// Verify bounded streaming-v2 tiles: request volumes, Draco payloads, budgets, and coverage.
import assert from 'node:assert/strict'
import { readFileSync, writeFileSync } from 'node:fs'
import { resolve, join } from 'node:path'
import draco3d from 'draco3d'
import { tileRasterBudget } from './raster-budget.mjs'
import { verifyMaterialClosure } from './verify-material-closure.mjs'

const argv = process.argv.slice(2)
// Flat-face agreement is opt-in: curved/smooth library assets need not match each face normal.
const checkFlatNormals = argv.includes('--check-flat-normals')
if (checkFlatNormals) argv.splice(argv.indexOf('--check-flat-normals'), 1)
const reportIndex = argv.indexOf('--report')
const reportPath = reportIndex < 0 ? null : argv.splice(reportIndex, 2)[1]
const dirs = argv.length ? argv : [process.argv[2]]
assert.ok(dirs[0], 'batch directory required')
const decoderModule = await draco3d.createDecoderModule({})

function parseGlb(path) {
    const bytes = readFileSync(path)
    assert.equal(bytes.toString('ascii', 0, 4), 'glTF', path)
    assert.equal(bytes.readUInt32LE(4), 2, path)
    assert.equal(bytes.readUInt32LE(8), bytes.length, path)
    const jsonLength = bytes.readUInt32LE(12)
    const json = JSON.parse(bytes.toString('utf8', 20, 20 + jsonLength))
    const binOffset = 20 + jsonLength
    assert.equal(bytes.toString('ascii', binOffset + 4, binOffset + 8), 'BIN\0', path)
    const binLength = bytes.readUInt32LE(binOffset)
    return { bytes, json, bin: bytes.subarray(binOffset + 8, binOffset + 8 + binLength) }
}
function decodePrimitive(path, json, bin, primitive, translation, bounds) {
    const extension = primitive.extensions?.KHR_draco_mesh_compression
    assert.ok(extension, `${path}: missing Draco extension`)
    const view = json.bufferViews[extension.bufferView]
    assert.ok(view, `${path}: missing Draco bufferView`)
    const encoded = bin.subarray(view.byteOffset || 0, (view.byteOffset || 0) + view.byteLength)
    const decoder = new decoderModule.Decoder()
    const buffer = new decoderModule.DecoderBuffer()
    const mesh = new decoderModule.Mesh()
    let status
    try {
        buffer.Init(new Int8Array(encoded.buffer, encoded.byteOffset, encoded.byteLength), encoded.byteLength)
        status = decoder.DecodeBufferToMesh(buffer, mesh)
        assert.ok(status.ok(), `${path}: ${status.error_msg()}`)
        const points = mesh.num_points()
        const faces = mesh.num_faces()
        assert.equal(points, json.accessors[primitive.attributes.POSITION].count, `${path}: point count mismatch`)
        assert.equal(faces * 3, json.accessors[primitive.indices].count, `${path}: face count mismatch`)
        const attribute = decoder.GetAttributeByUniqueId(mesh, extension.attributes.POSITION)
        assert.equal(attribute.num_components(), 3)
        const positionBytes = points * 3 * 4
        const positionPtr = decoderModule._malloc(positionBytes)
        let decodedPositions
        try {
            decoder.GetAttributeDataArrayForAllPoints(mesh, attribute, decoderModule.DT_FLOAT32, positionBytes, positionPtr)
            const positions = new Float32Array(decoderModule.HEAPF32.buffer, positionPtr, points * 3)
            for (let index = 0; index < points; index++) {
                const enu = [positions[index * 3] + translation[0], -(positions[index * 3 + 2] + translation[2]),
                    positions[index * 3 + 1] + translation[1]]
                for (let axis = 0; axis < 3; axis++) {
                    assert.ok(Number.isFinite(enu[axis]), `${path}: non-finite position`)
                    assert.ok(enu[axis] >= bounds.min[axis] - 0.05 && enu[axis] <= bounds.max[axis] + 0.05,
