// Acceptance for the CAD-driven BIM: geometry provenance, scene bounds and export accounting.
import { readFileSync, existsSync } from 'node:fs'
import { resolve } from 'node:path'
import { Cartesian3, Matrix4, Cartographic } from 'cesium'
import { PRIMARY_AREA_BOUNDS } from './primary-area.mjs'

const dir = resolve('tools/city-massing/city/cad-bim')
const seated = JSON.parse(readFileSync(resolve(dir, 'seated-plan.json'), 'utf8'))
const previewDir = resolve(dir, 'lod-preview')
const failures = []

if (!existsSync(resolve(previewDir, 'manifest.json'))) {
    console.log(JSON.stringify({ passed: false, reason: 'no exported manifest yet', expected: resolve(previewDir, 'manifest.json') }, null, 1))
    process.exit(1)
}
const manifest = JSON.parse(readFileSync(resolve(previewDir, 'manifest.json'), 'utf8'))
const tileset = JSON.parse(readFileSync(resolve(previewDir, 'tileset.json'), 'utf8'))

// 1. Root anchor must be a valid GLB, otherwise Cesium skips the tree.
const anchorUri = tileset.root?.content?.uri
if (!anchorUri) failures.push('root has no content anchor')
else {
    const anchor = readFileSync(resolve(previewDir, anchorUri))
    if (anchor.toString('ascii', 0, 4) !== 'glTF' || anchor.readUInt32LE(4) !== 2 ||
        anchor.readUInt32LE(8) !== anchor.length || anchor.toString('ascii', 16, 20) !== 'JSON')
        failures.push('root anchor GLB header is invalid')
    else {
        try {
            JSON.parse(anchor.toString('utf8', 20, 20 + anchor.readUInt32LE(12)))
        } catch {
            failures.push('root anchor GLB JSON chunk is invalid')
        }
    }
}

// 2. Every placed building must trace back to a seated building.
const byId = new Map(seated.buildings.map((b) => [b.id, b]))
const placed = new Set(manifest.cells.flatMap((cell) => cell.buildingIds))
const orphans = [...placed].filter((id) => !byId.has(id))
if (orphans.length) failures.push(`${orphans.length} placed ids have no seated building (first: ${orphans[0]})`)

// 3. The primary area as an ENU box; footprints are stored in ENU metres.
const inverse = Matrix4.inverseTransformation(Matrix4.fromArray(seated.transform), new Matrix4())
const corners = [
    [PRIMARY_AREA_BOUNDS[0], PRIMARY_AREA_BOUNDS[1]], [PRIMARY_AREA_BOUNDS[2], PRIMARY_AREA_BOUNDS[1]],
    [PRIMARY_AREA_BOUNDS[2], PRIMARY_AREA_BOUNDS[3]], [PRIMARY_AREA_BOUNDS[0], PRIMARY_AREA_BOUNDS[3]],
].map(([lon, lat]) => Matrix4.multiplyByPoint(inverse, Cartesian3.fromDegrees(lon, lat), new Cartesian3()))
const box = {
    minX: Math.min(...corners.map((c) => c.x)), maxX: Math.max(...corners.map((c) => c.x)),
    minY: Math.min(...corners.map((c) => c.y)), maxY: Math.max(...corners.map((c) => c.y)),
}
let outside = 0
for (const building of seated.buildings) {
    for (const [x, y] of building.footprintENU) {
        if (x < box.minX - 0.5 || x > box.maxX + 0.5 || y < box.minY - 0.5 || y > box.maxY + 0.5) {
            outside++
            if (outside <= 3) failures.push(`${building.id} footprint vertex outside the primary area`)
            break
        }
    }
}

// 4. Geometry sanity: massing needs a real outline, heights must be usable.
let degenerateOutlines = 0
let badHeights = 0
for (const building of seated.buildings) {
    const ring = building.footprintENU
    if (building.kind === 'massing' && (!Array.isArray(ring) || ring.length < 3)) degenerateOutlines++
    if (!(building.heightM > 0) || !Number.isFinite(building.positionENU?.[2]) || !Number.isFinite(building.foundationBottom))
        badHeights++
}
if (degenerateOutlines) failures.push(`${degenerateOutlines} massing buildings have fewer than 3 outline points`)
if (badHeights) failures.push(`${badHeights} buildings have unusable height or elevation`)

const byTier = {}
const byKind = {}
for (const building of seated.buildings) {
    byTier[building.tier] = (byTier[building.tier] || 0) + 1
    byKind[building.kind] = (byKind[building.kind] || 0) + 1
}
const report = {
    passed: failures.length === 0,
    source: seated.source,
    seated: seated.buildings.length,
    byTier,
    byKind,
    construction: seated.construction,
    excludedRelief: (seated.excluded || []).filter((e) => e.relief !== undefined).length,
    exported: {
        placed: placed.size,
        cells: manifest.cellCount,
        coarseCells: manifest.hierarchy?.coarseCellCount ?? 0,
        lod1Bytes: manifest.totals?.lod1?.bytes ?? null,
        lod0Bytes: manifest.totals?.lod0?.bytes ?? null,
        lod1Triangles: manifest.totals?.lod1?.triangles ?? null,
        lod0Triangles: manifest.totals?.lod0?.triangles ?? null,
    },
    outsidePrimaryArea: outside,
    failures: failures.slice(0, 15),
}
console.log(JSON.stringify(report, null, 1))
if (failures.length) process.exitCode = 1