import type {
  HostToKernelMessage,
  KernelToHostMessage,
} from "../../bridge/protocol.ts";
import {
  JavaScriptKernel,
  type JavaScriptKernelOptions,
} from "../js/context-manager.ts";
import type { JavaScriptRunInput, ResultMessage } from "../js/kernel-contract.ts";
import type { EvalKernel, KernelInterruptHandle } from "../../tool/types.ts";
import {
  resetTypeScriptCellState,
  typeCheckCell,
  typeErrorsMessage,
  transpileTypeScriptCell,
} from "./checker.ts";

export type TypeScriptKernelOptions = JavaScriptKernelOptions;

/**
 * Type-checked TypeScript kernel. Each cell is type-checked (wrapped in one
 * async function, type-correctness codes filtered) before it runs; a cell
 * with errors is rejected without touching the worker. A clean cell is
 * transpiled to JavaScript and runs in the JS worker, so it inherits the JS
 * kernel's state persistence, tool bridge, strings, timeouts, and interrupts.
 */
export class TypeScriptKernel implements EvalKernel {
  readonly #inner: JavaScriptKernel;

  constructor(options: TypeScriptKernelOptions) {
    this.#inner = new JavaScriptKernel(options);
  }

  async run(input: JavaScriptRunInput): Promise<ResultMessage> {
    const startedAtMs = performance.now();
    const errors = typeCheckCell(input.code);
    if (errors.length > 0) {
      return {
        type: "result",
        cellId: input.cellId,
        ok: false,
        error: { message: typeErrorsMessage(errors) },
        durationMs: Math.max(0, Math.round(performance.now() - startedAtMs)),
      };
    }
    return await this.#inner.run({
      ...input,
      code: transpileTypeScriptCell(input.code),
    });
  }

  async close(): Promise<void> {
    await this.#inner.close();
  }

  async reset(): Promise<void> {
    resetTypeScriptCellState();
    await this.#inner.reset();
  }

  interrupt(reason?: string): Promise<KernelInterruptHandle> {
    return this.#inner.interrupt(reason);
  }

  deliverToolReply(
    message: Extract<HostToKernelMessage, { type: "tool-reply" }>
  ): void {
    this.#inner.deliverToolReply(message);
  }
}