initial commit

27 files changed, 596 insertions, 0 deletions

diff --git a/frontend/.gitignore b/frontend/.gitignore
new file mode 100644
index 0000000..8225baa
--- /dev/null
+++ b/frontend/.gitignore
@@ -0,0 +1,2 @@
+/node_modules
+/dist
diff --git a/frontend/build.mjs b/frontend/build.mjs
new file mode 100644
index 0000000..d48c546
--- /dev/null
+++ b/frontend/build.mjs
@@ -0,0 +1,13 @@
+import esbuild from 'esbuild';
+
+await esbuild.build({
+  entryPoints: ['src/game.jsx', 'src/watch.jsx'],
+  outdir: 'dist/js',
+  bundle: true,
+  // minify: true,
+  minify: false,
+  sourcemap: true,
+  platform: 'browser',
+  format: 'esm',
+  jsx: 'automatic',
+});
diff --git a/frontend/package-lock.json b/frontend/package-lock.json
new file mode 100644
index 0000000..7ed1aea
--- /dev/null
+++ b/frontend/package-lock.json
@@ -0,0 +1,143 @@
+{
+  "name": "frontend",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "frontend",
+      "version": "1.0.0",
+      "license": "ISC",
+      "dependencies": {
+        "react": "^18.3.1",
+        "react-dom": "^18.3.1",
+        "react-use-websocket": "^4.8.1",
+        "use-debounce": "^10.0.1"
+      },
+      "devDependencies": {
+        "esbuild": "^0.21.4"
+      }
+    },
+    "node_modules/@esbuild/linux-x64": {
+      "version": "0.21.4",
+      "resolved": "https://registry.npmjs.org/@esbuild/linux-x64/-/linux-x64-0.21.4.tgz",
+      "integrity": "sha512-Td9jv782UMAFsuLZINfUpoF5mZIbAj+jv1YVtE58rFtfvoKRiKSkRGQfHTgKamLVT/fO7203bHa3wU122V/Bdg==",
+      "cpu": [
+        "x64"
+      ],
+      "dev": true,
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/esbuild": {
+      "version": "0.21.4",
+      "resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.21.4.tgz",
+      "integrity": "sha512-sFMcNNrj+Q0ZDolrp5pDhH0nRPN9hLIM3fRPwgbLYJeSHHgnXSnbV3xYgSVuOeLWH9c73VwmEverVzupIv5xuA==",
+      "dev": true,
+      "hasInstallScript": true,
+      "bin": {
+        "esbuild": "bin/esbuild"
+      },
+      "engines": {
+        "node": ">=12"
+      },
+      "optionalDependencies": {
+        "@esbuild/aix-ppc64": "0.21.4",
+        "@esbuild/android-arm": "0.21.4",
+        "@esbuild/android-arm64": "0.21.4",
+        "@esbuild/android-x64": "0.21.4",
+        "@esbuild/darwin-arm64": "0.21.4",
+        "@esbuild/darwin-x64": "0.21.4",
+        "@esbuild/freebsd-arm64": "0.21.4",
+        "@esbuild/freebsd-x64": "0.21.4",
+        "@esbuild/linux-arm": "0.21.4",
+        "@esbuild/linux-arm64": "0.21.4",
+        "@esbuild/linux-ia32": "0.21.4",
+        "@esbuild/linux-loong64": "0.21.4",
+        "@esbuild/linux-mips64el": "0.21.4",
+        "@esbuild/linux-ppc64": "0.21.4",
+        "@esbuild/linux-riscv64": "0.21.4",
+        "@esbuild/linux-s390x": "0.21.4",
+        "@esbuild/linux-x64": "0.21.4",
+        "@esbuild/netbsd-x64": "0.21.4",
+        "@esbuild/openbsd-x64": "0.21.4",
+        "@esbuild/sunos-x64": "0.21.4",
+        "@esbuild/win32-arm64": "0.21.4",
+        "@esbuild/win32-ia32": "0.21.4",
+        "@esbuild/win32-x64": "0.21.4"
+      }
+    },
+    "node_modules/js-tokens": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-4.0.0.tgz",
+      "integrity": "sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ=="
+    },
+    "node_modules/loose-envify": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/loose-envify/-/loose-envify-1.4.0.tgz",
