#
#  AutoScribeShader.cmake
#
#  Created by Sam Gateau on 12/17/14.
#  Copyright 2014 High Fidelity, Inc.
#
#  Distributed under the Apache License, Version 2.0.
#  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
#

function(AUTOSCRIBE_SHADER SHADER_FILE)
  # Grab include files
  foreach(includeFile  ${ARGN})
    list(APPEND SHADER_INCLUDE_FILES ${includeFile})
  endforeach()

  foreach(SHADER_INCLUDE ${SHADER_INCLUDE_FILES})
    get_filename_component(INCLUDE_DIR ${SHADER_INCLUDE} PATH)
    list(APPEND SHADER_INCLUDES_PATHS ${INCLUDE_DIR})
  endforeach()

  #Extract the unique include shader paths
  set(INCLUDES ${HIFI_LIBRARIES_SHADER_INCLUDE_FILES})
  #message(${TARGET_NAME} Hifi for includes ${INCLUDES})
  foreach(EXTRA_SHADER_INCLUDE ${INCLUDES})
    list(APPEND SHADER_INCLUDES_PATHS ${EXTRA_SHADER_INCLUDE})
  endforeach()

  list(REMOVE_DUPLICATES SHADER_INCLUDES_PATHS)
  #message(ready for includes ${SHADER_INCLUDES_PATHS})

  # make the scribe include arguments
  set(SCRIBE_INCLUDES)
  foreach(INCLUDE_PATH ${SHADER_INCLUDES_PATHS})
    set(SCRIBE_INCLUDES ${SCRIBE_INCLUDES} -I ${INCLUDE_PATH}/)
  endforeach()

  # Define the final name of the generated shader file
  get_filename_component(SHADER_TARGET ${SHADER_FILE} NAME_WE)
  get_filename_component(SHADER_EXT ${SHADER_FILE} EXT)
  if(SHADER_EXT STREQUAL .slv)
    set(SHADER_TYPE vert)
  elseif(${SHADER_EXT} STREQUAL .slf)
    set(SHADER_TYPE frag)
  elseif(${SHADER_EXT} STREQUAL .slg)
    set(SHADER_TYPE geom)
  endif()
  set(SHADER_TARGET ${SHADER_TARGET}_${SHADER_TYPE})

  set(SHADER_TARGET "${SHADERS_DIR}/${SHADER_TARGET}")
  set(SHADER_TARGET_HEADER ${SHADER_TARGET}.h)
  set(SHADER_TARGET_SOURCE ${SHADER_TARGET}.cpp)
  set(SCRIBE_COMMAND scribe)

  # Target dependant Custom rule on the SHADER_FILE
  if (APPLE)
    set(GLPROFILE MAC_GL)
  elseif (ANDROID)
    set(GLPROFILE LINUX_GL)
    set(SCRIBE_COMMAND ${NATIVE_SCRIBE})
  elseif (UNIX)
    set(GLPROFILE LINUX_GL)
  else ()
    set(GLPROFILE PC_GL)
  endif()
  set(SCRIBE_ARGS -c++ -T ${SHADER_TYPE} -D GLPROFILE ${GLPROFILE} ${SCRIBE_INCLUDES} -o ${SHADER_TARGET} ${SHADER_FILE})
  add_custom_command(
    OUTPUT ${SHADER_TARGET_HEADER} ${SHADER_TARGET_SOURCE} 
    COMMAND ${SCRIBE_COMMAND} ${SCRIBE_ARGS} 
    DEPENDS ${SCRIBE_COMMAND} ${SHADER_INCLUDE_FILES} ${SHADER_FILE}
  )

  #output the generated file name
  set(AUTOSCRIBE_SHADER_RETURN ${SHADER_TARGET_HEADER} ${SHADER_TARGET_SOURCE} PARENT_SCOPE)

  file(GLOB INCLUDE_FILES ${SHADER_TARGET_HEADER})

endfunction()


macro(AUTOSCRIBE_SHADER_LIB)
  set(HIFI_LIBRARIES_SHADER_INCLUDE_FILES "")
  file(RELATIVE_PATH RELATIVE_LIBRARY_DIR_PATH ${CMAKE_CURRENT_SOURCE_DIR} "${HIFI_LIBRARY_DIR}")
  foreach(HIFI_LIBRARY ${ARGN})
    #if (NOT TARGET ${HIFI_LIBRARY})
    #  file(GLOB_RECURSE HIFI_LIBRARIES_SHADER_INCLUDE_FILES ${RELATIVE_LIBRARY_DIR_PATH}/${HIFI_LIBRARY}/src/)
    #endif ()

    #file(GLOB_RECURSE HIFI_LIBRARIES_SHADER_INCLUDE_FILES ${HIFI_LIBRARY_DIR}/${HIFI_LIBRARY}/src/*.slh)
    list(APPEND HIFI_LIBRARIES_SHADER_INCLUDE_FILES ${HIFI_LIBRARY_DIR}/${HIFI_LIBRARY}/src)
  endforeach()
  #message("${TARGET_NAME} ${HIFI_LIBRARIES_SHADER_INCLUDE_FILES}")

  file(GLOB_RECURSE SHADER_INCLUDE_FILES src/*.slh)
  file(GLOB_RECURSE SHADER_SOURCE_FILES src/*.slv src/*.slf src/*.slg)

  #make the shader folder
  set(SHADERS_DIR "${CMAKE_CURRENT_BINARY_DIR}/shaders/${TARGET_NAME}")
  file(MAKE_DIRECTORY ${SHADERS_DIR})

  #message("${TARGET_NAME} ${SHADER_INCLUDE_FILES}")
  set(AUTOSCRIBE_SHADER_SRC "")
  foreach(SHADER_FILE ${SHADER_SOURCE_FILES})
    AUTOSCRIBE_SHADER(${SHADER_FILE} ${SHADER_INCLUDE_FILES})
    file(TO_CMAKE_PATH "${AUTOSCRIBE_SHADER_RETURN}" AUTOSCRIBE_GENERATED_FILE)
    set_property(SOURCE ${AUTOSCRIBE_GENERATED_FILE} PROPERTY SKIP_AUTOMOC ON)
    list(APPEND AUTOSCRIBE_SHADER_SRC ${AUTOSCRIBE_GENERATED_FILE})
  endforeach()
  #message(${TARGET_NAME} ${AUTOSCRIBE_SHADER_SRC})

  if (WIN32)
    source_group("Shaders" FILES ${SHADER_INCLUDE_FILES})
    source_group("Shaders" FILES ${SHADER_SOURCE_FILES})
    source_group("Shaders\\generated" FILES ${AUTOSCRIBE_SHADER_SRC})
  endif()

  list(APPEND AUTOSCRIBE_SHADER_LIB_SRC ${SHADER_INCLUDE_FILES})
  list(APPEND AUTOSCRIBE_SHADER_LIB_SRC ${SHADER_SOURCE_FILES})
  list(APPEND AUTOSCRIBE_SHADER_LIB_SRC ${AUTOSCRIBE_SHADER_SRC})

  # Link library shaders, if they exist
  include_directories("${SHADERS_DIR}")

  # Add search directory to find gpu/Shader.h
  include_directories("${HIFI_LIBRARY_DIR}/gpu/src")

endmacro()