from __future__ import annotations

import configparser
import logging
from io import StringIO
from pathlib import Path

from app.models import Mirror
from app.services.host import host_path, run_on_host

logger = logging.getLogger(__name__)

MARKER = "mirror-manager"
INSTEAD_SECTION = f'url "https://github.com/" managed by {MARKER}'


def _gitconfig_paths() -> list[Path]:
    paths = []
    for rel in ("root/.gitconfig", "home/.gitconfig"):
        p = host_path(rel)
        if p not in paths:
            paths.append(p)
    local = Path.home() / ".gitconfig"
    if local not in paths:
        paths.append(local)
    system = host_path("etc/gitconfig")
    if system not in paths:
        paths.append(system)
    return paths


def read_current_github() -> dict:
    configs = {}
    for path in _gitconfig_paths():
        if path.exists():
            configs[str(path)] = path.read_text(encoding="utf-8")
    return configs


def _parse_gitconfig(content: str) -> configparser.ConfigParser:
    parser = configparser.ConfigParser()
    parser.read_string(content if content.strip() else "[core]\n")
    return parser


def _serialize_gitconfig(parser: configparser.ConfigParser) -> str:
    buf = StringIO()
    parser.write(buf)
    return buf.getvalue()


def _remove_mirror_sections(parser: configparser.ConfigParser) -> None:
    to_remove = []
    for section in parser.sections():
        if not section.startswith('url "'):
            continue
        instead_of = parser.get(section, "insteadOf", fallback="")
        if instead_of in ("https://github.com/", "git@github.com:"):
            to_remove.append(section)
    for section in to_remove:
        parser.remove_section(section)


def apply_github(mirror: Mirror) -> dict:
    meta = mirror.get_meta()
    instead_prefix = meta.get("instead_prefix") or mirror.url
    if not instead_prefix:
        return {"success": False, "error": "prefix میرور GitHub تعریف نشده"}

    instead_prefix = instead_prefix.rstrip("/") + "/"
    section_name = f'url "{instead_prefix}"'

    applied_paths = []
    for path in _gitconfig_paths():
        content = path.read_text(encoding="utf-8") if path.exists() else ""
        parser = _parse_gitconfig(content)
        _remove_mirror_sections(parser)

        if not parser.has_section(section_name):
            parser.add_section(section_name)
        parser.set(section_name, "insteadOf", "https://github.com/")

        path.parent.mkdir(parents=True, exist_ok=True)
        path.write_text(_serialize_gitconfig(parser), encoding="utf-8")
        applied_paths.append(str(path))

    test = run_on_host(
        ["git", "ls-remote", "https://github.com/octocat/Hello-World.git", "HEAD"],
        timeout=60,
    )

    return {
        "success": test.returncode == 0,
        "message": f"GitHub mirror اعمال شد: {mirror.name}",
        "paths": applied_paths,
        "test_output": (test.stdout or test.stderr)[:300] if test.returncode != 0 else "git ls-remote موفق",
        "error": test.stderr[:300] if test.returncode != 0 else None,
    }


def remove_github_config() -> None:
    for path in _gitconfig_paths():
        if not path.exists():
            continue
        parser = _parse_gitconfig(path.read_text(encoding="utf-8"))
        _remove_mirror_sections(parser)
        path.write_text(_serialize_gitconfig(parser), encoding="utf-8")