+      "integrity": "sha512-lyuxPGr/Wfhrlem2CL/UcnUc1zcqKAImBDzukY7Y5F/yQiNdko6+fRLevlw1HgMySw7f611UIY408EtxRSoK3Q==",
+      "dependencies": {
+        "js-tokens": "^3.0.0 || ^4.0.0"
+      },
+      "bin": {
+        "loose-envify": "cli.js"
+      }
+    },
+    "node_modules/react": {
+      "version": "18.3.1",
+      "resolved": "https://registry.npmjs.org/react/-/react-18.3.1.tgz",
+      "integrity": "sha512-wS+hAgJShR0KhEvPJArfuPVN1+Hz1t0Y6n5jLrGQbkb4urgPE/0Rve+1kMB1v/oWgHgm4WIcV+i7F2pTVj+2iQ==",
+      "dependencies": {
+        "loose-envify": "^1.1.0"
+      },
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
+    "node_modules/react-dom": {
+      "version": "18.3.1",
+      "resolved": "https://registry.npmjs.org/react-dom/-/react-dom-18.3.1.tgz",
+      "integrity": "sha512-5m4nQKp+rZRb09LNH59GM4BxTh9251/ylbKIbpe7TpGxfJ+9kv6BLkLBXIjjspbgbnIBNqlI23tRnTWT0snUIw==",
+      "dependencies": {
+        "loose-envify": "^1.1.0",
+        "scheduler": "^0.23.2"
+      },
+      "peerDependencies": {
+        "react": "^18.3.1"
+      }
+    },
+    "node_modules/react-use-websocket": {
+      "version": "4.8.1",
+      "resolved": "https://registry.npmjs.org/react-use-websocket/-/react-use-websocket-4.8.1.tgz",
+      "integrity": "sha512-FTXuG5O+LFozmu1BRfrzl7UIQngECvGJmL7BHsK4TYXuVt+mCizVA8lT0hGSIF0Z0TedF7bOo1nRzOUdginhDw==",
+      "peerDependencies": {
+        "react": ">= 18.0.0",
+        "react-dom": ">= 18.0.0"
+      }
+    },
+    "node_modules/scheduler": {
+      "version": "0.23.2",
+      "resolved": "https://registry.npmjs.org/scheduler/-/scheduler-0.23.2.tgz",
+      "integrity": "sha512-UOShsPwz7NrMUqhR6t0hWjFduvOzbtv7toDH1/hIrfRNIDBnnBWd0CwJTGvTpngVlmwGCdP9/Zl/tVrDqcuYzQ==",
+      "dependencies": {
+        "loose-envify": "^1.1.0"
+      }
+    },
+    "node_modules/use-debounce": {
+      "version": "10.0.1",
+      "resolved": "https://registry.npmjs.org/use-debounce/-/use-debounce-10.0.1.tgz",
+      "integrity": "sha512-0uUXjOfm44e6z4LZ/woZvkM8FwV1wiuoB6xnrrOmeAEjRDDzTLQNRFtYHvqUsJdrz1X37j0rVGIVp144GLHGKg==",
+      "engines": {
+        "node": ">= 16.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=16.8.0"
+      }
+    }
+  }
+}
diff --git a/frontend/package.json b/frontend/package.json
new file mode 100644
index 0000000..dd13aac
--- /dev/null
+++ b/frontend/package.json
@@ -0,0 +1,20 @@
+{
+  "name": "frontend",
+  "version": "1.0.0",
+  "description": "",
+  "scripts": {
+    "build": "node build.mjs",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "react-use-websocket": "^4.8.1",
+    "use-debounce": "^10.0.1"
+  },
+  "devDependencies": {
+    "esbuild": "^0.21.4"
+  }
+}
diff --git a/frontend/public/golf/game.html b/frontend/public/golf/game.html
new file mode 100644
index 0000000..bbe949f
--- /dev/null
+++ b/frontend/public/golf/game.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Golf | Albatross.swift</title>
+  </head>
+  <body>
+    <h1>Golf</h1>
+    <div id="app"></div>
+    <script type="module" src="/js/game.js"></script>
+  </body>
+</html>
diff --git a/frontend/public/golf/index.html b/frontend/public/golf/index.html
new file mode 100644
index 0000000..1d5bc9d
--- /dev/null
+++ b/frontend/public/golf/index.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Golf | Albatross.swift</title>
+  </head>
+  <body>
+    <h1>Golf</h1>
+    <form method="post">
+      <div>
+        <label for="name">名前</label>
