import os
import re
import shutil
import sys

component_subdirs = ["extras", "docker-data"]
components = {% set components = cookiecutter.__component_list_slug.split(',') -%}
[
{%- for component in components -%}
    "{{ component }}"
    {%- if not loop.last -%}
        ,
    {%- endif %}
{%- endfor -%}
]
project_dir = os.getcwd()
build_context_dir_name = "build-context"
build_ctx_dir_abs = os.path.join(project_dir, build_context_dir_name)
base_dockerfile_abs = os.path.join(build_ctx_dir_abs, "Dockerfile")
base_dockerfile_rel = os.path.relpath(base_dockerfile_abs, project_dir)
re_string_component = "~~component~~"
re_pattern_component = re.compile(re_string_component, re.IGNORECASE)
re_string_component_upper = "~~component_upper~~"
re_pattern_component_upper = re.compile(re_string_component_upper, re.IGNORECASE)


def render_dockerfile(arg_dockerfile_abs: str, arg_component: str) -> None:
    dockerfile_abs = arg_dockerfile_abs
    component = arg_component
    try:
        with open(dockerfile_abs, 'r+') as dockerfile:
            text = dockerfile.read()
            text = re.sub(re_pattern_component, component, text)
            text = re.sub(re_pattern_component_upper, component.upper(), text)
            dockerfile.seek(0)
            dockerfile.write(text)
            dockerfile.truncate()
    except OSError:
        print(f"Unable to open Dockerfile './{component_dockerfile_rel}'. Aborting and exiting 5 ...")
        sys.exit(5)


for component in components:
    if len(components) > 1:
        component_dir_abs = os.path.join(build_ctx_dir_abs, component)
    else:
        component_dir_abs = build_ctx_dir_abs
    component_dir_rel = os.path.relpath(component_dir_abs, project_dir)
    try:
        os.makedirs(component_dir_abs, exist_ok=True)
    except FileExistsError:
        print(f"Dir './{component_dir_rel}' already exists when it shouldn't. Aborting and exiting 1 ...")
        sys.exit(1)
    for component_subdir_name in component_subdirs:
        component_subdir_abs = os.path.join(component_dir_abs, component_subdir_name)
        try:
            os.mkdir(component_subdir_abs)
        except FileExistsError:
            print(f"Dir '{component_subdir_name}' inside './{component_dir_rel}' exists when it shouldn't. "
                  f"Aborting and exiting 1 ...")
            sys.exit(1)

for root, subdirs, filelist in os.walk(project_dir):
    for subdir_name in subdirs:
        if subdir_name in component_subdirs:
            subdir_abs = os.path.join(root, subdir_name)
            gitkeep_file_abs = os.path.join(subdir_abs, ".gitkeep")
            gitkeep_file_rel = os.path.relpath(gitkeep_file_abs, project_dir)
            try:
                with open(gitkeep_file_abs, mode='a'):
                    pass
            except IOError:
                print(f"Can't write './{gitkeep_file_rel}'. Aborting and exiting 2 ...")
                sys.exit(2)
        if len(components) > 1:
            if subdir_name in components:
                component_dir_abs = os.path.join(root, subdir_name)
                component_dockerfile_abs = os.path.join(component_dir_abs, "Dockerfile")
                component_dockerfile_rel = os.path.relpath(component_dockerfile_abs, project_dir)
                try:
                    shutil.copyfile(base_dockerfile_abs, component_dockerfile_abs)
                    render_dockerfile(component_dockerfile_abs, subdir_name)
                except shutil.SameFileError:
                    print(f"Unable to copy base_dockerfile_abs ('{base_dockerfile_abs}') to "
                          f"component_dockerfile_abs ('{component_dockerfile_abs}'). They're the same file. "
                          f"Aborting and exiting 4 ...")
                    sys.exit(4)
                except shutil.SpecialFileError:
                    print(f"Unable to copy base_dockerfile_abs ('{base_dockerfile_abs}') to "
                          f"component_dockerfile_abs ('{component_dockerfile_abs}'). Source is a named pipe. "
                          f"Aborting and exiting 4 ...")
                    sys.exit(4)
                except FileNotFoundError:
                    print(f"Unable to copy base_dockerfile_abs ('{base_dockerfile_abs}') to "
                          f"component_dockerfile_abs ('{component_dockerfile_abs}'). Destination dir does not exist. "
                          f"Aborting and exiting 4 ...")
                    sys.exit(4)
                except OSError:
                    print(f"Unable to copy base_dockerfile_abs ('{base_dockerfile_abs}') to "
                          f"component_dockerfile_abs ('{component_dockerfile_abs}'). Source file likely does not exist. "
                          f"Aborting and exiting 4 ...")
                    sys.exit(4)
        else:
            render_dockerfile(base_dockerfile_abs, components[0])
if len(components) > 1:
    try:
        os.remove(base_dockerfile_abs)
    except OSError:
        print(f"Unable to delete original template Dockerfile at './{base_dockerfile_rel}'. "
              f"Aborting and exiting 6 ...")
        sys.exit(6)