#!/usr/bin/env python
"""Configure the build.

- Fetch HDF5 headers.
- Create pbdata/LibBlasrConfig.h
- Create defines.mk

Putting LibBlasrConfig.h into a src-dir is not ideal, but simplifies a lot.

This is not used by './unittest/'.
"""
import commands
import contextlib
import os
import sys

thisdir = os.path.dirname(os.path.abspath(__file__))

def log(msg):
    sys.stderr.write(msg)
    sys.stderr.write('\n')

def shell(cmd):
    log(cmd)
    status, output = commands.getstatusoutput(cmd)
    if status:
        raise Exception('%d <- %r' %(status, cmd))
    return output

def update_content(fn, content):
    direc = os.path.abspath(os.path.dirname(fn))
    if not os.path.isdir(direc):
        shell('mkdir -p %s' %direc)
    current_content = open(fn).read() if os.path.exists(fn) else None
    if content != current_content:
        log('writing to %r' %fn)
        log('"""\n' + content + '"""')
        open(fn, 'w').write(content)

def compose_libconfig(pbbam=False):
    if pbbam:
        content = """
#define USE_PBBAM
"""
    else:
        content = """
"""
    return content

def compose_defines_with_hdf(HDF5_INC, HDF5_LIB):
    """We have to use := for HDF5_LIB b/c blasr
    is using it to mean the directory, not the file,
    and it's in the environment.
    """
    return """
HDF5_INC:=%(HDF5_INC)s
HDF5_LIB:=%(HDF5_LIB)s
LIBPBDATA_INC     ?=../pbdata
LIBPBIHDF_INC     ?=../hdf
LIBBLASR_INC      ?=../alignment
LIBPBDATA_LIB     ?=../pbdata
LIBPBIHDF_LIB     ?=../hdf
LIBBLASR_LIB      ?=../alignment
"""%(dict(
    thisdir=thisdir,
    HDF5_INC=HDF5_INC,
    HDF5_LIB=HDF5_LIB))


def compose_defines_with_hdf_headers(HDF_HEADERS):
    return """
HDF_HEADERS:=%(HDF_HEADERS)s
#HDF5_INC  ?=${HDF_HEADERS}/src
CPPFLAGS+= -I${HDF_HEADERS}/src -I${HDF_HEADERS}/c++/src
LIBPBDATA_LIB     ?=../pbdata/
LIBPBIHDF_LIB     ?=../hdf/
LIBBLASR_LIB      ?=../alignment/
"""%(dict(thisdir=thisdir, HDF_HEADERS=HDF_HEADERS))

def compose_defines():
    """
    Note that our local 'hdf' subdir will not even build
    in this case.
    """
    return """
LIBPBDATA_INC ?=../pbdata
LIBPBIHDF_INC ?=../hdf
LIBBLASR_INC  ?=../alignment
LIBPBDATA_LIB ?=%(thisdir)s/pbdata/
LIBPBIHDF_LIB ?=%(thisdir)s/hdf/
LIBBLASR_LIB  ?=%(thisdir)s/alignment/
nohdf         ?=1
"""%(dict(thisdir=thisdir))

def get_OS_STRING():
    G_BUILDOS_CMD = """bash -c 'set -e; set -o pipefail; id=$(lsb_release -si | tr "[:upper:]" "[:lower:]"); rel=$(lsb_release -sr); case $id in ubuntu) printf "$id-%04d\n" ${rel/./};; centos) echo "$id-${rel%%.*}";; *) echo "$id-$rel";; esac' 2>/dev/null"""
    return shell(G_BUILDOS_CMD)

