const SelfClosingTags = ["meta", "link", "base"];

const propsToString = (props) => {
  const handledAttributes = [];
  for (const [key, value] of Object.entries(props)) {
    if (value === false || value == null)
      continue;
    let attribute = key;
    if (value !== true)
      attribute += `="${String(value).replace(/"/g, """)}"`;
    handledAttributes.push(attribute);
  }
  return handledAttributes.length > 0 ? ` ${handledAttributes.join(" ")}` : "";
};

const tagToString = (tag) => {
  const attrs = propsToString(tag.props);
  const openTag = `<${tag.tag}${attrs}>`;
  return SelfClosingTags.includes(tag.tag) ? openTag : `${openTag}${tag.children || ""}</${tag.tag}>`;
};

function ssrRenderTags(tags) {
  const schema = { htmlAttrs: {}, bodyAttrs: {}, tags: { head: [], bodyClose: [], bodyOpen: [] } };
  for (const tag of tags) {
    if (tag.tag === "htmlAttrs" || tag.tag === "bodyAttrs") {
      schema[tag.tag] = { ...schema[tag.tag], ...tag.props };
      continue;
    }
    schema.tags[tag.tagPosition || "head"].push(tagToString(tag));
  }
  return {
    headTags: schema.tags.head.join("\n"),
    bodyTags: schema.tags.bodyClose.join("\n"),
    bodyTagsOpen: schema.tags.bodyOpen.join("\n"),
    htmlAttrs: propsToString(schema.htmlAttrs),
    bodyAttrs: propsToString(schema.bodyAttrs)
  };
}

async function renderSSRHead(head) {
  const beforeRenderCtx = { shouldRender: true };
  await head.hooks.callHook("ssr:beforeRender", beforeRenderCtx);
  if (!beforeRenderCtx.shouldRender) {
    return {
      headTags: "",
      bodyTags: "",
      bodyTagsOpen: "",
      htmlAttrs: "",
      bodyAttrs: ""
    };
  }
  const ctx = { tags: await head.resolveTags() };
  await head.hooks.callHook("ssr:render", ctx);
  const html = ssrRenderTags(ctx.tags);
  const renderCtx = { tags: ctx.tags, html };
  await head.hooks.callHook("ssr:rendered", renderCtx);
  return renderCtx.html;
}

export { renderSSRHead };