"""Central configuration for the recipe-maintainer-3 project.

Resolves the workspace root, provides paths to key directories,
and loads instance/deployment configuration from TOML files.

All paths are resolved lazily on first access and cached.
"""

import os
import tomllib
from pathlib import Path

# ---------------------------------------------------------------------------
# Workspace root detection
# ---------------------------------------------------------------------------

_workspace: Path | None = None


def get_workspace() -> Path:
    """Auto-detect the workspace root by walking up to find AGENTS.md."""
    global _workspace
    if _workspace is not None:
        return _workspace

    # Start from this file's location (lib/config.py → lib/ → workspace root)
    candidate = Path(__file__).resolve().parent.parent
    if (candidate / "AGENTS.md").exists():
        _workspace = candidate
        return _workspace

    # Fallback: walk up from cwd
    candidate = Path.cwd()
    for _ in range(10):
        if (candidate / "AGENTS.md").exists():
            _workspace = candidate
            return _workspace
        parent = candidate.parent
        if parent == candidate:
            break
        candidate = parent

    raise RuntimeError(
        "Could not find workspace root (no AGENTS.md found). "
        "Are you running from within the recipe-maintainer-3 directory?"
    )


# ---------------------------------------------------------------------------
# Path constants (lazy)
# ---------------------------------------------------------------------------

def _ws() -> Path:
    return get_workspace()


class _Paths:
    """Lazy path accessors for key project directories."""

    @property
    def WORKSPACE(self) -> Path:
        return _ws()

    @property
    def LIB_DIR(self) -> Path:
        return _ws() / "lib"

    @property
    def SCRIPTS_DIR(self) -> Path:
        return _ws() / "scripts"

    @property
    def RECIPE_INFO_DIR(self) -> Path:
        return _ws() / "recipe-info"

    @property
    def TESTSECRETS_DIR(self) -> Path:
        return _ws() / "recipe-info" / "testsecrets"

    @property
    def LOGS_DIR(self) -> Path:
        return _ws() / "logs"

    @property
    def PLANS_DIR(self) -> Path:
        return _ws() / "plans"

    @property
    def PLANNED_UPDATES_DIR(self) -> Path:
        return _ws() / "planned-updates"

    @property
    def TERRAFORM_DIR(self) -> Path:
        return _ws() / "terraform"

    @property
    def ABRA_DIR(self) -> Path:
        env = os.environ.get("ABRA_DIR")
        if env:
            return Path(env)
        return Path.home() / ".abra"

    @property
    def ABRA_RECIPES_DIR(self) -> Path:
        return self.ABRA_DIR / "recipes"

    @property
    def ABRA_SERVERS_DIR(self) -> Path:
        return self.ABRA_DIR / "servers"


paths = _Paths()


# ---------------------------------------------------------------------------
# Settings
# ---------------------------------------------------------------------------

def load_settings() -> dict:
    """Load settings.toml from the workspace root."""
    p = paths.WORKSPACE / "settings.toml"
    if not p.exists():
        return {}
    with open(p, "rb") as f:
        return tomllib.load(f)


# ---------------------------------------------------------------------------
# Instance loading (from settings.toml [instances.*])
# ---------------------------------------------------------------------------

def _load_instances_from_settings() -> dict:
    """Load the [instances] section from settings.toml."""
    settings = load_settings()
    return settings.get("instances", {})


def get_instance_names() -> list[str]:
    """Return all instance names from settings.toml [instances.*]."""
    return list(_load_instances_from_settings().keys())


def get_default_instance_name() -> str:
    """Return the default instance from settings.toml."""
    settings = load_settings()
    default = settings.get("default_instance")
    if not default:
        raise RuntimeError("No default_instance set in settings.toml")
    if default not in get_instance_names():
        raise RuntimeError(
            f"default_instance '{default}' from settings.toml "
            f"not found in settings.toml [instances]"
        )
    return default


def load_instance_toml(name: str) -> dict:
    """Load raw TOML data for a specific instance from settings.toml."""
    instances = _load_instances_from_settings()
    if name not in instances:
        raise ValueError(f"Instance '{name}' not found in settings.toml [instances]")
    data = dict(instances[name])
    data["name"] = name
    return data


def load_recipe_toml(recipe_name: str) -> dict:
    """Load recipe-info/<recipe>/recipe.toml."""
    p = paths.RECIPE_INFO_DIR / recipe_name / "recipe.toml"
    if not p.exists():
        return {"name": recipe_name}
    with open(p, "rb") as f:
        data = tomllib.load(f)
    data.setdefault("name", recipe_name)
    return data