from itertools import chain
import re
from SCons.Script import *

_BACKEND_DEPENDENCIES = {
    'sdl3': {
        'SDL': {
            'min': (3, 0, 0)
        }
    }
}

def _dependencies(env: Environment, version, options: dict) -> dict:
    deps = {}
    for backend in chain(env.get('IMGUI_BACKENDS', []), options.get('backends', [])):
        deps.update(_BACKEND_DEPENDENCIES.get(backend, {}))
    return deps

def _git_cook(env: Environment, repo: dict, options: dict) -> dict:
    imgui_source_files = [
        os.path.join(repo['checkout_root'], 'imgui.cpp'),
        os.path.join(repo['checkout_root'], 'imgui_draw.cpp'),
        os.path.join(repo['checkout_root'], 'imgui_tables.cpp'),
        os.path.join(repo['checkout_root'], 'imgui_widgets.cpp')
    ]

    for backend in chain(env.get('IMGUI_BACKENDS', []), options.get('backends', [])):
        imgui_source_files.append(os.path.join(repo['checkout_root'], 'backends', f'imgui_impl_{backend}.cpp'))

    lib_imgui = env.StaticLibrary(
        CPPPATH = [repo['checkout_root']],
        CPPDEFINES = ['IMGUI_IMPL_VULKAN_NO_PROTOTYPES=1'],
        target = env['LIB_DIR'] + '/imgui',
        source = imgui_source_files,
        dependencies = _dependencies(env, None, options)
    )
    return {
        'CPPPATH': [repo['checkout_root']],
        'LIBS': [lib_imgui]
    }

def _tag_pattern(env, options: dict):
    if options.get('docking'):
        return re.compile(r'^v([0-9]+)\.([0-9]+)\.([0-9]+)\-docking$')
    else:
        return re.compile(r'^v([0-9]+)\.([0-9]+)\.([0-9]+)$')

def _tag_fn(version, options: dict) -> str:
    if options.get('docking'):
        return f'v{version[0]}.{version[1]}.{version[2]}-docking'
    else:
        return f'v{version[0]}.{version[1]}.{version[2]}'

env.GitRecipe(
    globals = globals(),
    repo_name = 'imgui',
    repo_url = 'https://github.com/ocornut/imgui.git',
    tag_pattern = _tag_pattern,
    tag_fn = _tag_fn,
    cook_fn = _git_cook,
    dependencies = _dependencies
)