import { TagsWithInnerContent, SelfClosingTags } from '@unhead/shared';

function encodeAttribute(value) {
  return String(value).replace(/"/g, """);
}
function propsToString(props) {
  const attrs = [];
  for (const [key, value] of Object.entries(props)) {
    if (value !== false && value !== null)
      attrs.push(value === true ? key : `${key}="${encodeAttribute(value)}"`);
  }
  return `${attrs.length > 0 ? " " : ""}${attrs.join(" ")}`;
}

function escapeHtml(str) {
  return str.replace(/[&<>"'/]/g, (char) => {
    switch (char) {
      case "&":
        return "&amp;";
      case "<":
        return "&lt;";
      case ">":
        return "&gt;";
      case '"':
        return "&quot;";
      case "'":
        return "&#x27;";
      case "/":
        return "&#x2F;";
      default:
        return char;
    }
  });
}
function tagToString(tag) {
  const attrs = propsToString(tag.props);
  const openTag = `<${tag.tag}${attrs}>`;
  if (!TagsWithInnerContent.includes(tag.tag))
    return SelfClosingTags.includes(tag.tag) ? openTag : `${openTag}</${tag.tag}>`;
  let content = String(tag.innerHTML || "");
  if (tag.textContent)
    content = escapeHtml(String(tag.textContent));
  return SelfClosingTags.includes(tag.tag) ? openTag : `${openTag}${content}</${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 { escapeHtml, propsToString, renderSSRHead, ssrRenderTags, tagToString };