import fs from "node:fs/promises";
import path from "node:path";
import { execFile as callback } from "node:child_process";
import { promisify } from "node:util";
import { authoringContext } from "./authoring-context.js";
import { inspectAuthoringRepository } from "./authoring-inspect.js";
import { checkRecordName } from "./authoring-check.js";
import { loadQuixosLock } from "../resource-lock/index.js";
import { checkerIdentity } from "./checked-build.js";

const execFile = promisify(callback);
export async function authoringWorklist(start: string) {
  const context = await authoringContext(start);
  const entries: {directory: string; resourceId?: string; phase: string; message: string; next: string}[] = [];
  const dependencies = new Map<string, string[]>();
  for (const resource of context.resources) {
    const root = path.join(context.workbench, resource.directory);
    const add = (phase: string, message: string) => entries.push({directory: resource.directory, resourceId: resource.resourceId, phase, message,
      next: phase === "syntax" ? `qx-workspace inspect ${resource.directory}` : phase === "evolution" ? "Inspect evolution.json in the check output; resolve its named migration/review requirements before cutover" : `cd ${resource.directory} && qx-workspace check`});
    try {
      if (await fs.realpath(root) !== root) throw new Error("Registered checkout crosses a symlink");
      const inspected = await inspectAuthoringRepository(root);
      for (const file of inspected.files) if (file.currentErrors.length) add("syntax", `${file.file}: ${JSON.stringify(file.currentErrors)}${file.status === "historical" ? `; historical contract available at ${file.revision}` : ""}`);
      const lock = await loadQuixosLock(path.join(root, "quixos.lock"));
      if (!lock.ok) add("resolution", lock.diagnostics.map(entry => `${entry.fileName}: ${entry.message}`).join("\n"));
      else dependencies.set(resource.directory, lock.lock.resources.flatMap(dependency => {
        const selected = context.resources.find(entry => entry.kind === dependency.kind && entry.source?.repository === dependency.source.repository);
        if (selected?.source && selected.source.commit !== dependency.source.commit) add("propagation", `Dependency ${dependency.binding} has advanced; check will repin it automatically`);
        return selected ? [selected.directory] : [];
      }));
      let record;
      try { record = JSON.parse(await fs.readFile(path.join(context.workbench, ".quixos/checks", checkRecordName(resource.directory)), "utf8")); }
      catch (error) { if ((error as NodeJS.ErrnoException).code !== "ENOENT") throw error; }
      if (!record?.commit) {
        if (record?.blockers?.length) add(record.phase, record.blockers.join("\n"));
        else add("unchecked", "No immutable candidate check recorded yet");
        continue;
      }
      if (record.checker !== checkerIdentity()) add("unchecked", "The installed checker changed since the last check");
      const env = {...process.env, QUIXOS_JJ_NO_CHECKPOINT: "1"};
      const commit = (await execFile("jj", ["--ignore-working-copy", "log", "--no-graph", "-r", "@", "-T", "commit_id"], {cwd: root, env})).stdout.trim();
      const dirty = await execFile("git", ["diff", "--quiet", "--no-ext-diff", record.commit, "--"], {cwd: root}).then(() => false, () => true);
      const untracked = (await execFile("git", ["ls-files", "--others", "--exclude-standard"], {cwd: root})).stdout;
      if (commit !== record.commit || dirty || untracked) add("unchecked", `Edits are newer than the last check (${record.commit.slice(0, 12)})`);
      else if (record.blockers?.length) add(record.phase, record.blockers.join("\n"));
    } catch (error) { add("inspection", String(error).slice(0, 3000)); }
  }
  // Fixed-point propagation, independent of registration order.
  const blocked = new Set(entries.map(entry => entry.directory));
  let changed = true;
  while (changed) {
    changed = false;
    for (const [directory, required] of dependencies) if (!blocked.has(directory)) {
      const waiting = required.filter(dependency => blocked.has(dependency));
      if (waiting.length) { blocked.add(directory); changed = true; entries.push({directory, phase: "dependency", message: `Waiting for ${waiting.join(", ")}`, next: "Resolve the named repositories, then rerun check"}); }
    }
  }
  return { workbench: context.workbench, verificationEvidence: false, worklist: entries,
    note: "Derived authoring guidance, not activation approval. Independent repositories can be delegated separately; join writers before a root check." };
}