#!/usr/bin/env python3
"""Shared Gitea configuration helpers for issue scripts."""

from __future__ import annotations

import os
import re
import shlex
import subprocess
from pathlib import Path
from urllib.parse import urlparse


DEFAULT_ENV_FILE = Path("~/.config/gitea/gitea.env").expanduser()
SECRETS_ENV_FILE = Path("~/.config/secrets/gitea.env").expanduser()
LEGACY_ENV_FILE = Path("~/.config/gitea/data-analysis-agent.env").expanduser()
REQUIRED_ENV = ("GITEA_BASE_URL", "GITEA_OWNER", "GITEA_REPO", "GITEA_TOKEN")


def load_env_file(path: Path) -> dict[str, str]:
    values: dict[str, str] = {}
    if not path.exists():
        return values

    for raw_line in path.read_text(encoding="utf-8").splitlines():
        line = raw_line.strip()
        if not line or line.startswith("#"):
            continue
        if line.startswith("export "):
            line = line[len("export ") :]
        if "=" not in line:
            continue
        key, raw_value = line.split("=", 1)
        key = key.strip()
        try:
            parsed = shlex.split(raw_value.strip(), comments=False, posix=True)
        except ValueError as exc:
            raise SystemExit(f"Could not parse {path}: {exc}") from exc
        values[key] = parsed[0] if parsed else ""
    return values


def discover_origin_config() -> dict[str, str]:
    try:
        remote = subprocess.run(
            ["git", "remote", "get-url", "origin"],
            capture_output=True,
            text=True,
            check=True,
        ).stdout.strip()
    except (subprocess.CalledProcessError, FileNotFoundError):
        return {}

    if not remote:
        return {}

    parsed = urlparse(remote)
    host = ""
    path = ""
    if parsed.scheme in {"http", "https", "ssh"} and parsed.netloc:
        host = parsed.hostname or parsed.netloc.split("@")[-1].split(":")[0]
        path = parsed.path.lstrip("/")
    else:
        match = re.match(r"(?:(?P<user>[^@]+)@)?(?P<host>[^:]+):(?P<path>.+)$", remote)
        if match:
            host = match.group("host")
            path = match.group("path")

    if not host or not path:
        return {}

    if path.endswith(".git"):
        path = path[:-4]
    parts = [part for part in path.split("/") if part]
    if len(parts) < 2:
        return {}

    return {
        "GITEA_BASE_URL": f"https://{host}",
        "GITEA_OWNER": parts[-2],
        "GITEA_REPO": parts[-1],
    }


def config(env_file: Path | None = None) -> dict[str, str]:
    env_path = (env_file or DEFAULT_ENV_FILE).expanduser()
    file_values = load_env_file(env_path)
    if env_path == DEFAULT_ENV_FILE:
        secrets_values = load_env_file(SECRETS_ENV_FILE)
        legacy_values = load_env_file(LEGACY_ENV_FILE)
        file_values = {**legacy_values, **secrets_values, **file_values}

    origin_values = discover_origin_config()
    base_url = (
        os.environ.get("GITEA_BASE_URL")
        or os.environ.get("GITEA_URL")
        or origin_values.get("GITEA_BASE_URL")
        or file_values.get("GITEA_BASE_URL")
        or file_values.get("GITEA_URL", "")
    )
    values = {
        "GITEA_BASE_URL": base_url,
        "GITEA_OWNER": os.environ.get("GITEA_OWNER")
        or origin_values.get("GITEA_OWNER")
        or file_values.get("GITEA_OWNER", ""),
        "GITEA_REPO": os.environ.get("GITEA_REPO")
        or origin_values.get("GITEA_REPO")
        or file_values.get("GITEA_REPO", ""),
        "GITEA_TOKEN": os.environ.get("GITEA_TOKEN") or file_values.get("GITEA_TOKEN", ""),
    }
    missing = [key for key, value in values.items() if not value]
    if missing:
        raise SystemExit(
            "Missing required Gitea configuration: "
            + ", ".join(missing)
            + f"\nSet them in the shell, {env_path}, {SECRETS_ENV_FILE}, "
            + "or run from a git repo with a Gitea origin."
        )
    return values


def auth_config(env_file: Path | None = None) -> dict[str, str]:
    """Return Gitea API auth config without requiring a repository context."""
    env_path = (env_file or DEFAULT_ENV_FILE).expanduser()
    file_values = load_env_file(env_path)
    if env_path == DEFAULT_ENV_FILE:
        secrets_values = load_env_file(SECRETS_ENV_FILE)
        legacy_values = load_env_file(LEGACY_ENV_FILE)
        file_values = {**legacy_values, **secrets_values, **file_values}

    origin_values = discover_origin_config()
    base_url = (
        os.environ.get("GITEA_BASE_URL")
        or os.environ.get("GITEA_URL")
        or origin_values.get("GITEA_BASE_URL")
        or file_values.get("GITEA_BASE_URL")
        or file_values.get("GITEA_URL", "")
    )
    values = {
        "GITEA_BASE_URL": base_url,
        "GITEA_OWNER": os.environ.get("GITEA_OWNER")
        or origin_values.get("GITEA_OWNER")
        or file_values.get("GITEA_OWNER", ""),
        "GITEA_TOKEN": os.environ.get("GITEA_TOKEN") or file_values.get("GITEA_TOKEN", ""),
    }
    missing = [key for key in ("GITEA_BASE_URL", "GITEA_TOKEN") if not values[key]]
    if missing:
        raise SystemExit(
            "Missing required Gitea configuration: "
            + ", ".join(missing)
            + f"\nSet them in the shell, {env_path}, {SECRETS_ENV_FILE}, "
            + "or run from a git repo with a Gitea origin."
        )
    return values