import { DEFAULT_AI_SETTINGS, type AISettings } from "./types"

const STORAGE_KEY = "devvault.ai-settings"

export function loadAISettings(): AISettings {
  if (typeof window === "undefined") return { ...DEFAULT_AI_SETTINGS }
  try {
    const raw = window.localStorage.getItem(STORAGE_KEY)
    if (!raw) return { ...DEFAULT_AI_SETTINGS }
    const parsed = JSON.parse(raw) as Partial<AISettings>
    return { ...DEFAULT_AI_SETTINGS, ...parsed }
  } catch {
    return { ...DEFAULT_AI_SETTINGS }
  }
}

export function saveAISettings(settings: AISettings): void {
  if (typeof window === "undefined") return
  window.localStorage.setItem(STORAGE_KEY, JSON.stringify(settings))
}

export function clearApiKey(): AISettings {
  const current = loadAISettings()
  const next = { ...current, apiKey: "" }
  saveAISettings(next)
  return next
}

export function resetAISettings(): AISettings {
  const next = { ...DEFAULT_AI_SETTINGS }
  saveAISettings(next)
  return next
}

/** Returns an error message if the settings are not usable for a request, otherwise null. */
export function validateForRequest(settings: AISettings): string | null {
  if (!settings.baseUrl.trim()) return "请先在设置中填写 API Base URL"
  if (!settings.model.trim()) return "请先在设置中填写 Model"
  if (!settings.apiKey.trim()) return "请先在设置中填写 API Key"
  return null
}