#!/usr/bin/env node
// ═══════════════════════════════════════════════════════════════════════════
// System Graph Reasoning Engine
// Traverserar kunskapsgrafen för att besvara frågor om systemet
// ═══════════════════════════════════════════════════════════════════════════

import { readFileSync } from 'fs';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';

const __dirname = dirname(fileURLToPath(import.meta.url));
const graphPath = join(__dirname, 'SYSTEM_GRAPH.json');

let graph;
try {
  graph = JSON.parse(readFileSync(graphPath, 'utf8'));
} catch (e) {
  console.error('❌ Kunde inte ladda SYSTEM_GRAPH.json:', e.message);
  process.exit(1);
}

// ── Hjälpfunktioner ───────────────────────────────────────────────────────

function getNode(id) {
  return graph.nodes.find(n => n.id === id);
}

function getEdgesFrom(nodeId) {
  return graph.edges.filter(e => e.from === nodeId);
}

function getEdgesTo(nodeId) {
  return graph.edges.filter(e => e.to === nodeId);
}

function getRelatedNodes(nodeId, direction = 'both') {
  const related = new Set();
  if (direction === 'from' || direction === 'both') {
    getEdgesFrom(nodeId).forEach(e => related.add(e.to));
  }
  if (direction === 'to' || direction === 'both') {
    getEdgesTo(nodeId).forEach(e => related.add(e.from));
  }
  return Array.from(related).map(id => getNode(id)).filter(Boolean);
}

// ── Traversering ──────────────────────────────────────────────────────────

function traverse(nodeId, visited = new Set(), depth = 0, maxDepth = 10) {
  if (depth > maxDepth || visited.has(nodeId)) return [];
  visited.add(nodeId);
  
  const node = getNode(nodeId);
  if (!node) return [];
  
  const edges = getEdgesFrom(nodeId);
  const results = [{ node, depth, edges }];
  
  for (const edge of edges) {
    results.push(...traverse(edge.to, visited, depth + 1, maxDepth));
  }
  
  return results;
}

function reverseTraverse(nodeId, visited = new Set(), depth = 0, maxDepth = 10) {
  if (depth > maxDepth || visited.has(nodeId)) return [];
  visited.add(nodeId);
  
  const node = getNode(nodeId);
  if (!node) return [];
  
  const edges = getEdgesTo(nodeId);
  const results = [{ node, depth, edges }];
  
  for (const edge of edges) {
    results.push(...reverseTraverse(edge.from, visited, depth + 1, maxDepth));
  }
  
  return results;
}

// ── Query-handlers ────────────────────────────────────────────────────────

function impactAnalysis(componentId) {
  console.log(`\n🔍 IMPACT ANALYSIS: ${componentId}\n`);
  
  const node = getNode(componentId);
  if (!node) {
    console.log(`❌ Komponent "${componentId}" hittades inte i grafen`);
    return;
  }
  
  console.log(`📍 Komponent: ${node.label} (${node.type})`);
  if (node.critical) console.log(`⚠️  KRITISK KOMPONENT`);
  console.log('');
  
  const impacted = traverse(componentId);
  
  const byDepth = {};
  impacted.forEach(({ node, depth }) => {
    if (depth === 0) return; // Skip self
    if (!byDepth[depth]) byDepth[depth] = [];
    byDepth[depth].push(node);
  });
  
  console.log('📊 Påverkade komponenter:\n');
  
  for (const [depth, nodes] of Object.entries(byDepth)) {
    console.log(`  Nivå ${depth} (direkt${depth > 1 ? ' + indirekt' : ''}):`);
    nodes.forEach(n => {
      const icon = n.critical ? '🔴' : n.type === 'actor' ? '👤' : n.type === 'service' ? '⚙️' : n.type === 'database' ? '🗄️' : '📦';
      console.log(`    ${icon} ${n.label} (${n.type})${n.critical ? ' [KRITISK]' : ''}`);
    });
    console.log('');
  }
  
  // Affärsprocesser som påverkas
  const businessProcesses = impacted.filter(({ node }) => node.type === 'business_process');
  if (businessProcesses.length > 0) {
    console.log('🏭 Affärsprocesser som påverkas:');
    businessProcesses.forEach(({ node }) => {
      console.log(`    • ${node.label}`);
    });
    console.log('');
  }
  
