import { app } from 'electron'
import { join } from 'path'
import { readFileSync, writeFileSync, existsSync } from 'fs'
import type { ErrorLogEntry } from '@shared/ipc'
import { isValidErrorLogEntry } from './validation'

// Plain JSON in userData, same shape as history.ts. Persisted so a failure
// report survives the queue item being cleared (Seal's "debug report").
const MAX_ENTRIES = 200

function errorLogFile(): string {
  return join(app.getPath('userData'), 'errorlog.json')
}

// Per-entry validation (isValidErrorLogEntry, in validation.ts) so a hand-edited
// or corrupted errorlog.json can't feed the UI entries with the wrong shape —
// invalid rows are dropped. (audit S5)
export function listErrorLog(): ErrorLogEntry[] {
  try {
    if (!existsSync(errorLogFile())) return []
    const data = JSON.parse(readFileSync(errorLogFile(), 'utf8'))
    return Array.isArray(data) ? data.filter(isValidErrorLogEntry) : []
  } catch {
    return []
  }
}

function save(entries: ErrorLogEntry[]): void {
  try {
    writeFileSync(errorLogFile(), JSON.stringify(entries.slice(0, MAX_ENTRIES), null, 2))
  } catch {
    /* best-effort; a read-only data dir just means no persisted error log */
  }
}

export function addErrorLog(entry: ErrorLogEntry): ErrorLogEntry[] {
  const entries = [entry, ...listErrorLog()]
  save(entries)
  return entries
}

export function clearErrorLog(): ErrorLogEntry[] {
  save([])
  return []
}