import BLE from './ble.js';
import UI from './ui.js';
import IK from './kinematics.js';
import Settings from './settings.js';

let isRunning = false;

function delayMs(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

export default {
  get isRunning() { return isRunning; },
  stop() { isRunning = false; },

  async run(sequence, spotsData, currentSteps1, currentSteps2, onStepComplete) {
    if (isRunning) {
      UI.log('A sequence is already running.', 'warn');
      return false;
    }

    isRunning = true;
    UI.log(`Running sequence: ${sequence.name}`, 'info');

    let steps1 = currentSteps1;
    let steps2 = currentSteps2;

    for (let i = 0; i < sequence.steps.length; i++) {
      if (!isRunning) {
        UI.log('Sequence stopped.', 'info');
        break;
      }

      const step = sequence.steps[i];
      let targetX, targetY, label;

      if (step.type === 'spot') {
        const spot = spotsData.find(s => s.id === step.id);
        if (!spot) {
          UI.log(`Sequence error: Spot '${step.id}' not found. Skipping.`, 'error');
          continue;
        }
        targetX = spot.x;
        targetY = spot.y;
        label = spot.label || spot.id;
      } else if (step.type === 'xy') {
        targetX = step.x;
        targetY = step.y;
        label = `(${targetX}, ${targetY})`;
      } else {
        UI.log(`Unknown step type: ${step.type}`, 'error');
        continue;
      }

      const wsCheck = IK.checkWorkspace(targetX, targetY);
      if (!wsCheck.ok) {
        UI.log(`⛔ ${wsCheck.reason} [${label}]`, 'error');
        continue; // or break? let's continue
      }

      const res = IK.solve(targetX, targetY);
      if (!res.reachable || IK.armsCrossed(res.theta1, res.theta2)) {
        UI.log(`Target ${label} is unreachable or crosses arms.`, 'error');
        continue;
      }

      const newSteps1 = IK.radToSteps(res.theta1);
      const newSteps2 = IK.radToSteps(res.theta2);
      const delta1 = newSteps1 - steps1;
      const delta2 = newSteps2 - steps2;

      steps1 = newSteps1;
      steps2 = newSteps2;

      if (onStepComplete) {
        onStepComplete(steps1, steps2);
      }

      const cmd1 = `S1${delta1 >= 0 ? '+' : ''}${delta1}`;
      const cmd2 = `S2${delta2 >= 0 ? '+' : ''}${delta2}`;

      UI.log(`Seq step: ${label}`, 'info');

      if (BLE.isConnected()) {
        try {
          await BLE.write(cmd1);
          await BLE.write(cmd2);
        } catch (e) {
          UI.log(`BLE error: ${e.message}`, 'error');
          isRunning = false;
          return false;
        }
      } else {
        console.log(`[sim] ${cmd1}  ${cmd2}`);
      }

      // Wait for delay
      const waitTime = typeof step.delay === 'number' ? step.delay : Settings.delay;
      await delayMs(waitTime);
    }

    isRunning = false;
    UI.log(`Sequence completed.`, 'success');
    return true;
  }
};