import csv
import re
from enum import Enum
from dataclasses import dataclass

class Difficulty(Enum):
    Terrible = -2
    Low = -1
    Moderate = 0
    High = 1
    Extreme = 2

    @classmethod
    def from_str(cls, name):
        name = name.strip().lower()
        for member in cls:
            if member.name.lower() == name:
                return member
        raise ValueError(f"{name!r} is not a valid {cls.__name__}")

@dataclass
class RollInfo:
    die_size: int
    dice_count: int = 1
    bonus: int = 0

    @classmethod
    def parse(cls, str_data):
        # match strings like 2d6+8 (15)
        match = re.fullmatch(r"^(\d+)d(\d+)\s*(\+\s*\d+)?\s*(\s*\(\s*\d+\s*\))?",
                             str_data)
        if not match:
            raise ValueError(f"{str_data!r} is not a valid RollInfo")
        res = RollInfo(int(match.group(2).strip()))
        res.dice_count = int(match.group(1).strip())
        bonus = match.group(3)
        if bonus:
            res.bonus = int(bonus.strip(" +"))
        return res


def safe_item_level(creature_level: int):
    if creature_level <= 3:
        return 0
    if creature_level == 4:
        return 1
    return creature_level - 4

def load_csv(name, value_parser=None):
    def parse_col_name(name):
        try:
            return Difficulty.from_str(name)
        except ValueError:
            return name.lower()

    if value_parser is None:
        value_parser = lambda x:x
    res = dict() # Table by level and Difficulty
    with open(f"creature_stats/{name}.csv", newline='', encoding='utf8') as file:
        reader = csv.DictReader(file)
        for row in reader:
            level = int(row.pop("Level"))
            res[level] = {parse_col_name(name):
                value_parser(val) for name,val in row.items()}
    return res

def parse_stat(str_data):
    try:
        return int(str_data)
    except ValueError:
        pass

    separator = "-"
    if separator in str_data:
        # parse range
        values = [int(i) for i in str_data.split(separator)[:2]]
        return tuple((min(*values), max(*values)))
    else:
        return RollInfo.parse(str_data)


class StatsDB:
    stat_names = ["ac","abilities","attack_bonus", "hp",
        "perception", "saves", "resistances", "skills", "strike_damage"]

    def __init__(self) -> None:
        self.stats = dict()
        for stat_name in StatsDB.stat_names:
            self.stats[stat_name] = load_csv(stat_name, parse_stat)
        self.stats["resistances"] = {k:(v["minimum"], v["maximum"])
                for k,v in self.stats["resistances"].items()}

stats = StatsDB()

# if __name__ == '__main__':
#     main()