// M0 T4 —— FileInfo 汇总（驱动 T5 骨架 / T6 网格 / T7a 曲线分类）。
// 见 docs/reference/steps/M0-gr2-reader.md
// 规格：granny_file_info.cpp (FileInfoType) / granny_animation.cpp (AnimationType)
#include "internal.h"
#include <cstdio>
#include <cstdlib>

namespace gr2 {

using detail::Ref;
using detail::TypeMember;

bool File::Impl::build_fileinfo(FileInfo& out, LoadError* err) {
    if (!root_obj.valid() || !root_type.valid()) {
        if (err) *err = {"fileinfo", "no root object / type"};
        return false;
    }
    const auto& rms = parse_type(root_type);
    if (rms.empty()) {
        if (err) *err = {"fileinfo", "root type has no members"};
        return false;
    }

    auto count_of = [&](const char* name) -> uint32_t {
        const TypeMember* m = find_member(rms, name);
        if (!m) return 0;
        int32_t c = rd_i32(member_slot(root_obj, *m));
        return (c > 0 && c < (1 << 24)) ? uint32_t(c) : 0;
    };

    if (const TypeMember* m = find_member(rms, "FromFileName"))
        out.from_file_name = rd_str(member_slot(root_obj, *m));

    out.texture_count  = count_of("Textures");
    out.material_count = count_of("Materials");
    out.model_count    = count_of("Models");

    // ── 材质图：root Materials[] 先入表（索引 = 文件顺序），子材质 / 只经 mesh 可达的追加 ──
    mats_out = &out.materials;
    mat_refs.clear();
    if (const TypeMember* mMa = find_member(rms, "Materials")) {
        auto refs = read_array_of_refs(root_obj, *mMa);
        for (Ref r : refs) intern_material(r, mMa->ref_type);
    }

    // ── 骨架（T5）────────────────────────────────────────────────────
    skels_cache.clear();
    skel_refs.clear();
    if (const TypeMember* mSk = find_member(rms, "Skeletons")) {
        auto refs = read_array_of_refs(root_obj, *mSk);
        for (Ref r : refs) {
            Skeleton sk;
            if (extract_skeleton(r, mSk->ref_type, sk)) {
                skels_cache.push_back(std::move(sk));
                skel_refs.push_back(r);
            }
        }
    }

    // ── 模型 → 骨架关联：把 model.InitialPlacement 写进对应 skeleton ─────
    // （很多 Metin2 骨架把 model 空间偏移放在 InitialPlacement 而非 root 骨骼的
    //  LocalTransform；不带上它，bind pose 自洽检查会对这些文件失败）
    if (const TypeMember* mMo = find_member(rms, "Models")) {
        auto refs = read_array_of_refs(root_obj, *mMo);
        const auto& moms = parse_type(mMo->ref_type);
        const TypeMember* mSkRef = find_member(moms, "Skeleton");
        const TypeMember* mIP    = find_member(moms, "InitialPlacement");
        for (Ref r : refs) {
            if (!r.valid() || !mSkRef) continue;
            Ref sref = read_reference(r, *mSkRef);
            for (size_t k = 0; k < skel_refs.size(); ++k) {
                if (skel_refs[k].section == sref.section && skel_refs[k].offset == sref.offset) {
                    if (mIP) {
                        uint32_t fl = 0;
                        transform_to_composite(member_slot(r, *mIP), skels_cache[k].initial_placement, fl);
                    }
                    break;
                }
            }
        }
    }
    out.skeletons = skels_cache;

    // ── 网格（T6）────────────────────────────────────────────────────
    std::vector<Ref> mesh_refs;   // 与 out.meshes 平行（model.MeshBindings 关联用）
    if (const TypeMember* mMe = find_member(rms, "Meshes")) {
        auto refs = read_array_of_refs(root_obj, *mMe);
        for (Ref r : refs) {
            Mesh me;
            bool ok = extract_mesh(r, mMe->ref_type, skels_cache, me);
            if (getenv("GR2_DEBUG"))
                fprintf(stderr, "[gr2]  mesh ref (%d,%u) -> %s  name=%s verts=%zu idx=%zu\n",
                        r.section, r.offset, ok ? "OK" : "FAIL", me.name.c_str(),
                        me.vertices.size(), me.indices.size());
            if (ok) { out.meshes.push_back(std::move(me)); mesh_refs.push_back(r); }
        }
    }

    // ── 模型：granny_model{String Name; Reference Skeleton; Transform InitialPlacement;
    //    RefToArray MeshBindings(model_mesh_binding{Reference Mesh}); VariantRef ExtendedData}
    if (const TypeMember* mMo = find_member(rms, "Models")) {
        auto refs = read_array_of_refs(root_obj, *mMo);
        const auto& moms = parse_type(mMo->ref_type);
        const TypeMember* mN  = find_member(moms, "Name");
        const TypeMember* mSk = find_member(moms, "Skeleton");
        const TypeMember* mIP = find_member(moms, "InitialPlacement");
        const TypeMember* mMB = find_member(moms, "MeshBindings");
        auto same = [](Ref a, Ref b) { return a.section == b.section && a.offset == b.offset; };
        for (Ref r : refs) {
            if (!r.valid()) continue;
            Model mo;
            if (mN) mo.name = rd_str(member_slot(r, *mN));
            if (mSk) {
                Ref sref = read_reference(r, *mSk);
                for (size_t k = 0; k < skel_refs.size(); ++k)
                    if (same(skel_refs[k], sref)) { mo.skeleton = int32_t(k); break; }
            }
            if (mIP) read_transform(member_slot(r, *mIP), mo.initial_placement);
            Ref bb; uint32_t bc = 0, bs = 0;
            if (mMB && read_ref_to_array(r, *mMB, bb, bc, bs) && bc && bs) {
                const auto& bms = parse_type(mMB->ref_type);
                const TypeMember* mMesh = find_member(bms, "Mesh");
                for (uint32_t i = 0; i < bc && i < 4096; ++i) {
                    int32_t idx = -1;
                    if (mMesh) {
                        Ref me = read_reference({bb.section, bb.offset + i * bs}, *mMesh);
                        for (size_t k = 0; k < mesh_refs.size(); ++k)
                            if (same(mesh_refs[k], me)) { idx = int32_t(k); break; }
                    }
                    mo.mesh_bindings.push_back(idx);
                }
            }
            out.models.push_back(std::move(mo));
        }
    }

    // ── 动画（T7a：名字 + 时长 + 每 track 的曲线子类型）─────────────────
    if (const TypeMember* mAn = find_member(rms, "Animations")) {
        auto refs = read_array_of_refs(root_obj, *mAn);
        const Skeleton* sk0 = skels_cache.empty() ? nullptr : &skels_cache[0];
        for (Ref r : refs) {
            if (!r.valid()) continue;
            Animation an;
            if (extract_animation(r, mAn->ref_type, sk0, an))
                out.animations.push_back(std::move(an));
        }
    }

    mats_out = nullptr;
    return true;
}

} // namespace gr2