cmake_minimum_required (VERSION 3.26)
project (HDF5_JAVA C Java)

#-----------------------------------------------------------------------------
# Include some macros for reusable code
#-----------------------------------------------------------------------------
include (UseJava)

if (WIN32)
  set (HDF_JRE_DIRECTORY "C:/Program Files/Java/jre")
else ()
  set (HDF_JRE_DIRECTORY "/usr/lib/jvm/jre")
endif ()

#-----------------------------------------------------------------------------
# Include the main src and config directories
#-----------------------------------------------------------------------------
set (HDF5_JAVA_INCLUDE_DIRECTORIES
    ${JAVA_INCLUDE_PATH}
    ${JAVA_INCLUDE_PATH2}
)
set_directory_properties(PROPERTIES INCLUDE_DIRECTORIES "${HDF5_JAVA_INCLUDE_DIRECTORIES}")

set (CMAKE_JAVA_INCLUDE_PATH "")

if (Java_VERSION_STRING VERSION_GREATER_EQUAL "25.0.0")
  if (HDF5_ENABLE_JNI)
    set (HDF5_JAVA_USE_FFM FALSE)
    message (STATUS "Building HDF5 Java with JNI implementation (explicitly requested via HDF5_ENABLE_JNI)")
  else ()
    set (HDF5_JAVA_USE_FFM TRUE)
    set (HDF5_ENABLE_JAVA_COMPAT TRUE)
    message (STATUS "Building HDF5 Java with FFM implementation (Java ${Java_VERSION_STRING})")

    # Find the jextract tool using the JEXTRACT_HOME or JAVA_HOME environment variable
    # On Windows, jextract uses .bat extension
    if (WIN32)
        find_program (JEXTRACT_EXECUTABLE
            NAMES jextract.bat jextract
            PATHS "$ENV{JEXTRACT_HOME}/bin" "$ENV{JAVA_HOME}/bin"
            REQUIRED
            NO_DEFAULT_PATH
        )
    else ()
        find_program (JEXTRACT_EXECUTABLE
            NAMES jextract
            PATHS "$ENV{JEXTRACT_HOME}/bin" "$ENV{JAVA_HOME}/bin"
            REQUIRED
            NO_DEFAULT_PATH
        )
    endif ()

    if (NOT JEXTRACT_EXECUTABLE)
        message (FATAL_ERROR "Could not find jextract executable. "
                             "Please set JEXTRACT_HOME or ensure jextract is in JAVA_HOME/bin\n"
                             "JEXTRACT_HOME=$ENV{JEXTRACT_HOME}\n"
                             "JAVA_HOME=$ENV{JAVA_HOME}")
    endif ()

    # jextract will output to the jsrc binary directory
    # When jsrc/CMakeLists.txt runs, HDF5_JAVA_JSRC_BINARY_DIR will be set to this location by CMake
    set (JEXTRACT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/jsrc)

    # Display jextract configuration
    message (STATUS "jextract executable: ${JEXTRACT_EXECUTABLE}")
    message (STATUS "jextract output directory: ${JEXTRACT_OUTPUT_DIR}")
    message (STATUS "HDF5 source directory: ${HDF5_SRC_DIR}")

    # Test if jextract executable exists and is runnable
    if (NOT EXISTS "${JEXTRACT_EXECUTABLE}")
        message (FATAL_ERROR "jextract executable does not exist at: ${JEXTRACT_EXECUTABLE}")
    endif ()

    # Try to run jextract --version as a test
    message (STATUS "Testing jextract executable...")
    execute_process (
        COMMAND ${JEXTRACT_EXECUTABLE} --version
        RESULT_VARIABLE JEXTRACT_VERSION_RESULT
        OUTPUT_VARIABLE JEXTRACT_VERSION_OUTPUT
        ERROR_VARIABLE JEXTRACT_VERSION_ERROR
        OUTPUT_STRIP_TRAILING_WHITESPACE
        ERROR_STRIP_TRAILING_WHITESPACE
    )
    message (STATUS "jextract version test result: ${JEXTRACT_VERSION_RESULT}")
    message (STATUS "jextract version output: ${JEXTRACT_VERSION_OUTPUT}")
    if (NOT "${JEXTRACT_VERSION_ERROR}" STREQUAL "")
        message (STATUS "jextract version error: ${JEXTRACT_VERSION_ERROR}")
    endif ()

    # Generate Java bindings with error handling
    message (STATUS "Running jextract to generate FFM bindings...")
    execute_process (
        COMMAND
            ${JEXTRACT_EXECUTABLE}
            --include-dir ${HDF5_SRC_DIR}
            --include-dir ${HDF5_SRC_BINARY_DIR}
            --include-dir ${H5FD_SUBFILING_DIR}
            --output ${JEXTRACT_OUTPUT_DIR}
            --target-package org.hdfgroup.javahdf5
            --library hdf5
            ${HDF5_SRC_DIR}/hdf5.h
        RESULT_VARIABLE JEXTRACT_RESULT
        OUTPUT_VARIABLE JEXTRACT_OUTPUT
        ERROR_VARIABLE JEXTRACT_ERROR
        ECHO_OUTPUT_VARIABLE
        ECHO_ERROR_VARIABLE
        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
    )

