http handler

Author: Ryan Miville

gleam.toml

@@ -17,6 +17,7 @@ target = "javascript"
 [dependencies]
 gleam_stdlib = ">= 0.34.0 and < 2.0.0"
 gleam_javascript = ">= 0.13.0 and < 1.0.0"
+gleam_http = ">= 3.7.0 and < 4.0.0"
 
 [dev-dependencies]
 gleeunit = ">= 1.0.0 and < 2.0.0"

manifest.toml

@@ -11,6 +11,7 @@ packages = [
   { name = "gleam_community_ansi", version = "1.4.1", build_tools = ["gleam"], requirements = ["gleam_community_colour", "gleam_stdlib"], otp_app = "gleam_community_ansi", source = "hex", outer_checksum = "4CD513FC62523053E62ED7BAC2F36136EC17D6A8942728250A9A00A15E340E4B" },
   { name = "gleam_community_colour", version = "1.4.0", build_tools = ["gleam"], requirements = ["gleam_json", "gleam_stdlib"], otp_app = "gleam_community_colour", source = "hex", outer_checksum = "795964217EBEDB3DA656F5EB8F67D7AD22872EB95182042D3E7AFEF32D3FD2FE" },
   { name = "gleam_erlang", version = "0.27.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_erlang", source = "hex", outer_checksum = "DE468F676D71B313C6C8C5334425CFCF827837333F8AB47B64D8A6D7AA40185D" },
+  { name = "gleam_http", version = "3.7.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_http", source = "hex", outer_checksum = "EA66440C2269F7CED0F6845E5BD0DB68095775D627FA709A841CA78A398D6D56" },
   { name = "gleam_javascript", version = "0.13.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_javascript", source = "hex", outer_checksum = "F98328FCF573DA6F3A35D7F6CB3F9FF19FD5224CCBA9151FCBEAA0B983AF2F58" },
   { name = "gleam_json", version = "1.0.1", build_tools = ["gleam"], requirements = ["gleam_stdlib", "thoas"], otp_app = "gleam_json", source = "hex", outer_checksum = "9063D14D25406326C0255BDA0021541E797D8A7A12573D849462CAFED459F6EB" },
   { name = "gleam_stdlib", version = "0.40.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "86606B75A600BBD05E539EB59FABC6E307EEEA7B1E5865AFB6D980A93BCB2181" },
@@ -26,6 +27,7 @@ packages = [
 
 [requirements]
 birdie = { version = ">= 1.2.3 and < 2.0.0" }
+gleam_http = { version = ">= 3.7.0 and < 4.0.0" }
 gleam_javascript = { version = ">= 0.13.0 and < 1.0.0" }
 gleam_stdlib = { version = ">= 0.34.0 and < 2.0.0" }
 gleeunit = { version = ">= 1.0.0 and < 2.0.0" }

src/glambda.gleam

@@ -1,7 +1,17 @@
+import gleam/bit_array
+import gleam/bool
 import gleam/dict.{type Dict}
 import gleam/dynamic.{type Dynamic}
+import gleam/http
+import gleam/http/request.{type Request, Request}
+import gleam/http/response.{type Response}
+import gleam/io
 import gleam/javascript/promise.{type Promise}
-import gleam/option.{type Option}
+import gleam/list
+import gleam/option.{type Option, None, Some}
+import gleam/regex
+import gleam/result
+import gleam/string
 
