"""
Brandable generator (no external APIs).

Generates pronounceable strings and checks availability via internal DomainChecker.
"""

from __future__ import annotations

import asyncio
import secrets
from dataclasses import dataclass

from app.services.domain_checker import domain_checker


VOWELS = "aeiou"
CONSONANTS = "bcdfghjklmnpqrstvwxz"


def _rand_choice(alphabet: str) -> str:
    return alphabet[secrets.randbelow(len(alphabet))]


def generate_cvcvc() -> str:
    return (
        _rand_choice(CONSONANTS)
        + _rand_choice(VOWELS)
        + _rand_choice(CONSONANTS)
        + _rand_choice(VOWELS)
        + _rand_choice(CONSONANTS)
    )


def generate_cvccv() -> str:
    return (
        _rand_choice(CONSONANTS)
        + _rand_choice(VOWELS)
        + _rand_choice(CONSONANTS)
        + _rand_choice(CONSONANTS)
        + _rand_choice(VOWELS)
    )


HUMAN_SUFFIXES = ["ly", "ri", "ro", "na", "no", "mi", "li", "sa", "ta", "ya"]


def generate_human() -> str:
    # two syllable-ish: CV + CV + suffix
    base = _rand_choice(CONSONANTS) + _rand_choice(VOWELS) + _rand_choice(CONSONANTS) + _rand_choice(VOWELS)
    return base + HUMAN_SUFFIXES[secrets.randbelow(len(HUMAN_SUFFIXES))]


@dataclass(frozen=True)
class AvailabilityResult:
    domain: str
    is_available: bool | None
    status: str


async def check_domains(domains: list[str], *, concurrency: int = 25) -> list[AvailabilityResult]:
    sem = asyncio.Semaphore(concurrency)

    async def _one(d: str) -> AvailabilityResult:
        async with sem:
            try:
                res = await domain_checker.check_domain(d, quick=True)
                return AvailabilityResult(
                    domain=d,
                    is_available=bool(res.is_available),
                    status="available" if res.is_available else "taken",
                )
            except Exception:
                return AvailabilityResult(domain=d, is_available=None, status="unknown")

    return list(await asyncio.gather(*[_one(d) for d in domains]))