# Copyright 2013-2022 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

import glob

from spack import *


class Ffte(Package):
    """Fastest Fourier Transform in the East. Provides FFT for powers of 2, 3,
    and 5 lengths in one, two, and three dimensions. Support for vector
    hardware, MPI, and CUDA Fortran is also included."""

    homepage = 'http://www.ffte.jp/'
    url = 'http://www.ffte.jp/ffte-7.0.tgz'

    maintainers = ['luszczek']

    version('7.0', sha256='078d5f84a5f2479ca5c4a3bd777ad761fe98addf1642a045bac6602a0cae3da0')
    version('6.0', sha256='fc82595a8f8323b2796cc5eeb1cc9f7e50ca9e511a14365cc3984da6b7a9b8b4')
    version('5.0', sha256='1f46ca16badc3aca0ad13ca91a6a67829a57b403501cdc821b80cfa62b2a89c2')
    version('4.0', sha256='61680f73c48659ac45aec60ef5a725547f763bb9017edbd3f44a6a9ad0fda62f')
    version('3.0', sha256='dbaab8204a16072c8d572efa3733e9946a9be0d1a051fc19e2d9253be23247ff')
    version('2.0', sha256='f5cf1d1f880288e359f4d517191980ffca4420f817ecaa2d754ca5c5421271e3')
    version('1.0', sha256='35171e3324019018c25575b2807a6513fa85badad040f30f238fff03d4b4d1ab')

    variant('mpi', default=False, description='Build MPI library')
    variant('cuda', default=False, description='Use CUDA Fortran')
    variant('vector', default=False, description='Use vectorized FFT')

    depends_on('mpi', when='+mpi')

    conflicts('%cce', when='+cuda', msg='Must use NVHPC compiler')
    conflicts('%clang', when='+cuda', msg='Must use NVHPC compiler')
    conflicts('%gcc', when='+cuda', msg='Must use NVHPC compiler')
    conflicts('%llvm', when='+cuda', msg='Must use NVHPC compiler')
    conflicts('%nag', when='+cuda', msg='Must use NVHPC compiler')
    conflicts('%intel', when='+cuda', msg='Must use NVHPC compiler')

    def edit(self, spec, prefix):
        'No make-file, must create one from scratch.'

        open('mpi/param.h', 'w').write(open('param.h').read())

        for fpfx in ('.', 'mpi'):
            vrs = '%sfftever' % ['', '', '', 'p'][len(fpfx)]
            s6 = 6 * ' '
            fd = open('%s/%s.f' % (fpfx, vrs), 'w')
            fd.write('%ssubroutine %s(i,j,k)\n' % (s6, vrs))
            fd.write('%sinteger i,j,k\n' % s6)
            fd.write('%si=%s\n' % (s6, spec.version[0]))
            fd.write('%sj=%s\n' % (s6, spec.version[1]))
            fd.write('%sk=0\n%sreturn\n%send\n' % (3 * (s6,)))
            fd.close()

            ff, cuf, vf = [], [], []
            for f in glob.glob('%s/*.f' % fpfx):
                nf = f.replace('.f', '.o').replace('%s/' % fpfx, '')
                if '/cu' in f or '/pcu' in f:
                    cuf.append(nf)
                elif '/v' in f or '/pv' in f:
                    vf.append(nf)
                else:
                    ff.append(nf)

            if '.' == fpfx:
                lbnm = 'libffte.a'
            else:
                lbnm = 'libfftempi.a'

            for spc, vrf, rs, ip in (
                ('+vector', vf, 'v', 2),
                ('+cuda', cuf, 'cu', 3),
            ):
                if spc in spec:
                    for f in vrf:  # replace with variant versions
                        orgf = f[:ip].replace(rs, '') + f[ip:]
                        if orgf in ff:  # already reference implementation?
                            del ff[ff.index(orgf)]
                    ff.extend(vrf)

            aff = ' '.join(ff)
            fd = open('%s/Makefile' % fpfx, 'w')
            fd.write('all: %s\n' % lbnm)
            if '+mpi' in spec and '.' == fpfx:
                fd.write('\tcd mpi ; $(MAKE)\n')
            fd.write('\n%s: %s\n' % (lbnm, aff))
            fd.write('\tar rc %s %s\n' % (lbnm, aff))
            fd.write('\tranlib %s\n' % lbnm)
            fd.close()

    def install(self, spec, prefix):
        self.edit(spec, prefix)
        if '+mpi' in spec:
            env['CC'] = spec['mpi'].mpicc
            env['F77'] = spec['mpi'].mpif77
            env['FC'] = spec['mpi'].mpifc

        # allow real/complex aliasing in GNU Fortran 10 and up
        if spec.satisfies('%gcc@10:'):
            env['FFLAGS'] = '-fallow-argument-mismatch'

        # enable CUDA Fortran in NVHPC
        if spec.satisfies('%nvhpc'):
            env['FFLAGS'] = '-Mcuda'

        make()
        mkdirp(prefix.lib)
        install('libffte.a', prefix.lib)
        if '+mpi' in spec:
            install('mpi/libfftempi.a', prefix.lib)