import type { SiteSettings } from "../types";

export function parseFrontmatter(source: string) {
  const match = source.match(/^---\r?\n([\s\S]*?)\r?\n---\r?\n?/);

  if (!match) {
    return {
      title: "",
      description: "",
      content: source,
    };
  }

  const frontmatter = match[1];
  const title = frontmatter.match(/^title:\s*(.+)$/m)?.[1]?.trim().replace(/^["']|["']$/g, "") ?? "";
  const description =
    frontmatter.match(/^description:\s*(.+)$/m)?.[1]?.trim().replace(/^["']|["']$/g, "") ?? "";

  return {
    title,
    description,
    content: source.slice(match[0].length),
  };
}

export function stringifyMarkdownPage(page: {
  title: string;
  description: string;
  content: string;
}) {
  const frontmatter = [
    "---",
    `title: ${page.title || "未命名页面"}`,
    `description: ${page.description || ""}`,
    "---",
    "",
  ].join("\n");

  return `${frontmatter}${page.content.trimStart()}`;
}

function readStringValue(source: string, key: string, fallback = "") {
  const pattern = new RegExp(`${key}:\\s*["'\`]([^"'\`]+)["'\`]`);
  return source.match(pattern)?.[1] ?? fallback;
}

function readBooleanValue(source: string, key: string, fallback = false) {
  const pattern = new RegExp(`${key}:\\s*(true|false)`);
  const value = source.match(pattern)?.[1];
  return value ? value === "true" : fallback;
}

export function parseSiteSettings(source: string): SiteSettings {
  const socialLinksSource = source.match(/socialLinks:\s*\[([\s\S]*?)\]/)?.[1] ?? "";

  return {
    title: readStringValue(source, "title", "VitePress Site"),
    description: readStringValue(source, "description"),
    logo: readStringValue(source, "logo", "/logo.svg"),
    lastUpdated: readBooleanValue(source, "lastUpdated", true),
    localSearch: /search:\s*{[\s\S]*?provider:\s*["']local["'][\s\S]*?}/.test(source),
    outline: readBooleanValue(source, "outline", true),
    socialKind: readStringValue(socialLinksSource, "icon", "github"),
    socialLink: readStringValue(socialLinksSource, "link", "https://github.com/example/vitepress-cms"),
  };
}

export function stringifySiteConfig(settings: SiteSettings) {
  const searchConfig = settings.localSearch
    ? `    search: {
      provider: "local",
    },`
    : "";

  return `import { defineConfig } from "vitepress";

export default defineConfig({
  title: ${JSON.stringify(settings.title)},
  description: ${JSON.stringify(settings.description)},
  lastUpdated: ${settings.lastUpdated},
  themeConfig: {
    logo: ${JSON.stringify(settings.logo)},
    outline: ${settings.outline},
    nav: [
      { text: "首页", link: "/" },
      { text: "指南", link: "/guide/getting-started" },
      { text: "配置", link: "/guide/config" },
      { text: "更新日志", link: "/changelog" },
    ],
    sidebar: {
      "/guide/": [
        {
          text: "指南",
          items: [
            { text: "快速开始", link: "/guide/getting-started" },
            { text: "页面管理", link: "/guide/pages" },
            { text: "配置说明", link: "/guide/config" },
          ],
        },
      ],
    },
    socialLinks: [
      { icon: ${JSON.stringify(settings.socialKind)}, link: ${JSON.stringify(settings.socialLink)} },
    ],
    footer: {
      message: "Powered by VitePress-CMS",
      copyright: "Copyright 2026",
    },
${searchConfig}
  },
});
`;
}