feat: 实现ChatGPT Codex路由器的核心功能

- 添加完整的项目基础结构，包括配置、类型定义和常量
- 实现OAuth认证流程和令牌管理
- 开发请求转换和响应处理逻辑
- 添加SSE流处理和ChatCompletions API转换
- 实现模型映射和提示指令系统
- 包含Docker部署配置和快速启动文档
- 添加自动登录功能和测试脚本

src/prompts/index.ts

@@ -0,0 +1,182 @@
+import { existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs";
+import { homedir } from "node:os";
+import { join, dirname } from "node:path";
+import { fileURLToPath } from "node:url";
+import { logError, logWarn } from "../logger.js";
+import { getModelFamily } from "../request/model-map.js";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const CACHE_DIR = join(homedir(), ".chatgpt-codex-router", "cache");
+
+const GITHUB_API_RELEASES =
+  "https://api.github.com/repos/openai/codex/releases/latest";
+const GITHUB_HTML_RELEASES =
+  "https://github.com/openai/codex/releases/latest";
+
+type ModelFamily = "gpt-5.2-codex" | "codex-max" | "codex" | "gpt-5.2" | "gpt-5.1";
+
+const PROMPT_FILES: Record<ModelFamily, string> = {
+  "gpt-5.2-codex": "gpt-5.2-codex_prompt.md",
+  "codex-max": "gpt-5.1-codex-max_prompt.md",
+  codex: "gpt_5_codex_prompt.md",
+  "gpt-5.2": "gpt_5_2_prompt.md",
+  "gpt-5.1": "gpt_5_1_prompt.md",
+};
+
+const CACHE_FILES: Record<ModelFamily, string> = {
+  "gpt-5.2-codex": "gpt-5.2-codex-instructions.md",
+  "codex-max": "codex-max-instructions.md",
+  codex: "codex-instructions.md",
+  "gpt-5.2": "gpt-5.2-instructions.md",
+  "gpt-5.1": "gpt-5.1-instructions.md",
+};
+
+interface CacheMetadata {
+  etag: string | null;
+  tag: string | null;
+  lastChecked: number | null;
+  url: string;
+}
+
+async function getLatestReleaseTag(): Promise<string> {
+  try {
+    const response = await fetch(GITHUB_API_RELEASES);
+    if (response.ok) {
+      const data = (await response.json()) as { tag_name: string };
+      if (data.tag_name) {
+        return data.tag_name;
+      }
+    }
+  } catch {
+  }
+
+  const htmlResponse = await fetch(GITHUB_HTML_RELEASES);
+  if (!htmlResponse.ok) {
+    throw new Error(
+      `Failed to fetch latest release: ${htmlResponse.status}`,
+    );
+  }
+
+  const finalUrl = htmlResponse.url;
+  if (finalUrl) {
+    const parts = finalUrl.split("/tag/");
+    const last = parts[parts.length - 1];
+    if (last && !last.includes("/")) {
+      return last;
+    }
+  }
+
+  const html = await htmlResponse.text();
+  const match = html.match(/\/openai\/codex\/releases\/tag\/([^"]+)/);
+  if (match && match[1]) {
+    return match[1];
+  }
+
+  throw new Error("Failed to determine latest release tag from GitHub");
+}
+
+async function getCodexInstructions(
+  normalizedModel = "gpt-5.1-codex",
+): Promise<string> {
+  const modelFamily = getModelFamily(normalizedModel) as ModelFamily;
+  const promptFile = PROMPT_FILES[modelFamily];
+  const cacheFile = join(CACHE_DIR, CACHE_FILES[modelFamily]);
+  const cacheMetaFile = join(
+    CACHE_DIR,
+    `${CACHE_FILES[modelFamily].replace(".md", "-meta.json")}`,
+  );
+
+  try {
+    let cachedETag: string | null = null;
+    let cachedTag: string | null = null;
+    let cachedTimestamp: number | null = null;
+
+    if (existsSync(cacheMetaFile)) {
+      const metadata = JSON.parse(
+        readFileSync(cacheMetaFile, "utf8"),
+      ) as CacheMetadata;
+      cachedETag = metadata.etag;
+      cachedTag = metadata.tag;
+      cachedTimestamp = metadata.lastChecked;
+    }
+
+    const CACHE_TTL_MS = 15 * 60 * 1000; 
+    if (
+      cachedTimestamp &&
+      Date.now() - cachedTimestamp < CACHE_TTL_MS &&
+      existsSync(cacheFile)
+    ) {
+      return readFileSync(cacheFile, "utf8");
+    }
+
+    const latestTag = await getLatestReleaseTag();
+    const CODEX_INSTRUCTIONS_URL = `https://raw.githubusercontent.com/openai/codex/${latestTag}/codex-rs/core/${promptFile}`;
+
+    if (cachedTag !== latestTag) {
+      cachedETag = null;
+    }
+
+    const headers: Record<string, string> = {};
+    if (cachedETag) {
+      headers["If-None-Match"] = cachedETag;
+    }
+
+    const response = await fetch(CODEX_INSTRUCTIONS_URL, { headers });
+
+    if (response.status === 304) {
+      if (existsSync(cacheFile)) {
+        return readFileSync(cacheFile, "utf8");
+      }
+    }
+
+    if (response.ok) {
+      const instructions = await response.text();
+      const newETag = response.headers.get("etag");
+
+      if (!existsSync(CACHE_DIR)) {
+        mkdirSync(CACHE_DIR, { recursive: true });
+      }
+
+      writeFileSync(cacheFile, instructions, "utf8");
+      writeFileSync(
+        cacheMetaFile,
+        JSON.stringify({
+          etag: newETag,
+          tag: latestTag,
+          lastChecked: Date.now(),
+          url: CODEX_INSTRUCTIONS_URL,
+        } satisfies CacheMetadata),
+        "utf8",
+      );
+
+      return instructions;
+    }
+
+    throw new Error(`HTTP ${response.status}`);
+  } catch (error) {
+    const err = error as Error;
+    logError(null, `Failed to fetch ${modelFamily} instructions from GitHub: ${err.message}`);
+
+    if (existsSync(cacheFile)) {
+      logWarn(null, `Using cached ${modelFamily} instructions`);
+      return readFileSync(cacheFile, "utf8");
+    }
+
+    logWarn(null, `Using fallback instructions for ${modelFamily}`);
+    return getFallbackPrompt();
+  }
+}
+
+function getFallbackPrompt(): string {
+  return `You are a helpful AI assistant with strong coding capabilities. 
+You can help users with a wide range of programming tasks, including:
+- Writing and debugging code
+- Explaining programming concepts
+- Refactoring and optimizing code
+- Generating code examples
+- Answering technical questions
+
+Be concise, accurate, and provide practical solutions.`;
+}
+
+export { getCodexInstructions };