import fs from "fs/promises";
import path from "path";

const CONTENT_ROOT = path.join(process.cwd(), "content", "zhouyi", "docs");

export async function readGuaMarkdown(guaMark: string): Promise<string> {
  const filePath = path.join(CONTENT_ROOT, guaMark, "index.md");
  return fs.readFile(filePath, "utf-8");
}

export function extractZhangMingRen(guaDetail: string): string | undefined {
  return guaDetail
    .match(/(\*\*台灣張銘仁[\s\S]*?)(?=周易第\d+卦)/)?.[1]
    ?.replaceAll("\n\n", "\n");
}

export function extractChangeDetails(
  guaDetail: string,
  guaChange: string,
  guaTitle: string,
): string[] {
  const changeList: string[] = [];
  if (guaChange === "无变爻") {
    return changeList;
  }

  guaChange
    .split(":")[1]
    .trim()
    .split(",")
    .forEach((change) => {
      const detail = guaDetail
        .match(`(\\*\\*${change}變卦[\\s\\S]*?)(?=${guaTitle}|$)`)?.[1]
        ?.replaceAll("\n\n", "\n");
      if (detail) {
        changeList.push(detail.trim());
      }
    });

  return changeList;
}