+        <input type="text" name="name" required>
+      </div>
+      <div>
+        <button type="submit">開始</button>
+      </div>
+    </form>
+  </body>
+</html>
diff --git a/frontend/public/golf/watch.html b/frontend/public/golf/watch.html
new file mode 100644
index 0000000..6ab7699
--- /dev/null
+++ b/frontend/public/golf/watch.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Golf | Albatross.swift</title>
+  </head>
+  <body>
+    <h1>Golf</h1>
+    <div id="app"></div>
+    <script type="module" src="/js/watch.js"></script>
+  </body>
+</html>
diff --git a/frontend/public/index.html b/frontend/public/index.html
new file mode 100644
index 0000000..8101332
--- /dev/null
+++ b/frontend/public/index.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Albatross.swift</title>
+  </head>
+  <body>
+    <h1>Albatross.swift</h1>
+    <div>
+      <div>
+        <a href="/golf/">ゴルフ</a>
+      </div>
+      <div>
+        <a href="/race/">レース</a>
+      </div>
+    </div>
+  </body>
+</html>
diff --git a/frontend/public/race/game.html b/frontend/public/race/game.html
new file mode 100644
index 0000000..08810cc
--- /dev/null
+++ b/frontend/public/race/game.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Race | Albatross.swift</title>
+  </head>
+  <body>
+    <h1>Race</h1>
+    <div>
+    </div>
+  </body>
+</html>
diff --git a/frontend/public/race/index.html b/frontend/public/race/index.html
new file mode 100644
index 0000000..930f2e7
--- /dev/null
+++ b/frontend/public/race/index.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Race | Albatross.swift</title>
+  </head>
+  <body>
+    <h1>Race</h1>
+    <form>
+      <label for="name">名前</label>
+      <input type="text" name="name">
+      <button type="submit">開始</button>
+    </form>
+  </body>
+</html>
diff --git a/frontend/public/race/watch.html b/frontend/public/race/watch.html
new file mode 100644
index 0000000..08810cc
--- /dev/null
+++ b/frontend/public/race/watch.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Race | Albatross.swift</title>
+  </head>
+  <body>
+    <h1>Race</h1>
+    <div>
+    </div>
+  </body>
+</html>
diff --git a/frontend/src/game.jsx b/frontend/src/game.jsx
new file mode 100644
index 0000000..8b31d54
--- /dev/null
+++ b/frontend/src/game.jsx
@@ -0,0 +1,12 @@
+import { createRoot } from 'react-dom/client';
+import App from './game/App.jsx';
+
+const url = new URL(window.location.href);
+const path = url.pathname;
+const match = path.match(/\/golf\/(\d+)\/(a|b)\/$/);
+if (match) {
+  const gameId = match[1];
+  const team = match[2];
+
+  createRoot(document.getElementById('app')).render(<App gameId={gameId} team={team} />);
+}
diff --git a/frontend/src/game/App.jsx b/frontend/src/game/App.jsx
new file mode 100644
index 0000000..9a41ea4
--- /dev/null
+++ b/frontend/src/game/App.jsx
@@ -0,0 +1,99 @@
+import { useState, useEffect } from 'react';
+import useWebSocket, { ReadyState } from 'react-use-websocket';
+import { useDebouncedCallback } from 'use-debounce';
+import Connecting from './apps/Connecting.jsx';
+import Waiting from './apps/Waiting.jsx';
+import Starting from './apps/Starting.jsx';
+import Gaming from './apps/Gaming.jsx';
+import Finished from './apps/Finished.jsx';
+import Failed from './apps/Failed.jsx';
+import { GAME_STATE_CONNECTING, GAME_STATE_WAITING, GAME_STATE_STARTING, GAME_STATE_GAMING, GAME_STATE_FINISHED, GAME_STATE_FAILED } from './GameState.js';
