#!/usr/bin/env node

const assert = require("assert");
const cp = require("child_process");
const path = require("path");

const extension = require("../vscode-extension/extension");

class DapClient {
  constructor(spec) {
    this.child = cp.spawn(spec.command, spec.args, {
      cwd: spec.options && spec.options.cwd,
      detached: process.platform !== "win32"
    });
    this.seq = 1;
    this.buffer = Buffer.alloc(0);
    this.messages = [];
    this.waiters = [];
    this.stderr = "";

    this.child.stdout.on("data", (chunk) => {
      this.buffer = Buffer.concat([this.buffer, chunk]);
      this.parse();
    });
    this.child.stderr.on("data", (chunk) => {
      this.stderr += chunk.toString();
    });
    this.child.on("exit", () => this.flushWaiters());
  }

  send(command, args = {}) {
    const seq = this.seq++;
    const message = { seq, type: "request", command, arguments: args };
    const payload = Buffer.from(JSON.stringify(message));
    this.child.stdin.write(`Content-Length: ${payload.length}\r\n\r\n`);
    this.child.stdin.write(payload);
    return seq;
  }

  async response(seq, command) {
    const message = await this.waitFor(
      (item) =>
        item.type === "response" &&
        item.request_seq === seq &&
        item.command === command
    );
    if (!message.success) {
      throw new Error(`DAP ${command} failed: ${message.message || JSON.stringify(message)}`);
    }
    return message;
  }

  terminate() {
    if (this.child.exitCode !== null) return;
    if (process.platform === "win32") {
      this.child.kill("SIGKILL");
      return;
    }
    try {
      process.kill(-this.child.pid, "SIGKILL");
    } catch (_) {
      this.child.kill("SIGKILL");
    }
  }

  waitFor(predicate, timeoutMs = 240000) {
    const existing = this.messages.find(predicate);
    if (existing) return Promise.resolve(existing);

    return new Promise((resolve, reject) => {
      const timer = setTimeout(() => {
        this.terminate();
        reject(new Error(`timed out waiting for DAP message\n${this.stderr}`));
      }, timeoutMs);
      this.waiters.push({ predicate, resolve, timer });
    });
  }

  parse() {
    while (true) {
      const headerEnd = this.buffer.indexOf("\r\n\r\n");
      if (headerEnd < 0) return;
      const header = this.buffer.slice(0, headerEnd).toString();
      const match = header.match(/Content-Length: (\d+)/i);
      if (!match) throw new Error(`bad DAP header: ${header}`);
      const length = Number(match[1]);
      const start = headerEnd + 4;
      const end = start + length;
      if (this.buffer.length < end) return;
      const payload = this.buffer.slice(start, end).toString();
      this.buffer = this.buffer.slice(end);
      this.messages.push(JSON.parse(payload));
      this.flushWaiters();
    }
  }

  flushWaiters() {
    for (const waiter of [...this.waiters]) {
      const message = this.messages.find(waiter.predicate);
      if (!message) continue;
      clearTimeout(waiter.timer);
      this.waiters.splice(this.waiters.indexOf(waiter), 1);
      waiter.resolve(message);
    }
  }

  async close() {
    if (this.child.exitCode !== null) return;
    const seq = this.send("disconnect");
    await this.response(seq, "disconnect");
    this.child.stdin.end();
  }
}

(async () => {
  const repo = path.resolve(__dirname, "..");
  const project = path.join(repo, "examples/launch-build-demo");
  const launchConfig = extension.resolveDisasmerDebugConfiguration(
    { uri: { fsPath: project } },
    {}
  );

  assert.strictEqual(launchConfig.type, "disasmer");
  assert.strictEqual(launchConfig.request, "launch");
  assert.strictEqual(launchConfig.entry, "build");
  assert.strictEqual(launchConfig.project, project);
  assert.strictEqual(launchConfig.runtimeBackend, "local-services");

  const inspection = extension.refreshBundleBeforeLaunch(project, repo);
  assert.match(inspection.metadata.identity, /^sha256:/);

  const client = new DapClient(extension.debugAdapterExecutableSpec(repo));
  try {
    const initialize = client.send("initialize", {
      adapterID: "disasmer",
      linesStartAt1: true,
      columnsStartAt1: true
    });
    await client.response(initialize, "initialize");

    const launch = client.send("launch", launchConfig);
    await client.response(launch, "launch");
    await client.waitFor(
      (message) => message.type === "event" && message.event === "initialized"
    );