                        `${path}: decoded world position outside tile bounds`)
                }
            }
            decodedPositions = positions.slice()
        } finally { decoderModule._free(positionPtr) }
        const normalAttribute = decoder.GetAttributeByUniqueId(mesh, extension.attributes.NORMAL)
        assert.equal(normalAttribute.num_components(), 3, `${path}: NORMAL components`)
        const normalPtr = decoderModule._malloc(points * 12)
        let normals
        try {
            assert.ok(decoder.GetAttributeDataArrayForAllPoints(mesh, normalAttribute, decoderModule.DT_FLOAT32, points * 12, normalPtr))
            normals = new Float32Array(decoderModule.HEAPF32.buffer, normalPtr, points * 3).slice()
            for (let i = 0; i < points; i++) {
                const length = Math.hypot(...normals.subarray(i * 3, i * 3 + 3))
                assert.ok(Number.isFinite(length) && Math.abs(length - 1) < 0.01, `${path}: invalid normal`)
            }
        } finally { decoderModule._free(normalPtr) }
        let checkedNormalTriangles = 0, degenerateTriangles = 0, minNormalDot = 1
        const indexBytes = faces * 3 * 4
        const indexPtr = decoderModule._malloc(indexBytes)
        try {
            decoder.GetTrianglesUInt32Array(mesh, indexBytes, indexPtr)
            const indices = new Uint32Array(decoderModule.HEAPU32.buffer, indexPtr, faces * 3)
            for (const index of indices) assert.ok(index < points, `${path}: out-of-range triangle index`)
            for (let face = 0; face < faces; face++) {
                const ids = indices.subarray(face * 3, face * 3 + 3)
                const [a, b, c] = Array.from(ids, (id) => decodedPositions.subarray(id * 3, id * 3 + 3))
                const u = b.map((value, axis) => value - a[axis]), v = c.map((value, axis) => value - a[axis])
                const cross = [u[1]*v[2]-u[2]*v[1], u[2]*v[0]-u[0]*v[2], u[0]*v[1]-u[1]*v[0]]
                const area2 = Math.hypot(...cross)
                if (area2 < 1e-10) {
                    degenerateTriangles++
                    assert.ok(!checkFlatNormals, `${path}: triangle ${face} collapsed after decoding`)
                    continue
                }
                for (const id of ids) {
                    const dot = cross.reduce((sum, value, axis) => sum + value * normals[id * 3 + axis], 0) / area2
                    if (checkFlatNormals) assert.ok(dot >= 0.9, `${path}: material ${json.materials[primitive.material]?.name}, triangle ${face} normal/winding mismatch ${dot}; positions=${JSON.stringify([Array.from(a), Array.from(b), Array.from(c)])}, normal=${JSON.stringify(Array.from(normals.subarray(id * 3, id * 3 + 3)))}`)
                    minNormalDot = Math.min(minNormalDot, dot)
                }
                checkedNormalTriangles++
            }
        } finally { decoderModule._free(indexPtr) }
        return { points, triangles: faces, checkedNormalTriangles, degenerateTriangles, minNormalDot }
    } finally {
        if (status) decoderModule.destroy(status)
        decoderModule.destroy(mesh); decoderModule.destroy(buffer); decoderModule.destroy(decoder)
    }
}
function collectTiles(tile, out = []) {
    if (tile.content?.uri) out.push(tile)
    for (const child of tile.children || []) collectTiles(child, out)
    return out
}
function boxVolume(box) {
    assert.equal(box.length, 12)
    assert.deepEqual([box[4], box[5], box[6], box[8], box[9], box[10]], [0, 0, 0, 0, 0, 0])
    return Math.max(0.001, box[3] * 2) * Math.max(0.001, box[7] * 2) * Math.max(0.001, box[11] * 2)
}

const all = []
for (const directory of dirs) {
    const dir = resolve(directory)
    const tree = JSON.parse(readFileSync(join(dir, 'tileset.json'), 'utf8'))
