acecode_embed_assets.cmake

# acecode_embed_assets: 把 web/ 下的所有文件嵌入成 C++ 字节数组,在 build
# 时生成 ${CMAKE_BINARY_DIR}/generated/static_assets_data.cpp。
#
# 用法:
#   include(cmake/acecode_embed_assets.cmake)
#   acecode_generate_embedded_assets(${CMAKE_SOURCE_DIR}/web
#                                      ${CMAKE_BINARY_DIR}/generated/static_assets_data.cpp
#                                      ${BUILD_VERSION})
#
# 生成的文件实现 `acecode::web::lookup_embedded_asset(name)` —— 静态 std::map
# 把相对路径(如 "index.html" / "components/ace-app.js")映射到 std::span。
# index.html 的内容会做一次模板替换,把 `?v=__VERSION__` 替换成传入的
# BUILD_VERSION 字符串(失败 fallback 不替换 — 不阻断 build)。
#
# 注意: 单文件输出会让 MSVC 编译稍慢(几百 KB cpp);若以后嵌入资源膨胀严重
# 可拆多 TU。当前 web/ 总量 << 1MB,不优化。

function(acecode_generate_embedded_assets web_dir out_file version)
    if(NOT EXISTS "${web_dir}")
        message(STATUS "[acecode_embed_assets] web dir not found: ${web_dir} — generating empty asset map")
        file(WRITE "${out_file}" "// Auto-generated. web/ dir absent at configure time.\n#include \"web/static_assets.hpp\"\nnamespace acecode::web {\nconst std::map<std::string, std::pair<const unsigned char*, std::size_t>>& embedded_asset_map() {\n    static const std::map<std::string, std::pair<const unsigned char*, std::size_t>> m;\n    return m;\n}\n}\n")
        return()
    endif()

    file(GLOB_RECURSE rels CONFIGURE_DEPENDS RELATIVE "${web_dir}" "${web_dir}/*")
    list(FILTER rels EXCLUDE REGEX "(^|/)(README\\.md|\\.gitignore)$")

    set(content "// Auto-generated by acecode_embed_assets. DO NOT EDIT.\n")
    string(APPEND content "#include \"web/static_assets.hpp\"\n\n")
    string(APPEND content "namespace acecode::web {\n\n")

    set(map_entries "")
    set(idx 0)
    foreach(rel IN LISTS rels)
        set(src_file "${web_dir}/${rel}")
        if(IS_DIRECTORY "${src_file}")
            continue()
        endif()

        # index.html 走模板替换:把 ?v=__VERSION__ 替成 ?v=${version}
        # 其它文件原样读取。
        #
        # 关键:必须用 HEX(二进制)模式读,绝不能用文本模式 file(READ ... raw_text)。
        # 压缩后的前端 bundle 里含真实控制字节(某些库把 ASCII 控制符定义成裸字节,
        # 如 f.SUB="\x1a"),而 CMake 在 Windows 文本模式下会把 0x1A(Ctrl+Z)当 EOF,
        # 把 index.html 在该字节处截断 → 嵌入的前端残缺 → 部署机(走嵌入)白屏。
        # 因此 __VERSION__ 的替换改在 hex 空间做(token 与 version 都是安全 ASCII)。
        if(rel STREQUAL "index.html")
            file(READ "${src_file}" hex_data HEX)
            # "__VERSION__" 的小写 hex(file(READ HEX) 输出小写)
            set(_token_hex "5f5f56455253494f4e5f5f")
            set(_ver_tmp "${out_file}.ver.tmp")
            file(WRITE "${_ver_tmp}" "${version}")
            file(READ "${_ver_tmp}" _version_hex HEX)
            file(REMOVE "${_ver_tmp}")
            string(REPLACE "${_token_hex}" "${_version_hex}" hex_data "${hex_data}")
        else()
            file(READ "${src_file}" hex_data HEX)
        endif()

        # 文件名 → C++ 变量名:非字母数字转 _,加序号防 collision
        string(REGEX REPLACE "[^A-Za-z0-9]" "_" var_safe "${rel}")
        set(var_name "asset_${idx}_${var_safe}")

        # 把每两位 hex 转成 0xXX, 格式
        string(REGEX REPLACE "(..)" "0x\\1," hex_arr "${hex_data}")
        string(LENGTH "${hex_data}" hex_len)
        math(EXPR data_len "${hex_len} / 2")

        # 空文件:hex_arr 为空,需要一个最小占位避免 "{}; " 编译失败 —
        # 写一个 0 字节占位,size 仍为 0。
        if(data_len EQUAL 0)
            string(APPEND content "static const unsigned char ${var_name}[1] = {0};\n")
        else()
            string(APPEND content "static const unsigned char ${var_name}[] = {${hex_arr}};\n")
        endif()
        # 把反斜杠路径分隔符换成 / 让 map key 跨平台一致。
        string(REPLACE "\\" "/" rel_norm "${rel}")
        string(APPEND map_entries "    {\"${rel_norm}\", {${var_name}, ${data_len}}},\n")

        math(EXPR idx "${idx} + 1")
    endforeach()

    string(APPEND content "\nconst std::map<std::string, std::pair<const unsigned char*, std::size_t>>& embedded_asset_map() {\n")
    string(APPEND content "    static const std::map<std::string, std::pair<const unsigned char*, std::size_t>> m = {\n${map_entries}    };\n")
    string(APPEND content "    return m;\n}\n\n")
    string(APPEND content "} // namespace acecode::web\n")

    file(WRITE "${out_file}" "${content}")
    message(STATUS "[acecode_embed_assets] wrote ${out_file} with ${idx} assets (BUILD_VERSION=${version})")
endfunction()

# 拿 git short hash 作 BUILD_VERSION;非 git 环境 fallback 用日期+秒。
function(acecode_compute_build_version out_var)
    set(_version "unknown")
    find_package(Git QUIET)
    if(GIT_FOUND)
        execute_process(
            COMMAND ${GIT_EXECUTABLE} rev-parse --short HEAD
            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
            OUTPUT_VARIABLE git_hash
            OUTPUT_STRIP_TRAILING_WHITESPACE
            ERROR_QUIET
            RESULT_VARIABLE rc
        )
        if(rc EQUAL 0 AND git_hash)
            set(_version "${git_hash}")
        endif()
    endif()
    if(_version STREQUAL "unknown")
        string(TIMESTAMP _version "%Y%m%d%H%M")
    endif()
    set(${out_var} "${_version}" PARENT_SCOPE)
endfunction()