cmake_policy(PUSH)
cmake_policy(SET CMP0057 NEW)

##############################################################
##  enable shader lang by shader compiler: glslcc
macro(glslcc_option variable value)
    if(NOT DEFINED ${variable})
        set(${variable} ${value} CACHE STATIC "" FORCE)
    endif()
endmacro()

glslcc_option(GLSLCC_FRAG_SOURCE_FILE_EXTENSIONS ".frag;.fsh")
glslcc_option(GLSLCC_VERT_SOURCE_FILE_EXTENSIONS ".vert;.vsh")
glslcc_option(GLSLCC_OUT_DIR ${CMAKE_BINARY_DIR}/runtime/axslc)
glslcc_option(GLSLCC_FIND_PROG_ROOT "")

find_program(GLSLCC_EXE NAMES glslcc
    PATHS ${GLSLCC_FIND_PROG_ROOT}
)

if (NOT GLSLCC_EXE)
    message(STATUS, "glslcc not found.")
    message(FATAL_ERROR "Please run setup.ps1 again to download glslcc, and run CMake again.")
endif()

message(STATUS "GLSLCC_OUT_DIR=${GLSLCC_OUT_DIR}")
message(STATUS "GLSLCC_FIND_PROG_ROOT=${GLSLCC_FIND_PROG_ROOT}")
message(STATUS "GLSLCC_FRAG_SOURCE_FILE_EXTENSIONS=${GLSLCC_FRAG_SOURCE_FILE_EXTENSIONS}")
message(STATUS "GLSLCC_VERT_SOURCE_FILE_EXTENSIONS=${GLSLCC_VERT_SOURCE_FILE_EXTENSIONS}")

# PROPERTY: include direcotries (optional)
define_property(SOURCE PROPERTY GLSLCC_INCLUDE_DIRS
                BRIEF_DOCS "Compiled shader include directories"
                FULL_DOCS "Compiled shader include directories, seperated with comma")

# PROPERTY: defines (optional) TODO: rename to PREPROCESSOR_LIST
define_property(SOURCE PROPERTY GLSLCC_DEFINES
                BRIEF_DOCS "Compiled shader defines"
                FULL_DOCS "Compiled shader defines, seperated with comma")

# PROPERTY: output1 (optional) TODO: rename to PREPROCESSOR_LIST
define_property(SOURCE PROPERTY GLSLCC_OUTPUT1
                BRIEF_DOCS "Compiled shader output1 additional defines"
                FULL_DOCS "Compiled shader output1 additional defines, seperated with comma")

# PROPERTY: glscc output (optional)
define_property(SOURCE PROPERTY GLSLCC_OUTPUT
BRIEF_DOCS "The compiled sources shader output path list"
FULL_DOCS "The compiled shaders output list, seperated with comma")

# Find shader sources in specified directory
# syntax: ax_find_shaders(dir shader_sources [RECURSE])
# examples:
#   - ax_find_shaders("${CMAKE_CURRENT_LIST_DIR}/core/renderer/shaders" runtime_shader_sources)
#   - ax_find_shaders("${CMAKE_CURRENT_LIST_DIR}/Source" custom_shader_sources RECURSE)
function (ax_find_shaders dir varName)
    set(options RECURSE)
    cmake_parse_arguments(opt "${options}" "" "" ${ARGN})

    set(SC_FILTERS "")
    foreach(fileext ${GLSLCC_FRAG_SOURCE_FILE_EXTENSIONS})
        list(APPEND SC_FILTERS "${dir}/*${fileext}")
    endforeach()
    foreach(fileext ${GLSLCC_VERT_SOURCE_FILE_EXTENSIONS})
        list(APPEND SC_FILTERS "${dir}/*${fileext}")
    endforeach()
    if (opt_RECURSE)
        file(GLOB_RECURSE out_files ${SC_FILTERS})
    else()
        file(GLOB out_files ${SC_FILTERS})
    endif()
    set(${varName} ${out_files} PARENT_SCOPE)
endfunction()

# This function allow make shader files (.frag, .vert) compiled with glslcc
# usage:
#   - ax_target_compile_shaders(axmol FILES source_files): output compiled shader to ${CMAKE_BINARY_DIR}/runtime/axslc/xxx_fs
#   - ax_target_compile_shaders(axmol FILES source_files CUSTOM): output compiled shader to ${CMAKE_BINARY_DIR}/runtime/axslc/custom/xxx_fs
#   - ax_target_compile_shaders(axmol FILES source_files CVAR): the shader will compiled to c hex header for embed include by C/C++ use
# Use global variable to control shader file extension:
#   - GLSLCC_FRAG_SOURCE_FILE_EXTENSIONS: default is .frag;.fsh
#   - GLSLCC_VERT_SOURCE_FILE_EXTENSIONS: default is .vert;.vsh
# 
function (ax_target_compile_shaders target_name)
    set(options RUNTIME CVAR CUSTOM)
    set(multiValueArgs FILES)
    cmake_parse_arguments(opt "${options}" "" "${multiValueArgs}" ${ARGN})

    foreach(SC_FILE ${opt_FILES})
        get_filename_component(FILE_EXT ${SC_FILE} LAST_EXT)
        get_filename_component(FILE_NAME ${SC_FILE} NAME_WE)
        string(TOLOWER "${FILE_EXT}" FILE_EXT)

        set(SC_DEFINES "")

