from modelspace.Essentials import SetsDict
from modelspace.ModelPackage import ModelPackage
from modelspace.ModelPackageSubRepository import ModelPackageSubRepository


def select_elements(lst, selection_string):
    """
    Выбирает элементы из списка согласно строке выбора

    Args:
        lst: Исходный список
        selection_string: Строка вида "1 2 4-6 all"

    Returns:
        Новый список с выбранными элементами, отсортированными по номерам
    """
    selection_string = selection_string.strip()
    if not selection_string.strip():
        return []

    if selection_string == "all":
        return lst.copy()

    selected_indices = set()
    parts = selection_string.split()

    for part in parts:
        if '-' in part:
            # Обработка диапазона
            start, end = map(int, part.split('-'))
            # Обработка диапазона в любом направлении
            if start <= end:
                selected_indices.update(range(start, end + 1))
            else:
                selected_indices.update(range(start, end - 1, -1))
        else:
            # Обработка отдельного элемента
            selected_indices.add(int(part))

    # Преобразуем в список и сортируем по номерам
    sorted_indices = sorted(selected_indices)

    # Выбираем элементы
    result = []
    for idx in sorted_indices:
        if 0 <= idx < len(lst):
            result.append(lst[idx])

    return result

def format_bytes(bytes_size):
    """Convert bytes to human readable format"""
    if bytes_size < 1024:
        return f"{bytes_size} B"

    for unit in ['B', 'KB', 'MB', 'GB', 'TB']:
        if bytes_size < 1024.0:
            return f"{bytes_size:.1f} {unit}"
        bytes_size /= 1024.0

    return f"{bytes_size:.1f} PB"


"""
Инициация: repo - репозиторий, из которого устанавливаются пакеты
Вход:   resource - текстовое имя ресурса





"""


class ModelPackageSelector:
    empty_str = ''

    def __init__(self, repo: ModelPackageSubRepository, installed_packages: set[ModelPackage]):
        self.repo: ModelPackageSubRepository = repo
        self._pending_files = SetsDict()
        self._installed_packages: set[ModelPackage] = installed_packages

    #   Completed
    def run(self, resource: str, answer = None) -> set[ModelPackage]:
        available_packages = self.repo.packages_by_resource(resource)
        if len(available_packages) == 0: raise RuntimeError
        installed_packages = available_packages & self._installed_packages
        available_packages = available_packages - installed_packages

        if len(available_packages) == 0:
            print("All possible packages for your query had been installed")
            return available_packages
        if len(available_packages) == 1:
            self._installed_packages = self._installed_packages | set(available_packages)
            return available_packages

        # running interactive selection
        return self._interactive(resource, list(available_packages), list(installed_packages), answer)


    def _interactive(self, resource: str, available, installed, answer = None) -> set[ModelPackage]:
        print(f'There are several packages, satisfies resource {resource}. Please select one or more. Syntax: 1 2 4-5 all')


        print_data = {'Installed packages: ' : installed, 'Available packages: ' : available, }
        for prompt, pr_packages in print_data.items():
            if len(pr_packages) == 0: continue
            print(prompt)
            cols = [['N'], ['name'], ['ver'], ['quant'], ['size']]
            descs = []

            for i in range(len(pr_packages)):
                p: ModelPackage = pr_packages[i]
                cols[0].append(i)
                cols[1].append(p.name)
                cols[2].append(p.version)
                cols[3].append(p.quantization)
                cols[4].append(format_bytes(p.size_bytes))
                descs.append(p.description)

            col_widths = [0, 0, 0, 0, 0]
            for i in range(len(cols)):
                for elem in cols[i]:
                    length = len(str(elem))
                    if length > col_widths[i] - 1: col_widths[i] = length + 1

            for i in range(len(cols[0])):
                print('  ' +
                      f'{cols[0][i]:<{col_widths[0]}}' +
                      f'{cols[1][i]:<{col_widths[1]}}' +
                      f'{cols[2][i]:<{col_widths[2]}}' +
                      f'{cols[3][i]:<{col_widths[3]}}' +
                      f'{cols[4][i]:<{col_widths[4]}}'
                      )
                if i != 0: print('  ' + f'{self.empty_str:<{col_widths[0]}}' + f'{descs[i - 1]}')

        while True:
            if answer:
                inp = answer
                answer = None
            else:
                inp = input("Your choice: ")

            if inp == '': continue
            try:
                selected_packages: list[ModelPackage] = select_elements(available, selection_string=inp)
            except Exception:
                continue
            if selected_packages and len(selected_packages) > 0:
                self._installed_packages = self._installed_packages | set(selected_packages)
                return set(selected_packages)

        return set()