#!/usr/bin/env python
#
# Command line tool to convert simple ESP-IDF Makefile & component.mk files to
# CMakeLists.txt files
#
import argparse
import glob
import os.path
import re
import subprocess

debug = False


def get_make_variables(path, makefile='Makefile', expected_failure=False, variables={}):
    """
    Given the path to a Makefile of some kind, return a dictionary of all variables defined in this Makefile

    Uses 'make' to parse the Makefile syntax, so we don't have to!

    Overrides IDF_PATH= to avoid recursively evaluating the entire project Makefile structure.
    """
    variable_setters = [('%s=%s' % (k,v)) for (k,v) in variables.items()]

    cmdline = ['make', '-rpn', '-C', path, '-f', makefile] + variable_setters
    if debug:
        print('Running %s...' % (' '.join(cmdline)))

    p = subprocess.Popen(cmdline, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (output, stderr) = p.communicate('\n')

    if (not expected_failure) and p.returncode != 0:
        raise RuntimeError('Unexpected make failure, result %d' % p.returncode)

    if debug:
        print('Make stdout:')
        print(output)
        print('Make stderr:')
        print(stderr)

    next_is_makefile = False  # is the next line a makefile variable?
    result = {}
    BUILT_IN_VARS = set(['MAKEFILE_LIST', 'SHELL', 'CURDIR', 'MAKEFLAGS'])

    for line in output.decode('utf-8').split('\n'):
        if line.startswith('# makefile'):  # this line appears before any variable defined in the makefile itself
            next_is_makefile = True
        elif next_is_makefile:
            next_is_makefile = False
            m = re.match(r'(?P<var>[^ ]+) :?= (?P<val>.+)', line)
            if m is not None:
                if not m.group('var') in BUILT_IN_VARS:
                    result[m.group('var')] = m.group('val').strip()

    return result


def get_component_variables(project_path, component_path):
    make_vars = get_make_variables(component_path,
                                   os.path.join(os.environ['IDF_PATH'],
                                                'make',
                                                'component_wrapper.mk'),
                                   expected_failure=True,
                                   variables={
                                       'COMPONENT_MAKEFILE': os.path.join(component_path, 'component.mk'),
                                       'COMPONENT_NAME': os.path.basename(component_path),
                                       'PROJECT_PATH': project_path,
                                   })

    if 'COMPONENT_OBJS' in make_vars:  # component.mk specifies list of object files
        # Convert to sources
        def find_src(obj):
            obj = os.path.splitext(obj)[0]
            for ext in ['c', 'cpp', 'S']:
                if os.path.exists(os.path.join(component_path, obj) + '.' + ext):
                    return obj + '.' + ext
            print("WARNING: Can't find source file for component %s COMPONENT_OBJS %s" % (component_path, obj))
            return None

        srcs = []
        for obj in make_vars['COMPONENT_OBJS'].split():
            src = find_src(obj)
            if src is not None:
                srcs.append(src)
        make_vars['COMPONENT_SRCS'] = ' '.join(srcs)
    else:
        component_srcs = list()
        for component_srcdir in make_vars.get('COMPONENT_SRCDIRS', '.').split():
            component_srcdir_path = os.path.abspath(os.path.join(component_path, component_srcdir))

            srcs = list()
            srcs += glob.glob(os.path.join(component_srcdir_path, '*.[cS]'))
            srcs += glob.glob(os.path.join(component_srcdir_path, '*.cpp'))
            srcs = [('"%s"' % str(os.path.relpath(s, component_path))) for s in srcs]

        make_vars['COMPONENT_ADD_INCLUDEDIRS'] = make_vars.get('COMPONENT_ADD_INCLUDEDIRS', 'include')
        component_srcs += srcs
        make_vars['COMPONENT_SRCS'] = ' '.join(component_srcs)

    return make_vars


def convert_project(project_path):
    if not os.path.exists(project_path):
        raise RuntimeError("Project directory '%s' not found" % project_path)
    if not os.path.exists(os.path.join(project_path, 'Makefile')):
        raise RuntimeError("Directory '%s' doesn't contain a project Makefile" % project_path)

    project_cmakelists = os.path.join(project_path, 'CMakeLists.txt')
    if os.path.exists(project_cmakelists):
        raise RuntimeError('This project already has a CMakeLists.txt file')

    project_vars = get_make_variables(project_path, expected_failure=True)
    if 'PROJECT_NAME' not in project_vars:
        raise RuntimeError('PROJECT_NAME does not appear to be defined in IDF project Makefile at %s' % project_path)

    component_paths = project_vars['COMPONENT_PATHS'].split()

    converted_components = 0

    # Convert components as needed
    for p in component_paths:
        if 'MSYSTEM' in os.environ:
            cmd = ['cygpath', '-w', p]
            p = subprocess.check_output(cmd).decode('utf-8').strip()

        converted_components += convert_component(project_path, p)

    project_name = project_vars['PROJECT_NAME']

    # Generate the project CMakeLists.txt file
    with open(project_cmakelists, 'w') as f:
        f.write("""
# (Automatically converted from project Makefile by convert_to_cmake.py.)

# The following lines of boilerplate have to be in your project's CMakeLists
# in this exact order for cmake to work correctly
cmake_minimum_required(VERSION 3.5)

""")
        f.write("""
include($ENV{IDF_PATH}/tools/cmake/project.cmake)
""")
        f.write('project(%s)\n' % project_name)

    print('Converted project %s' % project_cmakelists)

    if converted_components > 0:
        print('Note: Newly created component CMakeLists.txt do not have any REQUIRES or PRIV_REQUIRES '
              'lists to declare their component requirements. Builds may fail to include other '
              "components' header files. If so requirements need to be added to the components' "
              "CMakeLists.txt files. See the 'Component Requirements' section of the "
              'Build System docs for more details.')


def convert_component(project_path, component_path):
    if debug:
        print('Converting %s...' % (component_path))
    cmakelists_path = os.path.join(component_path, 'CMakeLists.txt')
    if os.path.exists(cmakelists_path):
        print('Skipping already-converted component %s...' % cmakelists_path)
        return 0
    v = get_component_variables(project_path, component_path)

    # Look up all the variables before we start writing the file, so it's not
    # created if there's an erro
    component_srcs = v.get('COMPONENT_SRCS', None)

    component_add_includedirs = v['COMPONENT_ADD_INCLUDEDIRS']
    cflags = v.get('CFLAGS', None)

    with open(cmakelists_path, 'w') as f:
        if component_srcs is not None:
            f.write('idf_component_register(SRCS %s)\n' % component_srcs)
            f.write('                       INCLUDE_DIRS %s' % component_add_includedirs)
            f.write('                       # Edit following two lines to set component requirements (see docs)\n')
            f.write('                       REQUIRES '')\n')
            f.write('                       PRIV_REQUIRES '')\n\n')
        else:
            f.write('idf_component_register()\n')
        if cflags is not None:
            f.write('target_compile_options(${COMPONENT_LIB} PRIVATE %s)\n' % cflags)

    print('Converted %s' % cmakelists_path)
    return 1


def main():
    global debug

    parser = argparse.ArgumentParser(description='convert_to_cmake.py - ESP-IDF Project Makefile to CMakeLists.txt converter', prog='convert_to_cmake')

    parser.add_argument('--debug', help='Display debugging output',
                        action='store_true')

    parser.add_argument('project', help='Path to project to convert (defaults to CWD)', default=os.getcwd(), metavar='project path', nargs='?')

    args = parser.parse_args()
    debug = args.debug
    print('Converting %s...' % args.project)
    convert_project(args.project)


if __name__ == '__main__':
    main()