import fs from "fs"
import path from "path"
import os from "os"

const CONFIG_DIR = path.join(os.homedir(), ".llmtune")
const CONFIG_FILE = path.join(CONFIG_DIR, "config.json")

export interface AuthConfig {
  apiKey: string
  apiBase: string
  defaultModel?: string
}

export interface AppConfig {
  defaultProvider?: string
  providers?: Record<string, AuthConfig>
  [key: string]: unknown
}

export function ensureConfigDir(): void {
  if (!fs.existsSync(CONFIG_DIR)) {
    fs.mkdirSync(CONFIG_DIR, { recursive: true })
  }
  const memDir = path.join(CONFIG_DIR, "memory")
  if (!fs.existsSync(memDir)) {
    fs.mkdirSync(memDir, { recursive: true })
  }
  const sessionsDir = path.join(CONFIG_DIR, "sessions")
  if (!fs.existsSync(sessionsDir)) {
    fs.mkdirSync(sessionsDir, { recursive: true })
  }
  const logsDir = path.join(CONFIG_DIR, "logs")
  if (!fs.existsSync(logsDir)) {
    fs.mkdirSync(logsDir, { recursive: true })
  }
}

export function loadConfig(): AppConfig {
  ensureConfigDir()
  if (!fs.existsSync(CONFIG_FILE)) {
    return {}
  }
  try {
    const raw = fs.readFileSync(CONFIG_FILE, "utf-8")
    return JSON.parse(raw) as AppConfig
  } catch {
    return {}
  }
}

export function saveConfig(config: AppConfig): void {
  ensureConfigDir()
  fs.writeFileSync(CONFIG_FILE, JSON.stringify(config, null, 2), "utf-8")
}

export function getApiKey(): string | null {
  const config = loadConfig()
  return (config.apiKey as string) ?? null
}

export function getApiBase(): string {
  const config = loadConfig()
  return (config.apiBase as string) ?? "https://api.llmtune.io/api/agent/v1"
}

export function getDefaultModel(): string {
  const config = loadConfig()
  return (config.defaultModel as string) ?? "z-ai/GLM-5.1"
}

export function isLoggedIn(): boolean {
  return getApiKey() !== null
}

export function logout(): void {
  const config = loadConfig()
  delete config.apiKey
  delete config.apiBase
  delete config.defaultModel
  saveConfig(config)
}

export function getConfigPath(): string {
  return CONFIG_FILE
}

export function getConfigDir(): string {
  return CONFIG_DIR
}