 pub type JsEvent
 
@@ -182,6 +192,108 @@ pub fn to_handler(
   }
 }
 
+pub fn http_handler(
+  handler: fn(Request(BitArray), Context) -> Promise(Response(BitArray)),
+) -> JsHandler {
+  api_gateway_proxy_v2_handler(fn(event, ctx) {
+    event
+    |> create_request
+    |> handler(ctx)
+    |> promise.map(create_response)
+  })
+}
+
+fn create_request(event: ApiGatewayProxyEventV2) -> Request(BitArray) {
+  io.debug(event.headers)
+  let method =
+    event.request_context.http.method
+    |> http.parse_method
+    |> result.unwrap(http.Get)
+  let headers = case event.cookies {
+    Some([_] as cookies) -> {
+      event.headers
+      |> dict.insert("cookie", string.join(cookies, "; "))
+      |> dict.to_list
+    }
+    _ -> dict.to_list(event.headers)
+  }
+  let body =
+    event.body
+    |> body_bit_array(event.is_base64_encoded)
+    |> result.unwrap(<<>>)
+  let host = event.request_context.domain_name
+  let path = event.raw_path
+  let query = string.to_option(event.raw_query_string)
+
+  Request(
+    method:,
+    headers:,
+    body:,
+    scheme: http.Https,
+    host:,
+    port: None,
+    path:,
+    query:,
+  )
+}
+
+fn body_bit_array(
+  body: Option(String),
+  is_base64_encoded: Bool,
+) -> Result(BitArray, Nil) {
+  use body <- result.try(option.to_result(body, Nil))
+  use <- bool.guard(!is_base64_encoded, Ok(bit_array.from_string(body)))
+  use body <- result.try(bit_array.base64_decode(body))
+  Ok(body)
+}
+
+fn create_response(response: Response(BitArray)) -> ApiGatewayProxyResultV2 {
+  let is_content_type_binary =
+    response.get_header(response, "content-type")
+    |> result.map(is_content_type_binary)
+
+  let is_base64_encoded = case is_content_type_binary {
+    Ok(True) -> True
+    _ -> {
+      response.get_header(response, "content-encoding")
+      |> result.map(is_content_encoding_binary)
+      |> result.unwrap(False)
+    }
+  }
+
+  let body = case is_base64_encoded {
+    True -> bit_array.base64_encode(response.body, False)
+    False -> bit_array.to_string(response.body) |> result.unwrap("")
+  }
+  let cookies = get_cookies(response)
+
+  ApiGatewayProxyResultV2(
+    status_code: response.status,
+    headers: dict.from_list(response.headers),
+    body: string.to_option(body),
+    is_base64_encoded:,
+    cookies:,
+  )
+}
+
+fn get_cookies(response: Response(a)) -> List(String) {
+  response.get_cookies(response)
+  |> list.map(fn(cookie) { cookie.0 <> "=" <> cookie.1 })
+}
+
+fn is_content_type_binary(content_type: String) -> Bool {
+  let assert Ok(re) =
+    regex.from_string(
+      "!/^(text\\/(plain|html|css|javascript|csv).*|application\\/(.*json|.*xml).*|image\\/svg\\+xml.*)$/",
+    )
+  regex.check(re, content_type)
+}
+
+fn is_content_encoding_binary(content_encoding: String) -> Bool {
+  let assert Ok(re) = regex.from_string("/^(gzip|deflate|compress|br)/")
+  regex.check(re, content_encoding)
+}
+
 pub fn api_gateway_proxy_v2_handler(
   handler: Handler(ApiGatewayProxyEventV2, ApiGatewayProxyResultV2),
 ) -> JsHandler {

src/glambda_ffi.mjs

@@ -1,5 +1,6 @@
 import { List } from "./gleam.mjs";
 import { Some, None, unwrap } from "../gleam_stdlib/gleam/option.mjs";
+import * as $dict from "../gleam_stdlib/gleam/dict.mjs";
 import {
   ApiGatewayProxyEventV2,
   ApiGatewayRequestContextV2,
@@ -26,10 +27,10 @@ export function to_api_gateway_proxy_event_v2(event) {
     event.rawPath,
     event.rawQueryString,
     maybeList(event.cookies),
-    event.headers,
-    maybe(event.queryStringParameters),
-    maybe(event.pathParameters),
-    maybe(event.stageVariables),
+    toDict(event.headers),
+    maybeDict(event.queryStringParameters),
+    maybeDict(event.pathParameters),
+    maybeDict(event.stageVariables),
     to_request_context(event.requestContext),
     maybe(event.body),
     event.isBase64Encoded,
@@ -134,6 +135,13 @@ function maybeList(a) {
   return new None();
 }
 
+function maybeDict(a) {
+  if (a) {
+    return new Some(toDict(a));
+  }
+  return new None();
+}
+
 export function from_api_gateway_proxy_result_v2(result) {
   return {
     statusCode: result.status_code,
@@ -163,7 +171,6 @@ function to_cognito_identity(identity) {
   if (!identity) {
     return undefined;
   }
-  console.log(identity);
   return new CognitoIdentity(
     identity.cognitoIdentityId,
     identity.cognitoIdentityPoolId,
@@ -200,3 +207,7 @@ function to_client_context_env(env) {
     env.timezone,
   );
 }
+
+function toDict(obj) {
+  return $dict.from_list(List.fromArray(Object.entries(obj)));
+}