import { createServerFn } from "@tanstack/react-start";
import { z } from "zod";
import { requireViewer, viewerMiddleware } from "./middleware";
import { repoDb } from "~/server/scoped-db";
import { randomId } from "~/server/crypto";
import { limitWrite } from "~/server/limits";
import { convertIssue, repoCategories, requireDiscussionAccess } from "~/server/discussions";
import { loadIssue, setIssueState } from "~/server/issues";
import { assertCount, PLANNING_CAPS } from "~/server/planning";
import { badRequest, notFoundError } from "~/server/errors";
import { repoRef } from "~/lib/validation";

const issueRef = repoRef.extend({ number: z.number().int().positive() });

export const saveDiscussionCategory = createServerFn({ method: "POST" })
  .middleware([viewerMiddleware])
  .validator(
    repoRef.extend({
      id: z.string().max(64).nullable(),
      name: z.string().trim().min(1).max(40),
      emoji: z.string().max(8),
      description: z.string().max(200),
      answerable: z.boolean(),
    }),
  )
  .handler(async ({ data, context }) => {
    const viewer = requireViewer(context.viewer);
    await limitWrite(viewer);
    const { repo } = await requireDiscussionAccess(data, viewer, "write", true);
    if (data.id) {
      await repoDb(repo.id).run(
        "UPDATE discussion_categories SET name = ?, emoji = ?, description = ?, answerable = ? WHERE id = ? AND repo_id = ?",
        data.name,
        data.emoji,
        data.description,
        data.answerable ? 1 : 0,
        data.id,
        repo.id,
      );
      return { ok: true };
    }
    await assertCount(
      "SELECT COUNT(*) AS count FROM discussion_categories WHERE repo_id = ?",
      repo.id,
      PLANNING_CAPS.categoriesPerRepo,
      "discussion categories",
      repoDb(repo.id),
    );
    await repoDb(repo.id).run(
      "INSERT INTO discussion_categories (id, repo_id, name, emoji, description, answerable) VALUES (?, ?, ?, ?, ?, ?)",
      randomId(),
      repo.id,
      data.name,
      data.emoji,
      data.description,
      data.answerable ? 1 : 0,
    );
    return { ok: true };
  });

export const deleteDiscussionCategory = createServerFn({ method: "POST" })
  .middleware([viewerMiddleware])
  .validator(repoRef.extend({ id: z.string().max(64) }))
  .handler(async ({ data, context }) => {
    const viewer = requireViewer(context.viewer);
    await limitWrite(viewer);
    const { repo } = await requireDiscussionAccess(data, viewer, "write", true);
    const used = await repoDb(repo.id).first(
      "SELECT 1 FROM discussions WHERE category_id = ? AND repo_id = ? LIMIT 1",
      data.id,
      repo.id,
    );
    if (used) throw badRequest("Move or delete this category's discussions first");
    await repoDb(repo.id).run("DELETE FROM discussion_categories WHERE id = ? AND repo_id = ?", data.id, repo.id);
    return { ok: true };
  });

export const convertIssueToDiscussion = createServerFn({ method: "POST" })
  .middleware([viewerMiddleware])
  .validator(issueRef.extend({ categoryId: z.string().max(64).optional() }))
  .handler(async ({ data, context }) => {
    const viewer = requireViewer(context.viewer);
    await limitWrite(viewer);
    const { repo } = await requireDiscussionAccess(data, viewer, "write", true);
    const issue = await loadIssue(repo.id, data.number);
    if (!issue) throw notFoundError("Issue not found");
    if (issue.is_pull === 1) throw badRequest("Pull requests cannot become discussions");
    const converted = await repoDb(repo.id).first<{ number: number | null }>(
      `SELECT json_extract(data, '$.number') AS number FROM issue_events
       WHERE issue_id = ? AND kind = 'converted_to_discussion' ORDER BY created_at LIMIT 1`,
      issue.id,
    );
    if (converted?.number) return { number: converted.number };
    const categories = await repoCategories(repo.id);
    const category =
      categories.find((item) => item.id === data.categoryId) ??
      categories.find((item) => item.name === "General") ??
      categories[0];
    if (!category) throw badRequest("Create a discussion category first");
    const number = await convertIssue(issue, category.id, viewer.id);
    await setIssueState(issue, "closed", viewer.id, { discussion: number });
    return { number };
  });