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

// Plain JSON in userData (portable build redirects userData next to the exe).
// Kept simple per the build plan; can migrate to better-sqlite3 later.
const MAX_ENTRIES = 500

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

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

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

export function addHistory(entry: HistoryEntry): HistoryEntry[] {
  // De-dupe by id (a retry of the same item replaces its prior entry).
  const entries = [entry, ...listHistory().filter((e) => e.id !== entry.id)]
  save(entries)
  return entries
}

export function removeHistory(id: string): HistoryEntry[] {
  const entries = listHistory().filter((e) => e.id !== id)
  save(entries)
  return entries
}

export function removeManyHistory(ids: string[]): HistoryEntry[] {
  const remove = new Set(ids)
  const entries = listHistory().filter((e) => !remove.has(e.id))
  save(entries)
  return entries
}

export function clearHistory(): HistoryEntry[] {
  save([])
  return []
}