import type { Role, RoleResult, StartStep, WorkflowMessage } from "@uncaged/nerve-core";
import { lastMetaForRole } from "../../lib/meta-helpers.js";
import { runTestCommand } from "../../lib/run-test-command.js";
import type { ImplementerMeta } from "../implementer/index.js";
import type { PlannerMeta } from "../planner/index.js";

export type TestCommandResult = {
  command: string;
  ok: boolean;
  stdoutPreview: string;
  stderrPreview: string;
};

export type TesterMeta = {
  passed: boolean;
  attempt: number;
  failureReason: string | null;
  testCommandResults: TestCommandResult[] | null;
};

export type BuildTesterDeps = {
  nerveRoot: string;
};

export function buildTesterRole({ nerveRoot }: BuildTesterDeps): Role<TesterMeta> {
  return async (_start: StartStep, messages: WorkflowMessage[]): Promise<RoleResult<TesterMeta>> => {
    const plannerMeta = lastMetaForRole<PlannerMeta>(messages, "planner");
    const implementerMeta = lastMetaForRole<ImplementerMeta>(messages, "implementer");
    const attempt = messages.filter((message) => message.role === "tester").length + 1;

    if (implementerMeta === null || !implementerMeta.implementationOk || implementerMeta.branchName === null) {
      return {
        content: "tester cannot continue: no successful implementer output",
        meta: {
          passed: false,
          attempt,
          failureReason: "no successful implementer output",
          testCommandResults: null,
        },
      };
    }

    const commands =
      plannerMeta?.testCommands !== null && plannerMeta?.testCommands !== undefined && plannerMeta.testCommands.length > 0
        ? plannerMeta.testCommands
        : ["pnpm test"];

    const testCommandResults: TestCommandResult[] = [];
    for (const command of commands) {
      const run = await runTestCommand(nerveRoot, command);
      testCommandResults.push({
        command,
        ok: run.ok,
        stdoutPreview: run.stdoutPreview,
        stderrPreview: run.stderrPreview,
      });
      if (!run.ok) {
        return {
          content: `test failed: ${command}\n${run.reason ?? "unknown error"}`,
          meta: {
            passed: false,
            attempt,
            failureReason: `command failed: ${command} (${run.reason ?? "unknown error"})`,
            testCommandResults,
          },
        };
      }
    }

    return {
      content: `all tests passed on branch ${implementerMeta.branchName}`,
      meta: {
        passed: true,
        attempt,
        failureReason: null,
        testCommandResults,
      },
    };
  };
}