/**
 * @copyright Sister Software
 * @license AGPL-3.0
 * @author Teffen Ellis, et al.
 *
 *   `usgov-irs-bmf`: IRS Exempt Organizations Business Master File (EO BMF) CSV consumer.
 *
 *   The EO BMF is the IRS's authoritative registry of US tax-exempt organizations (charities,
 *   churches, foundations, ...), published as per-region CSVs at
 *   `https://www.irs.gov/charities-non-profits/exempt-organizations-business-master-file-extract-eo-bmf`
 *   (`eo1.csv`..`eo4.csv`, `eo_pr.csv`, `eo_xx.csv`). Each row includes an organization name plus
 *   its mailing address. It complements `usgov-nppes` with a different venue population
 *   (non-profits vs healthcare providers) and, notably, a high share of PO-box addresses — useful
 *   `po_box`-tag signal (a tag with historically low recall).
 *
 *   Output: one row per record with a usable city + postcode. name → `venue`; the street line becomes
 *   `po_box` when it's a PO-box, else `house_number` + `street`; city/state/ZIP fill the locality
 *   line. state is already a USPS abbreviation in the source. License: `"Public Domain"` (US
 *   federal).
 */

import { formatAddressRow } from "@mailwoman/codex/address/format"
import { CSVSpliterator } from "spliterator"

import { stableSourceID } from "#adapters/source-id"
import { splitStreetLine } from "#adapters/street-line"
import { SourceRegister } from "#registers"
import { AddressRole, type AdapterOptions, type CanonicalRow, type CorpusAdapter, SurfaceOrigin } from "#types"

/**
 * Registry id for this adapter.
 *
 * Stamped into every row it emits, so a corpus record can be traced back to the dataset it came from.
 */
export const USGOV_IRS_BMF_ADAPTER_ID = "usgov-irs-bmf"
/**
 * License assigned by this source (Public Domain), attached to each row so downstream
 * consumers inherit the terms rather than having to look them up.
 */
export const USGOV_IRS_BMF_DEFAULT_LICENSE = "Public Domain"

/**
 * PO box in its many written forms: "PO BOX 12", "P.O.
 *
 * BOX 12", "P O BOX 12", "POB 12", "BOX 12".
 */
const PO_BOX = /^\s*(?:P\.?\s?O\.?\s*BOX|POB|BOX)\s+\w/i

interface IRSBMFRow {
	EIN: string
	NAME: string
	STREET: string
	CITY: string
	STATE: string
	ZIP: string
}

/**
 * Classify the street line into a `po_box` or a `{house_number?, street}` split.
 *
 * BMF mixes street addresses and PO boxes in one `street` column, so the PO-box shapes
 * have to be claimed before the shared house-number split runs.
 * Otherwise `splitStreetLine` would hand back `"PO Box 1234"` as a plain street.
 * which is correct for every other US adapter and wrong here.
 */
function splitStreetLineOrPOBox(street: string): { po_box: string } | { house_number?: string; street: string } | null {
	const trimmed = street.trim()

	if (PO_BOX.test(trimmed)) return { po_box: trimmed }

	return splitStreetLine(trimmed)
}

export function createUSGovIRSBMFAdapter(): CorpusAdapter {
	return {
		id: USGOV_IRS_BMF_ADAPTER_ID,
		defaultLicense: USGOV_IRS_BMF_DEFAULT_LICENSE,
		addressRole: AddressRole.Mailing,
		register: SourceRegister.IRSBusinessMasterFile,
		surface: SurfaceOrigin.Rendered,
		description:
			"IRS Exempt Organizations Business Master File — US non-profit venue+address (public-domain), with strong PO-box coverage.",

		async *rows(opts: AdapterOptions): AsyncIterable<CanonicalRow> {
			if (opts.country && opts.country !== "US") {
				throw new Error(`usgov-irs-bmf adapter: only US supported, got country=${opts.country}`)
			}

			const rows = CSVSpliterator.fromAsync(opts.inputPath, {
				normalizeKeys: false,
			})

			let emitted = 0

			for await (const record of rows as AsyncIterable<IRSBMFRow>) {
				if (opts.signal?.aborted) break

				if (opts.limit !== undefined && emitted >= opts.limit) break

				const ein = record.EIN ?? ""
				const venue = (record.NAME ?? "") || undefined
				const street = record.STREET ?? ""
				const city = record.CITY ?? ""
				const state = record.STATE ?? ""
				const zipRaw = record.ZIP ?? ""

				if (!city || !zipRaw) continue
				const postcode = zipRaw.split("-")[0]!.trim() // 5-digit. drop the optional +4

				const split = splitStreetLineOrPOBox(street)

				if (!split) continue

				const components: CanonicalRow["components"] = {
					...(venue ? { venue } : {}),
					...("po_box" in split
						? { po_box: split.po_box }
						: { ...(split.house_number ? { house_number: split.house_number } : {}), street: split.street }),
					locality: city,
					...(state ? { region: state } : {}),
					postcode,
				}

				const rendered = formatAddressRow(components, "US", { singleLine: true })

				if (!rendered) continue

				const { raw, components: aligned } = rendered

				if (Object.keys(aligned).length <= 2) continue

				const sourceID = ein ? `${USGOV_IRS_BMF_ADAPTER_ID}-${ein}` : stableSourceID(USGOV_IRS_BMF_ADAPTER_ID, aligned)

				yield {
					raw,
					components: aligned,
					country: "US",
					locale: "en-US",
					source: USGOV_IRS_BMF_ADAPTER_ID,
					source_id: sourceID,
					corpus_version: "",
					license: USGOV_IRS_BMF_DEFAULT_LICENSE,
				}

				emitted++
			}
		},
	}
}

/**
 * The configured adapter instance registered with the corpus builder.
 */
export const USGovIRSBMFAdapter = createUSGovIRSBMFAdapter()