;============================================================
;   iron_vrm.hsp — VRM 1.0 メタデータローダ (最小実装)
;
;   VRM は glTF 2.0 の拡張 (extensions.VRMC_vrm)。本モジュールは
;   iron_gltf でメッシュ読込、加えて VRM のメタ情報 (キャラクター名 /
;   作者 / ライセンス / サムネイル index / version) を JSON から抽出。
;
;   注意:
;     .vrm ファイルの実体は .glb (glTF Binary)。本モジュールは
;     .glb / .vrm / .gltf(JSON) のいずれも受け取り、内部で JSON chunk を
;     自動抽出してメタ情報を返す。メッシュ本体のロードは iron_gltf.hsp で。
;
;   API:
;     vrm_load_meta "model.vrm" (.vrm/.glb/.gltf いずれも可),
;                   var_name, var_author, var_license, var_version
;         → stat 0=OK
;
;     vrm_describe "path", var_text
;         JSON から抽出した全 VRM メタを "key=val" の改行区切りで返す
;
;   依存: iron_json.hsp
;============================================================
#ifndef __iron_vrm_hsp__
#define __iron_vrm_hsp__

#include "iron_json.hsp"

#module iron_vrm

;---------------------------------------------------------
; internal: .vrm/.glb/.gltf ファイルから JSON 本体を var_out に書き出す
;---------------------------------------------------------
#deffunc _vrm_extract_json str path, var v_out, \
	local _size, local _fb, local _magic, local _total_len, \
	local _cp, local _clen, local _ctype
	sdim v_out, 1
	exist path
	_size = strsize
	if _size <= 0 : return -1
	sdim _fb, _size + 16
	bload path, _fb, _size
	if _size < 12 {
		sdim v_out, _size + 16
		memcpy v_out, _fb, _size
		return _size
	}
	_magic = lpeek(_fb, 0)
	if _magic != 0x46546C67 {
		; 非 GLB (plain .gltf JSON)
		sdim v_out, _size + 16
		memcpy v_out, _fb, _size
		return _size
	}
	; GLB: JSON chunk を取り出す
	_total_len = lpeek(_fb, 8)
	if _total_len > _size : _total_len = _size
	_cp = 12
	repeat
		if _cp + 8 > _total_len : return -2
		_clen  = lpeek(_fb, _cp)
		_ctype = lpeek(_fb, _cp + 4)
		_cp = _cp + 8
		if _ctype = 0x4E4F534A {       ; "JSON"
			sdim v_out, _clen + 16
			memcpy v_out, _fb, _clen, 0, _cp
			poke v_out, _clen, 0
			return _clen
		}
		_cp = _cp + _clen
		if _cp >= _total_len : break
	loop
	return -3

#deffunc vrm_load_meta str path, var v_name, var v_author, var v_license, var v_version, \
	local _buf, local _hid, local _n
	sdim v_name,    256
	sdim v_author,  256
	sdim v_license, 256
	sdim v_version, 64
	_vrm_extract_json path, _buf
	_n = stat
	if _n <= 0 : return -1
	_hid = json_load(_buf)
	if _hid < 0 : return -2
	; VRM 1.0
	v_name    = json_str(_hid, "extensions.VRMC_vrm.meta.name")
	v_author  = json_str(_hid, "extensions.VRMC_vrm.meta.authors[0]")
	v_license = json_str(_hid, "extensions.VRMC_vrm.meta.licenseUrl")
	v_version = json_str(_hid, "extensions.VRMC_vrm.specVersion")
	; VRM 0.x フォールバック
	if strlen(v_name) = 0    : v_name    = json_str(_hid, "extensions.VRM.meta.title")
	if strlen(v_author) = 0  : v_author  = json_str(_hid, "extensions.VRM.meta.author")
	if strlen(v_license) = 0 : v_license = json_str(_hid, "extensions.VRM.meta.licenseName")
	if strlen(v_version) = 0 : v_version = json_str(_hid, "extensions.VRM.exporterVersion")
	json_release _hid
	return 0

#deffunc vrm_describe str path, var v_out, \
	local _buf, local _hid, local _n, local _sb, \
	local _name, local _author, local _lic, local _ver, \
	local _contact, local _allow_sexual, local _allow_violent, \
	local _allow_commercial, local _thumb_idx
	sdim v_out, 4096
	v_out = ""
	_vrm_extract_json path, _buf
	_n = stat
	if _n <= 0 : return -1
	_hid = json_load(_buf)
	if _hid < 0 : return -2

	_name   = json_str(_hid, "extensions.VRMC_vrm.meta.name")
	_author = json_str(_hid, "extensions.VRMC_vrm.meta.authors[0]")
	_lic    = json_str(_hid, "extensions.VRMC_vrm.meta.licenseUrl")
	_ver    = json_str(_hid, "extensions.VRMC_vrm.specVersion")
	_contact= json_str(_hid, "extensions.VRMC_vrm.meta.contactInformation")
	_allow_sexual    = json_str(_hid, "extensions.VRMC_vrm.meta.allowExcessivelySexualUsage")
	_allow_violent   = json_str(_hid, "extensions.VRMC_vrm.meta.allowExcessivelyViolentUsage")
	_allow_commercial= json_str(_hid, "extensions.VRMC_vrm.meta.commercialUsage")
	_thumb_idx       = json_int(_hid, "extensions.VRMC_vrm.meta.thumbnailImage")

	if strlen(_name) = 0    : _name    = json_str(_hid, "extensions.VRM.meta.title")
	if strlen(_author) = 0  : _author  = json_str(_hid, "extensions.VRM.meta.author")
	if strlen(_lic) = 0     : _lic     = json_str(_hid, "extensions.VRM.meta.licenseName")

	_sb = ""
	_sb = _sb + "name=" + _name + "\n"
	_sb = _sb + "author=" + _author + "\n"
	_sb = _sb + "licenseUrl=" + _lic + "\n"
	_sb = _sb + "specVersion=" + _ver + "\n"
	_sb = _sb + "contactInformation=" + _contact + "\n"
	_sb = _sb + "allowExcessivelySexualUsage=" + _allow_sexual + "\n"
	_sb = _sb + "allowExcessivelyViolentUsage=" + _allow_violent + "\n"
	_sb = _sb + "commercialUsage=" + _allow_commercial + "\n"
	_sb = _sb + "thumbnailImage=" + _thumb_idx + "\n"
	v_out = _sb

	json_release _hid
	return 0

#global
#endif