    const breakpoints = client.send("setBreakpoints", {
      source: { path: path.join(project, "src/build.rs") },
      breakpoints: [{ line: 22 }, { line: 31 }, { line: 60 }]
    });
    const breakpointResponse = await client.response(breakpoints, "setBreakpoints");
    assert.strictEqual(breakpointResponse.body.breakpoints[0].verified, true);

    const configurationDone = client.send("configurationDone");
    await client.response(configurationDone, "configurationDone");
    const stopped = await client.waitFor(
      (message) => message.type === "event" && message.event === "stopped"
    );
    assert.strictEqual(stopped.body.allThreadsStopped, true);
    assert.strictEqual(stopped.body.reason, "breakpoint");

    const threadsRequest = client.send("threads");
    const threads = (await client.response(threadsRequest, "threads")).body.threads;
    const linuxThread = threads.find((thread) => thread.name.includes("compile linux"));
    assert(linuxThread, "F5 launch must expose the Linux task as a virtual thread");

    const stackRequest = client.send("stackTrace", {
      threadId: linuxThread.id,
      startFrame: 0,
      levels: 1
    });
    const stack = (await client.response(stackRequest, "stackTrace")).body.stackFrames;
    assert.strictEqual(stack[0].line, 22);
    assert.strictEqual(stack[0].source.path, path.join(project, "src/build.rs"));
    assert.strictEqual(stack[0].source.sourceReference || 0, 0);

    const sourceRequest = client.send("source", { source: stack[0].source });
    const source = (await client.response(sourceRequest, "source")).body;
    assert.match(source.content, /compile_linux/);

    const nextRequest = client.send("next", { threadId: linuxThread.id });
    await client.response(nextRequest, "next");
    const stepped = await client.waitFor(
      (message) =>
        message.type === "event" &&
        message.event === "stopped" &&
        message.body.reason === "step"
    );
    assert.strictEqual(stepped.body.threadId, linuxThread.id);

    const steppedStackRequest = client.send("stackTrace", {
      threadId: linuxThread.id,
      startFrame: 0,
      levels: 1
    });
    const steppedStack = (await client.response(steppedStackRequest, "stackTrace")).body.stackFrames;
    assert.strictEqual(steppedStack[0].line, 23);

    const scopesRequest = client.send("scopes", { frameId: steppedStack[0].id });
    const scopes = (await client.response(scopesRequest, "scopes")).body.scopes;
    const localsScope = scopes.find((scope) => scope.name === "Source Locals");
    const argsScope = scopes.find((scope) => scope.name === "Task Args and Handles");
    const runtimeScope = scopes.find((scope) => scope.name === "Disasmer Runtime");
    const outputScope = scopes.find((scope) => scope.name === "Recent Output");
    assert(localsScope, "F5 launch must expose source locals scope");
    assert(argsScope, "F5 launch must expose task args and handles");
    assert(runtimeScope, "F5 launch must expose Disasmer runtime state");
    assert(outputScope, "F5 launch must expose recent output state");

    const localsRequest = client.send("variables", {
      variablesReference: localsScope.variablesReference
    });
    const locals = (await client.response(localsRequest, "variables")).body.variables;
    assert(
      locals.some(
        (variable) =>
          variable.name === "unavailable-local-diagnostic" &&
          String(variable.value).includes("cannot be inspected")
      ),
      "source locals scope must report unavailable real Rust locals explicitly"
    );

    const argsRequest = client.send("variables", {
      variablesReference: argsScope.variablesReference
    });
    const args = (await client.response(argsRequest, "variables")).body.variables;
    assert(args.some((variable) => variable.name === "return_value"));
    assert(args.some((variable) => variable.name === "artifact"));
    assert(args.some((variable) => variable.name === "source_snapshot"));
    assert(args.some((variable) => variable.name === "blob"));
    assert(args.some((variable) => variable.name === "vfs_mounts"));

    const runtimeRequest = client.send("variables", {
      variablesReference: runtimeScope.variablesReference
    });
    const runtime = (await client.response(runtimeRequest, "variables")).body.variables;
    assert(
      runtime.some(
        (variable) => variable.name === "runtime_backend" && variable.value === "LocalServices"
      ),
      "extension-resolved F5 launch must use the real local-services backend"
    );
    assert(
      runtime.some(
        (variable) => variable.name === "coordinator_task_events" && variable.value === 1
      ),
      "F5 launch must cross the coordinator/node boundary and record a task event"
    );
    assert(
      runtime.some(
        (variable) =>
          variable.name === "command_status" &&
          String(variable.value).includes("completed through local services")
      )
    );
    assert(runtime.some((variable) => variable.name === "command_spec"));
    assert(runtime.some((variable) => variable.name === "stdout_tail"));
    assert(runtime.some((variable) => variable.name === "stderr_tail"));

