#!/usr/bin/env node
/**
 * Local end-to-end test: loads the real extension through the pi CLI while the
 * Command Code API is replaced by a deterministic local mock server.
 */

import assert from "node:assert/strict";
import { spawn, spawnSync } from "node:child_process";
import {
  accessSync,
  constants,
  existsSync,
  mkdirSync,
  mkdtempSync,
  rmSync,
  writeFileSync,
} from "node:fs";
import { createServer } from "node:http";
import { homedir, tmpdir } from "node:os";
import { delimiter, dirname, join, resolve } from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = dirname(fileURLToPath(import.meta.url));
const PROJECT_DIR = resolve(__dirname, "..");
const EXT_PATH = resolve(PROJECT_DIR, "index.ts");
const TEST_MODEL = "deepseek/deepseek-v4-flash";

function findPiBinary() {
  if (process.env.PI_BIN) return process.env.PI_BIN;
  const localBin = resolve(PROJECT_DIR, "node_modules", ".bin");
  const candidates = (process.env.PATH ?? "")
    .split(delimiter)
    .map((entry) => resolve(entry, "pi"))
    .filter((candidate) => !candidate.startsWith(localBin));
  for (const candidate of candidates) {
    try {
      accessSync(candidate, constants.X_OK);
      return candidate;
    } catch {
      // Try next PATH entry.
    }
  }
  return undefined;
}

const PI_BIN = findPiBinary();
if (!PI_BIN) {
  console.log("[pi-local] SKIP — pi is not on PATH");
  process.exit(0);
}

const piCheck = spawnSync(PI_BIN, ["--help"], { stdio: "ignore" });
if (piCheck.error) {
  console.log(`[pi-local] SKIP — pi failed to start: ${piCheck.error.message}`);
  process.exit(0);
}

let requestCount = 0;
let lastRequestBody;
let lastRequestHeaders = {};

const server = createServer((req, res) => {
  if (req.method !== "POST" || req.url !== "/alpha/generate") {
    res.writeHead(404);
    res.end("Not found");
    return;
  }

  requestCount += 1;
  lastRequestHeaders = Object.fromEntries(
    Object.entries(req.headers).map(([key, value]) => [
      key,
      Array.isArray(value) ? value.join(", ") : (value ?? ""),
    ]),
  );

  let body = "";
  req.on("data", (chunk) => {
    body += chunk.toString("utf-8");
  });
  req.on("end", () => {
    try {
      lastRequestBody = JSON.parse(body);
    } catch {
      lastRequestBody = undefined;
    }

    res.writeHead(200, {
      "Content-Type": "text/plain; charset=utf-8",
      "Transfer-Encoding": "chunked",
    });
    res.write(
      `${JSON.stringify({ type: "text-delta", text: "mock-pi-ok" })}\n`,
    );
    res.write(
      `${JSON.stringify({ type: "finish", finishReason: "stop", totalUsage: { inputTokens: 1, outputTokens: 1 } })}\n`,
    );
    res.end();
  });
});

await new Promise((resolve) => server.listen(0, resolve));
const address = server.address();
const port = typeof address === "object" && address ? address.port : 0;
const apiBase = `http://127.0.0.1:${port}`;

function hasLivePiAuth() {
  return (
    !!process.env.COMMANDCODE_API_KEY ||
    existsSync(join(homedir(), ".commandcode", "auth.json")) ||
    existsSync(join(homedir(), ".pi", "agent", "auth.json"))
  );
}

let tempHome;
const env = {
  ...process.env,
  COMMANDCODE_API_BASE: apiBase,
};

if (hasLivePiAuth()) {
  console.log("[pi-local] using live pi auth");
} else {
  console.log("[pi-local] live pi auth not found; using mock auth fallback");
  tempHome = mkdtempSync(join(tmpdir(), "pi-cc-home-"));
  mkdirSync(join(tempHome, ".commandcode"), { recursive: true });
  writeFileSync(
    join(tempHome, ".commandcode", "auth.json"),
    JSON.stringify({ apiKey: "mock-key" }),
  );
  env.HOME = tempHome;
  env.USERPROFILE = tempHome;
  env.COMMANDCODE_API_KEY = "mock-key";
}

function runPi(args, timeoutMs = 30_000) {
  return new Promise((resolve) => {
    const child = spawn(PI_BIN, args, {
      cwd: PROJECT_DIR,
      env,
      stdio: ["ignore", "pipe", "pipe"],
    });
    let stdout = "";
    let stderr = "";
    const timer = setTimeout(() => {
      child.kill();
      resolve({
        code: -1,
        stdout,
        stderr: `${stderr}\nTIMEOUT after ${timeoutMs}ms`,
      });
    }, timeoutMs);
    child.stdout.on("data", (chunk) => {
      stdout += chunk.toString("utf-8");
    });
    child.stderr.on("data", (chunk) => {
      stderr += chunk.toString("utf-8");
    });
    child.on("close", (code) => {
      clearTimeout(timer);
      resolve({ code, stdout, stderr });
    });
  });
}

