import { fromPromise } from "xstate";
import { TFile, Vault } from "obsidian";
import { format, parse } from "@formkit/tempo";
import { ContentNode, Lifelog } from "./query.ts";

interface WriteInput {
  vault: Vault;
  lifelog: Lifelog;
  rootDir: string;
}

// We could just use the markdown output, but the heading levels
// are one unit too high, and we don't need the timestamp links
function formatContentBlock(content: ContentNode): string {
  let markdown = "";

  if (content.type.startsWith("heading")) {
    const [, level] = content.type.split("heading");
    const levelNum = Number(level);

    markdown += `${"#".repeat(levelNum + 1)} ${content.content}`;
  } else if (content.type === "blockquote") {
    markdown += `> ${content.speakerName}: ${content.content}`;
  }

  for (const node of content?.children ?? []) {
    markdown += `\n\n${formatContentBlock(node)}`;
  }

  return markdown;
}

export const writeLifelog = fromPromise(
  async ({ input }: { input: WriteInput }) => {
    const { vault, lifelog, rootDir } = input;
    const start = parse(lifelog.startTime);
    const markdown = lifelog.contents.reduce((str, content) => {
      return str + `\n\n${formatContentBlock(content)}`;
    }, "");

    const folder = `${rootDir}/${format(start, "YYYY-MM")}`;
    const file = `${format(start, "DD")}.md`;

    const dir = vault.getAbstractFileByPath(folder);
    if (dir === null) {
      await vault.createFolder(folder);
    }

    const abstract = vault.getAbstractFileByPath(`${folder}/${file}`);
    if (abstract instanceof TFile) {
      await vault.append(abstract, markdown);
    } else {
      const page = `# ${format(start, "YYYY-MM-DD")}\n\n${markdown}`;
      await vault.create(`${folder}/${file}`, page);
    }

    return parse(lifelog.endTime);
  },
);