import * as Blockly from 'blockly';
import { pythonGenerator } from 'blockly/python';
import './blocks/esp32_blocks.js';
import './blocks/esp32_generators.js';
import {
  getDeviceId,
  setDeviceId,
  getDevice,
  canFlashInBrowser,
  buildToolbox,
} from './devices/registry.js';
import { connect, disconnect, isConnected, onData, writeString } from './serial/connection.js';
import { executeCode, stopExecution, saveToDevice, writeFileToDevice } from './serial/repl.js';
import { flashFirmware } from './serial/flasher.js';
import { appendToTerminal, clearTerminal } from './ui/terminal.js';
import { initResizablePanels, initPanelToggles, initProjectTabs, setProjectsPanelCallbacks } from './ui/panels.js';
import { initProjectsDialog, refreshAll as refreshProjects, refreshDeviceList } from './ui/projectsDialog.js';
import './style.css';

// ─── Blockly Workspace ───────────────────────────────────

const workspace = Blockly.inject('blockly-div', {
  toolbox: buildToolbox(getDeviceId()),
  theme: Blockly.Themes.Dark,
  grid: { spacing: 25, length: 3, colour: '#333', snap: true },
  zoom: { controls: true, wheel: true, startScale: 0.9, maxScale: 3, minScale: 0.3, scaleSpeed: 1.2 },
  trashcan: true,
  renderer: 'zelos',
});

// ─── Live Code Preview ───────────────────────────────────

const codeOutput = document.getElementById('code-output');

function updateCodePreview() {
  const code = pythonGenerator.workspaceToCode(workspace);
  codeOutput.textContent = code || '# Drag blocks to generate MicroPython code';
}

workspace.addChangeListener((event) => {
  if (event.isUiEvent) return;
  updateCodePreview();
});

updateCodePreview();

// ─── Workspace Persistence (localStorage) ────────────────

const STORAGE_KEY = 'esp32block_workspace';

function saveWorkspace() {
  const state = Blockly.serialization.workspaces.save(workspace);
  localStorage.setItem(STORAGE_KEY, JSON.stringify(state));
}

function loadWorkspace() {
  const json = localStorage.getItem(STORAGE_KEY);
  if (json) {
    try {
      const state = JSON.parse(json);
      Blockly.serialization.workspaces.load(state, workspace);
    } catch (_) {
      /* corrupted state, ignore */
    }
  }
}

workspace.addChangeListener((event) => {
  if (event.isUiEvent) return;
  saveWorkspace();
});

loadWorkspace();

// ─── Resize Handling ─────────────────────────────────────

function onResize() {
  const blocklyArea = document.getElementById('blockly-area');
  const blocklyDiv = document.getElementById('blockly-div');
  if (blocklyArea && blocklyDiv) {
    blocklyDiv.style.width = blocklyArea.offsetWidth + 'px';
    blocklyDiv.style.height = blocklyArea.offsetHeight + 'px';
    Blockly.svgResize(workspace);
  }
}

window.addEventListener('resize', onResize);
onResize();
initResizablePanels();
initPanelToggles();
initProjectTabs();
setProjectsPanelCallbacks({
  onDeviceTab: () => refreshDeviceList(),
  onExpand: () => refreshProjects(),
});

// ─── UI State Helpers ────────────────────────────────────

const deviceSelect = document.getElementById('device-select');
const btnConnect = document.getElementById('btn-connect');
const btnFlash = document.getElementById('btn-flash');
const btnRun = document.getElementById('btn-run');
const btnStop = document.getElementById('btn-stop');
const btnSave = document.getElementById('btn-save');
const btnProjects = document.getElementById('btn-projects');
const statusEl = document.getElementById('connection-status');
const terminalInput = document.getElementById('terminal-input');
const sendOverlayEl = document.getElementById('send-overlay');
const sendModalTitle = document.getElementById('send-modal-title');
const sendProgressFill = document.getElementById('send-progress-fill');
const sendProgressText = document.getElementById('send-progress-text');

function showSendProgress(title = 'Sending code to device') {
  sendModalTitle.textContent = title;
  sendProgressFill.style.width = '0%';
  sendProgressText.textContent = '0%';
  sendOverlayEl.classList.remove('hidden');
}

function updateSendProgress(sent, total) {
  const pct = total > 0 ? Math.round((sent / total) * 100) : 0;
  sendProgressFill.style.width = pct + '%';
  sendProgressText.textContent = pct + '%';
}

function hideSendProgress() {
  sendOverlayEl.classList.add('hidden');
  sendProgressFill.style.width = '0%';
}

