import { defineSource } from '@jaspers-ai/sdk'
import { z } from 'zod'


// The OECD's SDMX API. No key. Cross-country indicators, addressed by a dataflow and a key, which
// is how SDMX works and is not friendly; the shortcuts below are the ones worth having by name and
// each was checked against the live service.

const HOST = 'sdmx.oecd.org'

/** dataflow and key, for the series worth asking for by name. `%COUNTRY%` is filled in. */
const KNOWN: Record<string, { dataflow: string; key: string; what: string }> = {
  cpi: {
    dataflow: 'OECD.SDD.TPS,DSD_PRICES@DF_PRICES_ALL,1.0',
    key: '%COUNTRY%.M.N.CPI.PA._T.N.GY',
    what: 'Consumer prices, year on year, monthly',
  },
  production: {
    dataflow: 'OECD.SDD.STES,DSD_KEI@DF_KEI,4.0',
    key: '%COUNTRY%.M.PRVM.IX.....',
    what: 'Industrial production, index, monthly',
  },
}

interface Sdmx {
  dataSets?: { series: Record<string, { observations: Record<string, (number | null)[]> }> }[]
  structure?: { dimensions: { observation: { values: { id: string }[] }[] } }
}

export const series = defineSource({
  description: `A cross-country OECD series. Ask by name for one of: ${Object.entries(KNOWN)
    .map(([name, one]) => `${name} (${one.what})`)
    .join(', ')}. Anything else needs the dataflow and key SDMX addresses it by, which the OECD data explorer shows for a series.`,
  hosts: [HOST],
  input: z.object({
    series: z.string().default('cpi').describe(`One of ${Object.keys(KNOWN).join(', ')}, or "custom" with dataflow and key.`),
    country: z.string().default('USA').describe('An ISO three letter code, like USA, DEU, JPN.'),
    dataflow: z.string().optional().describe('For a series this does not know by name.'),
    key: z.string().optional(),
    points: z.number().int().min(1).max(2000).default(60),
  }),
  async run({ series: wanted, country, dataflow, key, points }, ctx) {
    const known = KNOWN[wanted.trim().toLowerCase()]
    const flow = known?.dataflow ?? dataflow
    const path = (known?.key ?? key)?.replace('%COUNTRY%', country.trim().toUpperCase())
    if (!flow || !path) {
      throw new Error(`No OECD series called "${wanted}". Ask for ${Object.keys(KNOWN).join(' or ')}, or give dataflow and key.`)
    }
    const url = `https://${HOST}/public/rest/data/${flow}/${path}?lastNObservations=${points}&format=jsondata`
    // The service returns the odd 500 on a request it answers a moment later, so one retry.
    let response = await ctx.fetch(url)
    if (response.status >= 500) {
      await new Promise((resolve) => setTimeout(resolve, 700))
      response = await ctx.fetch(url)
    }
    if (!response.ok) {
      const said = await response.text().catch(() => '')
      throw new Error(`The OECD answered ${response.status}. ${said.slice(0, 120)}`)
    }
    // The OECD wraps its payload in `data`, where the ECB puts the same fields at the top level.
    const body = (await response.json()) as { data?: Sdmx } & Partial<Sdmx>
    const payload = body.data ?? (body as Sdmx)
    const dates = payload.structure?.dimensions.observation[0]?.values.map((one) => one.id) ?? []
    const found = Object.values(payload.dataSets?.[0]?.series ?? {})[0]
    if (!found) throw new Error('The OECD has nothing for that country on that series.')
    const rows = Object.entries(found.observations)
      .map(([at, values]) => ({ country: country.toUpperCase(), date: dates[Number(at)] ?? at, value: values[0] }))
      .filter((one) => typeof one.value === 'number')
      .sort((a, b) => a.date.localeCompare(b.date))
    return { series: wanted, what: known?.what ?? 'custom', rows }
  },
})