import { App, Context, staticFiles } from "fresh";
import { type State } from "./utils.ts";
import "$std/dotenv/load.ts";
import { checkDatabaseConnection } from "./db/db.ts";

const isDevelopment = Deno.env.get("DEVELOPMENT") === "true";
//console.log("Development mode:", isDevelopment);

/** Error page HTML for service unavailability */
const SERVICE_UNAVAILABLE_HTML = `<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Service Unavailable</title>
  <style>
    * { margin: 0; padding: 0; box-sizing: border-box; }
    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 20px;
    }
    .container {
      background: white;
      border-radius: 16px;
      padding: 48px;
      max-width: 500px;
      text-align: center;
      box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    }
    .icon {
      font-size: 64px;
      margin-bottom: 24px;
    }
    h1 {
      color: #1a202c;
      font-size: 24px;
      margin-bottom: 16px;
    }
    p {
      color: #4a5568;
      font-size: 16px;
      line-height: 1.6;
    }
  </style>
</head>
<body>
  <div class="container">
    <div class="icon">🔧</div>
    <h1>The problem is on our side!</h1>
    <p>We will fix this as soon as we can.</p>
  </div>
</body>
</html>`;

/** Check if required KV cache files exist */
function checkKvCacheFiles(): boolean {
  // const requiredFiles = ["./data/kv-cache-shm", "./data/kv-cache-wal"];
  // for (const file of requiredFiles) {
  //   try {
  //     Deno.statSync(file);
  //   } catch {
  //     console.error(`⚠️  Required file missing: ${file}`);
  //     return false;
  //   }
  // }
  return true;
}

/** Perform all startup checks */
async function performStartupChecks(): Promise<boolean> {
  //console.log("Checking startup requirements...");

  // Check KV cache files
  const kvFilesExist = checkKvCacheFiles();
  if (!kvFilesExist) {
    console.error(
      "⚠️  KV cache files missing - app will display maintenance page",
    );
    return false;
  }
  //console.log("✅ KV cache files found");

  // Check database connection
  //console.log("Checking database connection...");
  const dbAvailable = await checkDatabaseConnection();
  if (!dbAvailable) {
    console.error(
      "⚠️  Database connection failed - app will display maintenance page",
    );
    return false;
  }
  //console.log("✅ Database connection successful");

  return true;
}

// Run startup checks first
const isAppReady = await performStartupChecks();

// Create app based on startup check result
export const app = new App<State>();

if (isAppReady) {
  // Full app with all routes and middleware
  const { InitiPGSessionMiddleware } = await import(
    "./services/stateMiddleware.ts"
  );

  app.use(staticFiles());

  app.get("/health", (_ctx: Context<State>) => {
    console.log("Health check");
    return new Response("OK");
  });

  // app.post("/graph-update", async (ctx: Context<State>) => {
  //   console.log("Graph update");
  //   const body = await ctx.req.json();
  //   //console.log(body);
  //   //const { userId, roles, organization } = body;

  //   // await inMemoryCacheKv.set(["ciam", userId], {
  //   //   userId,
  //   //   roles,
  //   //   organization,
  //   //   lastSynced: Date.now(),
  //   // });

  //   //console.log(`Graph update applied for user ${userId}`);
  //   return new Response("Graph update stored in cache", { status: 202 });
  // });

  // TODO: add a well-known endpoint
  // app.get("/.well-known/acme-challenge/:token", (ctx: Context<State>) => {
  //   const token = ctx.params.token;
  //   const content = `${token}.EXAMPLE_ACCOUNT_THUMBPRINT`;
  //   return new Response(content, {
  //     status: 200,
  //     headers: {
  //       "content-type": "text/plain; charset=utf-8",
  //       "cache-control": "public, max-age=0, must-revalidate",
  //     },
  //   });
  // });

  app.use(InitiPGSessionMiddleware());
  app.fsRoutes();

  //console.log("✅ Full application loaded");
} else {
  // Maintenance mode - serve error page for all routes
  app.use(staticFiles());

  app.get("/health", () => {
    return new Response("Service Unavailable", { status: 503 });
  });

  app.use(() => {
    return new Response(SERVICE_UNAVAILABLE_HTML, {
      status: 503,
      headers: { "Content-Type": "text/html; charset=utf-8" },
    });
  });

  console.log("⚠️  Maintenance mode - serving error page only");

  // Start periodic database connection check (every 60 seconds)
  setInterval(async () => {
    console.log("🔄 Checking if database connection is restored...");
    const dbAvailable = await checkDatabaseConnection();
    if (dbAvailable) {
      console.log("✅ Database connection restored! Restarting app...");

      // Check if running in development mode
      const restartCmd = isDevelopment ? "exec deno task dev" : "exec ./server";

      // Use exec to replace shell with new process, keeping terminal connection
      const command = new Deno.Command("sh", {
        args: [
          "-c",
          `lsof -ti:8080 | xargs kill -9 2>/dev/null || true; ${restartCmd}`,
        ],
        cwd: Deno.cwd(),
        stdin: "inherit",
        stdout: "inherit",
        stderr: "inherit",
      });
      command.spawn();
      Deno.exit(0);
    } else {
      console.log("❌ Database still unavailable, will retry in 60 seconds");
    }
  }, 60_000);
}

// if (import.meta.main) {
//   await app.listen();
// }