import { existsSync, readFileSync, readdirSync } from "fs";
import { join } from "path";
import yaml from "js-yaml";
import { getNiaHome } from "../utils/paths";
import { log } from "../utils/log";
import type { EmployeeInfo } from "../types/employee";

function getEmployeesDir(): string {
  return join(getNiaHome(), "employees");
}

export function scanEmployees(): EmployeeInfo[] {
  const employees: EmployeeInfo[] = [];
  const dir = getEmployeesDir();
  if (!existsSync(dir)) return employees;

  const entries = readdirSync(dir, { withFileTypes: true }).sort((a, b) => a.name.localeCompare(b.name));

  for (const entry of entries) {
    if (!entry.isDirectory() || entry.name.startsWith(".")) continue;

    const empFile = join(dir, entry.name, "EMPLOYEE.md");
    if (!existsSync(empFile)) continue;

    const content = readFileSync(empFile, "utf8");
    const fmMatch = content.match(/^---\n([\s\S]*?)\n---/);
    if (!fmMatch) continue;

    let meta: Record<string, unknown> = {};
    try {
      meta = (yaml.load(fmMatch[1]) as Record<string, unknown>) || {};
    } catch (err) {
      log.warn({ err, employee: entry.name, path: empFile }, "failed to parse employee metadata, skipping");
      continue;
    }

    const name = (typeof meta.name === "string" ? meta.name : "") || entry.name;
    const body = content.replace(/^---\n[\s\S]*?\n---\n*/, "").trim();

    employees.push({
      name,
      dirName: entry.name,
      project: typeof meta.project === "string" ? meta.project : "",
      repo: typeof meta.repo === "string" ? meta.repo : "",
      role: typeof meta.role === "string" ? meta.role : "Employee",
      model: typeof meta.model === "string" ? meta.model : undefined,
      status:
        meta.status === "onboarding" || meta.status === "active" || meta.status === "paused"
          ? meta.status
          : "onboarding",
      maxSubEmployees: typeof meta.maxSubEmployees === "number" ? meta.maxSubEmployees : 3,
      body,
      created: typeof meta.created === "string" ? meta.created : new Date().toISOString().slice(0, 10),
      parent: typeof meta.parent === "string" ? meta.parent : undefined,
      source: "nia",
    });
  }

  return employees;
}

export function getEmployee(name: string): EmployeeInfo | undefined {
  return scanEmployees().find((e) => e.name.toLowerCase() === name.toLowerCase());
}

export function getEmployeeDir(name: string): string {
  // Look up actual directory — name in frontmatter may differ from dir name
  const emp = scanEmployees().find((e) => e.name.toLowerCase() === name.toLowerCase());
  if (emp) return join(getEmployeesDir(), emp.dirName);
  // Fallback for new employees being created (not yet on disk)
  return join(getEmployeesDir(), name);
}

export function getEmployeesSummary(): string {
  const employees = scanEmployees();
  if (employees.length === 0) return "";
  const lines = employees.map((e) => `- @${e.name}: ${e.role} — ${e.project || "(no project)"} [${e.status}]`);
  return `Available employees:\n${lines.join("\n")}`;
}

export function listEmployeesForMcp(): string {
  const employees = scanEmployees();
  if (employees.length === 0) return "No employees found.";
  return JSON.stringify(
    employees.map((e) => ({
      name: e.name,
      role: e.role,
      project: e.project,
      repo: e.repo,
      status: e.status,
      model: e.model,
    })),
    null,
    2,
  );
}

/** Injected into employee prompt only when status=onboarding. */
export const ONBOARDING_INSTRUCTIONS = `## Onboarding

You are in onboarding status. Be proactive — don't wait for the user to drive. You're a co-founder getting up to speed, not an assistant being briefed.

IMPORTANT: One thing at a time. Each message should focus on ONE step. Don't dump all steps on the user at once. Move to the next step only after the current one is resolved.

During the brief, don't just record — challenge. Ask follow-up questions. If the vision sounds vague, say so. If the goals are unrealistic, push back. If something sounds like it matters more than what the user is focused on, flag it.

### Steps (do these in order, one per message)
1. **Identity** — If your name is a placeholder (starts with "new-employee"), suggest 3-4 real names and ask the user to pick. Update the name field in your EMPLOYEE.md frontmatter. Do NOT rename the directory — the system resolves it from frontmatter.
2. **Project & Repo** — If project or repo are empty, ask what you'll be working on. Get the repo path. Update your EMPLOYEE.md.
3. **Brief** — Ask the user about the project: goals, what's working, what's not, their vision. Save to onboarding/brief.md.
4. **Self-Discovery** — Explore the repo autonomously. Read code, README, recent commits, deployment config. Save findings to onboarding/discovery.md. Report back to user for corrections.
5. **Initial Plan** — Propose top 3-5 priorities with first actions for each. Save to onboarding/plan.md. Get user approval.

After all steps are done, update your EMPLOYEE.md status from "onboarding" to "active".

Skip any step where the info is already filled in.`;