  // Tester som behövs
  const services = impacted.filter(({ node }) => node.type === 'service');
  if (services.length > 0) {
    console.log('🧪 Tester som måste köras:');
    services.forEach(({ node }) => {
      if (node.endpoints) {
        console.log(`    • ${node.label}:`);
        node.endpoints.forEach(ep => console.log(`      - ${ep}`));
      }
    });
    console.log('');
  }
}

function failureAnalysis(componentId) {
  console.log(`\n💥 FAILURE ANALYSIS: ${componentId}\n`);
  
  const node = getNode(componentId);
  if (!node) {
    console.log(`❌ Komponent "${componentId}" hittades inte`);
    return;
  }
  
  console.log(`📍 Komponent som fallerar: ${node.label}\n`);
  
  // Hitta alla noder som ENDAST kan nås via denna komponent
  const allNodes = graph.nodes.filter(n => n.id !== componentId);
  const cutOff = [];
  
  for (const target of allNodes) {
    const paths = findAllPaths(target.id, componentId);
    if (paths.length === 0) continue;
    
    // Kolla om det finns vägar som INTE går via componentId
    const alternativePaths = paths.filter(p => !p.includes(componentId));
    if (alternativePaths.length === 0) {
      cutOff.push(target);
    }
  }
  
  if (cutOff.length === 0) {
    console.log('✅ Ingen komponent är helt beroende av denna. Systemet har redundans.');
    return;
  }
  
  console.log('❌ Komponenter som BLIR OTILLGÄNGLIGA:\n');
  
  const byType = {};
  cutOff.forEach(n => {
    if (!byType[n.type]) byType[n.type] = [];
    byType[n.type].push(n);
  });
  
  for (const [type, nodes] of Object.entries(byType)) {
    const icon = type === 'actor' ? '👤' : type === 'service' ? '⚙️' : type === 'business_process' ? '🏭' : type === 'database' ? '🗄️' : '📦';
    console.log(`  ${icon} ${type.toUpperCase()}:`);
    nodes.forEach(n => {
      console.log(`    • ${n.label}${n.critical ? ' [KRITISK]' : ''}`);
    });
    console.log('');
  }
  
  // Affärspåverkan
  const businessImpact = cutOff.filter(n => n.type === 'business_process');
  if (businessImpact.length > 0) {
    console.log('💰 AFFÄRSPÅVERKAN:\n');
    businessImpact.forEach(n => {
      console.log(`    🏭 ${n.label}`);
      console.log(`       Steg: ${n.steps?.join(' → ') || 'okänt'}`);
    });
    console.log('');
  }
}

function findAllPaths(targetId, excludeId = null, currentPath = [], visited = new Set()) {
  if (currentPath.length > 10) return [];
  
  const paths = [];
  const edges = getEdgesTo(targetId);
  
  for (const edge of edges) {
    if (edge.from === excludeId) continue;
    if (visited.has(edge.from)) continue;
    
    const newPath = [edge.from, ...currentPath];
    if (newPath.length > 1) {
      paths.push(newPath);
    }
    
    visited.add(edge.from);
    paths.push(...findAllPaths(edge.from, excludeId, newPath, visited));
  }
  
  return paths;
}

function blastRadius(tableName) {
  console.log(`\n💣 BLAST RADIUS: ${tableName}\n`);
  
  const tableNode = graph.nodes.find(n => n.label === tableName && n.type === 'domain');
  if (!tableNode) {
    console.log(`❌ Tabell "${tableName}" hittades inte`);
    return;
  }
  
  console.log(`📍 Tabell: ${tableNode.label}\n`);
  
  const impacted = reverseTraverse(tableNode.id);
  
  console.log('🔍 Komponenter som använder denna tabell:\n');
  
  const services = [];
  const processes = [];
  
  impacted.forEach(({ node, depth }) => {
    if (depth === 0) return;
    if (node.type === 'service') services.push({ node, depth });
    if (node.type === 'business_process') processes.push({ node, depth });
  });
  
  if (services.length > 0) {
    console.log('  ⚙️  TJÄNSTER:');
    services.forEach(({ node, depth }) => {
      console.log(`    ${'  '.repeat(depth - 1)}• ${node.label} ${node.endpoints ? `(${node.endpoints.length} endpoints)` : ''}`);
    });
    console.log('');
  }
  
  if (processes.length > 0) {
    console.log('  🏭 AFFÄRSPROCESSER:');
    processes.forEach(({ node }) => {
      console.log(`    • ${node.label}`);
    });
    console.log('');
  }
  