        # silent when compile shader success
        set(SC_FLAGS "--silent" "--err-format=msvc")
        
        # shader lang
        set(SC_PROFILE "")
        if(AX_GLES_PROFILE)
            # version 300 es
            if (AX_GLES_PROFILE EQUAL 300)
                set(OUT_LANG "ESSL")
                set(SC_PROFILE "300")
            else()
                # GLSL2 use glsl100 syntax es profile alka essl100
                set(OUT_LANG "ESSL")
                set(SC_PROFILE "100")
                set(SC_DEFINES "GLES2")
            endif()
            list(APPEND SC_FLAGS  "--lang=gles" "--profile=${SC_PROFILE}")
        elseif (AX_USE_GL)
            # version 330
            set(OUT_LANG "GLSL")
            set(SC_PROFILE "330")
            list(APPEND SC_FLAGS  "--lang=glsl" "--profile=${SC_PROFILE}")
        elseif (AX_USE_METAL) 
            set(OUT_LANG "MSL")
            list(APPEND SC_FLAGS  "--lang=msl")
            set(SC_DEFINES "METAL")
        endif()

        # automap, no-suffix since 1.18.1 released by axmolengine
        list(APPEND SC_FLAGS "--automap" "--no-suffix")

        # defines
        get_source_file_property(SOURCE_SC_DEFINES ${SC_FILE} GLSLCC_DEFINES)
        if (NOT (SOURCE_SC_DEFINES STREQUAL "NOTFOUND"))
            set(SC_DEFINES "${SC_DEFINES},${SOURCE_SC_DEFINES}")
        endif()

        if (SC_DEFINES)
            list(APPEND SC_FLAGS "\"--defines=${SC_DEFINES}\"")
        endif()

        # includes
        get_source_file_property(INC_DIRS ${SC_FILE} GLSLCC_INCLUDE_DIRS)
        if (INC_DIRS STREQUAL "NOTFOUND")
            set(INC_DIRS "")
        endif()
        list(APPEND INC_DIRS "${_AX_ROOT}/core/renderer/shaders")
        list(APPEND SC_FLAGS "--include-dirs=${INC_DIRS}")

        if (opt_CVAR)
            list(APPEND SC_FLAGS "--cvar=shader_rt_${FILE_NAME}")
        endif()

        # sgs, because Apple Metal lack of shader uniform reflect so use --sgs --refelect
        if (AX_USE_METAL)
            list(APPEND SC_FLAGS "--sgs" "--reflect")
        endif()
    
        # input
        if (${FILE_EXT} IN_LIST GLSLCC_FRAG_SOURCE_FILE_EXTENSIONS)
            list(APPEND SC_FLAGS "--frag=${SC_FILE}")
            set(SC_TYPE "fs")
        elseif(${FILE_EXT} IN_LIST GLSLCC_VERT_SOURCE_FILE_EXTENSIONS)
            set(SC_TYPE "vs")
            list(APPEND SC_FLAGS "--vert=${SC_FILE}")
        else()
            message(FATAL_ERROR "Invalid shader source, the file extesion must be one of .frag;.vert")
        endif()

        # output
        set(OUT_DIR ${GLSLCC_OUT_DIR})
        if(opt_CUSTOM)
            set(OUT_DIR "${OUT_DIR}/custom")
        endif()
        if (NOT (IS_DIRECTORY ${OUT_DIR}))
            file(MAKE_DIRECTORY ${OUT_DIR})
        endif()
        
        set(SC_OUTPUT "${OUT_DIR}/${FILE_NAME}_${SC_TYPE}")

        set(SC_COMMENT "Compiling shader ${SC_FILE} for ${OUT_LANG}${SC_PROFILE} ...")
    
