Merge pull request #14 from winglang/dynamo-simulation

winglang · Aug 16, 2023 · 7680296 · 7680296
2 parents 558fa3b + 0be5983
commit 7680296
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Showing 5 changed files with 188 additions and 40 deletions.
diff --git a/README.md b/README.md
@@ -15,9 +15,6 @@ Inspired by https://eloeverything.co/.
 
 ## Development
 
-> **Note**
-> This project can't be tested using the Wing simulator yet.
-
 ### Deployment
 
 To deploy your own copy of the app, first make sure you have AWS credentials configured in your terminal for the account and region you want to deploy to.

diff --git a/dynamo.js b/dynamo.js
@@ -25,6 +25,9 @@ export async function _getItem(tableName, key) {
 
   const response = await client.send(command);
   console.log(response);
+  if (!data.Item) {
+    return undefined;
+  }
   return response;
 }
 

diff --git a/dynamodb.w b/dynamodb.w
@@ -1,5 +1,6 @@
 bring "@cdktf/provider-aws" as tfaws;
 bring aws;
+bring cloud;
 bring util;
 
 // --- dynamodb ---
@@ -15,23 +16,67 @@ struct Attribute {
   value: Json;
 }
 
+class Util {
+  extern "./util.js" static inflight jsonToMutArray(json: Json): MutArray<Map<Attribute>>;
+  extern "./util.js" static inflight jsonToArray(json: Json): Array<Map<Attribute>>;
+  extern "./util.js" static inflight mutArrayToJson(json: MutArray<Map<Attribute>>): Json;
+}
+
 // TODO: https://github.com/winglang/wing/issues/3350
 // typealias Item = Map<Attribute>;
 
 struct DynamoDBTableProps {
   hashKey: str;
 }
 
-class DynamoDBTable {
+class DynamoDBTableSim {
+  key: str;
+  data: cloud.Bucket;
+
+  init(props: DynamoDBTableProps) {
+    this.key = "data.json";
+    this.data = new cloud.Bucket();
+    this.data.addObject(this.key, "[]");
+  }
+
+  inflight putItem(item: Map<Attribute>) {
+    let items = this.data.getJson(this.key);
+    let itemsMut = Util.jsonToMutArray(items);
+    itemsMut.push(item);
+    this.data.putJson(this.key, Util.mutArrayToJson(itemsMut));
+  }
+
+  inflight getItem(map: Map<Attribute>): Map<Attribute>? {
+    let items = this.data.getJson(this.key);
+    let itemsMut = Util.jsonToMutArray(items);
+    for item in itemsMut {
+      let var matches = true;
+      for key in map.keys() {
+        let attr1 = item.get(key);
+        let attr2 = map.get(key);
+        if attr1.value != attr2.value {
+          matches = false;
+          break;
+        }
+      }
+      if matches {
+        return item;
+      }
+    }
+    return nil;
+  }
+
+  inflight scan(): Array<Map<Attribute>> {
+    let items = this.data.getJson(this.key);
+    return Util.jsonToArray(items);
+  }
+}
+
+class DynamoDBTableAws {
   table: tfaws.dynamodbTable.DynamodbTable;
   tableName: str;
   hashKey: str;
   init(props: DynamoDBTableProps) {
-    let target = util.env("WING_TARGET");
-    if target != "tf-aws" {
-      throw("Unsupported target: ${target} (expected 'tf-aws')");
-    }
-
     this.hashKey = props.hashKey;
     this.table = new tfaws.dynamodbTable.DynamodbTable(
       name: "${this.node.id}-${this.node.addr.substring(this.node.addr.length - 8)}",
@@ -149,3 +194,84 @@ class DynamoDBTable {
     }
   }
 }
+
+class DynamoDBTable {
+  tableSim: DynamoDBTableSim?;
+  tableAws: DynamoDBTableAws?;
+
+  init(props: DynamoDBTableProps) {
+    let target = util.env("WING_TARGET");
+    if target == "sim" {
+      this.tableSim = new DynamoDBTableSim(props);
+    } elif target == "tf-aws" {
+      this.tableAws = new DynamoDBTableAws(props);
+    } else {
+      throw("DynamoDBTable doesn't support target '${target}'");
+    }
+  }
+
+  bind(host: std.IInflightHost, ops: Array<str>) {
+    // currently simulator does not require permissions
+    // may change with https://github.com/winglang/wing/issues/3082
+    if let tableAws = this.tableAws {
+      if let host = aws.Function.from(host) {
+        if ops.contains("putItem") {
+          host.addPolicyStatements([aws.PolicyStatement {
+            actions: ["dynamodb:PutItem"],
+            resources: [tableAws.table.arn],
+            effect: aws.Effect.ALLOW,
+          }]);
+        }
+
+        if ops.contains("getItem") {
+          host.addPolicyStatements([aws.PolicyStatement {
+            actions: ["dynamodb:GetItem"],
+            resources: [tableAws.table.arn],
+            effect: aws.Effect.ALLOW,
+          }]);
+        }
+
+        if ops.contains("scan") {
+          host.addPolicyStatements([aws.PolicyStatement {
+            actions: ["dynamodb:Scan"],
+            resources: [tableAws.table.arn],
+            effect: aws.Effect.ALLOW,
+          }]);
+        }
+      }
+    }
+  }
+
+  inflight getItem(key: Map<Attribute>): Map<Attribute>? {
+    assert(key.size() == 1);
+    if let tableSim = this.tableSim {
+      return tableSim.getItem(key);
+    }
+    if let tableAws = this.tableAws {
+      return tableAws.getItem(key);
+    }
+    throw("no table instance found for getItem");
+  }
+
+  inflight putItem(item: Map<Attribute>) {
+    if let tableSim = this.tableSim {
+      tableSim.putItem(item);
+      return;
+    }
+    if let tableAws = this.tableAws {
+      tableAws.putItem(item);
+      return;
+    }
+    throw("no table instance found for putItem");
+  }
+
+  inflight scan(): Array<Map<Attribute>> {
+    if let tableSim = this.tableSim {
+      return tableSim.scan();
+    }
+    if let tableAws = this.tableAws {
+      return tableAws.scan();
+    }
+    throw("no table instance found for scan");
+  }
+}
diff --git a/main.w b/main.w
@@ -2,8 +2,6 @@ bring "./dynamodb.w" as ddb;
 bring cloud;
 bring math;
 