// Sync device dropdown with stored device
deviceSelect.value = getDeviceId();
deviceSelect.addEventListener('change', () => {
  setDeviceId(deviceSelect.value);
  workspace.updateToolbox(buildToolbox(getDeviceId()));
  updateCodePreview();
  // Update Flash button tooltip/label based on device
  btnFlash.title = canFlashInBrowser()
    ? 'Flash MicroPython firmware'
    : 'Download firmware (drag to device)';
});
btnFlash.title = canFlashInBrowser()
  ? 'Flash MicroPython firmware'
  : 'Download firmware (drag to device)';

function setConnectedUI(connected) {
  btnConnect.textContent = connected ? '⏏ Disconnect' : '▶ Connect';
  btnRun.disabled = !connected;
  btnStop.disabled = !connected;
  btnSave.disabled = !connected;
  terminalInput.disabled = !connected;
  statusEl.textContent = connected ? 'Connected' : 'Disconnected';
  statusEl.className = connected ? 'status-connected' : 'status-disconnected';
}

// ─── Serial Capture (reusable promise-based) ─────────────

let captureState = null;

onData((text) => {
  if (!captureState) {
    appendToTerminal(text);
    return;
  }

  const { startMarker, endMarker } = captureState;
  captureState.raw += text;
  const raw = captureState.raw;

  const startIdx = raw.indexOf(startMarker);

  if (startIdx === -1) {
    const keep = startMarker.length - 1;
    if (raw.length > keep) {
      appendToTerminal(raw.substring(0, raw.length - keep));
      captureState.raw = raw.substring(raw.length - keep);
    }
    return;
  }

  const contentStart = startIdx + startMarker.length;
  const endIdx = raw.indexOf(endMarker, contentStart);

  if (endIdx === -1) {
    if (!captureState.flushedPre && startIdx > 0) {
      appendToTerminal(raw.substring(0, startIdx));
      captureState.flushedPre = true;
    }
    return;
  }

  const content = raw.substring(contentStart, endIdx);
  const beforeStart = startIdx > 0 && !captureState.flushedPre
    ? raw.substring(0, startIdx) : '';
  const afterEnd = raw.substring(endIdx + endMarker.length);
  const resolve = captureState.resolve;

  captureState = null;

  if (beforeStart) appendToTerminal(beforeStart);
  if (afterEnd.trim()) appendToTerminal(afterEnd);

  resolve(content);
});

function captureDeviceOutput(script) {
  return new Promise((resolve, reject) => {
    const ts = Date.now();
    const sm = `__CAP_S_${ts}__`;
    const em = `__CAP_E_${ts}__`;

    captureState = {
      startMarker: sm,
      endMarker: em,
      raw: '',
      flushedPre: false,
      resolve,
    };

    const wrapped = `print('${sm}',end='')\n${script}\nprint('${em}',end='')`;
    executeCode(wrapped).catch(err => {
      captureState = null;
      reject(err);
    });

    setTimeout(() => {
      if (captureState?.resolve === resolve) {
        captureState = null;
        reject(new Error('Timeout waiting for device response'));
      }
    }, 10000);
  });
}

