#!/usr/bin/env python

""" Create a skeleton of new MXE package.

This file is part of MXE. See LICENSE.md for licensing information.
"""

import argparse
import hashlib
import os
import re
import shutil
import subprocess
import tempfile
try:
    import urllib2
except:
    # Python 3
    import urllib.request as urllib2

MK_TEMPLATE = r'''
# This file is part of MXE. See LICENSE.md for licensing information.

PKG             := %(name)s
$(PKG)_WEBSITE  := %(website)s
$(PKG)_DESCR    := %(description)s
$(PKG)_IGNORE   :=
$(PKG)_VERSION  := %(version)s
$(PKG)_CHECKSUM := %(checksum)s
%(file_specs)s
$(PKG)_DEPS     := cc
%(update)s
define $(PKG)_BUILD
    %(build)s
endef
'''

GH_CONF=r'''
$(PKG)_GH_CONF  := %(gh_conf)s
'''

FILE_SPECS=r'''
$(PKG)_SUBDIR   := %(subdir_template)s
$(PKG)_FILE     := %(filename_template)s
$(PKG)_URL      := %(file_url_template)s
'''

UPDATE = r'''
define $(PKG)_UPDATE
    $(call GET_LATEST_VERSION, %(update_url_template)s)
endef
# $(call GET_LATEST_VERSION, base url[, prefix, ext, filter, separator])
#  base url : required page returning list of versions
#               e.g https://ftp.gnu.org/gnu/libfoo
#  prefix   : segment before version
#               defaults to lastword of url with dash i.e. `libfoo-`
#  ext      : segment ending version - default `\.tar`
#  filter   : `grep -i` filter-out pattern - default alpha\|beta\|rc
#  separator: transform char to `.` - typically `_`

# test with make check-update-package-%(name)s and delete comments
'''

CMAKE_BUILD = r'''
    # build and install the library
    cd '$(BUILD_DIR)' && $(TARGET)-cmake \
        '$(SOURCE_DIR)'
    $(MAKE) -C '$(BUILD_DIR)' -j '$(JOBS)'
    $(MAKE) -C '$(BUILD_DIR)' -j 1 install
'''

AUTOTOOLS_BUILD = r'''
    # build and install the library
    cd '$(BUILD_DIR)' && $(SOURCE_DIR)/configure \
        $(MXE_CONFIGURE_OPTS)
    $(MAKE) -C '$(BUILD_DIR)' -j '$(JOBS)'
    $(MAKE) -C '$(BUILD_DIR)' -j 1 install \
        bin_PROGRAMS= \
        sbin_PROGRAMS= \
        noinst_PROGRAMS=
'''

MAKE_BUILD = r'''
    # build and install the library
    $(MAKE) -C '$(SOURCE_DIR)' -j '$(JOBS)'
    $(MAKE) -C '$(SOURCE_DIR)' -j 1 install
'''

BUILDERS = {
    'autotools': AUTOTOOLS_BUILD,
    'make': MAKE_BUILD,
    'cmake': CMAKE_BUILD,
}

PC_AND_TEST = r'''
    # create pkg-config file
    $(INSTALL) -d '$(PREFIX)/$(TARGET)/lib/pkgconfig'
    (echo 'Name: $(PKG)'; \
     echo 'Version: $($(PKG)_VERSION)'; \
     echo 'Description: $($(PKG)_DESCR)'; \
     echo 'Requires:'; \
     echo 'Libs: -l%(libname)s'; \
     echo 'Cflags.private:';) \
     > '$(PREFIX)/$(TARGET)/lib/pkgconfig/$(PKG).pc'