    # Check if jextract succeeded
    message (STATUS "jextract exit code: ${JEXTRACT_RESULT}")
    if (NOT JEXTRACT_RESULT EQUAL 0)
        message (STATUS "jextract output length: ${JEXTRACT_OUTPUT}")
        message (STATUS "jextract error length: ${JEXTRACT_ERROR}")
        message (FATAL_ERROR "jextract failed with exit code ${JEXTRACT_RESULT}\n"
                             "Executable: ${JEXTRACT_EXECUTABLE}\n"
                             "Working dir: ${CMAKE_CURRENT_BINARY_DIR}\n"
                             "Output: ${JEXTRACT_OUTPUT}\n"
                             "Error: ${JEXTRACT_ERROR}")
    endif ()

    # Verify that key FFM binding files were generated
    set (EXPECTED_FFM_FILE "${JEXTRACT_OUTPUT_DIR}/org/hdfgroup/javahdf5/hdf5_h.java")
    if (NOT EXISTS "${EXPECTED_FFM_FILE}")
        message (FATAL_ERROR "jextract did not generate expected file: ${EXPECTED_FFM_FILE}")
    endif ()

    message (STATUS "FFM bindings generated successfully at ${JEXTRACT_OUTPUT_DIR}")
  endif ()
else ()
  set (HDF5_JAVA_USE_FFM FALSE)
  set (HDF5_ENABLE_JNI TRUE)
  message (STATUS "Building HDF5 Java with JNI implementation (Java ${Java_VERSION_STRING})")
  if (Java_VERSION_STRING VERSION_LESS "11.0.0")
    message (FATAL_ERROR "Java version ${Java_VERSION_STRING} is not supported. Minimum required: Java 11")
  endif ()
endif ()

# Update global cache variables based on detected implementation
if (HDF5_JAVA_USE_FFM)
  set (HDF5_JAVA_IMPLEMENTATION "FFM" CACHE STRING "Java implementation being built" FORCE)
  set (HDF5_JAVA_ARTIFACT_ID "hdf5-java-ffm" CACHE STRING "Maven artifact ID for Java bindings" FORCE)
  set (DOXYGEN_JAVA_DIR ${HDF5_JAVA_SRC_PATH})
else ()
  set (HDF5_JAVA_IMPLEMENTATION "JNI" CACHE STRING "Java implementation being built" FORCE)
  set (HDF5_JAVA_ARTIFACT_ID "hdf5-java-jni" CACHE STRING "Maven artifact ID for Java bindings" FORCE)
  set (DOXYGEN_JAVA_DIR ${HDF5_JAVA_SRCJNI_PATH})
endif ()
set_property(CACHE HDF5_JAVA_IMPLEMENTATION PROPERTY STRINGS FFM JNI)
mark_as_advanced (HDF5_JAVA_IMPLEMENTATION HDF5_JAVA_ARTIFACT_ID)

# Display final configuration
message (STATUS "Java implementation: ${HDF5_JAVA_IMPLEMENTATION}")
message (STATUS "Java Maven artifact: org.hdfgroup:${HDF5_JAVA_ARTIFACT_ID}")

#-----------------------------------------------------------------------------
# Traverse source subdirectory
#-----------------------------------------------------------------------------
# Build appropriate subdirectories based on implementation
if (HDF5_JAVA_USE_FFM)
  add_subdirectory (jsrc)
  if (HDF5_ENABLE_JAVA_COMPAT)
    add_subdirectory (hdf)
  endif ()
  if (NOT HDF5_EXTERNALLY_CONFIGURED AND BUILD_TESTING)
    add_subdirectory (jtest)
    if (HDF5_ENABLE_JAVA_COMPAT)
      add_subdirectory (test)
    endif ()
  endif ()
else ()
  add_subdirectory (src-jni)
endif ()

#-----------------------------------------------------------------------------
# Add Required Jar(s)
#-----------------------------------------------------------------------------
install (
    FILES
        ${HDF5_JAVA_LOGGING_JAR}
        ${HDF5_JAVA_LOGGING_NOP_JAR}
        ${HDF5_JAVA_LOGGING_SIMPLE_JAR}
    DESTINATION ${HDF5_INSTALL_JAR_DIR}
    COMPONENT libraries
)

#-----------------------------------------------------------------------------
# Option to include jre
#-----------------------------------------------------------------------------
option (HDF5_JAVA_PACK_JRE  "Package a JRE installer directory" OFF)
if (HDF5_JAVA_PACK_JRE)
  install (
      DIRECTORY ${HDF_JRE_DIRECTORY}
      DESTINATION ${HDF5_INSTALL_BIN_DIR}
      USE_SOURCE_PERMISSIONS
  )
endif ()