import { spawn } from "child_process";
import kill from "tree-kill";
import type { IRunner, IRunnerReturn, RunResult } from "./types.cjs";
import { timeoutSeconds } from "./settings.cjs";

export const runCSharp: IRunner = async function (params: {
  srcDir: string;
  input: string;
  outputCallback?: (data: string) => void;
}): Promise<IRunnerReturn> {
  console.log(`- RUN: ${params.srcDir}`);
  const child = spawn("dotnet run", { shell: true, cwd: params.srcDir });

  try {
    let outputBuffer = "";
    child.stdout.setEncoding("utf8");
    child.stdout.on("data", (data) => {
      outputBuffer += data.toString();
      params.outputCallback?.(data.toString());
    });
    child.stderr.setEncoding("utf8");
    child.stderr.on("data", (data) => {
      outputBuffer += data.toString();
      params.outputCallback?.(data.toString());
    });

    const runStartTime = performance.now();
    child.stdin.write(params.input);
    child.stdin.end();

    let timeLimitExceeded = false;
    let completedNormally = false;

    return {
      success: true,
      runResult: new Promise<RunResult>((resolve) => {
        child.on("close", () => {
          completedNormally = !timeLimitExceeded;

          const runEndTime = performance.now();
          const runtimeMilliseconds = Math.floor(runEndTime - runStartTime);

          if (completedNormally) {
            clearTimeout(timeoutHandle);
            resolve({
              kind: "Completed",
              output: outputBuffer,
              exitCode: child.exitCode!,
              runtimeMilliseconds,
            });
          } else {
            console.log(
              `Process terminated, total sandbox time: ${runtimeMilliseconds}ms`
            );
            resolve({
              kind: "TimeLimitExceeded",
              output: outputBuffer,
              resultKindReason: `Timeout after ${timeoutSeconds} seconds`,
            });
          }
        });

        const timeoutHandle = setTimeout(() => {
          if (completedNormally) {
            return;
          }

          console.log(
            `Run timed out after ${timeoutSeconds} seconds, killing process...`
          );
          timeLimitExceeded = true;

          child.stdin.end();
          child.stdin.destroy();
          child.stdout.destroy();
          child.stderr.destroy();
          if (child.pid !== undefined) {
            kill(child.pid);
          }
        }, timeoutSeconds * 1000);
      }),
      killFunc() {
        if (child.pid !== undefined) {
          if (!completedNormally && !timeLimitExceeded) {
            kill(child.pid);
            params.outputCallback?.("\n[Manually stopped]");
          }
        }
      },
    };
  } catch (error) {
    return { success: false, runResult: { kind: "RunError" } };
  }
};