Response structure

src/Main.agda

@@ -23,41 +23,98 @@ open import NonEmpty
 open import Parse-HTTP
 open import Parse-HTTP.URL hiding (_/_)
 open import Parse-HTTP.Methods
+open import Parse-HTTP.Helpers
 open import HTML
 import HTML.Syntax
 import HTML.Render
 import UTF-8
 
-response-with-content : ℕ → S.String → String → List Byte → List Byte
-response-with-content status-code status content-type response-data =
-  UTF-8.encode-string (S.toList (status-line S.++ "\r\n" S.++ headers-lines S.++ "\r\n")) L.++ response-data
+data Content-Type : Type where
+  text/plain text/html : Content-Type
+
+instance
+  ShowContent-Type : Show Content-Type
+  ShowContent-Type .show text/plain = "text/plain"
+  ShowContent-Type .show text/html = "text/html"
+
+record Response : Type where
+  field
+    status-code : ℕ
+    status : String
+    headers : List Header -- all headers besides Content-Type and Content-Length
+    content : Maybe (Content-Type × List Byte) -- mime type and data
+open Response
+
+crlfᵇ : List Byte
+crlfᵇ = string-to-ascii-list "\r\n"
+
+encode-response : Response → List Byte
+encode-response res =
+  UTF-8.encode-string (S.toList (status-line)) L.++ crlfᵇ L.++
+  encoded-headers L.++ crlfᵇ L.++
+  (proj₂ <$> res .content or-else L.[])
   where
     status-line : String
-    status-line = "HTTP/1.1 " S.++ show status-code S.++ " " S.++ status
+    status-line = "HTTP/1.1 " S.++ show (res .status-code) S.++ " " S.++ (res .status)
 
-    response-headers : List String
-    response-headers =
-      ("Content-Type: " S.++ content-type S.++ "; charset=utf-8")
-      L.∷ ("Content-Length: " S.++ (show (L.length response-data)))
+    extra-headers : List Header
+    extra-headers = case res .content of λ where
+      cake → L.[]
+      (real (content-type , content)) →
+        record
+          { name = string-to-ascii-list⁺ "Content-Type"
+          ; value = UTF-8.encode-string (S.toList (show content-type)) ++⁺ string-to-ascii-list⁺ "; charset=utf-8"
+          }
+        L.∷ record
+          { name = string-to-ascii-list⁺ "Content-Length"
+          ; value =
+            (list-to-list⁺? (UTF-8.encode-string (S.toList (show (L.length content)))))
+            or-else (string-to-ascii-list⁺ "mjau")
+          }
         L.∷ L.[]
 
-    headers-lines : String
-    headers-lines = L.foldr (λ hdr rest → hdr S.++ "\r\n" S.++ rest) "" response-headers
+    encode-header : Header → List Byte
+    encode-header hdr = list⁺-to-list (hdr .name ⁺++⁺ string-to-ascii-list⁺ ": " ⁺++⁺ hdr .value)
+      where
+        open Header
 
-response-without-content : ℕ → S.String → List Byte
-response-without-content status-code status =
-  UTF-8.encode-string (S.toList (
-    "HTTP/1.1 " S.++ show status-code S.++ " " S.++ status S.++ "\r\n\r\n"
-  ))
+    encoded-headers : List Byte
+    encoded-headers =
+      L.concat (
+        L.map
+          (λ h → encode-header h L.++ crlfᵇ)
+          (res .headers L.++ extra-headers)
+      )
 
-200-ok : S.String → List Byte → List Byte
-200-ok content-type response-data = response-with-content 200 "OK" content-type response-data
+200-ok : Content-Type → List Byte → List Byte
+200-ok content-type content =
+  encode-response
+    record
+    { status-code = 200
+    ; status = "OK"
+    ; headers = L.[]
+    ; content = real (content-type , content)
+    }
 
 400-bad-request : List Byte
-400-bad-request = response-without-content 400 "Bad Request"
+400-bad-request =
+  encode-response
+    record
+    { status-code = 400
+    ; status = "Bad Request"
+    ; headers = L.[]
+    ; content = real (text/plain , string-to-ascii-list "what is bro doing")
+    }
 
 404-not-found : List Byte
-404-not-found = response-with-content 404 "Not Found" "text/plain" (UTF-8.encode-string (S.toList "3: could not find the resource :("))
+404-not-found =
+  encode-response
+    record
+    { status-code = 404
+    ; status = "Not Found"
+    ; headers = L.[]
+    ; content = real (text/plain , string-to-ascii-list "not found :(")
+    }
 
 module Pages where
   open HTML
@@ -91,7 +148,7 @@ handle-request req =
   if (req .target .path) == ("index.html" / $)
     then pure (
       200-ok
-        "text/html"
+        text/html
         (UTF-8.encode-string (S.toList (
           HTML.Render.render-element (Pages.render-index (req .target .query))
         )))