#!/usr/bin/env node
// session-start-context.mjs
// Shows active utredning sessions and KB staleness on session start.
// Output: plain text to stdout (advisory, never blocking).

import { readdirSync, statSync, existsSync } from 'node:fs';
import { join, relative } from 'node:path';

const pluginRoot = process.env.CLAUDE_PLUGIN_ROOT || join(process.cwd());
const cwd = process.cwd();

const lines = [];

// --- 1. Check for active utredning sessions (.work/ directories) ---
const workDir = join(cwd, '.work');
let activeUtredninger = 0;

if (existsSync(workDir)) {
  try {
    const entries = readdirSync(workDir, { withFileTypes: true });
    for (const entry of entries) {
      if (entry.isDirectory()) {
        activeUtredninger++;
      }
    }
  } catch {
    // Ignore read errors
  }
}

// Also check docs/**/utredning.md
const docsDir = join(cwd, 'docs');
let utredningFiles = 0;

if (existsSync(docsDir)) {
  try {
    utredningFiles = countFiles(docsDir, 'utredning.md');
  } catch {
    // Ignore
  }
}

// --- 2. Check KB staleness (stat mtime, no content reading) ---
const staleLevels = { critical: 0, high: 0, medium: 0 };
const now = Date.now();
const DAY_MS = 24 * 60 * 60 * 1000;

const skillsDir = join(pluginRoot, 'skills');
if (existsSync(skillsDir)) {
  try {
    const skillDirs = readdirSync(skillsDir, { withFileTypes: true });
    for (const skill of skillDirs) {
      if (!skill.isDirectory()) continue;
      const refsDir = join(skillsDir, skill.name, 'references');
      if (!existsSync(refsDir)) continue;
      countStaleFiles(refsDir, staleLevels, now);
    }
  } catch {
    // Ignore
  }
}

// --- 3. Check EU AI Act deadlines ---
const AI_ACT_DEADLINES = [
  { date: new Date('2025-02-02'), label: 'Forbudte AI-praksiser (Art. 5)' },
  { date: new Date('2025-08-02'), label: 'Governance + sanksjoner (Art. 99)' },
  { date: new Date('2026-08-02'), label: 'GPAI-krav + høyrisiko i Annex III' },
  { date: new Date('2027-08-02'), label: 'Alle høyrisiko-krav (full compliance)' },
];

let nearestDeadline = null;
for (const dl of AI_ACT_DEADLINES) {
  const daysLeft = Math.ceil((dl.date.getTime() - now) / DAY_MS);
  if (daysLeft > 0 && daysLeft <= 180) {
    if (!nearestDeadline || daysLeft < nearestDeadline.daysLeft) {
      nearestDeadline = { ...dl, daysLeft };
    }
  }
}

// --- 4. Check onboarding status ---
const orgDir = join(pluginRoot, 'org');
const ORG_FILES = [
  'organization-profile.md',
  'technology-stack.md',
  'security-compliance.md',
  'architecture-decisions.md',
  'business-references.md',
];
let orgComplete = 0;
const orgExists = existsSync(orgDir);
if (orgExists) {
  for (const f of ORG_FILES) {
    if (existsSync(join(orgDir, f))) orgComplete++;
  }
}

// --- 4. Build output ---
const parts = [];

if (activeUtredninger > 0) {
  parts.push(`${activeUtredninger} aktiv(e) utredning(er) i .work/`);
}
if (utredningFiles > 0) {
  parts.push(`${utredningFiles} utredningsdokument(er) i docs/`);
}

if (!orgExists || orgComplete === 0) {
  parts.push('Ingen virksomhetstilpasning. Kjør /architect:onboard (~5 min)');
} else if (orgComplete < ORG_FILES.length) {
  parts.push(`Onboarding ${orgComplete}/${ORG_FILES.length}. Kjør /architect:onboard for å fullføre`);
}

const staleEntries = [];
if (staleLevels.critical > 0) staleEntries.push(`${staleLevels.critical} critical`);
if (staleLevels.high > 0) staleEntries.push(`${staleLevels.high} high`);
if (staleLevels.medium > 0) staleEntries.push(`${staleLevels.medium} medium`);

if (staleEntries.length > 0) {
  parts.push(`KB stale: ${staleEntries.join(', ')}`);
}

if (nearestDeadline) {
  parts.push(`EU AI Act: ${nearestDeadline.daysLeft} dager til ${nearestDeadline.label}. Kjør /architect:classify`);
}

if (parts.length > 0) {
  lines.push(`Architect: ${parts.join('. ')}. /architect:help`);
} else {
  lines.push('Architect: Ingen aktive sesjoner. KB oppdatert. /architect:help');
}

if (lines.length > 0) {
  process.stdout.write(lines.join('\n') + '\n');
}

// --- Helpers ---

function countFiles(dir, filename) {
  let count = 0;
  try {
    const entries = readdirSync(dir, { withFileTypes: true });
    for (const entry of entries) {
      const fullPath = join(dir, entry.name);
      if (entry.isDirectory()) {
        count += countFiles(fullPath, filename);
      } else if (entry.name === filename) {
        count++;
      }
    }
  } catch {
    // Ignore permission errors
  }
  return count;
}

function countStaleFiles(dir, levels, now) {
  try {
    const entries = readdirSync(dir, { withFileTypes: true });
    for (const entry of entries) {
      const fullPath = join(dir, entry.name);
      if (entry.isDirectory()) {
        countStaleFiles(fullPath, levels, now);
      } else if (entry.name.endsWith('.md')) {
        try {
          const mtime = statSync(fullPath).mtimeMs;
          const ageDays = (now - mtime) / DAY_MS;
          if (ageDays > 180) levels.critical++;
          else if (ageDays > 90) levels.high++;
          else if (ageDays > 60) levels.medium++;
        } catch {
          // Skip unreadable files
        }
      }
    }
  } catch {
    // Ignore
  }
}