import {z} from 'zod'

export type SpendingGoalPost = {categoryId: string, periodType?: ('monthly' | 'annual') | undefined, periodStart?: string | undefined, amount: {value: number}};

export type CreateApiSpendingGoalsArgs = {body: SpendingGoalPost};

export type CreateApiSpendingGoalsOptions = {baseUrl?: string | undefined, Bearer?: string | undefined, fetch?: typeof fetch | undefined};

export const spendingGoal = z.object({categoryId: z.string(), dateCreated: z.string(), periodType: z.enum(["monthly", "annual"]), periodStart: z.string(), id: z.string(), amount: z.object({value: z.number().int().gte(0), majorUnits: z.number().int().optional(), minorUnits: z.number().int().optional(), currency: z.string()}), spending: z.array(z.object({date: z.string(), spent: z.number().int()}))});

export const links = z.object({next: z.string().optional(), prev: z.string().optional(), self: z.string()});

export const createApiSpendingGoalsResponse = z.object({data: spendingGoal.optional(), links: links.optional(), meta: z.object({}).optional()});

export const validateResponse = async <Output>(
  schema: {
    readonly '~standard': {
      readonly validate: (value: unknown) => ({ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }) | Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }>
    }
  },
  value: unknown
): Promise<Output> => {
  const result = await schema['~standard'].validate(value)

  if (result.issues !== undefined) {
    const detail = result.issues
      .map(({ message, path }) =>
        path?.length
          ? `${path.map((segment) => String(typeof segment === 'object' ? segment.key : segment)).join('.')}: ${message}`
          : message
      )
      .join('; ')

    throw new Error(`Response does not match the schema: ${detail}`, { cause: { issues: result.issues } })
  }

  return result.value
};

/**
 * Create a single spending goal for a user
 * 
 * POST /spending-goals
 */
export const createApiSpendingGoals = async (args: CreateApiSpendingGoalsArgs, options?: CreateApiSpendingGoalsOptions) => {
const {baseUrl = "https://api.moneyhub.co.uk/v2.0", fetch: fetchFn = fetch, Bearer} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('content-type', "application/json")
headers.set('accept', "application/json")

if (Bearer !== undefined) headers.set("Authorization", Bearer)

const url = `${baseUrl.replace(/\/+$/, '')}/spending-goals${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "POST", headers, body: JSON.stringify(args.body)})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(createApiSpendingGoalsResponse, await res.json())
};