"""
Centralised settings for Kanbante.

Every setting is read from the environment at call time (no import-time
freezing), so tests and operators can change them without code edits.

Environment variables:
    GITEA_URL                    Base URL of the Gitea instance.
    GITEA_TOKEN                  Gitea API token (read/write issues).
    KANBANTE_DB_PATH             Path of the local SQLite database.
    KANBANTE_AUTH_USER           Basic-auth username (with _PASSWORD: enables auth).
    KANBANTE_AUTH_PASSWORD       Basic-auth password.
    KANBANTE_REQUIRE_AUTH        "1" = refuse to serve if auth is not configured.
    KANBANTE_ACTIVE_WINDOW_DAYS  A non-archived repo updated within this many
                                 days counts as "active" (default 365).
    KANBANTE_CACHE_TTL           Seconds to cache Gitea list responses (default 30).
    KANBANTE_MAX_NOTE_CHARS      Maximum size of a project note (default 20000).
    KANBANTE_SYNC_GITEA          "1" (default) = moving a card to/from "done"
                                 closes / reopens the Gitea issue.
    KANBANTE_WIP_LIMITS          Comma list "column:limit" (e.g.
                                 "in_progress:5,review:3"). Columns not
                                 listed are unlimited. Soft limits: the UI
                                 warns, moves are never blocked.
    KANBANTE_AGING_DAYS          Days in the same column before a card is
                                 flagged as aging (default 7; "stale" at 2x).
    KANBANTE_WEBHOOK_SECRET      Shared secret for the Gitea webhook
                                 (POST /webhooks/gitea). When set, the
                                 X-Gitea-Signature HMAC is enforced.
    KANBANTE_SYNC_LABELS         "1" (default) = mirror intermediate
                                 columns to Gitea labels named kanban:<col>.
"""

import os
from dataclasses import dataclass
from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent.parent

APP_VERSION = "0.4.0"


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


def _env_int(name: str, default: int) -> int:
    raw = os.getenv(name)
    try:
        return int(raw) if raw is not None else default
    except ValueError:
        return default


def _env_float(name: str, default: float) -> float:
    raw = os.getenv(name)
    try:
        return float(raw) if raw is not None else default
    except ValueError:
        return default


def _env_wip_limits(name: str) -> dict[str, int]:
    limits: dict[str, int] = {}
    for chunk in os.getenv(name, "").split(","):
        column, sep, value = chunk.partition(":")
        column = column.strip()
        if sep and column and value.strip().isdigit():
            limits[column] = int(value.strip())
    return limits


@dataclass(frozen=True)
class Settings:
    gitea_url: str = "https://git.dracodev.net"
    gitea_token: str = ""
    db_path: str = "~/.kanbante/kanbante.db"
    auth_user: str = ""
    auth_password: str = ""
    require_auth: bool = False
    active_window_days: int = 365
    cache_ttl: float = 30.0
    max_note_chars: int = 20_000
    sync_gitea: bool = True
    wip_limits: dict | None = None
    aging_days: int = 7
    webhook_secret: str = ""
    sync_labels: bool = True

    @property
    def auth_enabled(self) -> bool:
        return bool(self.auth_user and self.auth_password)


def get_settings() -> Settings:
    """Build settings from the current environment."""
    return Settings(
        gitea_url=os.getenv("GITEA_URL", "https://git.dracodev.net").rstrip("/"),
        gitea_token=os.getenv("GITEA_TOKEN", ""),
        db_path=os.getenv(
            "KANBANTE_DB_PATH", os.path.expanduser("~/.kanbante/kanbante.db")
        ),
        auth_user=os.getenv("KANBANTE_AUTH_USER", ""),
        auth_password=os.getenv("KANBANTE_AUTH_PASSWORD", ""),
        require_auth=_env_bool("KANBANTE_REQUIRE_AUTH", False),
        active_window_days=_env_int("KANBANTE_ACTIVE_WINDOW_DAYS", 365),
        cache_ttl=_env_float("KANBANTE_CACHE_TTL", 30.0),
        max_note_chars=_env_int("KANBANTE_MAX_NOTE_CHARS", 20_000),
        sync_gitea=_env_bool("KANBANTE_SYNC_GITEA", True),
        wip_limits=_env_wip_limits("KANBANTE_WIP_LIMITS"),
        aging_days=_env_int("KANBANTE_AGING_DAYS", 7),
        webhook_secret=os.getenv("KANBANTE_WEBHOOK_SECRET", ""),
        sync_labels=_env_bool("KANBANTE_SYNC_LABELS", True),
    )