"""Configuration settings for Gitea MCP HTTP transport."""

from pathlib import Path
from typing import Optional

from pydantic import Field, field_validator
from pydantic_settings import BaseSettings, SettingsConfigDict


class GiteaSettings(BaseSettings):
    """Configuration settings loaded from environment or .env file."""

    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        case_sensitive=False,
        extra="ignore",
    )

    # Gitea Configuration
    gitea_url: str = Field(
        ...,
        description="Gitea instance URL (e.g., https://git.example.com)",
    )
    gitea_token: str = Field(
        ...,
        description="Gitea API token for authentication",
    )
    gitea_owner: str = Field(
        ...,
        description="Default repository owner/organization",
    )
    gitea_repo: str | None = Field(
        default=None,
        description="Default repository name (optional)",
    )

    # HTTP Server Configuration
    http_host: str = Field(
        default="0.0.0.0",
        description="HTTP server bind address",
    )
    http_port: int = Field(
        default=8080,
        ge=1,
        le=65535,
        description="HTTP server port",
    )

    # Authentication Configuration
    auth_token: Optional[str] = Field(
        default=None,
        description="Bearer token for HTTP authentication (optional)",
    )
    mcp_auth_mode: str = Field(
        default="optional",
        description="MCP authentication mode: 'required', 'optional', or 'none'",
    )

    # Tool Filtering Configuration
    enabled_tools: Optional[str] = Field(
        default=None,
        description="Comma-separated list of enabled tools (optional, enables all if not set)",
    )
    disabled_tools: Optional[str] = Field(
        default=None,
        description="Comma-separated list of disabled tools (optional)",
    )

    @field_validator("gitea_url")
    @classmethod
    def validate_gitea_url(cls, v: str) -> str:
        """Ensure Gitea URL is properly formatted."""
        if not v.startswith(("http://", "https://")):
            raise ValueError("gitea_url must start with http:// or https://")
        return v.rstrip("/")

    @property
    def enabled_tools_list(self) -> Optional[list[str]]:
        """Parse enabled_tools into a list."""
        if not self.enabled_tools:
            return None
        return [tool.strip() for tool in self.enabled_tools.split(",") if tool.strip()]

    @property
    def disabled_tools_list(self) -> Optional[list[str]]:
        """Parse disabled_tools into a list."""
        if not self.disabled_tools:
            return None
        return [tool.strip() for tool in self.disabled_tools.split(",") if tool.strip()]


def load_settings(env_file: Optional[Path] = None) -> GiteaSettings:
    """
    Load settings from environment or .env file.

    Args:
        env_file: Optional path to .env file. If not provided, searches for .env in current directory.

    Returns:
        GiteaSettings instance with loaded configuration.

    Raises:
        ValidationError: If required settings are missing or invalid.
    """
    if env_file:
        return GiteaSettings(_env_file=env_file)
    return GiteaSettings()