from __future__ import annotations

import os
from dataclasses import dataclass
from pathlib import Path


def load_env_file(path: Path) -> None:
    if not path.exists():
        return
    for raw_line in path.read_text(encoding="utf-8").splitlines():
        line = raw_line.strip()
        if not line or line.startswith("#") or "=" not in line:
            continue
        key, value = line.split("=", 1)
        os.environ.setdefault(key.strip(), value.strip())


@dataclass(slots=True)
class ServerConfig:
    host: str
    port: int
    model: str
    workspace_root: Path
    session_dir: Path
    state_dir: Path
    system_prompt: str
    max_tool_rounds: int
    max_file_read_bytes: int
    max_command_output_bytes: int
    tool_policy: str
    approval_timeout_seconds: int
    jobs_retention_seconds: int
    approvals_retention_seconds: int
    tavily_api_key: str
    google_search_api_key: str
    google_search_engine_id: str

    @classmethod
    def load(cls) -> "ServerConfig":
        base_dir = Path(__file__).resolve().parent
        load_env_file(base_dir / ".env")
        workspace_root = Path(
            os.environ.get("NEW_QWEN_WORKSPACE_ROOT", str(Path.cwd()))
        ).expanduser()
        session_dir = Path(
            os.environ.get(
                "NEW_QWEN_SESSION_DIR",
                str(base_dir.parent / ".new-qwen" / "sessions"),
            )
        ).expanduser()
        state_dir = Path(
            os.environ.get(
                "NEW_QWEN_STATE_DIR",
                str(base_dir.parent / ".new-qwen" / "state"),
            )
        ).expanduser()
        return cls(
            host=os.environ.get("NEW_QWEN_HOST", "127.0.0.1"),
            port=int(os.environ.get("NEW_QWEN_PORT", "8080")),
            model=os.environ.get("NEW_QWEN_MODEL", "qwen3.6-plus"),
            workspace_root=workspace_root.resolve(),
            session_dir=session_dir.resolve(),
            state_dir=state_dir.resolve(),
            system_prompt=os.environ.get("NEW_QWEN_SYSTEM_PROMPT", "").strip(),
            max_tool_rounds=int(os.environ.get("NEW_QWEN_MAX_TOOL_ROUNDS", "8")),
            max_file_read_bytes=int(
                os.environ.get("NEW_QWEN_MAX_FILE_READ_BYTES", "200000")
            ),
            max_command_output_bytes=int(
                os.environ.get("NEW_QWEN_MAX_COMMAND_OUTPUT_BYTES", "12000")
            ),
            tool_policy=os.environ.get("NEW_QWEN_TOOL_POLICY", "full-access").strip(),
            approval_timeout_seconds=int(
                os.environ.get("NEW_QWEN_APPROVAL_TIMEOUT_SECONDS", "3600")
            ),
            jobs_retention_seconds=int(
                os.environ.get("NEW_QWEN_JOBS_RETENTION_SECONDS", str(7 * 24 * 3600))
            ),
            approvals_retention_seconds=int(
                os.environ.get(
                    "NEW_QWEN_APPROVALS_RETENTION_SECONDS",
                    str(7 * 24 * 3600),
                )
            ),
            tavily_api_key=os.environ.get("NEW_QWEN_TAVILY_API_KEY", "").strip(),
            google_search_api_key=os.environ.get(
                "NEW_QWEN_GOOGLE_SEARCH_API_KEY",
                "",
            ).strip(),
            google_search_engine_id=os.environ.get(
                "NEW_QWEN_GOOGLE_SEARCH_ENGINE_ID",
                "",
            ).strip(),
        )