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

_VERSIONS_URL = 'https://www.lua.org/ftp/'
_VERSION_PATTERN = re.compile(r'HREF="lua-([0-9]+)\.([0-9]+)\.([0-9]+)\.tar\.gz"')

def versions(env: Environment, update: bool = False):
    versions_file = os.path.join(env['DOWNLOAD_DIR'], 'lua_versions.json')
    if update or not os.path.exists(versions_file):
        req = requests.get(_VERSIONS_URL)
        result = []
        for match in _VERSION_PATTERN.finditer(req.text):
            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('lua_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:
    url = f'https://www.lua.org/ftp/lua-{version[0]}.{version[1]}.{version[2]}.tar.gz'
    repo = env.DownloadAndExtract(f'lua_{version[0]}.{version[1]}.{version[2]}', url = url, skip_folders = 1)
    checkout_root = repo['extracted_root']
    src_folder = os.path.join(checkout_root, 'src')
    lua_source_files = [f for f in env.RGlob(src_folder, '*.c') if f.name != 'lua.c']
    lib_lua = env.StaticLibrary(
        CCFLAGS = env['CCFLAGS'] + ['-Wno-pedantic'], # Lua uses a GNU extension for taking addresses of labels
        target = env['LIB_DIR'] + '/lua_full',
        source = lua_source_files
    )
    
    return {
        'CPPPATH': [src_folder],
        'LIBS': [lib_lua]
    }