project(BlangDoc NONE)

option(SPHINX_MAN "Build man pages with Sphinx" OFF)
option(SPHINX_HTML "Build html pages with Sphinx" OFF)
find_program(SPHINX_EXECUTABLE
  NAMES sphinx-build
  DOC "Sphinx Documentation Builder (sphinx-doc.org)"
  )

if(NOT SPHINX_MAN AND NOT SPHINX_HTML)
  return()
elseif(NOT SPHINX_EXECUTABLE)
  message(FATAL_ERROR "SPHINX_EXECUTABLE (sphinx-build) is not found!")
endif()

set(conf_path "${CMAKE_CURRENT_SOURCE_DIR}")
configure_file(conf.py.in conf.py @ONLY)

set(doc_formats "")
if(SPHINX_HTML)
  list(APPEND doc_formats html)
endif()
if(SPHINX_MAN)
  list(APPEND doc_formats man)
endif()

set(doc_format_outputs "")
set(doc_format_last "")
foreach(format ${doc_formats})
  set(doc_format_output "doc_format_${format}")
  set(doc_format_log "build-${format}.log")
  add_custom_command(
    OUTPUT ${doc_format_output}
    COMMAND ${SPHINX_EXECUTABLE}
            -c ${CMAKE_CURRENT_BINARY_DIR}
            -d ${CMAKE_CURRENT_BINARY_DIR}/doctrees
            -b ${format}
            ${g1m_assembler_SOURCE_DIR}/doc/
            ${CMAKE_CURRENT_BINARY_DIR}/${format}
            > ${doc_format_log} # log stdout, pass stderr
    DEPENDS ${doc_format_last}
    COMMENT "sphinx-build ${format}: see doc/${doc_format_log}"
    VERBATIM
    )
  set_property(SOURCE ${doc_format_output} PROPERTY SYMBOLIC 1)
  list(APPEND doc_format_outputs ${doc_format_output})
  set(doc_format_last ${doc_format_output})
endforeach()

add_custom_target(documentation ALL DEPENDS ${doc_format_outputs})

if(SPHINX_HTML)
  install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/html
          DESTINATION ${INSTALL_DOC_DIR}
          PATTERN .buildinfo EXCLUDE
          PATTERN objects.inv EXCLUDE
          )
endif()