"""
Configuration for the mckicad MCP server.

All config is accessed via functions to avoid module-level os.environ.get()
race conditions with .env loading.
"""

import os
import platform


def get_system() -> str:
    """Get the current operating system name."""
    return platform.system()


def get_kicad_user_dir() -> str:
    """Get KiCad user documents directory, respecting env override."""
    env_val = os.environ.get("KICAD_USER_DIR")
    if env_val:
        return os.path.expanduser(env_val)

    system = get_system()
    if system == "Darwin" or system == "Windows":
        return os.path.expanduser("~/Documents/KiCad")
    elif system == "Linux":
        return os.path.expanduser("~/KiCad")
    return os.path.expanduser("~/Documents/KiCad")


def get_kicad_app_path() -> str:
    """Get KiCad application installation path, respecting env override."""
    env_val = os.environ.get("KICAD_APP_PATH")
    if env_val:
        return env_val

    _app_paths = {
        "Darwin": "/Applications/KiCad/KiCad.app",
        "Windows": r"C:\Program Files\KiCad",
        "Linux": "/usr/share/kicad",
    }
    return _app_paths.get(get_system(), "/Applications/KiCad/KiCad.app")


def get_search_paths() -> list[str]:
    """Read KICAD_SEARCH_PATHS from env, expand ~, filter to existing dirs."""
    paths: list[str] = []

    env_val = os.environ.get("KICAD_SEARCH_PATHS", "")
    if env_val:
        for p in env_val.split(","):
            expanded = os.path.expanduser(p.strip())
            if os.path.isdir(expanded) and expanded not in paths:
                paths.append(expanded)

    # Auto-detect common project locations
    default_locations = [
        "~/Documents/PCB",
        "~/PCB",
        "~/Electronics",
        "~/Projects/Electronics",
        "~/Projects/PCB",
        "~/Projects/KiCad",
    ]
    for loc in default_locations:
        expanded = os.path.expanduser(loc)
        if os.path.isdir(expanded) and expanded not in paths:
            paths.append(expanded)

    return paths


# --- Static configuration (no env dependency) ---

KICAD_EXTENSIONS = {
    "project": ".kicad_pro",
    "pcb": ".kicad_pcb",
    "schematic": ".kicad_sch",
    "design_rules": ".kicad_dru",
    "worksheet": ".kicad_wks",
    "footprint": ".kicad_mod",
    "netlist": "_netlist.net",
    "kibot_config": ".kibot.yaml",
}

DATA_EXTENSIONS = [".csv", ".pos", ".net", ".zip", ".drl"]

INLINE_RESULT_THRESHOLD = 20

TIMEOUT_CONSTANTS = {
    "kicad_cli_version_check": 10.0,
    "kicad_cli_export": 30.0,
    "application_open": 10.0,
    "subprocess_default": 30.0,
}

COMMON_LIBRARIES = {
    "basic": {
        "resistor": {"library": "Device", "symbol": "R"},
        "capacitor": {"library": "Device", "symbol": "C"},
        "inductor": {"library": "Device", "symbol": "L"},
        "led": {"library": "Device", "symbol": "LED"},
        "diode": {"library": "Device", "symbol": "D"},
    },
    "power": {
        "vcc": {"library": "power", "symbol": "VCC"},
        "gnd": {"library": "power", "symbol": "GND"},
        "+5v": {"library": "power", "symbol": "+5V"},
        "+3v3": {"library": "power", "symbol": "+3V3"},
    },
    "connectors": {
        "conn_2pin": {"library": "Connector", "symbol": "Conn_01x02_Male"},
        "conn_4pin": {"library": "Connector_Generic", "symbol": "Conn_01x04"},
    },
}

POWER_SYMBOL_DEFAULTS = {
    "stub_length": 5.08,
    "grid_snap": 2.54,
    "fine_grid": 1.27,
}

DECOUPLING_DEFAULTS = {
    "cols": 6,
    "h_spacing": 12.7,
    "v_spacing": 15.0,
    "offset_below_ic": 20.0,
}

BATCH_LIMITS = {
    "max_components": 500,
    "max_wires": 1000,
    "max_labels": 500,
    "max_total_operations": 2000,
}

LABEL_DEFAULTS = {
    "stub_length": 7.62,  # 3 grid units (2.54mm each), clears component bodies
}

AUTOWIRE_DEFAULTS = {
    "direct_wire_max_distance": 50.0,
    "crossing_threshold": 2,
    "high_fanout_threshold": 5,
    "label_min_distance": 10.0,
}

DEFAULT_FOOTPRINTS = {
    "R": [
        "Resistor_SMD:R_0805_2012Metric",
        "Resistor_SMD:R_0603_1608Metric",
        "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal",
    ],
    "C": [
        "Capacitor_SMD:C_0805_2012Metric",
        "Capacitor_SMD:C_0603_1608Metric",
        "Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P5.00mm",
    ],
    "LED": ["LED_SMD:LED_0805_2012Metric", "LED_THT:LED_D5.0mm"],
    "D": ["Diode_SMD:D_SOD-123", "Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal"],
}