import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import {
  buildTaskContext,
  parseQueue,
  readIndexedTask,
  verifyTaskIndex,
} from "./task-context-lib.mjs";
import { collectGeneratedGapPreflight } from "./generated-gap-preflight.mjs";

const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
const requested = process.argv.indexOf("--task");
const requestedTask = requested >= 0 ? process.argv[requested + 1] : undefined;
const issues = [];
const add = (code, detail) => issues.push({ code, detail });
const relative = (file) => path.relative(repoRoot, file).replaceAll(path.sep, "/");

let queue;
let index;
let entry;
try {
  queue = parseQueue();
  index = verifyTaskIndex();
  const task = requestedTask ?? queue.currentTask;
  const checkingCurrent = requestedTask === undefined;
  entry = readIndexedTask(task);
  if (!entry) add("TASK_NOT_INDEXED", task);

  const parentPath = path.resolve(repoRoot, queue.parentManifest);
  if (checkingCurrent && !fs.existsSync(parentPath)) add("PARENT_MANIFEST_MISSING", queue.parentManifest);
  else if (checkingCurrent) {
    const parent = JSON.parse(fs.readFileSync(parentPath, "utf8"));
    if (parent.nextTask !== queue.currentTask) add("PARENT_NEXT_TASK_MISMATCH", `${parent.nextTask ?? "NONE"}!=${queue.currentTask}`);
  }

  if (index) {
    if (checkingCurrent && index.activeTask !== queue.currentTask) add("INDEX_ACTIVE_TASK_MISMATCH", `${index.activeTask ?? "NONE"}!=${queue.currentTask}`);
    const catalogPath = path.resolve(repoRoot, index.catalog.path);
    const active = fs.readFileSync(catalogPath, "utf8").trimEnd().split("\n").filter(Boolean)
      .map((line) => JSON.parse(line)).filter((record) => record.state === "active");
    if (checkingCurrent && active.length !== 1) add("CATALOG_ACTIVE_TASK_COUNT", `count=${active.length}`);
    else if (checkingCurrent && active[0].id !== queue.currentTask) add("CATALOG_ACTIVE_TASK_MISMATCH", `${active[0].id}!=${queue.currentTask}`);
  }

  const cardPath = path.join(repoRoot, "docs/tasks", `${task}.md`);
  if (!fs.existsSync(cardPath) || fs.statSync(cardPath).size === 0) add("TASK_CARD_MISSING", relative(cardPath));
  else if (checkingCurrent) {
    const context = buildTaskContext(task);
    if (context.context.task !== task) add("TASK_CONTEXT_MISMATCH", `${context.context.task}!=${task}`);
  }

  for (const issue of collectGeneratedGapPreflight({ root: repoRoot, task: requestedTask ?? queue.currentTask, entry })) {
    add(issue.code, issue.detail);
  }
}
catch (error) {
  add("HEALTH_CHECK_ERROR", error instanceof Error ? error.message : String(error));
}

const report = {
  schemaVersion: 1,
  operation: "WEB_EXECUTION_HEALTH",
  status: issues.length === 0 ? "PASS" : "BLOCKED",
  queueTask: queue?.currentTask ?? null,
  checkedTask: requestedTask ?? queue?.currentTask ?? null,
  indexActiveTask: index?.activeTask ?? null,
  issueCount: issues.length,
  issues,
  remediation: [
    ...(issues.some(({ code }) => ["INDEX_ACTIVE_TASK_MISMATCH", "CATALOG_ACTIVE_TASK_MISMATCH", "CATALOG_ACTIVE_TASK_COUNT", "PARENT_NEXT_TASK_MISMATCH"].includes(code))
      ? ["repair the queue/index/catalog pointer through the repository generator"] : []),
    ...(issues.some(({ code }) => code === "TASK_CARD_MISSING")
      ? ["generate the compact task card before running a gap checker"] : []),
    ...(issues.some(({ code }) => ["TASK_NOT_RUNNABLE", "INPUT_MISSING", "INPUT_NOT_FILE"].includes(code))
      ? ["do not start Blender or load WASM until the task state and inputs are ready"] : []),
  ],
};
process.stdout.write(`${JSON.stringify(report)}\n`);
if (issues.length !== 0) process.exitCode = 2;