-// TODO: add image for each item?
-
 // --- types ---
 
 struct Entry {
@@ -66,17 +64,21 @@ class Store {
     this.table.putItem(_entryToMap(entry));
   }
 
-  inflight getEntry(name: str): Entry {
+  inflight getEntry(name: str): Entry? {
     let item = this.table.getItem(Map<ddb.Attribute> {
       "Name" => ddb.Attribute {
         type: ddb.AttributeType.String,
         value: name,
       },
     });
-    return Entry {
-      name: name,
-      score: num.fromStr(str.fromJson(item.get("Score").value)),
-    };
+    if let item = item {
+      return Entry {
+        name: name,
+        score: num.fromStr(str.fromJson(item.get("Score").value)),
+      };
+    } else {
+      return nil;
+    }
   }
 
   inflight getRandomPair(): Array<Entry> {
@@ -96,8 +98,20 @@ class Store {
   inflight updateScores(winner: str, loser: str): Array<num> {
     let entries = this.list();
 
-    let winnerScore = this.getEntry(winner).score;
-    let loserScore = this.getEntry(loser).score;
+    let winnerEntry = this.getEntry(winner);
+    let loserEntry = this.getEntry(loser);
+    let var winnerScore = 0;
+    let var loserScore = 0;
+    if let winnerEntry = winnerEntry {
+      winnerScore = winnerEntry.score;
+    } else {
+      throw("Winner is not a valid item");
+    }
+    if let loserEntry = loserEntry {
+      loserScore = loserEntry.score;
+    } else {
+      throw("Loser is not a valid item");
+    }
 
     // probability that the winner should have won
     let pWinner = 1.0 / (1.0 + 10 ** ((loserScore - winnerScore) / 400.0));
@@ -182,6 +196,12 @@ let api = new cloud.Api() as "VotingAppApi";
 let website = new cloud.Website(path: "./website/build");
 website.addJson("config.json", { apiUrl: api.url });
 
+let corsHeaders = {
+  "Access-Control-Allow-Headers" => "*",
+  "Access-Control-Allow-Origin" => "*",
+  "Access-Control-Allow-Methods" =>  "OPTIONS,GET",
+};
+
 // Select two random items from the list of items for the user to choose between
 api.post("/requestChoices", inflight (_) => {
   let entries = store.getRandomPair();
@@ -190,12 +210,7 @@ api.post("/requestChoices", inflight (_) => {
     entryNames.push(entry.name);
   }
   return cloud.ApiResponse {
-    // TODO: refactor to a constant - https://github.com/winglang/wing/issues/3119
-    headers: {
-      "Access-Control-Allow-Headers" => "*",
-      "Access-Control-Allow-Origin" => "*",
-      "Access-Control-Allow-Methods" =>  "OPTIONS,GET",
-    },
+    headers: corsHeaders,
     status: 200,
     body: Json.stringify(entryNames),
   };
@@ -205,12 +220,7 @@ api.post("/requestChoices", inflight (_) => {
 api.get("/leaderboard", inflight (_) => {
   let entries = store.list();
   return cloud.ApiResponse {
-    // TODO: refactor to a constant - https://github.com/winglang/wing/issues/3119
-    headers: {
-      "Access-Control-Allow-Headers" => "*",
-      "Access-Control-Allow-Origin" => "*",
-      "Access-Control-Allow-Methods" =>  "OPTIONS,GET",
-    },
+    headers: corsHeaders,
     status: 200,
     body: Json.stringify(entries),
   };
@@ -220,21 +230,25 @@ api.get("/leaderboard", inflight (_) => {
 api.post("/selectWinner", inflight (req) => {
   let body = Json.parse(req.body ?? "");
   log(Json.stringify(body, 2));
-  // TODO: https://github.com/winglang/wing/pull/3648
-  let selections = Util.jsonToSelectWinnerRequest(body);
-
-  let newScores = store.updateScores(selections.winner, selections.loser);
+  let selections = SelectWinnerRequest.fromJson(body);
+
+  let var newScores = Array<num>[];
+  try {
+     newScores = store.updateScores(selections.winner, selections.loser);
+  } catch e {
+    return cloud.ApiResponse {
+      headers: corsHeaders,
+      status: 400,
+      body: "Error: " + Json.stringify(e),
+    };
+  }
   let payload = SelectWinnerResponse {
     winner: newScores.at(0),
     loser: newScores.at(1),
   };
 
   return cloud.ApiResponse {
-    headers: {
-    "Access-Control-Allow-Headers" => "*",
-    "Access-Control-Allow-Origin" => "*",
-    "Access-Control-Allow-Methods" =>  "OPTIONS,GET",
-  },
+    headers: corsHeaders,
     status: 200,
     body: Json.stringify(payload),
   };

diff --git a/util.js b/util.js
@@ -1,3 +1,11 @@
-exports.jsonToSelectWinnerRequest = function(value) {
+exports.jsonToMutArray = function(value) {
+    return value;
+}
+
+exports.jsonToArray = function(value) {
+    return value;
+}
+
+exports.mutArrayToJson = function(value) {
     return value;
 }