#!/usr/bin/env python3
"""Merge all translation sources into a single JSON file."""
import glob
import itertools
import json
import os
import re
from typing import Dict, List, Union

FILENAME_FORMAT = re.compile(r"strings\.(?P<suffix>\w+)\.json")


def load_json(filename: str) -> Union[List, Dict]:
    """Load JSON data from a file and return as dict or list.

    Defaults to returning empty dict if file is not found.
    """
    with open(filename, encoding="utf-8") as fdesc:
        return json.loads(fdesc.read())
    return {}


def save_json(filename: str, data: Union[List, Dict]):
    """Save JSON data to a file.

    Returns True on success.
    """
    data = json.dumps(data, sort_keys=True, indent=4)
    with open(filename, "w", encoding="utf-8") as fdesc:
        fdesc.write(data)
        return True
    return False


def find_strings_files():
    """Return the paths of the strings source files."""
    return itertools.chain(
        glob.iglob("strings*.json"), glob.iglob(f"*{os.sep}strings*.json")
    )


def get_component_platform(path):
    """Get the component and platform name from the path."""
    directory, filename = os.path.split(path)
    match = FILENAME_FORMAT.search(filename)
    suffix = match.group("suffix") if match else None
    if directory:
        return directory, suffix
    else:
        return suffix, None


def get_translation_dict(translations, component, platform):
    """Return the dict to hold component translations."""
    if not component:
        return translations["component"]

    if component not in translations["component"]:
        translations["component"][component] = {}

    if not platform:
        return translations["component"][component]

    if "platform" not in translations["component"][component]:
        translations["component"][component]["platform"] = {}

    if platform not in translations["component"][component]["platform"]:
        translations["component"][component]["platform"][platform] = {}

    return translations["component"][component]["platform"][platform]


def main():
    """Run the script."""
    if not os.path.isfile("requirements_all.txt"):
        print("Run this from HA root dir")
        return

    root = os.getcwd()
    os.chdir(os.path.join("homeassistant", "components"))

    translations = {"component": {}}

    paths = find_strings_files()
    for path in paths:
        component, platform = get_component_platform(path)
        parent = get_translation_dict(translations, component, platform)
        strings = load_json(path)
        parent.update(strings)

    os.chdir(root)

    os.makedirs("build", exist_ok=True)

    save_json(os.path.join("build", "translations-upload.json"), translations)


if __name__ == "__main__":
    main()