+  
+  /// An additional note
+  [<CLIMutable>]
+  type NoteEntry =
+    { /// The notes being added
+      notes : string
+      }
+  
+  /// A prayer request
+  [<CLIMutable>]
+  type Request =
+    { /// The text of the request
+      requestText : string
+      }
+  
+  /// The time until which a request should not appear in the journal
+  [<CLIMutable>]
+  type SnoozeUntil =
+    { /// The time at which the request should reappear
+      until : int64
+      }
+
+
+/// /api/journal URLs
+module Journal =
+  
+  /// GET /api/journal
+  let journal : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      userId ctx
+      |> (db ctx).JournalByUserId
+      |> asJson next ctx
+
+
+/// /api/request URLs
+module Request =
+  
+  open NCuid
+  
+  /// POST /api/request
+  let add : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let! r     = ctx.BindJsonAsync<Models.Request> ()
+        let  db    = db ctx
+        let  reqId = Cuid.Generate ()
+        let  usrId = userId ctx
+        let  now   = jsNow ()
+        { Request.empty with
+            requestId    = reqId
+            userId       = usrId
+            enteredOn    = now
+            snoozedUntil = 0L
+          }
+        |> db.AddEntry
+        { History.empty with
+            requestId = reqId
+            asOf      = now
+            status    = "Created"
+            text      = Some r.requestText
+            }
+        |> db.AddEntry
+        let! _   = db.SaveChangesAsync ()
+        let! req = db.TryJournalById reqId usrId
+        match req with
+        | Some rqst -> return! (setStatusCode 201 >=> json rqst) next ctx
+        | None -> return! Error.notFound next ctx
+        }
+
+  /// POST /api/request/[req-id]/history
+  let addHistory reqId : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let  db  = db ctx
+        let! req = db.TryRequestById reqId (userId ctx)
+        match req with
+        | Some _ ->
+            let! hist = ctx.BindJsonAsync<Models.HistoryEntry> ()
+            { History.empty with
+                requestId = reqId
+                asOf      = jsNow ()
+                status    = hist.status
+                text      = match hist.updateText with null | "" -> None | x -> Some x
+              }
+            |> db.AddEntry
+            let! _ = db.SaveChangesAsync ()
+            return! created next ctx
+        | None -> return! Error.notFound next ctx
+        }
+  
+  /// POST /api/request/[req-id]/note
+  let addNote reqId : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let  db  = db ctx
+        let! req = db.TryRequestById reqId (userId ctx)
+        match req with
+        | Some _ ->
+            let! notes = ctx.BindJsonAsync<Models.NoteEntry> ()
+            { Note.empty with
+                requestId = reqId
+                asOf = jsNow ()
+                notes = notes.notes
+              }
+            |> db.AddEntry
+            let! _ = db.SaveChangesAsync ()
+            return! created next ctx
+        | None -> return! Error.notFound next ctx
+        }
+          
+  /// GET /api/requests/answered
+  let answered : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      userId ctx
+      |> (db ctx).AnsweredRequests
+      |> asJson next ctx
+  
+  /// GET /api/request/[req-id]
+  let get reqId : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let! req = (db ctx).TryJournalById reqId (userId ctx)
+        match req with
+        | Some r -> return! json r next ctx
+        | None -> return! Error.notFound next ctx
+        }
+  
+  /// GET /api/request/[req-id]/complete
+  let getComplete reqId : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let! req = (db ctx).TryCompleteRequestById reqId (userId ctx)
+        match req with
+        | Some r -> return! json r next ctx
+        | None -> return! Error.notFound next ctx
+        }
+  
+  /// GET /api/request/[req-id]/full
+  let getFull reqId : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let! req = (db ctx).TryFullRequestById reqId (userId ctx)
+        match req with
+        | Some r -> return! json r next ctx
+        | None -> return! Error.notFound next ctx
+        }
+  
+  /// GET /api/request/[req-id]/notes
+  let getNotes reqId : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let! notes = (db ctx).NotesById reqId (userId ctx)
+        return! json notes next ctx
+        }
+  
+  /// POST /api/request/[req-id]/snooze
+  let snooze reqId : HttpHandler =
+    authorize
+    >=> fun next ctx ->
+      task {
+        let  db  = db ctx
+        let! req = db.TryRequestById reqId (userId ctx)
+        match req with
+        | Some r ->
+            let! until = ctx.BindJsonAsync<Models.SnoozeUntil> ()
+            { r with snoozedUntil = until.until }
+            |> db.UpdateEntry
+            let! _ = db.SaveChangesAsync ()
+            return! setStatusCode 204 next ctx
+        | None -> return! Error.notFound next ctx
+        }