async function runRpcQuery(timeoutMs = 30_000) {
  const child = spawn(
    PI_BIN,
    [
      "--mode",
      "rpc",
      "-e",
      EXT_PATH,
      "--provider",
      "commandcode",
      "--model",
      TEST_MODEL,
    ],
    {
      cwd: PROJECT_DIR,
      env,
      stdio: ["pipe", "pipe", "pipe"],
    },
  );

  let stdout = "";
  let stderr = "";
  let buffer = "";
  let sawPromptAccepted = false;
  let sawAssistantMessage = false;
  let sawTextDelta = false;
  const events = [];

  const done = new Promise((resolve) => {
    const timer = setTimeout(() => {
      child.kill();
      resolve(false);
    }, timeoutMs);

    const finish = (ok) => {
      clearTimeout(timer);
      try {
        child.stdin.write(`${JSON.stringify({ type: "quit" })}\n`);
      } catch {
        // ignore shutdown race
      }
      child.kill();
      resolve(ok);
    };

    child.stdin.write(
      `${JSON.stringify({ id: "prompt-1", type: "prompt", message: "say mock token" })}\n`,
    );

    child.stdout.on("data", (chunk) => {
      const text = chunk.toString("utf-8");
      stdout += text;
      buffer += text;
      const lines = buffer.split("\n");
      buffer = lines.pop() ?? "";
      for (const line of lines) {
        const trimmed = line.trim();
        if (!trimmed) continue;
        try {
          const event = JSON.parse(trimmed);
          events.push(event);
          if (
            event.type === "response" &&
            event.id === "prompt-1" &&
            event.success === true
          ) {
            sawPromptAccepted = true;
          }
          if (
            event.type === "message_update" &&
            event.assistantMessageEvent?.type === "text_delta"
          ) {
            sawTextDelta = true;
          }
          if (
            event.type === "message_end" &&
            event.message?.role === "assistant"
          ) {
            sawAssistantMessage = true;
            finish(true);
          }
        } catch {
          // ignore non-JSON output
        }
      }
    });
    child.stderr.on("data", (chunk) => {
      stderr += chunk.toString("utf-8");
    });
    child.on("close", () => {
      if (!sawAssistantMessage) finish(false);
    });
  });

  const ok = await done;
  return {
    ok,
    stdout,
    stderr,
    events,
    sawPromptAccepted,
    sawAssistantMessage,
    sawTextDelta,
  };
}

try {
  console.log("[pi-local] list models through real extension");
  const list = await runPi(["-e", EXT_PATH, "--list-models"], 20_000);
  assert.equal(list.code, 0, list.stderr);
  assert.match(list.stdout, /commandcode/);
  assert.match(list.stdout, /deepseek\/deepseek-v4-flash/);

  console.log("[pi-local] print mode through real extension and mock API");
  requestCount = 0;
  const print = await runPi(
    [
      "-e",
      EXT_PATH,
      "-p",
      "say mock token",
      "--provider",
      "commandcode",
      "--model",
      TEST_MODEL,
    ],
    30_000,
  );
  assert.equal(print.code, 0, print.stderr);
  assert.match(print.stdout, /mock-pi-ok/);
  assert.equal(requestCount, 1);
  assert.ok(
    typeof lastRequestHeaders.authorization === "string" &&
      lastRequestHeaders.authorization.startsWith("Bearer "),
    "should send a bearer Authorization header",
  );
  assert.equal(lastRequestBody?.params?.model, TEST_MODEL);

  console.log("[pi-local] RPC prompt through real extension and mock API");
  requestCount = 0;
  const rpc = await runRpcQuery();
  assert.equal(
    rpc.ok,
    true,
    JSON.stringify(
      { stderr: rpc.stderr, stdout: rpc.stdout, events: rpc.events.slice(-10) },
      null,
      2,
    ),
  );
  assert.equal(rpc.sawPromptAccepted, true);
  assert.equal(rpc.sawAssistantMessage, true);
  assert.equal(rpc.sawTextDelta, true);
  assert.equal(requestCount, 1);

  console.log("[pi-local] PASS");
} finally {
  await new Promise((resolve) => server.close(resolve));
  if (tempHome) rmSync(tempHome, { recursive: true, force: true });
}