// ─── Toolbar Buttons ─────────────────────────────────────

btnConnect.addEventListener('click', async () => {
  try {
    if (isConnected()) {
      await disconnect();
      setConnectedUI(false);
      appendToTerminal('\n--- Disconnected ---\n');
    } else {
      await connect();
      setConnectedUI(true);
      appendToTerminal('--- Connected ---\n');
    }
  } catch (err) {
    appendToTerminal(`\nConnection error: ${err.message}\n`);
  }
});

const flashOverlay = document.getElementById('flash-overlay');
const flashLog = document.getElementById('flash-log');
const flashFill = document.getElementById('flash-progress-fill');
const flashPctText = document.getElementById('flash-progress-text');
const flashCloseBtn = document.getElementById('flash-close');

function showFlashOverlay() {
  flashLog.textContent = '';
  flashFill.style.width = '0%';
  flashPctText.textContent = '0%';
  flashCloseBtn.classList.add('hidden');
  flashOverlay.classList.remove('hidden');
}

function appendFlashLog(msg) {
  flashLog.textContent += msg;
  flashLog.scrollTop = flashLog.scrollHeight;
}

function setFlashProgress(pct) {
  flashFill.style.width = pct + '%';
  flashPctText.textContent = pct + '%';
}

flashCloseBtn.addEventListener('click', () => {
  flashOverlay.classList.add('hidden');
});

btnFlash.addEventListener('click', async () => {
  if (isConnected()) {
    await disconnect();
    setConnectedUI(false);
  }

  const device = getDevice();
  const fw = device.firmware;

  if (canFlashInBrowser()) {
    showFlashOverlay();
    try {
      await flashFirmware(
        (msg) => appendFlashLog(msg),
        (pct) => setFlashProgress(pct),
      );
      setFlashProgress(100);
      appendFlashLog('\nFlash complete! You can now Connect to use the device.\n');
    } catch (err) {
      appendFlashLog(`\nFlash error: ${err.message}\n`);
    } finally {
      flashCloseBtn.classList.remove('hidden');
    }
  } else {
    // Download firmware: open URL and show instructions
    window.open(fw.url, '_blank');
    appendToTerminal(`\n--- Firmware: ${fw.label} ---\n`);
    appendToTerminal(`Download opened in new tab: ${fw.url}\n`);
    if (fw.instructions) {
      appendToTerminal(`${fw.instructions}\n`);
    }
    appendToTerminal('After flashing, connect here to run code.\n');
  }
});

btnRun.addEventListener('click', async () => {
  const code = pythonGenerator.workspaceToCode(workspace);
  if (!code.trim()) {
    appendToTerminal('\nNo code to run. Add some blocks!\n');
    return;
  }
  appendToTerminal('\n>>> Running...\n');
  showSendProgress('Sending code to device');
  try {
    await executeCode(code, {
      onProgress: (sent, total) => updateSendProgress(sent, total),
    });
  } catch (err) {
    appendToTerminal(`\nRun error: ${err.message}\n`);
  } finally {
    hideSendProgress();
  }
});

btnStop.addEventListener('click', async () => {
  try {
    await stopExecution();
    appendToTerminal('\n--- Stopped ---\n');
  } catch (err) {
    appendToTerminal(`\nStop error: ${err.message}\n`);
  }
});

btnSave.addEventListener('click', async () => {
  const code = pythonGenerator.workspaceToCode(workspace);
  if (!code.trim()) {
    appendToTerminal('\nNo code to save.\n');
    return;
  }
  appendToTerminal('\nSaving to device as main.py...\n');
  showSendProgress('Saving to device');
  try {
    await saveToDevice(code, 'main.py', {
      onProgress: (sent, total) => updateSendProgress(sent, total),
    });
  } catch (err) {
    appendToTerminal(`\nSave error: ${err.message}\n`);
  } finally {
    hideSendProgress();
  }
});

// ─── Projects Dialog ────────────────────────────────────

initProjectsDialog({
  workspace,
  captureDeviceOutput,
  executeCode,
  writeFileToDevice,
  isConnected,
});

btnProjects.addEventListener('click', () => {
  const panel = document.getElementById('projects-panel');
  panel.classList.toggle('collapsed');
  const btn = panel.querySelector('.panel-toggle');
  if (btn) btn.innerHTML = panel.classList.contains('collapsed') ? '◂' : '▸';
  refreshProjects();
  window.dispatchEvent(new Event('resize'));
});

terminalInput.addEventListener('keydown', async (e) => {
  if (e.key === 'Enter') {
    const text = terminalInput.value;
    terminalInput.value = '';
    await writeString(text + '\r\n');
  }
});