from __future__ import annotations

import os

import pygame

_ASSETS = os.path.dirname(os.path.abspath(__file__))


def sprite(name: str, variant: str = "") -> str:
    """Path to a unit sprite, e.g. sprite('sweet pea') -> assets/sprites/sweet_pea.png.
    With a variant ('full' or 'head') looks under the split folders, e.g.
    sprite('daisy', 'head') -> assets/sprites/plant_head/daisy_head.png."""
    base = name.lower().replace(' ', '_')
    if variant:
        return os.path.join(_ASSETS, "sprites", f"plant_{variant}", f"{base}_{variant}.png")
    return os.path.join(_ASSETS, "sprites", f"{base}.png")


def load_sprite(name: str, variant: str = "") -> "pygame.Surface":
    """Load a unit sprite, trying the split variant first ('full'/'head') and
    falling back to the legacy single sprite when the variant file is missing.
    Returns a surface or None."""
    def _exists(nm):
        p = sprite(nm)
        if os.path.exists(p):
            return p
        return None
    try:
        if variant:
            path = sprite(name, variant)
            if not os.path.exists(path):
                path = _exists(name)
                if path is None:
                    return None
        else:
            path = _exists(name)
            if path is None:
                return None
        return pygame.image.load(path).convert_alpha()
    except (pygame.error, OSError):
        return None


def icon(category: str, name: str) -> str:
    """Path to an icon under a category folder, e.g. icon('currency_icons', 'coin')
    -> assets/icons/currency_icons/coin.png"""
    return os.path.join(_ASSETS, "icons", category, f"{name}.png")


def type_icon_path(ptype: str) -> str:
    """Path to a plant type icon, e.g. type_icon_path('radiant') -> assets/icons/types/radiant_icon.png"""
    return icon("types", f"{ptype}_icon")


def plot_icon_path(name: str) -> str:
    """Path to a soil plot sprite, e.g. plot_icon_path('soil_barren') -> assets/icons/plot/soil_barren.png"""
    return icon("plot", name)


def rune_icon_path(color: str) -> str:
    """Path to a rune sprite by color, e.g. rune_icon_path('red') -> assets/icons/runes/ruby_rune.png"""
    from engine import runes
    return icon("runes", runes.RUNE_ICON_FILES.get(color, "rune_brown"))