import { ref } from 'vue'
import { useI18n } from 'vue-i18n'
import { useAppStore } from '@/stores/app'
import { adminAPI } from '@/api/admin'

export interface GeminiTokenInfo {
  access_token?: string
  refresh_token?: string
  token_type?: string
  scope?: string
  expires_at?: number | string
  project_id?: string
  [key: string]: unknown
}

export function useGeminiOAuth() {
  const appStore = useAppStore()
  const { t } = useI18n()

  const authUrl = ref('')
  const sessionId = ref('')
  const state = ref('')
  const loading = ref(false)
  const error = ref('')

  const resetState = () => {
    authUrl.value = ''
    sessionId.value = ''
    state.value = ''
    loading.value = false
    error.value = ''
  }

  const generateAuthUrl = async (
    proxyId: number | null | undefined,
    redirectUri: string
  ): Promise<boolean> => {
    loading.value = true
    authUrl.value = ''
    sessionId.value = ''
    state.value = ''
    error.value = ''

    try {
      if (!redirectUri?.trim()) {
        error.value = t('admin.accounts.oauth.gemini.missingRedirectUri')
        appStore.showError(error.value)
        return false
      }

      const payload: Record<string, unknown> = { redirect_uri: redirectUri.trim() }
      if (proxyId) payload.proxy_id = proxyId

      const response = await adminAPI.gemini.generateAuthUrl(payload as any)
      authUrl.value = response.auth_url
      sessionId.value = response.session_id
      state.value = response.state
      return true
    } catch (err: any) {
      error.value = err.response?.data?.detail || t('admin.accounts.oauth.gemini.failedToGenerateUrl')
      appStore.showError(error.value)
      return false
    } finally {
      loading.value = false
    }
  }

  const exchangeAuthCode = async (params: {
    code: string
    sessionId: string
    state: string
    redirectUri: string
    proxyId?: number | null
  }): Promise<GeminiTokenInfo | null> => {
    const code = params.code?.trim()
    if (!code || !params.sessionId || !params.state || !params.redirectUri?.trim()) {
      error.value = t('admin.accounts.oauth.gemini.missingExchangeParams')
      return null
    }

    loading.value = true
    error.value = ''

    try {
      const payload: Record<string, unknown> = {
        session_id: params.sessionId,
        state: params.state,
        code,
        redirect_uri: params.redirectUri.trim()
      }
      if (params.proxyId) payload.proxy_id = params.proxyId

      const tokenInfo = await adminAPI.gemini.exchangeCode(payload as any)
      return tokenInfo as GeminiTokenInfo
    } catch (err: any) {
      error.value = err.response?.data?.detail || t('admin.accounts.oauth.gemini.failedToExchangeCode')
      appStore.showError(error.value)
      return null
    } finally {
      loading.value = false
    }
  }

  const buildCredentials = (tokenInfo: GeminiTokenInfo): Record<string, unknown> => {
    let expiresAt: string | undefined
    if (typeof tokenInfo.expires_at === 'number' && Number.isFinite(tokenInfo.expires_at)) {
      expiresAt = Math.floor(tokenInfo.expires_at).toString()
    } else if (typeof tokenInfo.expires_at === 'string' && tokenInfo.expires_at.trim()) {
      expiresAt = tokenInfo.expires_at.trim()
    }

    return {
      access_token: tokenInfo.access_token,
      refresh_token: tokenInfo.refresh_token,
      token_type: tokenInfo.token_type,
      expires_at: expiresAt,
      scope: tokenInfo.scope,
      project_id: tokenInfo.project_id
    }
  }

  return {
    authUrl,
    sessionId,
    state,
    loading,
    error,
    resetState,
    generateAuthUrl,
    exchangeAuthCode,
    buildCredentials
  }
}