from __future__ import annotations

from .plants import HP_MULT
from .skills import Skill, TARGET_ENEMY
from .types import TYPE_GARDEN
from .unit import TEAM_ENEMY, Unit

# A boss appears every BOSS_FLOOR_STEP floors (20, 40, 60, ...). Bosses are
# fought alone (1 vs the player's team) and have far bigger stats than normal
# floor enemies.
BOSS_FLOOR_STEP = 20

# Chance (0..1) a defeated boss drops one of its signature runes — much higher
# than the ~5-15% rune drop chance anywhere else.
BOSS_RUNE_DROP_CHANCE = 0.80

BOSS_SPECS = {
    "Stones": {
        "type": TYPE_GARDEN,
        # (attack, speed, defense, health) — medium attack, very low speed,
        # medium defense, high health (before HP_MULT).
        "stats": (110, 30, 90, 380),
        "sprite": "stones",
        "drop_runes": ("ruby", "amethyst"),
        "desc": "A slow, rocky guardian. Each Pebble Throw stacks its power "
                "(up to 3); at 3 stacks it unleashes Landslide for huge damage.",
    },
}


def is_boss(name: str) -> bool:
    return name in BOSS_SPECS


def boss_for_floor(floor: int):
    """The boss that appears on `floor`, or None if it's a normal floor."""
    if floor > 0 and floor % BOSS_FLOOR_STEP == 0:
        return "Stones"
    return None


def boss_type(name: str) -> str:
    return BOSS_SPECS[name]["type"]


def boss_stats(name: str) -> tuple:
    return BOSS_SPECS[name]["stats"]


def boss_sprite(name: str) -> str:
    return BOSS_SPECS[name]["sprite"]


def boss_drop_runes(name: str) -> tuple:
    return BOSS_SPECS[name]["drop_runes"]


def boss_floor_level(floor: int) -> int:
    """Display level for a boss at `floor` (scales with each boss appearance)."""
    return 1 + floor // BOSS_FLOOR_STEP


def make_boss(name: str, floor: int) -> Unit:
    """Build the boss unit for `floor`. Boss stats are already far above normal
    enemies and grow a little with each appearance so they stay threatening."""
    spec = BOSS_SPECS[name]
    atk, spd, dfn, hp = spec["stats"]
    lvl = boss_floor_level(floor)
    mult = 1 + 0.06 * (lvl - 1)
    atk = int(atk * mult)
    dfn = int(dfn * mult)
    hp = int(hp * mult)
    pebble = Skill("Pebble Throw", power=60, target=TARGET_ENEMY, cooldown=0,
                   mechanic="boss_stack", priority=2,
                   description="Medium damage; stacks the boss's power (up to 3).")
    landslide = Skill("Landslide", power=140, target=TARGET_ENEMY, cooldown=0,
                      mechanic="boss_landslide", priority=1,
                      description="Huge damage, releases all stacks. Needs 3 stacks.")
    u = Unit(name, TEAM_ENEMY, spec["type"], max_hp=int(hp * HP_MULT),
             attack=atk, speed=spd, defense=dfn, skills=[pebble, landslide],
             role="tank", crit=0.05)
    u.hp = u.max_hp
    return u