export type WidgetSize = 'standard' | 'full';

export const WIDGETS = [
  { id: 'cards', titleKey: 'dashboardSummaryCards', defaultSize: 'full', sizes: ['full'] },
  { id: 'attention', titleKey: 'dashboardTodayTitle', defaultSize: 'standard', sizes: ['standard', 'full'] },
  { id: 'funnel', titleKey: 'dashboardCurrentPipeline', defaultSize: 'standard', sizes: ['standard', 'full'] },
  { id: 'activity', titleKey: 'dashboardApplicationActivity', defaultSize: 'full', sizes: ['standard', 'full'] },
  { id: 'stageAge', titleKey: 'dashboardStageAge', defaultSize: 'standard', sizes: ['standard', 'full'] },
  { id: 'sources', titleKey: 'dashboardResponseSources', defaultSize: 'standard', sizes: ['standard', 'full'] },
  { id: 'salary', titleKey: 'dashboardSalaryInsights', defaultSize: 'full', sizes: ['standard', 'full'] },
  { id: 'companies', titleKey: 'dashboardTopCompaniesByActivity', defaultSize: 'standard', sizes: ['standard', 'full'] },
  { id: 'skills', titleKey: 'dashboardJobTags', defaultSize: 'standard', sizes: ['standard', 'full'] },
] as const;

export type WidgetId = typeof WIDGETS[number]['id'];
export type DashboardWidget = { id: WidgetId; visible: boolean; size: WidgetSize; x: number; y: number; w: number; h: number };
export type DashboardLayout = { version: 2; revision: number; widgets: DashboardWidget[] };

export function arrangeDashboardWidgets(widgets: DashboardWidget[]): DashboardWidget[] {
  let x = 0, y = 0, rowHeight = 0;
  return widgets.map(widget => {
    if (!widget.visible) return { ...widget };
    if (x + widget.w > 12) { x = 0; y += rowHeight; rowHeight = 0; }
    const placed = { ...widget, x, y };
    x += widget.w;
    rowHeight = Math.max(rowHeight, widget.h);
    return placed;
  });
}

export function defaultDashboardLayout(): DashboardLayout {
  return { version: 2, revision: 0, widgets: arrangeDashboardWidgets(WIDGETS.map(w => ({ id: w.id, visible: true, size: w.defaultSize,
    x: 0, y: 0, w: w.defaultSize === 'full' ? 12 : 6, h: w.id === 'cards' ? 5 : 8 }))) };
}

export function normalizeDashboardLayout(input: unknown): DashboardLayout {
  if (!input || typeof input !== 'object') return defaultDashboardLayout();
  const value = input as Record<string, unknown>;
  if ((value.version !== 1 && value.version !== 2) || !Number.isSafeInteger(value.revision) || (value.revision as number) < 0 || !Array.isArray(value.widgets)) return defaultDashboardLayout();
  const revision = value.revision as number;
  const widgets: DashboardWidget[] = [];
  const seen = new Set<WidgetId>();
  for (const item of value.widgets) {
    if (!item || typeof item !== 'object') continue;
    const definition = WIDGETS.find(w => w.id === item.id);
    if (!definition || seen.has(definition.id)) continue;
    seen.add(definition.id);
    const size: WidgetSize = (definition.sizes as readonly string[]).includes(item.size) ? item.size : definition.defaultSize;
    const valid = value.version === 2 && [item.x, item.y, item.w, item.h].every(Number.isInteger)
      && item.x >= 0 && item.y >= 0 && item.w >= 4 && item.w <= 12 && item.h >= 4 && item.h <= 24
      && item.x + item.w <= 12 && item.y + item.h <= 256 && (definition.id !== 'cards' || item.w === 12);
    const w = valid ? item.w : size === 'full' ? 12 : 6;
    widgets.push({ id: definition.id, visible: typeof item.visible === 'boolean' ? item.visible : revision === 0,
      size: w === 12 ? 'full' : 'standard', x: valid ? item.x : 0, y: valid ? item.y : 0, w,
      h: valid ? item.h : definition.id === 'cards' ? 5 : 8 });
  }
  for (const definition of WIDGETS) {
    if (!seen.has(definition.id)) widgets.push({ ...defaultDashboardLayout().widgets.find(w => w.id === definition.id)!, visible: revision === 0 });
  }
  return { version: 2, revision, widgets: value.version === 1 ? arrangeDashboardWidgets(widgets) : widgets };
}