  // Förslag på tester
  console.log('🧪 FÖRESLAGNA TESTER:\n');
  services.forEach(({ node }) => {
    if (node.endpoints) {
      console.log(`  ${node.label}:`);
      node.endpoints.forEach(ep => {
        console.log(`    - GET/POST ${ep} (med ${tableName} data)`);
      });
    }
  });
}

// ── Huvudmeny ─────────────────────────────────────────────────────────────

function printHelp() {
  console.log(`
🧠 System Graph Reasoning Engine

Användning:
  node graph-engine.mjs <kommando> [argument]

Kommandon:
  impact <komponent>     Visa vilka komponenter påverkas av en ändring
  failure <komponent>    Visa vad som går sönder om komponenten fallerar
  blast <tabell>         Visa vilka som använder en databastabell
  list                   Lista alla komponenter i grafen
  stats                  Visa statistik om grafen

Exempel:
  node graph-engine.mjs impact wallet
  node graph-engine.mjs failure stripe
  node graph-engine.mjs blast missions
`);
}

function listComponents() {
  console.log('\n📋 KOMPONENTER I SYSTEMET\n');
  
  const byType = {};
  graph.nodes.forEach(n => {
    if (!byType[n.type]) byType[n.type] = [];
    byType[n.type].push(n);
  });
  
  for (const [type, nodes] of Object.entries(byType)) {
    const icon = type === 'actor' ? '👤' : type === 'service' ? '⚙️' : type === 'database' ? '🗄️' : type === 'frontend' ? '🖥️' : type === 'business_process' ? '🏭' : type === 'domain' ? '📊' : type === 'risk' ? '⚠️' : type === 'agent' ? '🤖' : '📦';
    console.log(`${icon} ${type.toUpperCase()} (${nodes.length}):`);
    nodes.forEach(n => {
      const critical = n.critical ? ' 🔴' : '';
      console.log(`  • ${n.label}${critical}`);
    });
    console.log('');
  }
}

function stats() {
  console.log('\n📊 GRAF-STATISTIK\n');
  console.log(`  Noder: ${graph.nodes.length}`);
  console.log(`  Kanter: ${graph.edges.length}`);
  console.log(`  Affärsprocesser: ${graph.nodes.filter(n => n.type === 'business_process').length}`);
  console.log(`  Risker: ${graph.nodes.filter(n => n.type === 'risk').length}`);
  console.log(`  Kritiska komponenter: ${graph.nodes.filter(n => n.critical).length}`);
  console.log(`  Senast uppdaterad: ${graph.last_updated}`);
  console.log(`  Uppdateringskälla: ${graph.update_source}`);
  console.log('');
}

// ── Main ──────────────────────────────────────────────────────────────────

const [,, command, ...args] = process.argv;

if (!command || command === 'help') {
  printHelp();
  process.exit(0);
}

switch (command) {
  case 'impact':
    if (!args[0]) {
      console.log('❌ Ange komponent: node graph-engine.mjs impact <komponent>');
      process.exit(1);
    }
    impactAnalysis(args[0]);
    break;
    
  case 'failure':
    if (!args[0]) {
      console.log('❌ Ange komponent: node graph-engine.mjs failure <komponent>');
      process.exit(1);
    }
    failureAnalysis(args[0]);
    break;
    
  case 'blast':
    if (!args[0]) {
      console.log('❌ Ange tabell: node graph-engine.mjs blast <tabellnamn>');
      process.exit(1);
    }
    blastRadius(args[0]);
    break;
    
  case 'list':
    listComponents();
    break;
    
  case 'stats':
    stats();
    break;
    
  default:
    console.log(`❌ Okänt kommando: ${command}`);
    printHelp();
    process.exit(1);
}