def get_PBBAM(env, prefix):
    """
    key = 'PBBAM'
    if key in env:
        return env[key]
    cmd = 'cd $(THIRD_PARTY_PREFIX)/../lib/cpp/pbbam 2>/dev/null && pwd || echo -n notfound' %(
            THIRD_PARTY_PREFIX=prefix)
    return shell(cmd)
    """
def get_HTSLIB(env, prefix):
    """
    key = 'HTSLIB'
    if key in env:
        return env[key]
    cmd = 'cd $(THIRD_PARTY_PREFIX)/../lib/cpp/htslib 2>/dev/null && pwd || echo -n notfound' %(
            THIRD_PARTY_PREFIX=prefix)
    return shell(cmd)
    """
def ifenvf(env, key, func):
    if key in env:
        return env[key]
    else:
        return func()
def setifenvf(envout, envin, key, func):
    envout[key] = ifenvf(envin, key, func)
def setifenv(envout, envin, key, val):
    envout[key] = envin.get(key, val)
def setenv(envout, key, val):
    envout[key] = val
def update_env_if(envout, envin, keys):
    for key in keys:
        if key in envin:
            envout[key] = envin[key]
def compose_defs_env(env):
    # We disallow env overrides for anything with a default from GNU make.
    nons = ['CXX', 'CC', 'AR'] # 'SHELL'?
    ovr    = ['%-20s ?= %s' %(k, v) for k,v in sorted(env.items()) if k not in nons]
    nonovr = ['%-20s := %s' %(k, v) for k,v in sorted(env.items()) if k in nons]
    return '\n'.join(ovr + nonovr + [''])
def append_common(envin, content):
    """Dumb way to do this, but this whole thing is evolving.
    """
    content += """
# Use PREFIX dir, if available.
INCLUDES      += ${PREFIX_INC} ../pbdata
LIBS          += ${PREFIX_LIB}
"""
    env = dict(envin)
    # Some extra defs.
    if 'PREFIX' in envin:
        PREFIX = envin['PREFIX']
        setenv(env, 'PREFIX_INC', os.path.join(PREFIX, 'include'))
        setenv(env, 'PREFIX_LIB', os.path.join(PREFIX, 'lib'))
    poss = [
        'CXXFLAGS',
        'SH_LIB_EXT',
        'EXTRA_LDFLAGS',
        'PREFIX_LIB', 'PREFIX_INC',
    ]
    vals = ['%-20s := %s' %(k, v) for k,v in sorted(env.items()) if k in poss]
    return '\n'.join([''] + vals + ['']) + content
def compose_defines_pacbio(envin):
    """
    This is used by mobs via buildcntl.sh.
    """
    env = dict()
    setenv(env, 'SHELL', 'bash')
    #setifenvf(env, envin, 'OS_STRING', get_OS_STRING)
    setifenv(env, envin, 'LIBPBDATA_INC', '../pbdata')
    setifenv(env, envin, 'LIBPBIHDF_INC', '../hdf')
    setifenv(env, envin, 'LIBBLASR_INC', '../alignment')
    setifenv(env, envin, 'LIBPBDATA_LIB', '../pbdata/')
    setifenv(env, envin, 'LIBPBIHDF_LIB', '../hdf/')
    setifenv(env, envin, 'LIBBLASR_LIB', '../alignment/')
    if 'nohdf' in envin:
        env['nohdf'] = envin['nohdf']
        # Otherwise, do not define it at all. TODO(CD): Remove nohdf, as it is not used.
    nondefaults = set([
            'CXX', 'AR',
            'HDF5_INC', 'HDF5_LIB',
            'PBBAM_INC', 'PBBAM_LIB',
            'HTSLIB_CFLAGS', 'HTSLIB_LIBS',
            'BOOST_INC',
            'ZLIB_LIB',
            'GCC_LIB',
            'GTEST_INC', 'GTEST_SRCDIR',
    ])
    update_env_if(env, envin, nondefaults)
    return compose_defs_env(env)

@contextlib.contextmanager
def cd(nwd):
    cwd = os.getcwd()
    log('cd %r -> %r' %(cwd, nwd))
    os.chdir(nwd)
    yield
    os.chdir(cwd)
    log('cd %r <- %r' %(cwd, nwd))

def fetch_hdf5_headers():
    """Fetch into ./hdf/HEADERS directory.
    This should not be used when an external build-dir is needed.
    Return actual directory path, relative to subdirs.
    """
    version = 'hdf5-1.8.12-headers'
    version_dn = os.path.join(thisdir, 'hdf', version)
    if not os.path.isdir(version_dn):
        with cd(os.path.dirname(version_dn)):
            cmd = 'curl -k -L https://www.dropbox.com/s/8971bcyy5o42rxb/hdf5-1.8.12-headers.tar.bz2\?dl\=0 | tar xjf -'
            shell(cmd)
    return version_dn # Relative path might help caching.