    const manifest = JSON.parse(readFileSync(join(dir, 'manifest.json'), 'utf8'))
    assert.equal(manifest.provenance?.gisFootprints, true, `${directory}: GIS provenance missing`)
    assert.equal(manifest.provenance?.roadsProcedural, false, `${directory}: procedural roads provenance`)
    const tiles = collectTiles(tree.root).filter((tile) => tile !== tree.root)
    const records = new Map(manifest.files.map((record) => [record.uri, record]))
    assert.equal(records.size, manifest.files.length, `${directory}: duplicate file records`)
    assert.ok(tiles.length > 0, `${directory}: no content tiles`)
    assert.ok(tree.root.content?.uri, `${directory}: no root anchor`)
    const root = tree.root
    assert.ok(root.children?.length >= 2, `${directory}: too few structural children`)
    const ids = manifest.cells.flatMap((cell) => cell.buildingIds)
    assert.equal(ids.length, manifest.count, `${directory}: wrong building count`)
    assert.equal(new Set(ids).size, manifest.count, `${directory}: duplicate or missing building IDs`)
    const source = JSON.parse(readFileSync(join(dir, '..', 'manifest.json'), 'utf8'))
    assert.deepEqual([...ids].sort(), source.cells.flatMap((cell) => cell.buildingIds).sort(), `${directory}: source coverage changed`)
    const byLevel = { lod1: { triangles: 0, bytes: 0 }, lod0: { triangles: 0, bytes: 0 } }
    let files = 0, triangles = 0, vertices = 0, bytes = 0, maxVertices = 0, maxTriangles = 0
    let checkedNormalTriangles = 0, degenerateTriangles = 0, minNormalDot = 1, maxDecodedTextureBytes = 0
    for (const tile of tiles) {
        assert.ok(tile.viewerRequestVolume?.sphere, `${directory}: content missing viewerRequestVolume`)
        assert.ok(tile.content?.uri !== 'root-anchor.glb', `${directory}: anchor in a request tile`)
        const record = records.get(tile.content.uri)
        assert.ok(record, `${directory}: unrecorded ${tile.content.uri}`)
        assert.ok(tile.boundingVolume?.box, `${directory}: missing content box`)
        boxVolume(tile.boundingVolume.box)
        const box = tile.boundingVolume.box
        const center = box.slice(0, 3)
        const half = [box[3], box[7], box[11]]
        const bounds = { min: center.map((value, axis) => value - half[axis]), max: center.map((value, axis) => value + half[axis]) }
        const sphere = tile.viewerRequestVolume.sphere
        const distance = record.level === 'lod1' ? manifest.budget.coarseDistance : manifest.budget.detailDistance
        assert.equal(sphere.length, 4)
        sphere.slice(0, 3).forEach((value, axis) => assert.ok(Math.abs(value - center[axis]) < 0.01, `${directory}: request center drift`))
        assert.ok(Math.abs(sphere[3] - Math.hypot(...half) - distance) < 0.01, `${directory}: wrong distance request gate`)
        const path = join(dir, tile.content.uri)
        const { bytes: raw, json, bin } = parseGlb(path)
        verifyMaterialClosure(json, path)
        const nodes = json.nodes.filter((node) => node.mesh !== undefined)
        assert.equal(nodes.length, 1, `${path}: expected one mesh node`)
        assert.ok(!nodes[0].matrix && !nodes[0].rotation && !nodes[0].scale, `${path}: unexpected transform`)
        const translation = nodes[0].translation || [0, 0, 0]
        assert.equal(translation.length, 3)
        assert.ok(json.extensionsRequired?.includes('KHR_draco_mesh_compression'), `${path}: Draco is not required`)
        let fileTriangles = 0, fileVertices = 0
        for (const primitive of json.meshes[nodes[0].mesh].primitives) {
            const decoded = decodePrimitive(path, json, bin, primitive, translation, bounds)
            fileTriangles += decoded.triangles
            fileVertices += decoded.points
