import { cfg }       from './config.mjs'
import { readFile } from 'fs/promises'
import { resolve, dirname } from 'path'
import { fileURLToPath }    from 'url'

const DIR         = dirname(fileURLToPath(import.meta.url))
const SHAPES_PATH = resolve(DIR, 'public', 'aircraft.json')

const history = new Map() // icao -> [{lat, lon, alt, ts}]
const MAX_HISTORY = 500

export async function getShapes() {
	return JSON.parse(await readFile(SHAPES_PATH, 'utf8'))
}

export async function getAirTraffic() {
	const { ADSB_URL } = cfg()
	if (!ADSB_URL) return { data: [] }
	const r = await fetch(`${ADSB_URL}/data/aircraft.json`)
	const j = await r.json()
	const aircraft = j.aircraft || []

	for (const a of aircraft) {
		if (!a.hex || !a.lat || !a.lon) continue
		const key = a.hex.toLowerCase()
		if (!history.has(key)) history.set(key, [])
		const trail = history.get(key)
		trail.push({ latitude: a.lat, longitude: a.lon, altitude: a.alt_baro || 0, ts: Date.now() })
		if (trail.length > MAX_HISTORY) trail.shift()
	}

	return { data: aircraft }
}

export async function getAirTrafficHistory(icao) {
	return { history: history.get(icao?.toLowerCase()) || [] }
}