    const outputRequest = client.send("variables", {
      variablesReference: outputScope.variablesReference
    });
    const output = (await client.response(outputRequest, "variables")).body.variables;
    assert(output.some((variable) => variable.name === "stdout_tail"));
    assert(output.some((variable) => variable.name === "stderr_tail"));

    const continueToWasmLocals = client.send("continue", { threadId: linuxThread.id });
    await client.response(continueToWasmLocals, "continue");
    await client.waitFor((message) => message.type === "event" && message.event === "continued");
    const wasmLocalsStop = await client.waitFor(
      (message) =>
        message.type === "event" &&
        message.event === "stopped" &&
        message.body.reason === "breakpoint" &&
        message.body.threadId === 1
    );
    assert.strictEqual(wasmLocalsStop.body.allThreadsStopped, true);

    const wasmLocalsStackRequest = client.send("stackTrace", {
      threadId: 1,
      startFrame: 0,
      levels: 1
    });
    const wasmLocalsStack = (await client.response(wasmLocalsStackRequest, "stackTrace")).body
      .stackFrames;
    assert.strictEqual(wasmLocalsStack[0].line, 31);
    const wasmLocalsScopesRequest = client.send("scopes", {
      frameId: wasmLocalsStack[0].id
    });
    const wasmLocalsScopes = (await client.response(wasmLocalsScopesRequest, "scopes")).body.scopes;
    const wasmLocalsScope = wasmLocalsScopes.find((scope) => scope.name === "Wasm Frame Locals");
    assert(wasmLocalsScope, "F5 launch must expose Wasm frame locals scope");
    const wasmLocalsRequest = client.send("variables", {
      variablesReference: wasmLocalsScope.variablesReference
    });
    const wasmLocals = (await client.response(wasmLocalsRequest, "variables")).body.variables;
    assert(
      wasmLocals.some(
        (variable) =>
          variable.name === "wasm_local_0" &&
          String(variable.value).includes("41") &&
          variable.type === "wasm-frame-local"
      ),
      "Wasm frame locals must expose runtime values in the VS Code variables path"
    );

    const continueToLocals = client.send("continue", { threadId: 1 });
    await client.response(continueToLocals, "continue");
    await client.waitFor((message) => message.type === "event" && message.event === "continued");
    const sourceLocalsStop = await client.waitFor(
      (message) =>
        message.type === "event" &&
        message.event === "stopped" &&
        message.body.reason === "breakpoint" &&
        message.body.threadId === 1
    );
    assert.strictEqual(sourceLocalsStop.body.allThreadsStopped, true);

    const sourceLocalsStackRequest = client.send("stackTrace", {
      threadId: 1,
      startFrame: 0,
      levels: 1
    });
    const sourceLocalsStack = (await client.response(sourceLocalsStackRequest, "stackTrace")).body
      .stackFrames;
    assert.strictEqual(sourceLocalsStack[0].line, 60);

    const sourceLocalsScopesRequest = client.send("scopes", {
      frameId: sourceLocalsStack[0].id
    });
    const sourceLocalsScopes = (await client.response(sourceLocalsScopesRequest, "scopes")).body
      .scopes;
    const sourceLocalsScope = sourceLocalsScopes.find((scope) => scope.name === "Source Locals");
    assert(sourceLocalsScope, "source-local breakpoint must expose source locals");
    const sourceLocalsRequest = client.send("variables", {
      variablesReference: sourceLocalsScope.variablesReference
    });
    const sourceLocals = (await client.response(sourceLocalsRequest, "variables")).body.variables;
    assert(
      sourceLocals.some(
        (variable) =>
          variable.name === "linux" &&
          String(variable.value).includes("TaskHandle") &&
          String(variable.value).includes("compile-linux") &&
          String(variable.value).includes("virtual_thread_id = 2")
      ),
      "source locals must include the spawned Linux task handle value"
    );
    assert(
      sourceLocals.some((variable) => variable.name === "linux_thread" && variable.value === "2"),
      "source locals must include the Linux virtual thread id value"
    );
    assert(
      sourceLocals.some(
        (variable) =>
          variable.name === "linux_artifact" && String(variable.value).includes("Artifact")
      ),
      "source locals must include the Linux artifact handle value"
    );

    await client.close();
  } catch (error) {
    client.terminate();
    throw error;
  }

  console.log("VS Code F5 smoke passed");
})().catch((error) => {
  console.error(error.stack || error.message);
  process.exit(1);
});