import { mkdir, writeFile } from "node:fs/promises";
import { createServer } from "node:http";
import { existsSync } from "node:fs";
import { resolve } from "node:path";
import { createReadStream, statSync } from "node:fs";

import { chromium } from "../app/node_modules/playwright/index.mjs";

const repoRoot = resolve(import.meta.dirname, "../..");
const projectRoot = resolve(repoRoot, "web-rtcp-5axis-xyzbc-trt-sim-plan");
const appUrlPath = "/web-rtcp-5axis-xyzbc-trt-sim-plan/app/index.html";
const sourceRel = "configs/sim/axis/vismach/5axis/table-rotary-tilting/demos/xyzbc_switchkins.ngc";
const samplePeriodMs = 50;
const chromiumExecutable = process.env.CHROMIUM || findSystemChromium();
const timestamp = new Date().toISOString().replace(/[-:]/g, "").replace(/\.\d{3}Z$/, "Z");
const outputDir = resolve(
  projectRoot,
  "working/screenshots",
  `web-simulation-gcode-full-50ms-${timestamp}`,
);
const maxFramesArg = Number(process.env.MAX_FRAMES || process.argv.find((arg) => arg.startsWith("--max-frames="))?.split("=")[1] || 0);
const maxFrames = Number.isFinite(maxFramesArg) && maxFramesArg > 0 ? Math.floor(maxFramesArg) : null;

await mkdir(outputDir, { recursive: true });

const server = await startStaticServer(repoRoot);
let browser;
try {
  browser = await chromium.launch({
    headless: true,
    executablePath: chromiumExecutable || undefined,
    args: ["--disable-gpu", "--no-sandbox"],
  });
  const context = await browser.newContext({
    viewport: { width: 1600, height: 1000 },
    deviceScaleFactor: 1,
  });
  const page = await context.newPage();
  page.setDefaultTimeout(30000);
  await page.goto(`http://127.0.0.1:${server.port}${appUrlPath}`, { waitUntil: "networkidle" });

  await page.waitForFunction(() => Boolean(window.webRtcp5AxisSimulation?.getState));
  await Promise.all([
    page.evaluate(() => window.webRtcp5AxisSimulation.machineFileSeedReady),
    page.evaluate(() => window.webRtcp5AxisSimulation.interpreterRuntimeReady),
  ]);

  await page.evaluate((selectedSourceRel) => {
    const api = window.webRtcp5AxisSimulation;
    api.dispatch({
      type: "TASK_HAL_RUNTIME_FAILED",
      error: "disabled for deterministic 50ms screenshot playback; task/HAL path is covered by browser smoke",
    });
    api.dispatch({ type: "LOAD_LINUXCNC_GCODE_SOURCE", sourceRel: selectedSourceRel });
  }, sourceRel);

  await waitForState(page, (state) => (
    state.machineFileStaging?.selectedGcodeSourceRel === sourceRel &&
    Number(state.programAxisPreviewPath?.sampleCount || 0) > 0 &&
    state.programAxisPreviewPath?.samplePeriodMs === samplePeriodMs
  ), "real G-code sample stream loaded");

  await page.evaluate(() => window.webRtcp5AxisSimulation.dispatch({ type: "RUN_READY" }));
  await waitForState(page, (state) => (
    state.machine?.powerOn === true &&
    state.machine?.allHomed === true &&
    state.machine?.mode === "auto" &&
    state.rtcpState === "on"
  ), "RUN_READY state");

  const initial = await page.evaluate(() => window.webRtcp5AxisSimulation.getState());
  const sampleCount = Number(initial.programAxisPreviewPath?.sampleCount || 0);
  const frameCount = maxFrames ? Math.min(maxFrames, sampleCount) : sampleCount;
  const frames = [];

  await page.waitForSelector("[data-five-axis-canvas]");
  await page.waitForTimeout(100);

  for (let sampleIndex = 0; sampleIndex < frameCount; sampleIndex += 1) {
    await page.evaluate((targetSampleIndex) => {
      const api = window.webRtcp5AxisSimulation;
      const state = api.getState();
      state.programExecutionSampleIndex = targetSampleIndex - 1;
      state.machine.interpState = "idle";
      state.machine.interpResumeState = "idle";
      state.runState = "idle";
      api.dispatch({ type: "STEP" });
    }, sampleIndex);
    await waitForState(page, (state, sourceRel, samplePeriodMs, context) => (
      Number(state.programExecutionSampleIndex || 0) === context.sampleIndex &&
      state.programUiExecution?.source === "programAxisPreviewPath.samples"
    ), `sample ${sampleIndex}`, 30000, { sampleIndex });
    await page.waitForTimeout(16);

