import json
import os
import re
import requests
from SCons.Script import *

_VERSIONS_URL = 'https://api.github.com/repos/boostorg/boost/releases'
_VERSION_PATTERN = re.compile(r'^boost-([0-9]+)\.([0-9]+)\.([0-9]+)$')

def versions(env: Environment, update: bool = False):
    versions_file = os.path.join(env['DOWNLOAD_DIR'], 'boost_versions.json')
    if update or not os.path.exists(versions_file):
        req = requests.get(_VERSIONS_URL)
        versions_data = json.loads(req.text)
        result = []
        for version_data in versions_data:
            match = _VERSION_PATTERN.match(version_data['name'])
            if not match:
                continue
            result.append((int(match.groups()[0]), int(match.groups()[1]), int(match.groups()[2])))
        with open(versions_file, 'w') as f:
            json.dump(result, f)
        return result
    else:
        try:
            with open(versions_file, 'r') as f:
                return [tuple(v) for v in json.load(f)]
        except:
            print('boost_versions.json is empty or broken, redownloading.')
            return versions(env, update=True)

def dependencies(env: Environment, version) -> 'dict':
    return {}

def cook(env: Environment, version) -> dict:
    if env.get('BOOST_LIBS') is None:
        raise Exception('BOOST_LIBS not set. Set to a list of boost libs to link or "*" to link everything.')
    if version >= (1, 85, 0):
        url = f'https://github.com/boostorg/boost/releases/download/boost-{version[0]}.{version[1]}.{version[2]}/boost-{version[0]}.{version[1]}.{version[2]}-cmake.tar.gz'
    else:
        url = f'https://github.com/boostorg/boost/releases/download/boost-{version[0]}.{version[1]}.{version[2]}/boost-{version[0]}.{version[1]}.{version[2]}.tar.gz'
    repo = env.DownloadAndExtract(f'boost_{version[0]}.{version[1]}.{version[2]}', url = url, skip_folders = 1)
    checkout_root = repo['extracted_root']
    build_result = env.CMakeProject(checkout_root)

    libs = []
    if '*' in env['BOOST_LIBS']:
        lib_dir = build_result['LIBPATH'][0]
        for lib_file in os.listdir(lib_dir):
            fname = os.path.join(lib_dir, lib_file)
            if not os.path.isfile(fname):
                continue
            libs.append(fname)
    else:
        for lib in set(env['BOOST_LIBS']):
            if os.name == 'posix':
                libs.append(env.FindLib(f'boost_{lib}', paths=build_result['LIBPATH']))
            elif os.name == 'nt':
                libs.append(env.FindLib(f'libboost_{lib}-*', paths=build_result['LIBPATH'], use_glob=True))
            else:
                raise Exception('Boost not supported on this platform.')
    cpppath = {
        'nt': [f'{build_result['CPPPATH'][0]}/boost-{version[0]}_{version[1]}']
    }.get(os.name, build_result['CPPPATH'])
    return {
        'CPPPATH': cpppath,
        'LIBS': libs
    }