"""
Central place for all configuration.

Settings live in a .env file at the project root. This module wraps
python-dotenv so the rest of the app never touches the file directly -
that keeps the settings dialog, the services, and the database layer
all agreeing on where config comes from.

As we add ShipStation / Odoo / anything else, add the new keys to
DEFAULTS below and to .env.example - everything else (loading, saving,
the settings dialog) will pick them up automatically because the
dialog is built from this list.
"""
from __future__ import annotations

import os
from pathlib import Path
from typing import Dict

from dotenv import dotenv_values, set_key

# Project root = the folder containing this app/ package
PROJECT_ROOT = Path(__file__).resolve().parent.parent
ENV_PATH = PROJECT_ROOT / ".env"

# Every setting the app knows about, grouped for the settings UI.
# key -> (label, group, is_secret)
SETTINGS_SCHEMA: Dict[str, tuple[str, str, bool]] = {
    "DB_URL": ("Database URL", "Database", False),

    "JIRA_URL": ("JIRA Site URL", "JIRA", False),
    "JIRA_EMAIL": ("JIRA Account Email", "JIRA", False),
    "JIRA_API_TOKEN": ("JIRA API Token", "JIRA", True),
    "JIRA_JQL": ("JIRA Query (JQL)", "JIRA", False),
    "JIRA_SIGNIFY_SKU_FIELDS": (
        "Signify Health JIRA Deliverable Field IDs (comma-separated)",
        "JIRA",
        False,
    ),
    "JIRA_OAKSTREET_SKU_FIELDS": (
        "Oak Street Health JIRA Deliverable Field IDs (comma-separated)",
        "JIRA",
        False,
    ),

    "SHIPSTATION_API_KEY": ("ShipStation API Key", "ShipStation", True),
    "SHIPSTATION_STORE_MAP": (
        "Store ID -> Company (e.g. 123456:Signify Health,789012:Oak Street Health)",
        "ShipStation",
        False,
    ),

    "COMPANY_SKU_MAP": (
        "SKU Prefix -> Company (e.g. SH:Signify Health,OK:Oak Street Health)",
        "Companies",
        False,
    ),
    "TICKET_NUMBER_REGEX": (
        "Ticket Number Pattern (regex, e.g. AR-######)",
        "Companies",
        False,
    ),
}

DEFAULT_DB_URL = "sqlite:///orders.db"
DEFAULT_COMPANY_SKU_MAP = "SH:Signify Health,OK:Oak Street Health"
DEFAULT_TICKET_NUMBER_REGEX = r"\b[A-Z]{2,6}-\d{3,}\b"


def ensure_env_file_exists() -> None:
    """Create a .env from .env.example on first run if one doesn't exist yet."""
    if ENV_PATH.exists():
        return
    example = PROJECT_ROOT / ".env.example"
    if example.exists():
        ENV_PATH.write_text(example.read_text())
    else:
        ENV_PATH.touch()


def load_settings() -> Dict[str, str]:
    """Read current values from .env (does not touch os.environ)."""
    ensure_env_file_exists()
    values = dotenv_values(ENV_PATH)
    # Fill in blanks for any known key that's missing from the file
    return {key: values.get(key) or "" for key in SETTINGS_SCHEMA}


def save_settings(values: Dict[str, str]) -> None:
    """Write settings back to .env, one key at a time (preserves the file)."""
    ensure_env_file_exists()
    for key, value in values.items():
        if key in SETTINGS_SCHEMA:
            set_key(str(ENV_PATH), key, value or "")
    # Refresh the current process's environment too, so a running app
    # picks up the change without needing a restart for most settings.
    for key, value in values.items():
        os.environ[key] = value or ""


def get(key: str, default: str = "") -> str:
    """Convenience getter, e.g. config.get('DB_URL')."""
    return load_settings().get(key, default) or default