# Copyright Mozilla Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import annotations

from collections import defaultdict
from collections.abc import Iterator
from json import dumps
from typing import Any

from ...model import Entry, Message, PatternMessage, Resource


def plain_json_serialize(
    resource: Resource[str] | Resource[Message],
    trim_comments: bool = False,
) -> Iterator[str]:
    """
    Serialize a resource as a nested JSON object.

    Comments and metadata are not supported.

    Yields the entire JSON result as a single string.
    """

    def check(comment: str | None, meta: Any) -> None:
        if trim_comments:
            return
        if comment:
            raise ValueError("Resource and section comments are not supported")
        if meta:
            raise ValueError("Metadata is not supported")

    def ddict() -> dict[str, Any]:
        return defaultdict(ddict)

    check(resource.comment, resource.meta)
    root = ddict()
    for section in resource.sections:
        check(section.comment, section.meta)
        section_parent = root
        for part in section.id:
            section_parent = section_parent[part]
        for entry in section.entries:
            if isinstance(entry, Entry):
                check(entry.comment, entry.meta)
                if not entry.id:
                    raise ValueError(f"Unsupported empty identifier in {section.id}")
                msg = entry.value
                if isinstance(msg, str):
                    value = msg
                elif isinstance(msg, PatternMessage) and all(
                    isinstance(p, str) for p in msg.pattern
                ):
                    value = "".join(msg.pattern)  # type: ignore[arg-type]
                else:
                    raise ValueError(
                        f"Unsupported message for {section.id + entry.id}: {msg}"
                    )
                parent = section_parent
                for part in entry.id[:-1]:
                    parent = parent[part]
                parent[entry.id[-1]] = value
            else:
                check(entry.comment, None)
    yield dumps(root, indent=2, ensure_ascii=False)
    yield "\n"