    const live = await page.evaluate(() => {
      const state = window.webRtcp5AxisSimulation.getState();
      const programPane = document.querySelector('[data-region="program"]');
      const monitor = document.querySelector("[data-linuxcnc-process-monitor]");
      const canvas = document.querySelector("[data-five-axis-canvas]");
      return {
        runState: state.runState,
        activeLine: state.activeLine,
        programExecutionSampleIndex: state.programExecutionSampleIndex,
        programUiExecution: state.programUiExecution,
        programPaneDataset: { ...(programPane?.dataset || {}) },
        monitorDataset: { ...(monitor?.dataset || {}) },
        canvasDataset: {
          threeToolAxis: canvas?.dataset?.threeToolAxis || null,
          threeToolGlyphAxis: canvas?.dataset?.threeToolGlyphAxis || null,
        },
        axisPose: state.axisPose,
        toolAxisVector: state.toolAxisVector,
      };
    });

    const frameName = `frame-${String(sampleIndex).padStart(4, "0")}-t${String(sampleIndex * samplePeriodMs).padStart(6, "0")}ms.png`;
    await page.screenshot({ path: resolve(outputDir, frameName), fullPage: true });
    frames.push({
      index: sampleIndex,
      timeMs: sampleIndex * samplePeriodMs,
      file: frameName,
      sourceFile: live.programUiExecution?.sourceFile || null,
      line: live.programUiExecution?.line || null,
      statement: live.programUiExecution?.statement || "",
      operation: live.programUiExecution?.operation || null,
      gcodeStepIndex: live.programUiExecution?.gcodeStepIndex ?? null,
      segmentIndex: live.programUiExecution?.segmentIndex ?? null,
      motionType: live.programUiExecution?.motionType || null,
      activeKinematics: live.programUiExecution?.activeKinematics || null,
      joint: live.programUiExecution?.joint || null,
      tcp: live.programUiExecution?.tcp || null,
      toolAxis: live.programUiExecution?.toolAxis || null,
      axisPose: live.axisPose,
      toolAxisVector: live.toolAxisVector,
      canvasDataset: live.canvasDataset,
    });
  }

  const finalState = await page.evaluate(() => {
    const state = window.webRtcp5AxisSimulation.getState();
    return {
      activeProgram: state.activeProgram,
      selectedGcodeSourceRel: state.machineFileStaging?.selectedGcodeSourceRel || null,
      source: state.programAxisPreviewPath?.source || null,
      semanticBoundary: state.programAxisPreviewPath?.semanticBoundary || null,
      samplePeriodMs: state.programAxisPreviewPath?.samplePeriodMs || null,
      sampleCount: state.programAxisPreviewPath?.sampleCount || state.programAxisPreviewPath?.samples?.length || 0,
      capturedSampleIndex: state.programExecutionSampleIndex,
      runState: state.runState,
      programUiExecution: state.programUiExecution,
      gcodeExecutionProcess: {
        status: state.programAxisPreviewPath?.gcodeExecutionProcess?.status || null,
        executionStepCount: state.programAxisPreviewPath?.gcodeExecutionProcess?.executionStepCount || 0,
        summary: state.programAxisPreviewPath?.gcodeExecutionProcess?.summary || null,
      },
      lineExecutionTraceCount: state.programAxisPreviewPath?.lineExecutionTrace?.length || 0,
      axisValuesByLineCount: state.programAxisPreviewPath?.axisValuesByLine?.length || 0,
      programExecutionSourceMode: state.programExecutionSourceMode,
      taskHalRuntimeReadiness: state.taskHalRuntimeReadiness,
    };
  });

