cmake_minimum_required (VERSION 3.12.0)
include (FindPkgConfig REQUIRED)

if (DEFINED ENV{PETSC_DIR})
    message ("PETSC_DIR:\n$ENV{PETSC_DIR}\n")
else ()
    message (FATAL_ERROR "PETSc location (PETSC_DIR) is not defined")
endif ()

# Dummy project to determine compiler names and version
project (Prerequisites LANGUAGES)
set(ENV{PKG_CONFIG_PATH} "$ENV{PETSC_DIR}/$ENV{PETSC_ARCH}/lib/pkgconfig")
pkg_check_modules (PETSC REQUIRED PETSc>=3.12.0 PETSc<3.17.0)
pkg_get_variable (CMAKE_Fortran_COMPILER PETSc fcompiler)
pkg_get_variable (CMAKE_C_COMPILER PETSc ccompiler)

# Solver determines name of project
string(TOUPPER "${DAMASK_SOLVER}" DAMASK_SOLVER)
if (DAMASK_SOLVER STREQUAL "GRID")
    project (damask-grid HOMEPAGE_URL https://damask.mpie.de LANGUAGES Fortran C)
elseif (DAMASK_SOLVER STREQUAL "MESH")
    project (damask-mesh HOMEPAGE_URL https://damask.mpie.de LANGUAGES Fortran C)
else ()
    message (FATAL_ERROR "Invalid solver: DAMASK_SOLVER=${DAMASK_SOLVER}")
endif ()
add_definitions ("-D${DAMASK_SOLVER}")

file (STRINGS ${PROJECT_SOURCE_DIR}/VERSION DAMASK_VERSION)

message ("\nBuilding ${CMAKE_PROJECT_NAME} ${DAMASK_VERSION}\n")

add_definitions (-DPETSC)
add_definitions (-DDAMASKVERSION="${DAMASK_VERSION}")
add_definitions (-DCMAKE_SYSTEM="${CMAKE_SYSTEM}")

if (CMAKE_BUILD_TYPE STREQUAL "")
    set (CMAKE_BUILD_TYPE "RELEASE")
endif ()
string(TOUPPER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE)

# Predefined sets for OPTIMIZATION/OPENMP based on BUILD_TYPE
if (CMAKE_BUILD_TYPE STREQUAL "DEBUG" OR CMAKE_BUILD_TYPE STREQUAL "SYNTAXONLY")
    set (DEBUG_FLAGS "${DEBUG_FLAGS} -DDEBUG")
    set (PARALLEL "OFF")
    set (OPTI "OFF")
elseif (CMAKE_BUILD_TYPE STREQUAL "RELEASE")
    set (PARALLEL "ON")
    set (OPTI "DEFENSIVE")
elseif (CMAKE_BUILD_TYPE STREQUAL "DEBUGRELEASE")
    set (DEBUG_FLAGS "${DEBUG_FLAGS} -DDEBUG")
    set (PARALLEL "ON")
    set (OPTI "DEFENSIVE")
elseif (CMAKE_BUILD_TYPE STREQUAL "PERFORMANCE")
    set (PARALLEL "ON")
    set (OPTI "AGGRESSIVE")
else ()
    message (FATAL_ERROR "Invalid build type: CMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}")
endif ()

# $OPTIMIZATION takes precedence over $BUILD_TYPE defaults
if (OPTIMIZATION STREQUAL "" OR NOT DEFINED OPTIMIZATION)
    set (OPTIMIZATION "${OPTI}")
else ()
    set (OPTIMIZATION "${OPTIMIZATION}")
endif ()

# $OPENMP takes precedence over $BUILD_TYPE defaults
if (OPENMP STREQUAL "" OR NOT DEFINED OPENMP)
    set (OPENMP "${PARALLEL}")
else ()
    set(OPENMP "${OPENMP}")
endif ()

# syntax check only (mainly for pre-receive hook)
if (CMAKE_BUILD_TYPE STREQUAL "SYNTAXONLY")
    set (BUILDCMD_POST "${BUILDCMD_POST} -fsyntax-only")
endif ()


list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
if    (CMAKE_Fortran_COMPILER_ID STREQUAL "Intel")
    include (Compiler-Intel)
elseif(CMAKE_Fortran_COMPILER_ID STREQUAL "GNU")
    include (Compiler-GNU)
else ()
    message (FATAL_ERROR "Compiler type (CMAKE_Fortran_COMPILER_ID) not recognized")
endif ()

file (STRINGS "$ENV{PETSC_DIR}/$ENV{PETSC_ARCH}/lib/petsc/conf/petscvariables" PETSC_EXTERNAL_LIB REGEX "PETSC_WITH_EXTERNAL_LIB = .*$?")
string (REGEX MATCHALL "-[lLW]([^\" ]+)" PETSC_EXTERNAL_LIB "${PETSC_EXTERNAL_LIB}")
list (REMOVE_DUPLICATES PETSC_EXTERNAL_LIB)
string (REPLACE ";" " " PETSC_EXTERNAL_LIB "${PETSC_EXTERNAL_LIB}")
message ("PETSC_EXTERNAL_LIB:\n${PETSC_EXTERNAL_LIB}\n")

file (STRINGS "$ENV{PETSC_DIR}/$ENV{PETSC_ARCH}/lib/petsc/conf/petscvariables" PETSC_INCLUDES REGEX "PETSC_FC_INCLUDES = .*$?")
string (REGEX MATCHALL "-I([^\" ]+)" PETSC_INCLUDES "${PETSC_INCLUDES}")
list (REMOVE_DUPLICATES PETSC_INCLUDES)
string (REPLACE ";" " " PETSC_INCLUDES "${PETSC_INCLUDES}")
message ("PETSC_INCLUDES:\n${PETSC_INCLUDES}\n")

set (CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE} "${BUILDCMD_PRE} ${OPENMP_FLAGS} ${STANDARD_CHECK} ${OPTIMIZATION_FLAGS} ${COMPILE_FLAGS} ${PRECISION_FLAGS}")
set (CMAKE_Fortran_LINK_EXECUTABLE           "${BUILDCMD_PRE} ${CMAKE_Fortran_COMPILER} ${OPENMP_FLAGS} ${OPTIMIZATION_FLAGS} ${LINKER_FLAGS}")

if (CMAKE_BUILD_TYPE STREQUAL "DEBUG")
    set (CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE} "${CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE}} ${DEBUG_FLAGS}")
    set (CMAKE_Fortran_LINK_EXECUTABLE           "${CMAKE_Fortran_LINK_EXECUTABLE} ${DEBUG_FLAGS}")
endif ()

set (CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE}   "${CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE}} ${PETSC_INCLUDES} ${BUILDCMD_POST}")
set (CMAKE_Fortran_LINK_EXECUTABLE             "${CMAKE_Fortran_LINK_EXECUTABLE} <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${PETSC_EXTERNAL_LIB} -lz ${BUILDCMD_POST}")

message ("Fortran Compiler Flags:\n${CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE}}\n")
message ("C Compiler Flags:\n${CMAKE_C_FLAGS_${CMAKE_BUILD_TYPE}}\n")
message ("Fortran Linker Command:\n${CMAKE_Fortran_LINK_EXECUTABLE}\n")

# location of code
add_subdirectory (src)