// Deterministic balanced pilot selection for the CAD BIM pipeline.
// Keeps the city-core and southern/river masks represented, with both asset and exact-outline massing.
import { readFileSync, writeFileSync } from 'node:fs'

const source = JSON.parse(readFileSync('tools/city-massing/city/cad-bim/seated-plan.json', 'utf8'))
const targets = new Map([[66, 1800], [65, 700], [130, 300], [126, 200]])
const hash = (id) => {
    let value = 2166136261
    for (const ch of id) value = ((value ^ ch.charCodeAt(0)) * 16777619) >>> 0
    return value
}
const selected = []
const details = {}
for (const [maskId, target] of targets) {
    const group = source.buildings.filter((b) => Number(b.maskId) === maskId)
    const ordered = [...group].sort((a, b) => hash(a.id) - hash(b.id))
    const take = ordered.slice(0, Math.min(target, ordered.length))
    selected.push(...take)
    details[maskId] = { available: group.length, selected: take.length }
}
const out = {
    ...source,
    buildings: selected,
    pilot: {
        name: 'urban-mask-cad-bim-pilot-3000',
        selection: details,
        note: 'Bounded first CIM pass; full 48k seated buildings remain a later batched export.',
    },
}
writeFileSync('tools/city-massing/city/cad-bim/seated-pilot.json', JSON.stringify(out, null, 2))
console.log(JSON.stringify({ selected: selected.length, byMask: details, byKind: Object.fromEntries([...new Set(selected.map((b) => b.kind))].map((k) => [k, selected.filter((b) => b.kind === k).length])) }))