Implement local storage persistence and setting normalization for generation parameters

src/main.js

@@ -158,8 +158,89 @@ const defaultSettings = {
   baseModel: 'stabilityai/stable-diffusion-xl-base-1.0',
   vaeModel: 'madebyollin/sdxl-vae-fp16-fix',
 };
+const settingsStorageKey = 'skymap-gen:generation-settings:v1';
 let currentSettings = { ...defaultSettings };
 
+function clamp(value, min, max) {
+  return Math.max(min, Math.min(max, value));
+}
+
+function normalizeNumberSetting(value, fallback, { min, max, integer = false } = {}) {
+  const parsed = Number(value);
+  if (!Number.isFinite(parsed)) return fallback;
+  const rounded = integer ? Math.trunc(parsed) : parsed;
+  return clamp(rounded, min, max);
+}
+
+function selectHasValue(input, value) {
+  return Array.from(input.options).some(option => option.value === value);
+}
+
+function normalizeSelectSetting(value, input, fallback) {
+  return selectHasValue(input, value) ? value : fallback;
+}
+
+function normalizeTextSetting(value, fallback) {
+  return typeof value === 'string' && value.trim() ? value.trim() : fallback;
+}
+
+function normalizeSettings(settings = {}) {
+  return {
+    steps: normalizeNumberSetting(settings.steps, defaultSettings.steps, { min: 1, max: 80, integer: true }),
+    guidance: normalizeNumberSetting(settings.guidance, defaultSettings.guidance, { min: 0, max: 20 }),
+    width: normalizeNumberSetting(settings.width, defaultSettings.width, { min: 256, max: 4096, integer: true }),
+    height: normalizeNumberSetting(settings.height, defaultSettings.height, { min: 256, max: 4096, integer: true }),
+    scheduler: normalizeSelectSetting(settings.scheduler, schedulerInput, defaultSettings.scheduler),
+    upscale: normalizeSelectSetting(settings.upscale, upscaleInput, defaultSettings.upscale),
+    seamInpaint: settings.seamInpaint === true,
+    modelPath: normalizeTextSetting(settings.modelPath, defaultSettings.modelPath),
+    baseModel: normalizeTextSetting(settings.baseModel, defaultSettings.baseModel),
+    vaeModel: normalizeTextSetting(settings.vaeModel, defaultSettings.vaeModel),
+  };
+}
+
+function readSettingsFromInputs() {
+  return normalizeSettings({
+    steps: stepsInput.value,
+    guidance: guidanceInput.value,
+    width: widthInput.value,
+    height: heightInput.value,
+    scheduler: schedulerInput.value,
+    upscale: upscaleInput.value,
+    seamInpaint: seamInpaintInput.checked,
+    modelPath: modelPathInput.value,
+    baseModel: baseModelInput.value,
+    vaeModel: vaeModelInput.value,
+  });
+}
+
+function loadSavedSettings() {
+  try {
+    const raw = localStorage.getItem(settingsStorageKey);
+    if (!raw) return null;
+    const parsed = JSON.parse(raw);
+    return parsed && typeof parsed === 'object' ? normalizeSettings(parsed) : null;
+  } catch (err) {
+    console.warn('Failed to load saved generation settings', err);
+    return null;
+  }
+}
+
+function saveSettings(settings) {
+  const normalized = normalizeSettings(settings);
+  currentSettings = normalized;
+  try {
+    localStorage.setItem(settingsStorageKey, JSON.stringify(normalized));
+  } catch (err) {
+    console.warn('Failed to save generation settings', err);
+  }
+  return normalized;
+}
+
+function persistSettingsFromInputs() {
+  saveSettings(readSettingsFromInputs());
+}
+
 function setStatus(msg) {
   statusEl.textContent = msg || '';
   statusEl.style.opacity = msg ? '0.98' : '0';