+
+export default ({ gameId, team }) => {
+  // const socketUrl = `wss://t.nil.ninja/iosdc/2024/sock/golf/${gameId}/${team}/`;
+  const socketUrl = `ws://localhost:8002/sock/golf/${gameId}/${team}/`;
+
+  const { sendJsonMessage, lastJsonMessage, readyState } = useWebSocket(socketUrl);
+
+  const [gameState, setGameState] = useState(GAME_STATE_CONNECTING);
+
+  const [problem, setProblem] = useState(null);
+
+  // in seconds
+  const [timeLeft, setTimeLeft] = useState(null);
+  useEffect(() => {
+    if (gameState === GAME_STATE_STARTING && timeLeft !== null) {
+      const timer = setInterval(() => {
+        setTimeLeft(prevTime => {
+          if (prevTime <= 1) {
+            clearInterval(timer);
+            setGameState(GAME_STATE_GAMING);
+            return 0;
+          }
+          return prevTime - 1;
+        });
+      }, 1000);
+
+      return () => clearInterval(timer);
+    }
+  }, [gameState]);
+
+  const [score, setScore] = useState(null);
+
+  const [result, setResult] = useState(null);
+
+  const onCodeChange = useDebouncedCallback((data) => {
+    sendJsonMessage({ type: 'code', data });
+  }, 1000);
+
+  useEffect(() => {
+    if (readyState === ReadyState.UNINSTANTIATED) {
+      setGameState(GAME_STATE_FAILED);
+    } else if (readyState === ReadyState.CLOSING || readyState === ReadyState.CLOSED) {
+      if (gameState !== GAME_STATE_FINISHED) {
+        setGameState(GAME_STATE_FAILED);
+      }
+    } else if (readyState === ReadyState.CONNECTING) {
+      setGameState(GAME_STATE_CONNECTING);
+    } else if (readyState === ReadyState.OPEN) {
+      if (lastJsonMessage !== null) {
+        if (lastJsonMessage.type === 'prepare') {
+          const { problem } = lastJsonMessage.data;
+          setProblem(problem);
+          sendJsonMessage({ type: 'ready', data: {} });
+        } else if (lastJsonMessage.type === 'start') {
+          const { startTime } = lastJsonMessage.data;
+          const startTimeMs = Date.parse(startTime);
+          setTimeLeft(Math.max(0, Math.floor((startTimeMs - Date.now()) / 1000)));
+          setGameState(GAME_STATE_STARTING);
+        } else if (lastJsonMessage.type === 'finish') {
+          const result = lastJsonMessage.data;
+          setResult(result);
+          setGameState(GAME_STATE_FINISHED);
+        } else if (lastJsonMessage.type === 'score') {
+          const { score } = lastJsonMessage.data;
+          setScore(score);
+        } else {
+          setGameState(GAME_STATE_FAILED);
+        }
+      } else {
+        setGameState(GAME_STATE_WAITING);
+        sendJsonMessage({ type: 'connect', data: {} });
+      }
+    }
+  }, [readyState, lastJsonMessage]);
+
+  return (
+    <div>
+      <h1>Game #{gameId} (team #{team})</h1>
+      <div>
+        { gameState === GAME_STATE_CONNECTING ? (<Connecting gameId={gameId} team={team} />)
+          : gameState === GAME_STATE_WAITING ? (<Waiting gameId={gameId} team={team} />)
+          : gameState === GAME_STATE_STARTING ? (<Starting gameId={gameId} team={team} timeLeft={timeLeft} />)
+          : gameState === GAME_STATE_GAMING ? (<Gaming gameId={gameId} team={team} problem={problem} score={score} onCodeChange={onCodeChange} />)
+          : gameState === GAME_STATE_FINISHED ? (<Finished gameId={gameId} team={team} result={result} />)
+          : (<Failed />) }
