import type { ConvexHttpClient } from "convex/browser";
import { makeFunctionReference } from "convex/server";
import { CliArgError } from "./lib/cli-args";
import { parseEnvironmentOptions } from "./lib/environment-cli-args";

export const CONTEXT_SECTIONS = [
  "identity",
  "organisation",
  "user",
  "tools",
  "rules",
] as const;
export function validateContextSet(input: readonly string[]) {
  const parsed = parseEnvironmentOptions(
    input,
    ["--content"],
    ["--stdin", "--json"],
  );
  const [verb, section] = parsed.positional;
  if (
    verb !== "set" ||
    parsed.positional.length !== 2 ||
    !CONTEXT_SECTIONS.includes(section as never) ||
    parsed.child.length
  )
    throw new CliArgError(
      `Usage: dench context set <${CONTEXT_SECTIONS.join("|")}> --stdin | --content <text> [--json]`,
    );
  if (
    Number(parsed.flags["--stdin"] === true) +
      Number(typeof parsed.flags["--content"] === "string") !==
    1
  )
    throw new CliArgError(
      "Choose exactly one of --stdin or --content. Store credentials with dench secrets set, never in context.",
    );
  return {
    section: section as (typeof CONTEXT_SECTIONS)[number],
    content: parsed.flags["--content"] as string | undefined,
  };
}

export async function runContextSet(opts: {
  convex: ConvexHttpClient;
  args: string[];
  sessionToken?: string;
  readStdin?: () => Promise<string>;
}) {
  const parsed = validateContextSet(opts.args);
  const content =
    parsed.content ??
    (await (
      opts.readStdin ??
      (async () => {
        const chunks: Buffer[] = [];
        let size = 0;
        for await (const chunk of process.stdin) {
          size += Buffer.byteLength(chunk);
          if (size > 32000)
            throw new CliArgError(
              "Context exceeds 32 KB. Keep standing instructions short; use workspace files for references.",
            );
          chunks.push(Buffer.from(chunk));
        }
        return Buffer.concat(chunks).toString("utf8");
      })
    )());
  if (!content.trim() || Buffer.byteLength(content) > 32000)
    throw new CliArgError("Context must contain 1–32000 UTF-8 bytes.");
  const fn = {
    identity: "updateIdentity",
    organisation: "updateOrganisation",
    user: "updateUserProfile",
    tools: "updateToolsNotes",
    rules: "writeMagicFileFromUI",
  }[parsed.section];
  await opts.convex.mutation(
    makeFunctionReference<"mutation">(`functions/agentConfig:${fn}`),
    {
      ...(opts.sessionToken ? { sessionToken: opts.sessionToken } : {}),
      content,
      ...(parsed.section === "rules" ? { path: "/RULES.md" } : {}),
    },
  );
  console.log(JSON.stringify({ ok: true, section: parsed.section }));
}