import logging
import os
import sys
from pathlib import Path
from typing import Optional

sys.path.append(os.path.dirname(__file__))

from common import prompt_choices, prompt_path, prompt_yesno, run_script
from common.jinja import is_jinja_installed, generate_file


_PRIVATE_PATH = Path('private')
_PUBLIC_PATH = Path('public')
_HEADER_TEMPLATE_NAME = 'header.hpp.jinja'
_SOURCE_TEMPLATE_NAME = 'source.cpp.jinja'

_logger = logging.getLogger(__name__)
_header_path: Optional[Path] = None
_source_path: Optional[Path] = None
_namespace: str

def verify_tools() -> None:
    success = True
    if not is_jinja_installed():
        _logger.error('Python module Jinja2 is not installed.')
        success = False
    if not success:
        raise RuntimeError('one or more required tools could not be found')

def query_params() -> None:
    global _header_path, _source_path, _namespace
    header_folder = prompt_choices('Create Header?', {
        'public': _PUBLIC_PATH,
        'private': _PRIVATE_PATH,
        'no': None
    })
    do_create_source = prompt_yesno('Create source?')
    if header_folder is None and not do_create_source:
        raise RuntimeError('Neither header nor source selected for creation.')

    def _make_header_path(base_path: Path) -> Path:
        return header_folder / base_path.with_suffix('.hpp')

    def _make_source_path(base_path: Path) -> Path:
        return _PRIVATE_PATH / base_path.with_suffix('.cpp')

    def _validate_path(path: Path) -> bool:
        result = True
        if header_folder is not None:
            header_path = _make_header_path(path)
            if header_path.exists():
                print(f'Header file {header_path} already exists.')
                result = False
        if do_create_source:
            source_path = _make_source_path(path)
            if source_path.exists():
                print(f'Source file {source_path} already exists.')
                result = False
        return result

    input_path = prompt_path('Enter basename for the source (relative to public/private folder, no file extension).',
                        allow_slash=True, validator=_validate_path)
    _namespace = input_path.parts[0]

    if header_folder is not None:
        _header_path = _make_header_path(input_path)
    if do_create_source:
        _source_path = _make_source_path(input_path)


def create_header() -> None:
    if _header_path is None:
        return

    _logger.info('Generating header at %s.', str(_header_path))

    guard = '_'.join(_header_path.with_suffix('').parts[1:]).upper()
    generate_file(_HEADER_TEMPLATE_NAME, _header_path, {
        'guard': guard,
        'namespace': _namespace
    })


def create_source() -> None:
    if _source_path is None:
        return

    _logger.info('Generating source at %s.', str(_source_path))
    generate_file(_SOURCE_TEMPLATE_NAME, _source_path, {
        'header_path': '/'.join(_header_path.parts[1:]) if _header_path else None,
        'namespace': _namespace
    })

def script_main() -> None:
    verify_tools()
    query_params()
    create_header()
    create_source()

if __name__ == '__main__':
    run_script(script_main)