  const manifest = {
    apiName: "web-rtcp-5axis-xyzbc-trt-full-gcode-process-frame-capture",
    status: frameCount === sampleCount ? "complete" : "partial",
    capturedAt: new Date().toISOString(),
    projectRoot,
    outputDir,
    url: `http://127.0.0.1:${server.port}${appUrlPath}`,
    sourceRel,
    captureMethod: "Playwright drives the AXIS UI state one real programAxisPreviewPath sample at a time and screenshots after each 50ms sample.",
    samplePeriodMs,
    expectedSampleCount: sampleCount,
    capturedFrameCount: frames.length,
    firstFrame: frames[0] || null,
    lastFrame: frames[frames.length - 1] || null,
    gcodeExecutionProcess: finalState.gcodeExecutionProcess,
    lineExecutionTraceCount: finalState.lineExecutionTraceCount,
    axisValuesByLineCount: finalState.axisValuesByLineCount,
    finalState,
    frames,
    note: "executionStepCount is the expanded semantic G-code step count; capturedFrameCount is the 50ms visual frame count.",
  };
  await writeFile(resolve(outputDir, "manifest.json"), JSON.stringify(manifest, null, 2) + "\n", "utf8");
  console.log(`gcode_full_50ms_screenshots=${outputDir}`);
  console.log(`captured_frames=${frames.length}`);
  console.log(`sample_period_ms=${samplePeriodMs}`);
  console.log(`manifest=${resolve(outputDir, "manifest.json")}`);
} finally {
  await browser?.close().catch(() => {});
  await server.close();
}

async function waitForState(page, predicate, label, timeoutMs = 30000, context = {}) {
  const predicateText = predicate.toString();
  await page.waitForFunction(
    ([source, selectedSourceRel, selectedSamplePeriodMs, selectedContext]) => {
      const state = window.webRtcp5AxisSimulation?.getState?.();
      if (!state) return false;
      const sourceRel = selectedSourceRel;
      const samplePeriodMs = selectedSamplePeriodMs;
      const context = selectedContext || {};
      return Function("state", "sourceRel", "samplePeriodMs", "context", `return (${source})(state, sourceRel, samplePeriodMs, context);`)(
        state,
        sourceRel,
        samplePeriodMs,
        context,
      );
    },
    [predicateText, sourceRel, samplePeriodMs, context],
    { timeout: timeoutMs },
  ).catch(async (error) => {
    const state = await page.evaluate(() => window.webRtcp5AxisSimulation?.getState?.());
    throw new Error(`Timed out waiting for ${label}: ${error.message}\n${JSON.stringify({
      runState: state?.runState,
      activeLine: state?.activeLine,
      selectedGcodeSourceRel: state?.machineFileStaging?.selectedGcodeSourceRel,
      sampleIndex: state?.programExecutionSampleIndex,
      sampleCount: state?.programAxisPreviewPath?.sampleCount,
      operatorMessage: state?.operatorMessage,
      taskHalRuntimeReadiness: state?.taskHalRuntimeReadiness,
    }, null, 2)}`);
  });
}

function startStaticServer(root) {
  const server = createServer((request, response) => {
    const url = new URL(request.url || "/", "http://127.0.0.1");
    const decoded = decodeURIComponent(url.pathname);
    const relative = decoded === "/" ? "/index.html" : decoded;
    const target = resolve(root, `.${relative}`);
    if (!target.startsWith(root)) {
      response.writeHead(403);
      response.end("Forbidden");
      return;
    }
    let stat;
    try {
      stat = statSync(target);
      if (!stat.isFile()) throw new Error("not file");
    } catch {
      response.writeHead(404);
      response.end("Not found");
      return;
    }
    response.writeHead(200, {
      "content-type": contentType(target),
      "content-length": stat.size,
      "cache-control": "no-store",
    });
    createReadStream(target).pipe(response);
  });
  return new Promise((resolveStart, rejectStart) => {
    server.on("error", rejectStart);
    server.listen(0, "127.0.0.1", () => {
      const address = server.address();
      resolveStart({
        port: address.port,
        close: () => new Promise((resolveClose) => server.close(resolveClose)),
      });
    });
  });
}

function contentType(path) {
  if (path.endsWith(".html")) return "text/html; charset=utf-8";
  if (path.endsWith(".js") || path.endsWith(".mjs")) return "text/javascript; charset=utf-8";
  if (path.endsWith(".css")) return "text/css; charset=utf-8";
  if (path.endsWith(".json")) return "application/json; charset=utf-8";
  if (path.endsWith(".wasm")) return "application/wasm";
  if (path.endsWith(".png")) return "image/png";
  if (path.endsWith(".svg")) return "image/svg+xml";
  return "application/octet-stream";
}

function findSystemChromium() {
  return [
    "/usr/bin/google-chrome",
    "/usr/bin/google-chrome-stable",
    "/usr/bin/chromium",
    "/usr/bin/chromium-browser",
  ].find((candidate) => existsSync(candidate)) || null;
}