# SPDX-FileCopyrightText: © Jens Bergmann and contributors
# SPDX-License-Identifier: AGPL-3.0-or-later
# SPDX-ArtifactOfProjectHomePage: https://github.com/Second-Hand-Friends/kleinanzeigen-bot/
"""CI guard: verifies generated schema and default-config artifacts are up-to-date."""

from __future__ import annotations

import difflib
import subprocess  # noqa: S404
import sys
import tempfile
from pathlib import Path
from typing import TYPE_CHECKING, Final

from schema_utils import generate_schema_content

from kleinanzeigen_bot.model.ad_model import AdPartial
from kleinanzeigen_bot.model.config_model import Config

if TYPE_CHECKING:
    from pydantic import BaseModel

SCHEMA_DEFINITIONS:Final[tuple[tuple[str, type[BaseModel], str], ...]] = (
    ("schemas/config.schema.json", Config, "Config"),
    ("schemas/ad.schema.json", AdPartial, "Ad"),
)
DEFAULT_CONFIG_PATH:Final[Path] = Path("docs/config.default.yaml")


def generate_default_config_via_cli(path:Path, repo_root:Path) -> None:
    """
    Run `python -m kleinanzeigen_bot --config <path> create-config` to generate a default config snapshot.
    """
    try:
        subprocess.run(  # noqa: S603 trusted, static command arguments
            [
                sys.executable,
                "-m",
                "kleinanzeigen_bot",
                "--config",
                str(path),
                "create-config",
            ],
            cwd = repo_root,
            check = True,
            timeout = 60,
            capture_output = True,
            text = True,
        )
    except subprocess.CalledProcessError as error:
        stderr = error.stderr.strip() if error.stderr else "<empty>"
        stdout = error.stdout.strip() if error.stdout else "<empty>"
        raise RuntimeError(
            "Failed to generate default config via CLI.\n"
            f"Return code: {error.returncode}\n"
            f"stderr:\n{stderr}\n"
            f"stdout:\n{stdout}"
        ) from error


def get_schema_diffs(repo_root:Path) -> dict[str, str]:
    """
    Compare committed schema files with freshly generated schema content and return unified diffs per path.
    """
    diffs:dict[str, str] = {}
    for schema_path, model, schema_name in SCHEMA_DEFINITIONS:
        expected_schema_path = repo_root / schema_path
        expected = expected_schema_path.read_text(encoding = "utf-8") if expected_schema_path.is_file() else ""

        generated = generate_schema_content(model, schema_name)
        if expected == generated:
            continue

        diffs[schema_path] = "".join(
            difflib.unified_diff(
                expected.splitlines(keepends = True),
                generated.splitlines(keepends = True),
                fromfile = schema_path,
                tofile = f"<generated via: {model.__name__}.model_json_schema>",
            )
        )

    return diffs


def get_default_config_diff(repo_root:Path) -> str:
    """
    Compare docs/config.default.yaml with a freshly generated config artifact and return a unified diff string.
    """
    expected_config_path = repo_root / DEFAULT_CONFIG_PATH
    if not expected_config_path.is_file():
        raise FileNotFoundError(f"Missing required default config file: {DEFAULT_CONFIG_PATH}")

    with tempfile.TemporaryDirectory() as tmpdir:
        generated_config_path = Path(tmpdir) / "config.default.yaml"
        generate_default_config_via_cli(generated_config_path, repo_root)

        expected = expected_config_path.read_text(encoding = "utf-8")
        generated = generated_config_path.read_text(encoding = "utf-8")

    if expected == generated:
        return ""

    return "".join(
        difflib.unified_diff(
            expected.splitlines(keepends = True),
            generated.splitlines(keepends = True),
            fromfile = str(DEFAULT_CONFIG_PATH),
            tofile = "<generated via: python -m kleinanzeigen_bot --config /path/to/config.default.yaml create-config>",
        )
    )


def main() -> None:
    repo_root = Path(__file__).resolve().parent.parent

    schema_diffs = get_schema_diffs(repo_root)
    default_config_diff = get_default_config_diff(repo_root)

    if schema_diffs or default_config_diff:
        messages:list[str] = ["Generated artifacts are not up-to-date."]

        if schema_diffs:
            messages.append("Outdated schema files detected:")
            for path, schema_diff in schema_diffs.items():
                messages.append(f"- {path}")
                messages.append(schema_diff)

        if default_config_diff:
            messages.append("Outdated docs/config.default.yaml detected.")
            messages.append(default_config_diff)

        messages.append("Regenerate with one of the following:")
        messages.append("- Schema files: pdm run generate-schemas")
        messages.append("- Default config snapshot: pdm run generate-config")
        messages.append("- Both: pdm run generate-artifacts")
        raise SystemExit("\n".join(messages))

    print("Generated schemas and docs/config.default.yaml are up-to-date.")


if __name__ == "__main__":
    main()