import { readFileSync, writeFileSync, existsSync, mkdirSync } from 'fs'
import { execSync } from 'child_process'
import { globSync } from 'glob'
import path from 'path'

const PACKAGES = [
  'imhotep-solver',
  'imhotep-geometry',
  'imhotep-topology',
  'imhotep-dsl'
]

const MUTATIONS = [
  { name: 'reverse-equality', pattern: /===/g, replacement: '!==' },
  { name: 'reverse-inequality', pattern: /!==/g, replacement: '===' },
  { name: 'gt-to-gte', pattern: /(?<!<)>(?!=)/g, replacement: '>=' },
  { name: 'lt-to-lte', pattern: /(?<!>)<(?!-)/g, replacement: '<=' },
  { name: 'gte-to-gt', pattern: />=/g, replacement: '>' },
  { name: 'lte-to-lt', pattern: /<=/g, replacement: '<' },
  { name: 'and-to-or', pattern: /&&/g, replacement: '||' },
  { name: 'or-to-and', pattern: /\|\|/g, replacement: '&&' },
  { name: 'plus-to-minus', pattern: /(?<![+])\+(?![+=])/g, replacement: '-' },
  { name: 'minus-to-plus', pattern: /(?<!-)\-(?!\-|=)/g, replacement: '+' },
  { name: 'true-to-false', pattern: /: true\b/g, replacement: ': false' },
  { name: 'false-to-true', pattern: /: false\b/g, replacement: ': true' }
]

function getSourceFiles(pkg) {
  const srcDir = path.join('packages', pkg, 'src')
  return globSync('**/*.ts', { cwd: srcDir, absolute: true })
    .filter(f => !f.endsWith('.test.ts'))
}

function runTests(pkg) {
  try {
    execSync('npm test', {
      cwd: path.join('packages', pkg),
      stdio: 'pipe',
      timeout: 30000
    })
    return { passed: true }
  } catch (e) {
    return { passed: false, output: e.stdout?.toString() || e.message }
  }
}

function build(pkg) {
  try {
    execSync('npm run build', {
      cwd: path.join('packages', pkg),
      stdio: 'pipe',
      timeout: 60000
    })
    return true
  } catch (e) {
    return false
  }
}

function applyMutation(filePath, mutation, index) {
  const content = readFileSync(filePath, 'utf8')
  const matches = [...content.matchAll(mutation.pattern)]
  
  if (matches.length === 0) return null
  if (index >= matches.length) return null
  
  const match = matches[index]
  const before = content.slice(0, match.index)
  const after = content.slice(match.index + match[0].length)
  const mutated = before + mutation.replacement + after
  
  writeFileSync(filePath, mutated)
  return {
    line: content.slice(0, match.index).split('\n').length,
    original: match[0],
    mutated: mutation.replacement
  }
}

function restoreFile(filePath, original) {
  writeFileSync(filePath, original)
}

const results = {}

for (const pkg of PACKAGES) {
  console.log(`\n=== Package: ${pkg} ===`)
  const files = getSourceFiles(pkg)
  const pkgResults = {
    total: 0,
    killed: 0,
    survived: 0,
    timedOut: 0,
    mutants: []
  }
  
  for (const filePath of files) {
    const content = readFileSync(filePath, 'utf8')
    
    for (const mutation of MUTATIONS) {
      const matches = [...content.matchAll(mutation.pattern)]
      
      for (let i = 0; i < matches.length; i++) {
        const info = applyMutation(filePath, mutation, i)
        if (!info) continue
        
        pkgResults.total++
        const shortFile = path.relative(process.cwd(), filePath)
        
        process.stdout.write(`  Mutant ${pkgResults.total}: ${shortFile}:${info.line} ${info.original} -> ${info.mutated} `)
        
        const built = build(pkg)
        if (!built) {
          pkgResults.timedOut++
          console.log('BUILD ERROR')
          restoreFile(filePath, content)
          continue
        }
        
        const testResult = runTests(pkg)
        
        if (!testResult.passed) {
          pkgResults.killed++
          console.log('KILLED')
        } else {
          pkgResults.survived++
          console.log('SURVIVED')
          pkgResults.mutants.push({
            file: shortFile,
            line: info.line,
            mutation: `${info.original} -> ${info.mutated}`,
            type: mutation.name
          })
        }
        
        restoreFile(filePath, content)
      }
    }
  }
  
  const score = pkgResults.total > 0 
    ? Math.round((pkgResults.killed / pkgResults.total) * 100) 
    : 0
  pkgResults.score = score
  results[pkg] = pkgResults
  
  console.log(`\n  Score: ${score}% (${pkgResults.killed}/${pkgResults.total})`)
  console.log(`  Survived: ${pkgResults.survived}, TimedOut: ${pkgResults.timedOut}`)
}

console.log('\n\n========== MUTATION TESTING SUMMARY ==========')
console.log('| Package | Score | Survived | Killed | Timeout |')
console.log('|---------|-------|----------|--------|---------|')
for (const pkg of PACKAGES) {
  const r = results[pkg]
  console.log(`| ${pkg.padEnd(18)} | ${String(r.score).padStart(3)}% | ${String(r.survived).padStart(8)} | ${String(r.killed).padStart(6)} | ${String(r.timedOut).padStart(7)} |`)
}

console.log('\n\n========== SURVIVING MUTANTS ==========')
for (const pkg of PACKAGES) {
  const r = results[pkg]
  if (r.mutants.length === 0) continue
  
  console.log(`\n--- ${pkg} ---`)
  for (const m of r.mutants) {
    console.log(`  ${m.file}:${m.line}  ${m.mutation} (${m.type})`)
  }
}

console.log('\n\nDone.')