from __future__ import annotations

import os
from dataclasses import dataclass
from pathlib import Path

from dotenv import load_dotenv


def _bool_env(name: str, default: bool) -> bool:
    raw = os.getenv(name)
    if raw is None:
        return default
    return raw.strip().lower() in {"1", "true", "yes", "y", "on"}


def _int_env(name: str, default: int) -> int:
    raw = os.getenv(name)
    if not raw:
        return default
    return int(raw)


def _id_set(name: str) -> set[int]:
    raw = os.getenv(name, "")
    ids: set[int] = set()
    for part in raw.replace(";", ",").split(","):
        part = part.strip()
        if not part:
            continue
        ids.add(int(part))
    return ids


@dataclass(frozen=True)
class Config:
    telegram_bot_token: str
    allowed_user_ids: set[int]
    state_path: Path
    workspace_root: Path
    codex_bin: str
    codex_timeout_seconds: int
    codex_backend: str
    app_server_url: str
    app_server_model: str | None
    app_server_reasoning_effort: str | None
    app_server_speed_mode: str
    readonly_sandbox: str
    write_sandbox: str
    resume_json_flag_style: str
    allow_plain_text: bool
    timezone: str
    schedule_poll_seconds: int
    persistent_ws_idle_seconds: int
    gitea_base_url: str | None
    gitea_username: str | None
    gitea_email: str | None
    gitea_default_owner: str | None
    gitea_default_repo: str | None
    gitea_token_configured: bool

    @classmethod
    def load(cls) -> "Config":
        load_dotenv()
        token = os.getenv("TELEGRAM_BOT_TOKEN", "").strip()
        if not token:
            raise RuntimeError("TELEGRAM_BOT_TOKEN is required")

        backend = os.getenv("CODEX_BACKEND", "auto").strip().lower()
        if backend not in {"auto", "app-server", "exec"}:
            raise RuntimeError("CODEX_BACKEND must be one of: auto, app-server, exec")

        app_server_model = os.getenv("CODEX_APP_SERVER_MODEL", "").strip() or "gpt-5.5"
        app_server_reasoning_effort = (
            os.getenv("CODEX_MODEL_REASONING_EFFORT", "").strip() or "high"
        )
        app_server_speed_mode = os.getenv("CODEX_SPEED_MODE", "standard").strip().lower()
        if app_server_speed_mode not in {"standard", "fast"}:
            raise RuntimeError("CODEX_SPEED_MODE must be one of: standard, fast")

        return cls(
            telegram_bot_token=token,
            allowed_user_ids=_id_set("ALLOWED_TELEGRAM_USER_IDS"),
            state_path=Path(os.getenv("BOT_STATE_PATH", "/app/data/state.json")),
            workspace_root=Path(os.getenv("BOT_WORKSPACE_ROOT", "/workspaces")),
            codex_bin=os.getenv("CODEX_BIN", "codex"),
            codex_timeout_seconds=_int_env("CODEX_TIMEOUT_SECONDS", 1800),
            codex_backend=backend,
            app_server_url=os.getenv("CODEX_APP_SERVER_URL", "ws://127.0.0.1:4500"),
            app_server_model=app_server_model,
            app_server_reasoning_effort=app_server_reasoning_effort,
            app_server_speed_mode=app_server_speed_mode,
            readonly_sandbox=os.getenv("CODEX_READONLY_SANDBOX", "read-only"),
            write_sandbox=os.getenv("CODEX_WRITE_SANDBOX", "workspace-write"),
            resume_json_flag_style=os.getenv(
                "CODEX_RESUME_JSON_FLAG_STYLE", "before_resume"
            ),
            allow_plain_text=_bool_env("ALLOW_PLAIN_TEXT", True),
            timezone=os.getenv("BOT_TIMEZONE", "Asia/Seoul"),
            schedule_poll_seconds=_int_env("SCHEDULE_POLL_SECONDS", 30),
            persistent_ws_idle_seconds=_int_env("PERSISTENT_WS_IDLE_SECONDS", 600),
            gitea_base_url=os.getenv("GITEA_BASE_URL", "").strip() or None,
            gitea_username=os.getenv("GITEA_USERNAME", "").strip() or None,
            gitea_email=os.getenv("GITEA_EMAIL", "").strip() or None,
            gitea_default_owner=os.getenv("GITEA_DEFAULT_OWNER", "").strip() or None,
            gitea_default_repo=os.getenv("GITEA_DEFAULT_REPO", "").strip() or None,
            gitea_token_configured=bool(os.getenv("GITEA_TOKEN", "").strip()),
        )