import { type } from "arktype";
import type { ToolContext } from "./server.ts";
import { execute, tool } from "./shared.ts";

export const PullRequestInfo = type({
  pull_number: type.number.describe("The pull request number to fetch"),
});

export function PullRequestInfoTool(ctx: ToolContext) {
  return tool({
    name: "get_pull_request",
    description:
      "Retrieve PR metadata (title, body, state, branches, author, labels). " +
      "Example: `get_pull_request({ pull_number: 1234 })`. " +
      "To checkout a PR branch locally, use checkout_pr instead.",
    parameters: PullRequestInfo,
    execute: execute(async ({ pull_number }) => {
      const result = await ctx.gitea.rest.repository.repoGetPullRequest({
        owner: ctx.repo.owner,
        repo: ctx.repo.name,
        index: pull_number,
      });
      const data = result.data;
      const isFork = data.head?.repo?.full_name !== data.base?.repo?.full_name;

      return {
        number: data.number,
        url: data.html_url,
        title: data.title,
        body: data.body,
        state: data.state,
        draft: data.draft,
        merged: data.merged,
        maintainerCanModify: data.allow_maintainer_edit,
        base: data.base?.label,
        head: data.head?.label,
        isFork,
        author: data.user?.login,
        assignees: data.assignees
          ?.map((a) => a.login)
          .filter((n): n is string => n !== undefined),
        labels: data.labels
          ?.map((l) => (typeof l === "string" ? l : l.name))
          .filter((n): n is string => n !== undefined),
        closingIssues: [],
      };
    }),
  });
}