import { AxiosError } from 'axios'

import apiClient from './client'
import {
  BillingPortalError,
  type BillingPortalErrorCode,
  type BillingPortalSessionResponse,
  type BillingStateApiResponse,
  type BillingStatePayload,
  type CheckoutSessionRequest,
  type CheckoutSessionResponse,
} from '@/types/billing'

/**
 * Single boundary where the snake_case backend payload is transformed
 * into the camelCase shape used by the rest of the frontend.
 *
 * Keeping the transform here means the store, hooks, and components
 * never see snake_case keys.
 */
function transformBillingState(raw: BillingStateApiResponse): BillingStatePayload {
  return {
    subscription: raw.subscription ?? null,
    planBilling: raw.plan_billing ?? null,
    planLimits: raw.plan_limits ?? {},
    enabledFeatures: raw.enabled_features ?? {},
  }
}

export const billingApi = {
  async getState(): Promise<BillingStatePayload> {
    const response = await apiClient.get<BillingStateApiResponse>('/billing/state')
    return transformBillingState(response.data)
  },

  /**
   * Request a Stripe Customer Portal session URL for the active account.
   *
   * Throws a typed `BillingPortalError` when:
   * - HTTP 503 → `stripe_not_configured` (server-side Stripe is disabled)
   * - HTTP 400 + `error: 'no_stripe_customer'` → account hasn't been billed yet
   *
   * Other errors (5xx, network) propagate as the underlying AxiosError.
   */
  async getPortalSession(): Promise<BillingPortalSessionResponse> {
    try {
      const response = await apiClient.get<BillingPortalSessionResponse>(
        '/billing/portal-session',
      )
      return response.data
    } catch (err) {
      if (err instanceof AxiosError && err.response) {
        const { status, data } = err.response
        const code: BillingPortalErrorCode | null =
          status === 503
            ? 'stripe_not_configured'
            : status === 400 && data?.detail?.error === 'no_stripe_customer'
              ? 'no_stripe_customer'
              : null
        if (code) {
          throw new BillingPortalError(code)
        }
      }
      throw err
    }
  },

  async createCheckoutSession(
    payload: CheckoutSessionRequest,
  ): Promise<CheckoutSessionResponse> {
    const response = await apiClient.post<CheckoutSessionResponse>(
      '/billing/checkout-session',
      payload,
    )
    return response.data
  },
}

export default billingApi