import { createServerFn } from "@tanstack/react-start";
import { isTakenDown } from "~/lib/account-disable";
import { z } from "zod";
import { viewerMiddleware } from "./middleware";
import { first } from "~/server/db";
import { repoDb } from "~/server/scoped-db";
import { limitBrowse } from "~/server/limits";
import { loadRepo, repoPermission } from "~/server/repos";
import { withStore } from "~/server/git/store";
import { accountName } from "~/lib/validation";

const ISSUE_REF = /^([^/]+)\/([^#]+)#(\d+)$/;
const COMMIT_REF = /^([^/]+)\/([^@]+)@([0-9a-f]{7,40})$/;
const FULL_SHA = 40;
const SHORT_SHA = 7;
const MAX_TEXT = 200;

async function readableRepo(owner: string, name: string, viewer: Parameters<typeof repoPermission>[1]) {
  const repo = await loadRepo(owner, name);
  if (!repo || (await repoPermission(repo, viewer)) === "none") return null;
  return repo;
}

/** Preview data for `data-hovercard` links rendered by the markdown pipeline. */
export const getHovercard = createServerFn({ method: "GET" })
  .middleware([viewerMiddleware])
  .validator(z.object({ kind: z.enum(["issue", "user", "team", "commit"]), ref: z.string().min(1).max(300) }))
  .handler(async ({ data, context }) => {
    await limitBrowse(context.viewer);
    if (data.kind === "user" || data.kind === "team") {
      const name = accountName.safeParse(data.ref.split("/")[0]);
      if (!name.success) return null;
      const account = await first<{
        id: string;
        name: string;
        display_name: string | null;
        bio: string | null;
        kind: string;
        website: string | null;
        avatar_key: string | null;
        created_at: number;
        disabled_at: number | null;
        disabled_reason: string | null;
        followers: number;
        repos: number;
      }>(
        `SELECT a.id, a.name, a.display_name, a.bio, a.kind, a.website, a.avatar_key, a.created_at, a.disabled_at, a.disabled_reason,
           (SELECT COUNT(*) FROM follows f WHERE f.followee_id = a.id) AS followers,
           (SELECT COUNT(*) FROM repos r WHERE r.owner_id = a.id AND r.visibility = 'public') AS repos
         FROM accounts a
         WHERE a.id = COALESCE(
           (SELECT id FROM accounts WHERE name = ?1),
           (SELECT account_id FROM account_redirects WHERE old_name = ?1))`,
        name.data,
      );
      if (!account || (isTakenDown(account) && !context.viewer?.isAdmin)) return null;
      const team = data.kind === "team" ? data.ref.split("/").slice(1).join("/") : null;
      return {
        kind: data.kind,
        title: team ? `@${account.name}/${team}` : (account.display_name ?? account.name),
        subtitle: team ? `Team in ${account.name}` : `@${account.name} · ${account.kind}`,
        body: (account.bio ?? "").slice(0, MAX_TEXT),
        state: null,
        profile: team
          ? null
          : {
              name: account.name,
              avatarUrl: account.avatar_key ? `/avatars/${account.avatar_key}` : null,
              website: account.website,
              followers: account.followers,
              repos: account.repos,
              joinedAt: account.created_at,
            },
      };
    }
    if (data.kind === "issue") {
      const match = ISSUE_REF.exec(data.ref);
      if (!match) return null;
      const repo = await readableRepo(match[1], match[2], context.viewer);
      if (!repo) return null;
      const issue = await repoDb(repo.id).first<{
        title: string;
        state: string;
        is_pull: number;
        body: string;
        comments_count: number;
      }>(
        "SELECT title, state, is_pull, body, comments_count FROM issues WHERE repo_id = ? AND number = ? AND hidden_at IS NULL",
        repo.id,
        Number(match[3]),
      );
      if (!issue) return null;
      return {
        kind: "issue" as const,
        title: issue.title,
        subtitle: `${repo.owner_name}/${repo.name} ${issue.is_pull ? "pull request" : "issue"} #${match[3]} · ${issue.comments_count} comments`,
        body: issue.body.slice(0, MAX_TEXT),
        state: issue.state,
        profile: null,
      };
    }
    const match = COMMIT_REF.exec(data.ref);
    if (!match) return null;
    const repo = await readableRepo(match[1], match[2], context.viewer);
    if (!repo) return null;
    const sha = match[3];
    const commit = sha.length === FULL_SHA ? await withStore(repo.artifacts_name, (store) => store.commit(sha)) : null;
    return {
      kind: "commit" as const,
      title: commit ? commit.subject.slice(0, MAX_TEXT) : `Commit ${sha.slice(0, SHORT_SHA)}`,
      subtitle: `${repo.owner_name}/${repo.name}@${sha.slice(0, SHORT_SHA)}${commit ? ` · ${commit.authorName}` : ""}`,
      body: "",
      state: null,
      profile: null,
    };
  });