        get_source_file_property(SOURCE_SC_OUTPUT1 ${SC_FILE} GLSLCC_OUTPUT1)

        string(REPLACE ";" " " FULL_COMMAND_LINE "${GLSLCC_EXE};${SC_FLAGS} ...")
        if(SOURCE_SC_OUTPUT1 STREQUAL "NOTFOUND") # single output
            list(APPEND SC_FLAGS "--output=${SC_OUTPUT}")
            set_source_files_properties(${SC_FILE} DIRECTORY ${CMAKE_BINARY_DIR} PROPERTIES GLSLCC_OUTPUT ${SC_OUTPUT})
            add_custom_command(
                    MAIN_DEPENDENCY ${SC_FILE} OUTPUT ${SC_OUTPUT} COMMAND ${GLSLCC_EXE} ${SC_FLAGS}
                    COMMENT "${SC_COMMENT}"
                )
        else() # dual outputs
            set(SC_DEFINES1 "${SC_DEFINES},${SOURCE_SC_OUTPUT1}")

            set(SC_FLAGS1 ${SC_FLAGS})
            list(REMOVE_ITEM SC_FLAGS1 "\"--defines=${SC_DEFINES}\"")
            list(APPEND SC_FLAGS1 "\"--defines=${SC_DEFINES1}\"")

            list(APPEND SC_FLAGS "--output=${SC_OUTPUT}")

            set(SC_OUTPUT1 "${SC_OUTPUT}_1")
            list(APPEND SC_FLAGS1 "--output=${SC_OUTPUT1}")
            string(REPLACE ";" " " FULL_COMMAND_LINE1 "${GLSLCC_EXE};${SC_FLAGS1} ...")
            set_source_files_properties(${SC_FILE} DIRECTORY ${CMAKE_BINARY_DIR} PROPERTIES GLSLCC_OUTPUT "${SC_OUTPUT};${SC_OUTPUT1}")
            add_custom_command(
                    MAIN_DEPENDENCY ${SC_FILE} 
                    OUTPUT ${SC_OUTPUT} ${SC_OUTPUT1}
                    COMMAND ${GLSLCC_EXE} ${SC_FLAGS}
                    COMMAND ${GLSLCC_EXE} ${SC_FLAGS1}
                    COMMENT "${SC_COMMENT}"
                )
        endif()

    endforeach()
    target_sources(${target_name} PRIVATE ${opt_FILES})
endfunction()

function(ax_target_embed_compiled_shaders target_name rc_output)
    set(multiValueArgs FILES)
    cmake_parse_arguments(opt "" "" "${multiValueArgs}" ${ARGN})

    set(app_all_shaders_json "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n")
    set(app_all_shaders_json "${app_all_shaders_json}<Project DefaultTargets=\"Build\" ToolsVersion=\"12.0\" xmlns=\"http://schemas.microsoft.com/developer/msbuild/2003\">\n")
    set(app_all_shaders_json "${app_all_shaders_json}  <ItemGroup>\n")
    foreach(shader ${opt_FILES})
        get_source_file_property(compiled_shaders ${shader} DIRECTORY ${CMAKE_BINARY_DIR} GLSLCC_OUTPUT)
        if(compiled_shaders STREQUAL "NOTFOUND")
            message(FATAL_ERROR "Not found property GLSLCC_OUTPUT of file: ${shader}")
        endif()
        foreach(compiled_shader ${compiled_shaders})
            set(app_all_shaders_json "${app_all_shaders_json}    <None Include=\"${compiled_shader}\">\n")
            set(app_all_shaders_json "${app_all_shaders_json}      <Link>Content\\axslc\\%(FileName)%(Extension)</Link>\n")
            set(app_all_shaders_json "${app_all_shaders_json}      <DeploymentContent Condition=\"'\$(Configuration)|\$(Platform)'=='Debug|x64'\">true</DeploymentContent>\n")
            set(app_all_shaders_json "${app_all_shaders_json}      <DeploymentContent Condition=\"'\$(Configuration)|\$(Platform)'=='Release|x64'\">true</DeploymentContent>\n")
            set(app_all_shaders_json "${app_all_shaders_json}      <DeploymentContent Condition=\"'\$(Configuration)|\$(Platform)'=='MinSizeRel|x64'\">true</DeploymentContent>\n")
            set(app_all_shaders_json "${app_all_shaders_json}      <DeploymentContent Condition=\"'\$(Configuration)|\$(Platform)'=='RelWithDebInfo|x64'\">true</DeploymentContent>\n")
            set(app_all_shaders_json "${app_all_shaders_json}    </None>\n")
        endforeach()
    endforeach()
    set(app_all_shaders_json "${app_all_shaders_json}  </ItemGroup>\n</Project>\n")
    
    set(props_file "${rt_output}/axslc.props")
    write_file("${props_file}" "${app_all_shaders_json}")

    set_target_properties(${target_name} PROPERTIES VS_USER_PROPS "${props_file}")
endfunction()

cmake_policy(POP)