    # compile test
    '$(TARGET)-gcc' \
        -W -Wall -Werror -ansi -pedantic \
        '$(TEST_FILE)' -o '$(PREFIX)/$(TARGET)/bin/test-$(PKG).exe' \
        `'$(TARGET)-pkg-config' $(PKG) --cflags --libs`
'''

def get_filename(file_url):
    return file_url.rsplit('/', 1)[1]

def deduce_gh_conf(file_url):
    if deduce_website(file_url) == 'github.com':
        return '/'.join(file_url.split('://', 1)[1].split('/')[1:3])

def deduce_version(file_url):
    filename = get_filename(file_url)
    return re.search(r'\d[\d.-_]+\d|\d', filename).group()

def deduce_website(file_url):
    return file_url.split('://', 1)[1].split('/', 1)[0]

def download_file(destination, url):
    with open(destination, 'wb') as d:
        request =  urllib2.urlopen(url)
        shutil.copyfileobj(request, d)
        request.close()

def make_checksum(filepath):
    hasher = hashlib.sha256()
    with open(filepath, 'rb') as f:
        for chunk in iter(lambda: f.read(1024 ** 2), b''):
            hasher.update(chunk)
    return hasher.hexdigest()

def deduce_subdir(archive):
    args = ['tar', '-tf', archive]
    tar = subprocess.Popen(args, stdout=subprocess.PIPE)
    output = tar.communicate()[0]
    if not isinstance(output, str):
        # Python 3
        output = output.decode()
    files = output.strip().split('\n')
    first_file = files[0].strip()
    directory = first_file.split('/', 1)[0]
    return directory

def make_build(options, builder):
    commands_template = BUILDERS[builder].lstrip() + PC_AND_TEST.rstrip()
    return commands_template % options

def make_skeleton(
    name,
    description,
    file_url,
    version,
    subdir,
    website,
    builder,
):
    mk_filename = 'src/%s.mk' % name.lower()
    if os.path.isfile(mk_filename):
        raise Exception('File %s exists!' % mk_filename)
    if description is None:
        description = name
    if version is None:
        version = deduce_version(file_url)
    if website is None:
        website = deduce_website(file_url)
    gh_conf = deduce_gh_conf(file_url)
    if gh_conf is None:
        file_specs = FILE_SPECS
        update = UPDATE
    else:
        file_specs = GH_CONF
        update = ''
    with tempfile.NamedTemporaryFile() as pkg_file:
        download_file(pkg_file.name, file_url)
        checksum = make_checksum(pkg_file.name)
        if subdir is None:
            subdir = deduce_subdir(pkg_file.name)
    filename = get_filename(file_url)
    filename_template = filename.replace(version, '$($(PKG)_VERSION)')
    file_url_template = file_url.replace(version, '$($(PKG)_VERSION)')
    update_url_template = file_url.replace('/' + filename,'')
    subdir_template = subdir.replace(version, '$($(PKG)_VERSION)')
    libname = name
    if libname.startswith('lib'):
        libname = libname[3:]
    with open(mk_filename, 'wt') as mk:
        options = {
            'name': name,
            'description': description,
            'libname': libname,
            'website': website,
            'file_url_template': file_url_template,
            'update_url_template': update_url_template,
            'gh_conf': gh_conf,
            'checksum': checksum,
            'version': version,
            'subdir_template': subdir_template,
            'filename_template': filename_template,
        }
        options['file_specs'] = file_specs.strip() % options
        options['update'] = update % options
        options['build'] = make_build(options, builder)
        mk.write(MK_TEMPLATE.lstrip() % options)

def main():
    parser = argparse.ArgumentParser(
        description=__doc__,
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )
    parser.add_argument(
        '--name',
        type=str,
        help='Package name',
        required=True,
    )
    parser.add_argument(
        '--file-url',
        type=str,
        help='URL with file of package',
        required=True,
    )
    parser.add_argument(
        '--description',
        type=str,
        help='Package description (defaults to name)',
        required=False,
    )
    parser.add_argument(
        '--version',
        type=str,
        help='Package version (can be deduced from file)',
        required=False,
    )
    parser.add_argument(
        '--subdir',
        type=str,
        help='Package subdir (can be deduced from file)',
        required=False,
    )
    parser.add_argument(
        '--website',
        type=str,
        help='Package website (defaults to domain of file)',
        required=False,
    )
    parser.add_argument(
        '--builder',
        choices=sorted(BUILDERS.keys()),
        help='Template of $(PKG)_BUILD',
        default='autotools',
    )
    args = parser.parse_args()
    make_skeleton(
        args.name,
        args.description,
        args.file_url,
        args.version,
        args.subdir,
        args.website,
        args.builder,
    )

if __name__ == '__main__':
    main()