/// \file   09_brep_fab/main.cpp
/// \brief  Fabrication-oriented B-Rep modeling: box → shell → STEP + GLB export
///
/// Demonstrates a typical design-for-manufacturing workflow using boundary
/// representation (B-Rep).  The part is exported both to STEP (AP214, for
/// CAM/CNC) and to GLB (for quick 3D preview in any viewer).

#include <vde/brep/modeling.h>
#include <vde/brep/step_export.h>
#include <vde/foundation/io_gltf.h>
#include <vde/core/aabb.h>

#include <iostream>
#include <iomanip>

using namespace vde::brep;
using namespace vde::foundation;
using namespace vde::core;

// ═══════════════════════════════════════════════════════════════════════
//  Main — B-Rep Fabrication
// ═══════════════════════════════════════════════════════════════════════

int main() {
    std::cout << std::fixed << std::setprecision(3);
    std::cout << "╔══════════════════════════════════╗\n"
              << "║   B-Rep Fabrication             ║\n"
              << "╚══════════════════════════════════╝\n\n";

    // ── Step 1: Base solid box ───────────────────────────────────────
    //
    // External dimensions: 100 × 50 × 30 mm  (typical enclosure part)

    double w = 100.0, h = 50.0, d = 30.0;
    auto part = make_box(w, h, d);

    AABB3D bb_raw = part.bounds();
    std::cout << "Step 1: make_box(" << w << ", " << h << ", " << d << ")\n"
              << "  volume: " << w * h * d << " mm³ (raw)\n"
              << "  bbox:   (" << bb_raw.min().x() << ", " << bb_raw.min().y()
              << ", " << bb_raw.min().z() << ") → ("
              << bb_raw.max().x() << ", " << bb_raw.max().y()
              << ", " << bb_raw.max().z() << ")\n";

    // ── Step 2: Shell to a thin-walled enclosure ─────────────────────
    //
    // face_id = -1  →  closed shell (no openings, hollow interior)
    // thickness = 2.0 mm  →  typical for injection-moulded / 3D-printed parts

    const double wall_thickness = 2.0;
    part = shell(part, -1, wall_thickness);

    AABB3D bb_shell = part.bounds();
    std::cout << "\nStep 2: shell(face_id=-1, thickness=" << wall_thickness << ")\n"
              << "  faces: " << part.num_faces() << "\n"
              << "  edges: " << part.num_edges() << "\n"
              << "  bbox:  (" << bb_shell.min().x() << ", " << bb_shell.min().y()
              << ", " << bb_shell.min().z() << ") → ("
              << bb_shell.max().x() << ", " << bb_shell.max().y()
              << ", " << bb_shell.max().z() << ")\n";

    // ── Step 3: Export to STEP for CAM ────────────────────────────────
    //
    // AP214 format is the standard exchange format for CNC machining,
    // 5-axis milling, sheet-metal bending, and coordinate measurement.

    std::cout << "\nStep 3: Export STEP (AP214)\n";

    const char* step_path = "output_fab.stp";
    export_step_file(step_path, {part});

    // Show the raw STEP header for verification
    std::string step_str = export_step({part});
    // Find the end of the header section
    auto header_end = step_str.find("FILE_SCHEMA");
    if (header_end != std::string::npos) {
        header_end = step_str.find("ENDSEC;", header_end);
    }
    size_t preview_len = std::min(header_end + 6, step_str.size());
    if (preview_len > 0 && preview_len < step_str.size()) {
        std::cout << "  → " << step_path << "  ("
                  << step_str.size() << " chars)\n";
        std::cout << "  Header excerpt:\n"
                  << step_str.substr(0, preview_len) << "\n  ...\n";
    } else {
        std::cout << "  → " << step_path << "  ("
                  << step_str.size() << " chars)\n";
    }

    // ── Step 4: Export to GLB for 3D preview ─────────────────────────

    std::cout << "\nStep 4: Export GLB for visualization\n";

    const char* glb_path = "output_fab.glb";
    const int   tess_res = 32;  // segments per curved edge

    if (write_brep_gltf(glb_path, part, tess_res)) {
        std::cout << "  → " << glb_path << "  (tessellation level "
                  << tess_res << ")\n";
        std::cout << "  Open in: gltf-viewer.donmccurdy.com, blender, three.js editor\n";
    } else {
        std::cerr << "  ✗ Failed to write " << glb_path << "\n";
        return 1;
    }

    // ── Summary ──────────────────────────────────────────────────────

    std::cout << "\n╔══════════════════════════════════════════╗\n"
              << "║  Export Summary                          ║\n"
              << "╠══════════════════════════════════════════╣\n"
              << "║  B-Rep →  STEP  (CAM/CNC)  ✓             ║\n"
              << "║  B-Rep →  GLB   (Preview)  ✓             ║\n"
              << "╚══════════════════════════════════════════╝\n";

    std::cout << "\nDone.\n";
    return 0;
}