+      </div>
+    </div>
+  );
+};
diff --git a/frontend/src/game/GameState.js b/frontend/src/game/GameState.js
new file mode 100644
index 0000000..0e733af
--- /dev/null
+++ b/frontend/src/game/GameState.js
@@ -0,0 +1,6 @@
+export const GAME_STATE_CONNECTING = 'connecting';
+export const GAME_STATE_WAITING = 'waiting';
+export const GAME_STATE_STARTING = 'starting';
+export const GAME_STATE_GAMING = 'gaming';
+export const GAME_STATE_FINISHED = 'finished';
+export const GAME_STATE_FAILED = 'failed';
diff --git a/frontend/src/game/apps/Connecting.jsx b/frontend/src/game/apps/Connecting.jsx
new file mode 100644
index 0000000..464af23
--- /dev/null
+++ b/frontend/src/game/apps/Connecting.jsx
@@ -0,0 +1,7 @@
+export default () => {
+  return (
+    <div>
+      接続中です......
+    </div>
+  );
+}
diff --git a/frontend/src/game/apps/Failed.jsx b/frontend/src/game/apps/Failed.jsx
new file mode 100644
index 0000000..f96e999
--- /dev/null
+++ b/frontend/src/game/apps/Failed.jsx
@@ -0,0 +1,7 @@
+export default () => {
+  return (
+    <div>
+      エラー
+    </div>
+  );
+}
diff --git a/frontend/src/game/apps/Finished.jsx b/frontend/src/game/apps/Finished.jsx
new file mode 100644
index 0000000..efd4e81
--- /dev/null
+++ b/frontend/src/game/apps/Finished.jsx
@@ -0,0 +1,24 @@
+export default ({ result }) => {
+  const { yourScore, opponentScore } = result;
+  const yourScoreToCompare = yourScore ?? Infinity;
+  const opponentScoreToCompare = opponentScore ?? Infinity;
+  const resultText = yourScoreToCompare === opponentScoreToCompare ? '引き分け' : (yourScoreToCompare < opponentScoreToCompare ? 'あなたの勝ち' : 'あなたの負け');
+  return (
+    <>
+      <div>
+        対戦終了
+      </div>
+      <div>
+        <div>
+          {resultText}
+        </div>
+        <div>
+          あなたのスコア: {yourScore ?? 'なし'}
+        </div>
+        <div>
+          相手のスコア: {opponentScore ?? 'なし'}
+        </div>
+      </div>
+    </>
+  );
+}
diff --git a/frontend/src/game/apps/Gaming.jsx b/frontend/src/game/apps/Gaming.jsx
new file mode 100644
index 0000000..bf47860
--- /dev/null
+++ b/frontend/src/game/apps/Gaming.jsx
@@ -0,0 +1,24 @@
+export default ({ problem, onCodeChange, score }) => {
+  const handleTextChange = (e) => {
+    onCodeChange({ code: e.target.value });
+  };
+
+  return (
+    <div style={{ display: 'flex' }}>
+      <div style={{ flex: 1, padding: '10px', borderRight: '1px solid #ccc' }}>
+        <div>
+          {problem}
+        </div>
+        <div>
+          {score == null ? 'Score: -' : `Score: ${score} byte`}
+        </div>
+      </div>
+      <div style={{ flex: 1, padding: '10px' }}>
+        <textarea
+          style={{ width: '100%', height: '100%' }}
+          onChange={handleTextChange}
+        />
+      </div>
+    </div>
+  );
+};
diff --git a/frontend/src/game/apps/Starting.jsx b/frontend/src/game/apps/Starting.jsx
new file mode 100644
index 0000000..e66aa34
--- /dev/null
+++ b/frontend/src/game/apps/Starting.jsx
@@ -0,0 +1,9 @@
+export default ({ timeLeft }) => {
+  return (
+    <>
+      <div>
+        対戦相手が見つかりました。{timeLeft} 秒後にゲームを開始します。
+      </div>
+    </>
+  );
+}
diff --git a/frontend/src/game/apps/Waiting.jsx b/frontend/src/game/apps/Waiting.jsx
new file mode 100644
index 0000000..27fdd76
--- /dev/null
+++ b/frontend/src/game/apps/Waiting.jsx
@@ -0,0 +1,7 @@
+export default () => {
+  return (
+    <div>
+      対戦相手が現れるのを待っています......
