// @dsh-local/portal-entry — PoC host plugin for the dsh web profile.
//
// Goal: prove the official profile-plugin mechanism on dsh 0.1.2-rc.1
// (install -> load -> persist across restart -> remove), with zero risk to
// the running profile: every side effect is guarded, nothing can throw out
// of apply().
//
// v1 evidence channel: an append-only marker file
//   $DSH_HOME/.dsh-poc-portal-entry.log
// written when the row is instantiated. Tool registration (defineTool from
// @deepseek-ai/dsh-tools) is attempted defensively; failure is logged, never
// fatal.

import { appendFileSync } from "node:fs";
import { join } from "node:path";

const MARKER = ".dsh-poc-portal-entry.log";
const PORTAL_ROOT = process.env.DSH_SERVER_LOGIN_URL ?? "http://127.0.0.1:3080";

/** Append one line to the marker file. Never throws. */
function log(line) {
  try {
    const home = process.env.DSH_HOME || process.env.HOME || ".";
    appendFileSync(join(home, MARKER), `${new Date().toISOString()} ${line}\n`);
  } catch {
    // marker writes must never take the profile down
  }
}

/** Build the portal_ping tool definition (lazy import of defineTool). */
async function portalPingDefinition() {
  const { defineTool } = await import("@deepseek-ai/dsh-tools");
  return defineTool({
    name: "portal_ping",
    description:
      "PoC tool: probe the dsh-server-login portal reachable from this instance. Returns HTTP status and body size of the portal root.",
    parameters: {},
    output: {
      schema: {
        type: "object",
        additionalProperties: false,
        properties: {
          ok: { type: "boolean", required: true },
          status: { type: "number" },
          bytes: { type: "number" },
          note: { type: "string" }
        }
      }
    },
    isConcurrencySafe: () => true,
    async execute() {
      try {
        const res = await fetch(PORTAL_ROOT, { redirect: "manual" });
        const body = await res.arrayBuffer();
        return {
          ok: true,
          status: res.status,
          bytes: body.byteLength,
          note: `portal root reachable from instance (${PORTAL_ROOT})`
        };
      } catch (err) {
        return { ok: false, note: `portal unreachable: ${String(err?.message ?? err)}` };
      }
    }
  });
}

/** Cordis-style plugin apply. Row declares inject:[tools], so ctx.tools is
 * available; every failure is still contained and logged. */
export function apply(ctx) {
  log(`apply pid=${process.pid} dshHome=${process.env.DSH_HOME ?? ""} home=${process.env.HOME ?? ""}`);

  const register = () => {
    try {
      if (!ctx.tools || typeof ctx.tools.register !== "function") {
        log("tools service unavailable at apply time");
        return;
      }
      portalPingDefinition()
        .then((def) => {
          try {
            ctx.tools.register(def);
            log("tool portal_ping registered");
          } catch (err) {
            log(`tool register threw: ${String(err?.message ?? err)}`);
          }
        })
        .catch((err) => log(`tool build failed: ${String(err?.message ?? err)}`));
    } catch (err) {
      log(`tools access failed: ${String(err?.message ?? err)}`);
    }
  };

  try {
    register();
  } catch (err) {
    log(`register wrapper failed: ${String(err?.message ?? err)}`);
  }
}

export default apply;