ppt-tool/frontend/app/hooks/parseLayoutSchema.ts

"use client";

/**
 * parseLayoutSchema.ts
 * Parses the new JSON-based element model for slide layouts.
 * Replaces the Babel/TSX compile approach for custom templates.
 */

export interface SlideElement {
  id: string;
  type: "text" | "image" | "chart" | "shape";
  placeholder: string;
  x: number;
  y: number;
  w: number;
  h: number;
  style?: Record<string, string | number>;
  defaultContent?: string;
  content?: string;
  imageUrl?: string;
}

export interface LayoutSchema {
  layoutId: string;
  layoutName: string;
  slideWidth: number;
  slideHeight: number;
  background: string;
  elements: SlideElement[];
}

export interface ParsedLayout {
  layoutId: string;
  layoutName: string;
  layoutDescription: string;
  schema: LayoutSchema;
  sampleData: Record<string, string>;
  isJsonLayout: true;
}

/**
 * Detect if a layout_code string is the new JSON element model format.
 */
export function isJsonLayoutCode(layoutCode: string): boolean {
  if (!layoutCode || !layoutCode.trim().startsWith("{")) return false;
  try {
    const parsed = JSON.parse(layoutCode);
    return Array.isArray(parsed.elements) && typeof parsed.layoutId === "string";
  } catch {
    return false;
  }
}

/**
 * Parse a JSON layout schema string into a ParsedLayout.
 * Returns null if the string is not valid JSON or not the new format.
 */
export function parseLayoutSchema(layoutCode: string): ParsedLayout | null {
  try {
    const schema: LayoutSchema = JSON.parse(layoutCode);
    if (!schema.elements || !Array.isArray(schema.elements)) {
      return null;
    }

    // Build sample data from element defaults
    const sampleData: Record<string, string> = {};
    schema.elements.forEach((elem) => {
      if (elem.placeholder && elem.defaultContent) {
        sampleData[elem.placeholder] = elem.defaultContent;
      }
    });

    return {
      layoutId: schema.layoutId || "layout-0",
      layoutName: schema.layoutName || "Layout",
      layoutDescription: `${schema.elements.length} elements`,
      schema,
      sampleData,
      isJsonLayout: true,
    };
  } catch {
    return null;
  }
}

/**
 * Merge layout schema elements with slide content data.
 * Slide content keys map to element placeholder names.
 */
export function mergeElementsWithContent(
  schema: LayoutSchema,
  content?: Record<string, unknown>
): SlideElement[] {
  return schema.elements.map((elem) => ({
    ...elem,
    content:
      (content?.[elem.placeholder] as string) ??
      (content?.[elem.id] as string) ??
      elem.defaultContent ??
      "",
    imageUrl:
      (content?.[`${elem.placeholder}_url`] as string) ??
      (content?.[`image_url`] as string) ??
      undefined,
  }));
}