// Reuse verified cell ownership and immutable GLBs. Only rebuild the LOD index.
// Empty root + finite SSE errors avoid whole-city readiness and hard fine-distance gates.
import assert from 'node:assert/strict'
import { readFileSync, writeFileSync, mkdirSync, existsSync } from 'node:fs'
import { resolve, join, relative } from 'node:path'
const root = resolve('tools/city-massing/city/cad-bim')
const source = join(root, 'city-progressive-instanced-v1')
const output = join(root, process.argv[2] || 'city-continuous-v8')
assert.ok(!existsSync(output), 'use an immutable generation')
const tree = JSON.parse(readFileSync(join(source, 'tileset.json'), 'utf8'))
const manifest = JSON.parse(readFileSync(join(source, 'manifest.json'), 'utf8'))
assert.equal(manifest.instancedCells, 0, 'index rebuild expects the verified original geometry')
const records = new Map(manifest.records.map(r => [resolve(source, r.uri), r]))
const errors = { far: 128, near: 48 }
const coarseRequestMargin = 14000
const stats = { far: 0, near: 0, fine: 0, contents: 0 }
function adapt(tile) {
    const t = structuredClone(tile)
    if (tile.content) {
        const path = resolve(source, tile.content.uri), record = records.get(path)
        assert.ok(record && existsSync(path), path)
        t.content.uri = relative(output, path).replaceAll('\\', '/')
        stats[record.level]++; stats.contents++
        if (record.level === 'far') {
            t.geometricError = errors.far
            // Keep distant coarse retirement, preloaded before city overview approaches.
            const volume = t.boundingVolume.sphere
            assert.ok(volume)
            t.viewerRequestVolume = { sphere: [...volume.slice(0, 3), volume[3] + coarseRequestMargin] }
        } else {
            t.geometricError = record.level === 'near' ? errors.near : 0
            // Finite SSE is the request gate. A child outside a hard request sphere
            // would block traditional REPLACE and is requested anyway by base traversal.
            delete t.viewerRequestVolume
        }
    } else {
        t.geometricError = 1000000
        delete t.viewerRequestVolume
    }
    if (t.children?.length) {
        t.refine = 'REPLACE'
        assert.ok(t === tree.root || t.boundingVolume.sphere || !t.content)
        const children = t.content ? t.children.flatMap(child => {
            assert.ok(child.content || child.children?.length, 'empty leaf has no fallback')
            return child.content ? [child] : child.children
        }) : t.children
        t.children = children.map(adapt)
    }
    return t
}
const newRoot = adapt(tree.root)
delete newRoot.content
assert.equal(stats.contents, manifest.records.length)
mkdirSync(output, { recursive: true })
writeFileSync(join(output, 'tileset.json'), JSON.stringify({
    ...tree, asset: { version: '1.1', generator: 'Continuous cell replacement with finite SSE' }, root: newRoot,
}, null, 2) + '\n')
writeFileSync(join(output, 'manifest.json'), JSON.stringify({
    buildings: manifest.buildings, errors, coarseRequestMargin, ...stats,
    source: 'city-progressive-instanced-v1', geometryChanged: false, instancingEnabled: false,
    requiredTraversal: 'base', policy: 'Empty root; cell coarse -> bounded local coarse/fine. Finite SSE controls local requests; Parents remain until desired descendants are ready. Distant coarse has a +14000m request margin, bounded by the deployment whole-tree maximum distance. No new GLB, texture or geometry.',
    decisions: manifest.decisions.map(d => ({ cell: d.cell, buildingIds: d.buildingIds, wholeCellCoarse: d.wholeCellCoarse })),
    records: manifest.records.map(r => ({ ...r, uri: relative(output, resolve(source, r.uri)).replaceAll('\\', '/') })),
    runtimeValidated: false,
}, null, 2) + '\n')
console.log(JSON.stringify({ output, buildings: manifest.buildings, errors, ...stats, geometryChanged: false }))