+    </div>
+  );
+}
diff --git a/frontend/src/watch.jsx b/frontend/src/watch.jsx
new file mode 100644
index 0000000..c8dcda1
--- /dev/null
+++ b/frontend/src/watch.jsx
@@ -0,0 +1,11 @@
+import { createRoot } from 'react-dom/client';
+import App from './watch/App.jsx';
+
+const url = new URL(window.location.href);
+const path = url.pathname;
+const match = path.match(/\/golf\/(\d+)\/watch\/$/);
+if (match) {
+  const gameId = match[1];
+
+  createRoot(document.getElementById('app')).render(<App gameId={gameId} />);
+}
diff --git a/frontend/src/watch/App.jsx b/frontend/src/watch/App.jsx
new file mode 100644
index 0000000..fe415bf
--- /dev/null
+++ b/frontend/src/watch/App.jsx
@@ -0,0 +1,63 @@
+import { useState, useEffect } from 'react';
+import useWebSocket, { ReadyState } from 'react-use-websocket';
+import Connecting from './apps/Connecting.jsx';
+import Waiting from './apps/Waiting.jsx';
+import Gaming from './apps/Gaming.jsx';
+import Failed from './apps/Failed.jsx';
+import { WATCH_STATE_CONNECTING, WATCH_STATE_WAITING, WATCH_STATE_GAMING, WATCH_STATE_FINISHED, WATCH_STATE_FAILED } from './WatchState.js';
+
+export default ({ gameId }) => {
+  // const socketUrl = `wss://t.nil.ninja/iosdc/2024/sock/golf/${gameId}/watch/`;
+  const socketUrl = `ws://localhost:8002/sock/golf/${gameId}/watch/`;
+
+  const { lastJsonMessage, readyState } = useWebSocket(socketUrl);
+
+  const [watchState, setWatchState] = useState(WATCH_STATE_CONNECTING);
+
+  const [problem, setProblem] = useState(null);
+
+  const [scoreA, setScoreA] = useState(null);
+  const [codeA, setCodeA] = useState(null);
+  const [scoreB, setScoreB] = useState(null);
+  const [codeB, setCodeB] = useState(null);
+
+  useEffect(() => {
+    if (readyState === ReadyState.UNINSTANTIATED) {
+      setWatchState(WATCH_STATE_FAILED);
+    } else if (readyState === ReadyState.CLOSING || readyState === ReadyState.CLOSED) {
+      if (watchState !== WATCH_STATE_FINISHED) {
+        setWatchState(WATCH_STATE_FAILED);
+      }
+    } else if (readyState === ReadyState.CONNECTING) {
+      setWatchState(WATCH_STATE_CONNECTING);
+    } else if (readyState === ReadyState.OPEN) {
+      if (lastJsonMessage !== null) {
+        if (lastJsonMessage.type === 'watch') {
+          const { problem, scoreA: scoreA_, codeA: codeA_, scoreB: scoreB_, codeB: codeB_ } = lastJsonMessage.data;
+          setProblem(problem);
+          setScoreA(scoreA_);
+          setCodeA(codeA_);
+          setScoreB(scoreB_);
+          setCodeB(codeB_);
+          setWatchState(WATCH_STATE_GAMING);
+        } else {
+          setWatchState(WATCH_STATE_FAILED);
+        }
+      } else {
+        setWatchState(WATCH_STATE_WAITING);
+      }
+    }
+  }, [readyState, lastJsonMessage]);
+
+  return (
+    <div>
+      <h1>Game #{gameId} watching</h1>
+      <div>
+        { watchState === WATCH_STATE_CONNECTING ? (<Connecting gameId={gameId} />)
