/**
 * VM Disk Budget Step — rendered inside the Electron wizard.
 * Shows disk size presets, a custom slider, and real-time space check.
 * Add to wizard.js as a new render step between 'folder' and 'tier'.
 *
 * Exported function: renderDiskBudgetStep()
 * State updates: state.diskBudget.preset, state.diskBudget.customSizeGB
 */

function renderDiskBudgetStep() {
  const presets = [
    { id: 'minimal',  icon: '💽', sizeGB: 10,  label: 'Minimal',  desc: 'DashCaddy only, a few small apps' },
    { id: 'balanced', icon: '💿', sizeGB: 30,  label: 'Balanced', desc: 'DashCaddy + media tools + containers' },
    { id: 'power',    icon: '🧊', sizeGB: 100, label: 'Power',    desc: 'DashCaddy + heavy apps + lots of containers' },
    { id: 'custom',   icon: '⚙️', sizeGB: 0,   label: 'Custom',   desc: 'Pick your own size' },
  ];

  const selectedPreset = state.diskBudget?.preset || 'balanced';
  const selectedSize = state.diskBudget?.customSizeGB || presets.find(p => p.id === selectedPreset)?.sizeGB || 30;

  return `
    <div>
      <h2>Storage Budget</h2>
      <p>DashCaddy creates a <strong>sandboxed virtual disk</strong> for all its data.
         It can never exceed this limit — your main drive stays safe.</p>
      <p class="hint" style="margin-bottom: 20px;">
        💡 The disk starts nearly empty and only grows as you add apps and data.
        Deleting DashCaddy removes the entire disk instantly.
      </p>

      <div class="disk-presets" style="display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 20px;">
        ${presets.map(p => `
          <div class="disk-preset-card ${selectedPreset === p.id ? 'selected' : ''}"
               onclick="selectDiskPreset('${p.id}', ${p.sizeGB})"
               style="padding: 16px; border: 2px solid ${selectedPreset === p.id ? '#6366f1' : 'var(--border, #333)'}; border-radius: 10px; cursor: pointer; transition: all 0.2s; ${selectedPreset === p.id ? 'background: rgba(99, 102, 241, 0.1);' : ''}">
            <div style="font-size: 2rem; margin-bottom: 8px;">${p.icon}</div>
            <div style="font-weight: 600; font-size: 1.05rem;">${p.label}</div>
            <div style="font-size: 0.85rem; color: var(--muted, #888); margin-top: 4px;">
              ${p.sizeGB > 0 ? p.sizeGB + 'GB' : 'Custom'} — ${p.desc}
            </div>
          </div>
        `).join('')}
      </div>

      ${selectedPreset === 'custom' ? `
        <div class="folder-input" style="margin-bottom: 16px;">
          <label>Custom Disk Size</label>
          <div class="input-row" style="display: flex; align-items: center; gap: 12px;">
            <input type="range" id="disk-slider"
                   min="5" max="500" step="5"
                   value="${selectedSize}"
                   oninput="updateDiskSize(this.value)"
                   style="flex: 1;">
            <span id="disk-size-display" style="font-size: 1.3rem; font-weight: 700; min-width: 80px; text-align: right;">
              ${selectedSize}GB
            </span>
          </div>
          <p class="hint">Min 5GB, Max 500GB. DashCaddy uses a sparse image — it only consumes real disk space as data fills.</p>
        </div>
      ` : `
        <div style="padding: 12px 16px; background: rgba(99, 102, 241, 0.08); border-radius: 8px; border: 1px solid rgba(99, 102, 241, 0.2); margin-bottom: 16px;">
          <strong>${selectedSize}GB</strong> virtual disk will be created.
          The sandbox isolates Docker, all containers, and all DashCaddy data inside it.
        </div>
      `}

      <div id="disk-space-check" style="margin-top: 12px;"></div>
    </div>
  `;
}

// State management helpers — call from wizard.js
function selectDiskPreset(presetId, sizeGB) {
  if (!state.diskBudget) state.diskBudget = {};
  state.diskBudget.preset = presetId;
  if (presetId !== 'custom') {
    state.diskBudget.diskSizeGB = sizeGB;
  }
  checkDiskSpace(sizeGB);
  render(); // re-render the step
}

function updateDiskSize(val) {
  const sizeGB = parseInt(val);
  if (!state.diskBudget) state.diskBudget = {};
  state.diskBudget.diskSizeGB = sizeGB;
  state.diskBudget.customSizeGB = sizeGB;
  document.getElementById('disk-size-display').textContent = sizeGB + 'GB';
  checkDiskSpace(sizeGB);
}

async function checkDiskSpace(sizeGB) {
  const el = document.getElementById('disk-space-check');
  if (!el) return;

  try {
    const info = await window.electronAPI.getDiskSpace(state.paths.install || '');
    const freeGB = Math.round(info.free / 1024 / 1024 / 1024);
    const neededGB = sizeGB + 2; // 2GB buffer for DashCaddy itself

    if (freeGB < neededGB) {
      el.innerHTML = `<div style="padding: 10px 14px; background: rgba(239, 68, 68, 0.1); border-radius: 6px; border: 1px solid rgba(239, 68, 68, 0.3); color: #f87171; font-size: 0.85rem;">
        ⚠️ Not enough free space. You have ${freeGB}GB free, but need ${neededGB}GB.
      </div>`;
    } else {
      el.innerHTML = `<div style="padding: 10px 14px; background: rgba(34, 197, 94, 0.1); border-radius: 6px; border: 1px solid rgba(34, 197, 94, 0.2); color: #4ade80; font-size: 0.85rem;">
        ✓ You have ${freeGB}GB free — plenty of room for a ${sizeGB}GB disk.
      </div>`;
    }
  } catch {
    el.innerHTML = '';
  }
}