def update(content_defines_mk, content_libconfig_h):
    """ Write these relative to the same directory as *this* file.
    """
    fn_libconfig_h = os.path.join(thisdir, 'pbdata', 'LibBlasrConfig.h')
    update_content(fn_libconfig_h, content_libconfig_h)
    fn_defines_mk = 'defines.mk'
    update_content(fn_defines_mk, content_defines_mk)
    if thisdir == os.path.abspath('.'):
        # This was run in the root directory, so symlink defines.mk
        # in sub-dirs, which now include defines.mk from CURDIR
        # in order to facilitate building in external output directories.
        for sub in ('pbdata', 'hdf', 'alignment', 'unittest'):
            lname = os.path.join(sub, 'defines.mk')
            if not os.path.lexists(lname):
                os.symlink(os.path.join('..', 'defines.mk'), lname)

def configure_nopbbam(envin):
    """Use HDF5 from env-vars.
    This is the path used by blasr in a GitHub build, for now.
    """
    HDF5_INC = envin.get('HDF5_INC')
    if not HDF5_INC:
        HDF5_INC = envin['HDF5_INCLUDE']
    HDF5_LIB = envin['HDF5_LIB']
    content1 = compose_defines_with_hdf(HDF5_INC, HDF5_LIB)
    content1 = append_common(envin, content1)
    content2 = compose_libconfig(pbbam=False)
    update(content1, content2)

def configure_nopbbam_skip_hdf(envin):
    """Fetch HDF5 headers.
    We lack HDF5 libs, so we cannot build our hdf/ subdir.
    But the others are fine.
    """
    HDF_HEADERS = fetch_hdf5_headers()
    content1 = compose_defines_with_hdf_headers(HDF_HEADERS)
    content1 = append_common(envin, content1)
    content2 = compose_libconfig(pbbam=False)
    update(content1, content2)

def configure_nopbbam_nohdf5(envin):
    content1 = compose_defines()
    content1 = append_common(envin, content1)
    content2 = compose_libconfig(pbbam=False)
    update(content1, content2)

def configure_pacbio(envin):
    content1 = compose_defines_pacbio(envin)
    content1 = append_common(envin, content1)
    content2 = compose_libconfig(pbbam=True)
    update(content1, content2)

def get_make_style_env(envin, args):
    envout = dict()
    for arg in args:
        if '=' in arg:
            k, v = arg.split('=')
            envout[k] = v
    envout.update(envin)
    return envout

class OsType:
    Unknown, Linux, Darwin = range(3)

def getOsType():
    uname = shell('uname -s')
    log('uname=%r' %uname)
    if 'Darwin' in uname:
        return OsType.Darwin
    elif 'Linux' in uname:
        return OsType.Linux
    else:
        return OsType.Unknown

def update_env_for_linux(env):
    env['SET_LIB_NAME'] = '-soname'
    env['SH_LIB_EXT'] = '.so'
def update_env_for_darwin(env):
    env['SET_LIB_NAME'] = '-install_name'
    env['SH_LIB_EXT'] = '.dylib'
    env['EXTRA_LDFLAGS'] = '-flat_namespace'
    # -flat_namespace makes BSD ld act like Linux ld, finding
    # shared libs recursively.
def update_env_for_unknown(env):
    env['SET_LIB_NAME'] = '-soname'
    env['SH_LIB_EXT'] = '.so'
update_env_for_os = {
    OsType.Linux: update_env_for_linux,
    OsType.Darwin: update_env_for_darwin,
    OsType.Unknown: update_env_for_unknown,
}

def main(prog, *args):
    """Include shell environ plus KEY=VAL pairs in args.
    """
    ost = getOsType()
    envin = get_make_style_env(os.environ, args)
    update_env_for_os[ost](envin)
    if 'NOPBBAM' in envin:
        if 'NOHDF' in envin:
            configure_nopbbam_nohdf5(envin)
        else:
            if 'HDF5_LIB' in envin:
                if 'HDF5_INCLUDE' in envin:
                    if 'HDF5_INC' not in envin:
                        envin['HDF5_INC'] = envin['HDF5_INCLUDE']
                    else:
                        print("WARNING: Found both HDF5_INC and HDF5_INCLUDE in environ!")
                assert 'HDF5_INC' in envin, 'Hey! You have HDF5_LIB but not HDF5_INC!'
                configure_nopbbam(envin)
            else:
                configure_nopbbam_skip_hdf(envin)
    else:
        configure_pacbio(envin)


if __name__=="__main__":
    main(*sys.argv)