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 } from './ui/panels.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');
  blocklyDiv.style.width = blocklyArea.offsetWidth + 'px';
  blocklyDiv.style.height = blocklyArea.offsetHeight + 'px';
  Blockly.svgResize(workspace);
}

window.addEventListener('resize', onResize);
onResize();
initResizablePanels();

// ─── 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 btnSaveWorkspace = document.getElementById('btn-save-workspace');
const btnLoadWorkspace = document.getElementById('btn-load-workspace');
const statusEl = document.getElementById('connection-status');
const terminalInput = document.getElementById('terminal-input');

// 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;
  btnSaveWorkspace.disabled = !connected;
  btnLoadWorkspace.disabled = !connected;
  terminalInput.disabled = !connected;
  statusEl.textContent = connected ? 'Connected' : 'Disconnected';
  statusEl.className = connected ? 'status-connected' : 'status-disconnected';
}

// ─── Serial Event Listeners ──────────────────────────────

// Workspace loading state
let workspaceCaptureState = null;

onData((text) => {
  // Check if we're capturing workspace XML
  if (workspaceCaptureState) {
    const { startMarker, endMarker } = workspaceCaptureState;
    const startIdx = text.indexOf(startMarker);
    const endIdx = text.indexOf(endMarker);
    
    // PRIORITY 1: If already capturing, check for end marker first
    if (workspaceCaptureState.capturing) {
      if (endIdx !== -1) {
        // Found end marker - extract content
        workspaceCaptureState.buffer += text.substring(0, endIdx);
        const xmlContent = workspaceCaptureState.buffer.trim();
        
        // Parse and load XML
        try {
          const xmlDom = Blockly.Xml.textToDom(xmlContent);
          Blockly.Xml.domToWorkspace(xmlDom, workspace);
          appendToTerminal('Workspace loaded successfully!\n');
        } catch (parseErr) {
          appendToTerminal(`\nParse error: ${parseErr.message}\n`);
        }
        
        workspaceCaptureState = null;
        
        // Don't display the end marker, but show text after it
        const afterEnd = text.substring(endIdx + endMarker.length);
        if (afterEnd.trim()) {
          appendToTerminal(afterEnd);
        }
        return;
      } else {
        // Still capturing, accumulate buffer
        workspaceCaptureState.buffer += text;
        // Don't display captured content
        return;
      }
    }
    
    // PRIORITY 2: Both markers in the same chunk (not yet capturing)
    if (startIdx !== -1 && endIdx !== -1 && endIdx > startIdx) {
      const xmlContent = text.substring(startIdx + startMarker.length, endIdx);
      
      // Parse and load XML
      try {
        const xmlDom = Blockly.Xml.textToDom(xmlContent.trim());
        Blockly.Xml.domToWorkspace(xmlDom, workspace);
        appendToTerminal('Workspace loaded successfully!\n');
      } catch (parseErr) {
        appendToTerminal(`\nParse error: ${parseErr.message}\n`);
      }
      
      workspaceCaptureState = null;
      
      // Don't display the markers, but show text before/after
      const beforeStart = text.substring(0, startIdx);
      const afterEnd = text.substring(endIdx + endMarker.length);
      if (beforeStart.trim() || afterEnd.trim()) {
        appendToTerminal(beforeStart + afterEnd);
      }
      return;
    }
    
    // PRIORITY 3: Start marker found, start capturing
    if (startIdx !== -1) {
      workspaceCaptureState.capturing = true;
      workspaceCaptureState.buffer = text.substring(startIdx + startMarker.length);
      // Don't display the start marker or content after it
      const beforeStart = text.substring(0, startIdx);
      if (beforeStart.trim()) {
        appendToTerminal(beforeStart);
      }
      return;
    }
  }
  
  appendToTerminal(text);
});

// ─── 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');
  try {
    await executeCode(code);
  } catch (err) {
    appendToTerminal(`\nRun error: ${err.message}\n`);
  }
});

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');
  try {
    await saveToDevice(code);
  } catch (err) {
    appendToTerminal(`\nSave error: ${err.message}\n`);
  }
});

// ─── Workspace Save/Load ───────────────────────────────────

async function saveWorkspaceToDevice() {
  try {
    // Convert workspace to XML
    const xml = Blockly.Xml.workspaceToDom(workspace);
    const xmlText = Blockly.Xml.domToText(xml);
    
    appendToTerminal('\nSaving workspace to device...\n');
    await writeFileToDevice(xmlText, 'workspace.xml');
    appendToTerminal('Workspace saved to workspace.xml\n');
  } catch (err) {
    appendToTerminal(`\nSave workspace error: ${err.message}\n`);
  }
}

async function loadWorkspaceFromDevice() {
  try {
    appendToTerminal('\nLoading workspace from device...\n');
    
    // Use unique markers to identify workspace content
    const timestamp = Date.now();
    const startMarker = `__WS_START_${timestamp}__`;
    const endMarker = `__WS_END_${timestamp}__`;
    
    // Set up capture state
    workspaceCaptureState = {
      startMarker,
      endMarker,
      buffer: '',
      capturing: false,
    };
    
    const script = [
      `try:`,
      `  f = open('workspace.xml', 'r')`,
      `  data = f.read()`,
      `  f.close()`,
      `  print('${startMarker}')`,
      `  print(data, end='')`,
      `  print('${endMarker}')`,
      `except Exception as e:`,
      `  print('Error reading workspace.xml: ' + str(e))`,
    ].join('\n');
    
    await executeCode(script);
    
    // Clean up capture state after timeout
    setTimeout(() => {
      if (workspaceCaptureState) {
        appendToTerminal('\nTimeout waiting for workspace data\n');
        workspaceCaptureState = null;
      }
    }, 5000);
    
  } catch (err) {
    appendToTerminal(`\nLoad workspace error: ${err.message}\n`);
    workspaceCaptureState = null;
  }
}

btnSaveWorkspace.addEventListener('click', async () => {
  await saveWorkspaceToDevice();
});

btnLoadWorkspace.addEventListener('click', async () => {
  await loadWorkspaceFromDevice();
});

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