+          : watchState === WATCH_STATE_WAITING ? (<Waiting gameId={gameId} />)
+          : watchState === WATCH_STATE_GAMING || watchState === WATCH_STATE_FINISHED ? (<Gaming gameId={gameId} problem={problem} scoreA={scoreA} codeA={codeA} scoreB={scoreB} codeB={codeB} />)
+          : (<Failed />) }
+      </div>
+    </div>
+  );
+};
diff --git a/frontend/src/watch/WatchState.js b/frontend/src/watch/WatchState.js
new file mode 100644
index 0000000..71f0ba6
--- /dev/null
+++ b/frontend/src/watch/WatchState.js
@@ -0,0 +1,6 @@
+export const WATCH_STATE_CONNECTING = 'connecting';
+export const WATCH_STATE_WAITING = 'waiting';
+export const WATCH_STATE_STARTING = 'starting';
+export const WATCH_STATE_GAMING = 'gaming';
+export const WATCH_STATE_FINISHED = 'finished';
+export const WATCH_STATE_FAILED = 'failed';
diff --git a/frontend/src/watch/apps/Connecting.jsx b/frontend/src/watch/apps/Connecting.jsx
new file mode 100644
index 0000000..464af23
--- /dev/null
+++ b/frontend/src/watch/apps/Connecting.jsx
@@ -0,0 +1,7 @@
+export default () => {
+  return (
+    <div>
+      接続中です......
+    </div>
+  );
+}
diff --git a/frontend/src/watch/apps/Failed.jsx b/frontend/src/watch/apps/Failed.jsx
new file mode 100644
index 0000000..f96e999
--- /dev/null
+++ b/frontend/src/watch/apps/Failed.jsx
@@ -0,0 +1,7 @@
+export default () => {
+  return (
+    <div>
+      エラー
+    </div>
+  );
+}
diff --git a/frontend/src/watch/apps/Gaming.jsx b/frontend/src/watch/apps/Gaming.jsx
new file mode 100644
index 0000000..c844c46
--- /dev/null
+++ b/frontend/src/watch/apps/Gaming.jsx
@@ -0,0 +1,29 @@
+export default ({ problem, scoreA, codeA, scoreB, codeB }) => {
+  return (
+    <>
+      <div style={{ display: 'flex', flexDirection: 'column' }}>
+        <div style={{ display: 'flex', flex: 1, justifyContent: 'center' }}>
+          {problem}
+        </div>
+        <div style={{ display: 'flex', flex: 3 }}>
+          <div style={{ display: 'flex', flex: 3, flexDirection: 'column' }}>
+            <div style={{ flex: 1, justifyContent: 'center' }}>
+              {scoreA}
+            </div>
+            <div style={{ flex: 3 }}>
+              <pre><code>{codeA}</code></pre>
+            </div>
+          </div>
+          <div style={{ display: 'flex', flex: 3, flexDirection: 'column' }}>
+            <div style={{ flex: 1, justifyContent: 'center' }}>
+              {scoreB}
+            </div>
+            <div style={{ flex: 3 }}>
+              <pre><code>{codeB}</code></pre>
+            </div>
+          </div>
+        </div>
+      </div>
+    </>
+  );
+};
diff --git a/frontend/src/watch/apps/Waiting.jsx b/frontend/src/watch/apps/Waiting.jsx
new file mode 100644
index 0000000..27fdd76
--- /dev/null
+++ b/frontend/src/watch/apps/Waiting.jsx
@@ -0,0 +1,7 @@
+export default () => {
+  return (
+    <div>
+      対戦相手が現れるのを待っています......
+    </div>
+  );
+}