import type { Role, RoleResult, WorkflowMessage } from "@uncaged/nerve-core";
import type { SpawnError } from "@uncaged/nerve-workflow-utils";
import { cursorAgent, isDryRun } from "@uncaged/nerve-workflow-utils";
import { z } from "zod";
import type { CoderMeta } from "../coder/index.js";
import type { PlannerMeta } from "../planner/index.js";
import { testerPrompt } from "./prompt.js";

export const testerMetaSchema = z.object({
  workflowName: z.string().default(""),
  attempt: z.number().default(1),
  passed: z.boolean().default(false),
  dryRunLog: z.string().default(""),
  reason: z.string().default(""),
});

export type TesterMeta = z.infer<typeof testerMetaSchema>;

export type BuildTesterDeps = {
  nerveRoot: string;
};

function formatSpawnFailure(error: SpawnError): string {
  if (error.kind === "spawn_failed") {
    return error.message;
  }
  if (error.kind === "timeout") {
    return `timeout stdout=${error.stdout.slice(0, 300)} stderr=${error.stderr.slice(0, 300)}`;
  }
  return `exit ${error.exitCode} stderr=${error.stderr.slice(0, 500)}`;
}

function lastMetaForRole<M>(messages: WorkflowMessage[], role: string): M | null {
  for (let i = messages.length - 1; i >= 0; i--) {
    if (messages[i].role === role) {
      return messages[i].meta as M;
    }
  }
  return null;
}

export function buildTesterRole({ nerveRoot }: BuildTesterDeps): Role<TesterMeta> {
  return async (start, messages) => {
    const dry = isDryRun(start);
    const plannerMeta = lastMetaForRole<PlannerMeta>(messages, "planner");
    const coderMeta = lastMetaForRole<CoderMeta>(messages, "coder");
    const attempt = messages.filter((m) => m.role === "tester").length + 1;

    if (plannerMeta === null || coderMeta === null) {
      return {
        content: "tester cannot continue: missing planner/coder output",
        meta: {
          workflowName: "",
          attempt,
          passed: false,
          dryRunLog: "",
          reason: "missing planner/coder output",
        },
      } satisfies RoleResult<TesterMeta>;
    }

    if (!coderMeta.lintPassed || !coderMeta.buildPassed) {
      return {
        content: "tester blocked: coder has not passed lint+build",
        meta: {
          workflowName: coderMeta.workflowName,
          attempt,
          passed: false,
          dryRunLog: `${coderMeta.lintLog}\n\n${coderMeta.buildLog}`,
          reason: "coder did not pass lint+build",
        },
      } satisfies RoleResult<TesterMeta>;
    }

    if (dry) {
      return {
        content: "PASS — dry-run mode",
        meta: {
          workflowName: coderMeta.workflowName,
          attempt,
          passed: true,
          dryRunLog: "[dry-run] tester skipped external checks",
          reason: "dry-run mode",
        },
      } satisfies RoleResult<TesterMeta>;
    }

    const prompt = testerPrompt({
      workflowName: coderMeta.workflowName,
      plannerSpec: {
        roles: plannerMeta.roles,
        flowTransitions: plannerMeta.flowTransitions,
        validationLoopsDesign: plannerMeta.validationLoopsDesign,
        externalDeps: plannerMeta.externalDeps,
        dataFlow: plannerMeta.dataFlow,
      },
      coderOutput: coderMeta.cursorOutput,
      nerveRoot,
    });

    const run = await cursorAgent({
      prompt,
      mode: "ask",
      cwd: nerveRoot,
      env: null,
      timeoutMs: null,
      dryRun: false,
    });

    if (!run.ok) {
      return {
        content: "tester agent failed",
        meta: {
          workflowName: coderMeta.workflowName,
          attempt,
          passed: false,
          dryRunLog: "",
          reason: `tester agent failed: ${formatSpawnFailure(run.error)}`,
        },
      } satisfies RoleResult<TesterMeta>;
    }

    const text = run.value.trim();
    const pass = text.startsWith("PASS|");
    const fail = text.startsWith("FAIL|");
    if (!pass && !fail) {
      return {
        content: "tester format invalid",
        meta: {
          workflowName: coderMeta.workflowName,
          attempt,
          passed: false,
          dryRunLog: text,
          reason: "tester format invalid",
        },
      } satisfies RoleResult<TesterMeta>;
    }

    const parts = text.split("|");
    const reason = parts[1] ?? "no reason";
    const log = parts.slice(2).join("|").trim();
    return {
      content: `${pass ? "PASS" : "FAIL"} — ${reason}`,
      meta: {
        workflowName: coderMeta.workflowName,
        attempt,
        passed: pass,
        dryRunLog: log,
        reason,
      },
    } satisfies RoleResult<TesterMeta>;
  };
}