// 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");

    // ── 顶层材质表（调试 / 备用查找）────────────────────────────────────
    if (const TypeMember* mMa = find_member(rms, "Materials")) {
        auto refs = read_array_of_refs(root_obj, *mMa);
        const auto& mams = parse_type(mMa->ref_type);
        const TypeMember* mMN = find_member(mams, "Name");
        for (Ref r : refs) {
            if (!r.valid()) continue;
            Material mat;
            if (mMN) mat.name = rd_str(member_slot(r, *mMN));
            mat.diffuse_texture = material_texture_name(r, mMa->ref_type, 0);
            out.materials.push_back(std::move(mat));
        }
    }

    // ── 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）────────────────────────────────────────────────────
    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));
        }
    }

    // ── 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));
        }
    }

    return true;
}

} // namespace gr2