import type { IPNSPublishTarget } from '@wovin/core/ipns'
import { Logger } from 'besonders-logger'
import { base64pad } from 'multiformats/bases/base64'
import { CID } from 'multiformats/cid'
import * as W3Name from 'w3name'

const { WARN, LOG, DEBUG, ERROR } = Logger.setup(Logger.INFO)

/**
 * Try to resolve IPNS name to get existing revision.
 * Returns null if record doesn't exist (404).
 * Throws on network errors or server errors.
 *
 * This does a custom HTTP check first to distinguish 404 from network errors,
 * then delegates to W3Name.resolve() for validation if record exists.
 */
async function tryResolveIPNS(ipns: W3Name.WritableName): Promise<W3Name.Revision | null> {
	const url = `https://name.web3.storage/name/${ipns.toString()}`

	let response: Response
	try {
		response = await fetch(url, { signal: AbortSignal.timeout(30_000) })
	} catch (err) {
		// Network error (no connection, DNS failure, etc.)
		throw ERROR('[w3name] Network error resolving IPNS:', err)
	}

	// 404 = record never published
	if (response.status === 404) {
		DEBUG('[w3name] IPNS record not found (never published):', ipns.toString())
		return null
	}

	// Other HTTP errors (5xx server error, etc.)
	if (!response.ok) {
		throw ERROR(`[w3name] HTTP ${response.status} resolving IPNS:`, response.statusText)
	}

	// Success - use W3Name.resolve to get validated Revision
	// (We could parse the record ourselves, but W3Name does validation/signature checks)
	const existing = await W3Name.resolve(ipns)
	return existing
}

/**
 * Publish CID to IPNS, automatically handling increment vs v0.
 * Returns the revision for further processing (e.g., Kubo integration).
 */
export async function publishIPNS(ipnsPrivateKey: Uint8Array, cid: CID): Promise<W3Name.Revision> {
	const TIMEOUT_MS = 30_000
	const timeout = new Promise<never>((_, reject) =>
		setTimeout(() => reject(new Error(`publishIPNS timed out after ${TIMEOUT_MS}ms`)), TIMEOUT_MS),
	)
	return Promise.race([_publishIPNSImpl(ipnsPrivateKey, cid), timeout])
}

async function _publishIPNSImpl(ipnsPrivateKey: Uint8Array, cid: CID): Promise<W3Name.Revision> {
	const value = `/ipfs/${cid}`
	const ipns = await W3Name.from(ipnsPrivateKey)

	let revision: W3Name.Revision
	const existing = await tryResolveIPNS(ipns)

	if (existing) {
		// Record exists - increment sequence number
		revision = await W3Name.increment(existing, value)
		DEBUG('[w3name] incrementing revision for', ipns.toString())
	} else {
		// First publish - use v0
		revision = await W3Name.v0(ipns, value)
		DEBUG('[w3name] creating initial revision for', ipns.toString())
	}

	await W3Name.publish(revision, ipns.key)
	DEBUG('[w3name] published', cid.toString(), 'to', ipns.toString())

	return revision // Return for Kubo integration or other uses
}

/**
 * Create an IPNSPublishTarget that publishes to W3Name service via HTTP POST.
 */
export function w3nameTarget(serviceUrl = 'https://name.web3.storage'): IPNSPublishTarget {
	return {
		name: 'w3name',
		async publish(ipnsName: string, recordBytes: Uint8Array) {
			const res = await fetch(`${serviceUrl}/name/${ipnsName}`, {
				method: 'POST',
				body: base64pad.baseEncode(recordBytes),
			})
			if (!res.ok) throw new Error(`W3Name HTTP ${res.status}`)
		},
	}
}

export async function generateIpnsKey() {
	return W3Name.create() // Returns W3Name.WritableName type
}

export async function getW3NamePublic(pk: Uint8Array) {
	const ipns = await W3Name.from(pk)
	return ipns.toString()
}