/**
 * Session creation modal
 */

import { createSession } from '../app.js';

let overlay;

export function initSessionForm() {
  overlay = document.getElementById('modal-overlay');

  overlay.innerHTML = `
    <div class="modal">
      <div class="modal-header">
        <h2>New Session</h2>
        <button class="btn-icon" id="modal-close">&times;</button>
      </div>
      <div class="modal-body">
        <div class="form-group">
          <label>Project Profile (JSON)</label>
          <textarea id="field-profile" spellcheck="false">{
  "name": "",
  "tech_stack": [],
  "description": ""
}</textarea>
          <div class="error-text hidden" id="err-profile"></div>
        </div>
        <div class="form-group">
          <label>Immutable Rules</label>
          <div class="rules-list" id="rules-list">
            <div class="rule-row">
              <input type="text" placeholder="Add a rule..." />
              <button class="btn btn-sm" id="btn-add-rule">+</button>
            </div>
          </div>
        </div>
        <div class="form-group">
          <label>Metadata (JSON)</label>
          <textarea id="field-metadata" spellcheck="false">{}</textarea>
          <div class="error-text hidden" id="err-metadata"></div>
        </div>
      </div>
      <div class="modal-footer">
        <button class="btn" id="btn-cancel">Cancel</button>
        <button class="btn btn-primary" id="btn-create">Create Session</button>
      </div>
    </div>
  `;

  document.getElementById('modal-close').addEventListener('click', closeModal);
  document.getElementById('btn-cancel').addEventListener('click', closeModal);
  document.getElementById('btn-create').addEventListener('click', handleCreate);
  document.getElementById('btn-add-rule').addEventListener('click', addRuleRow);

  overlay.addEventListener('click', (e) => {
    if (e.target === overlay) closeModal();
  });

  // Format JSON on blur
  for (const id of ['field-profile', 'field-metadata']) {
    document.getElementById(id).addEventListener('blur', (e) => {
      try {
        const parsed = JSON.parse(e.target.value);
        e.target.value = JSON.stringify(parsed, null, 2);
        e.target.nextElementSibling.classList.add('hidden');
      } catch (err) {
        e.target.nextElementSibling.textContent = `Invalid JSON: ${err.message}`;
        e.target.nextElementSibling.classList.remove('hidden');
      }
    });
  }
}

function addRuleRow() {
  const list = document.getElementById('rules-list');
  const addBtn = document.getElementById('btn-add-rule');
  const row = document.createElement('div');
  row.className = 'rule-row';
  row.innerHTML = `
    <input type="text" placeholder="Add a rule..." />
    <button class="btn btn-sm btn-danger remove-rule">&minus;</button>
  `;
  row.querySelector('.remove-rule').addEventListener('click', () => row.remove());
  list.insertBefore(row, addBtn.closest('.rule-row'));
}

function getRules() {
  const inputs = document.querySelectorAll('#rules-list input');
  return Array.from(inputs).map(i => i.value.trim()).filter(Boolean);
}

function validateJSON(id) {
  const el = document.getElementById(id);
  try {
    return JSON.parse(el.value);
  } catch (err) {
    const errEl = document.getElementById(`err-${id.replace('field-', '')}`);
    errEl.textContent = `Invalid JSON: ${err.message}`;
    errEl.classList.remove('hidden');
    return null;
  }
}

async function handleCreate() {
  const profile = validateJSON('field-profile');
  const metadata = validateJSON('field-metadata');
  if (profile === null || metadata === null) return;

  const rules = getRules();

  const btn = document.getElementById('btn-create');
  btn.disabled = true;
  btn.textContent = 'Creating...';

  try {
    await createSession({
      project_profile: profile,
      immutable_rules: rules,
      metadata,
    });
    closeModal();
    resetForm();
  } catch (e) {
    alert(`Failed: ${e.message}`);
  } finally {
    btn.disabled = false;
    btn.textContent = 'Create Session';
  }
}

function resetForm() {
  document.getElementById('field-profile').value = '{\n  "name": "",\n  "tech_stack": [],\n  "description": ""\n}';
  document.getElementById('field-metadata').value = '{}';
  const list = document.getElementById('rules-list');
  const rows = list.querySelectorAll('.rule-row');
  rows.forEach((r, i) => { if (i < rows.length - 1) r.remove(); });
  const lastInput = list.querySelector('input');
  if (lastInput) lastInput.value = '';
}

export function openSessionForm() {
  overlay.classList.add('open');
}

function closeModal() {
  overlay.classList.remove('open');
}