/** Git merge-driver and explicit conflict-resolver entrypoint for pairing records. */

import { execFileSync } from 'node:child_process'
import { readFileSync, writeFileSync } from 'node:fs'
import {
  mergeTranslationPairingRecords,
  resolveTranslationPairingConflicts,
} from './translation-pairing-merge.ts'

const args = process.argv.slice(2)

try {
  const root = execFileSync('git', ['rev-parse', '--show-toplevel'], { encoding: 'utf8' }).trim()
  if (args[0] === '--resolve') {
    if (args.length !== 1) throw new Error('--resolve takes no paths; it inspects the unmerged index')
    const resolved = resolveTranslationPairingConflicts(root)
    if (resolved.length === 0) {
      console.log('merge-translation-pairing: no unresolved pairing records')
    } else {
      for (const path of resolved) console.log(`merge-translation-pairing: resolved ${path}`)
    }
  } else {
    if (args.length !== 4) {
      throw new Error('merge-driver mode requires <ancestor> <current> <other> <repository-path>')
    }
    const [ancestorPath, currentPath, otherPath, metaPath] = args
    if (ancestorPath === undefined || currentPath === undefined || otherPath === undefined || metaPath === undefined) {
      throw new Error('merge-driver arguments are incomplete')
    }
    const result = mergeTranslationPairingRecords(
      root,
      metaPath,
      readFileSync(ancestorPath, 'utf8'),
      readFileSync(currentPath, 'utf8'),
      readFileSync(otherPath, 'utf8'),
    )
    writeFileSync(currentPath, result.record)
  }
} catch (error) {
  console.error(`merge-translation-pairing: ${error instanceof Error ? error.message : String(error)}`)
  process.exitCode = 1
}