            checkedNormalTriangles += decoded.checkedNormalTriangles
            degenerateTriangles += decoded.degenerateTriangles
            minNormalDot = Math.min(minNormalDot, decoded.minNormalDot)
        }
        assert.equal(fileTriangles, record.triangles, `${path}: triangle total differs from manifest`)
        assert.equal(raw.length, record.bytes, `${path}: byte total differs from manifest`)
        assert.ok(fileVertices <= manifest.budget.maxVertices, `${path}: vertex budget exceeded`)
        assert.ok(fileTriangles <= manifest.budget.maxTriangles, `${path}: triangle budget exceeded`)
        if (manifest.budget.maxRasterBytes !== undefined) {
            const rasterBytes = (json.images || []).reduce((sum, image) => sum + json.bufferViews[image.bufferView].byteLength, 0)
            assert.equal(rasterBytes, record.rasterBytes, `${path}: raster total differs from manifest`)
            assert.ok(rasterBytes <= manifest.budget.maxRasterBytes, `${path}: raster budget exceeded`)
        }
        if (manifest.budget.maxDecodedTextureBytes !== undefined) {
            const images = (json.images || []).map((image) => {
                const view = json.bufferViews[image.bufferView]
                assert.ok(view && (view.byteOffset || 0) + view.byteLength <= bin.length, `${path}: invalid image view`)
                return { mimeType: image.mimeType, bytes: bin.subarray(view.byteOffset || 0, (view.byteOffset || 0) + view.byteLength) }
            })
            const allocation = tileRasterBudget(images, json.textures || [], manifest.budget)
            for (const [key, value] of Object.entries(allocation)) assert.equal(value, record[key], `${path}: ${key} differs from manifest`)
            maxDecodedTextureBytes = Math.max(maxDecodedTextureBytes, allocation.decodedTextureBytes)
        }
        byLevel[record.level].triangles += fileTriangles
        byLevel[record.level].bytes += raw.length
        assert.equal(fileVertices, record.vertices, `${path}: vertex total differs from manifest`)
        files++; triangles += fileTriangles; vertices += fileVertices; bytes += raw.length
        maxVertices = Math.max(maxVertices, fileVertices); maxTriangles = Math.max(maxTriangles, fileTriangles)
        records.delete(tile.content.uri)
    }
    assert.equal(records.size, 0, `${directory}: unreferenced manifest files`)
    for (const level of ['lod1', 'lod0']) {
        assert.deepEqual(byLevel[level], manifest.totals[level], `${directory}: ${level} totals differ from files`)
        assert.equal(byLevel[level].triangles, source.cells.reduce((sum, cell) => sum + cell[level].triangles, 0),
            `${directory}: ${level} source triangle count changed`)
    }
    const result = { directory, buildings: manifest.count, files, triangles, vertices, bytes, maxVertices, maxTriangles,
        budget: manifest.budget, normals: { flatFaceAgreementRequired: checkFlatNormals, checkedNormalTriangles,
            degenerateTriangles, minNormalDot }, maxDecodedTextureBytes: manifest.budget.maxDecodedTextureBytes === undefined ? null : maxDecodedTextureBytes,
        decodedTextureBudgetValidated: manifest.budget.maxDecodedTextureBytes !== undefined }
    all.push(result)
    console.log(JSON.stringify(result))
}
const result = { passed: true, batches: all, totals: {
    buildings: all.reduce((sum, item) => sum + item.buildings, 0),
    files: all.reduce((sum, item) => sum + item.files, 0),
    triangles: all.reduce((sum, item) => sum + item.triangles, 0),
    vertices: all.reduce((sum, item) => sum + item.vertices, 0),
    bytes: all.reduce((sum, item) => sum + item.bytes, 0),
} }
if (reportPath) writeFileSync(reportPath, JSON.stringify(result, null, 2) + '\n')
console.log(JSON.stringify(result))