import json
from datetime import date, datetime

import requests
from django.conf import settings


def _build_prompt(count, min_age):
    max_year = date.today().year - min_age
    return (
        "Turkiye icin gercekci kisi verisi uret. "
        "Turkce isim ve soyisim oncelikli olsun. "
        f"{count} adet kayit uret. "
        f"Her kaydin dogum yili en fazla {max_year} olsun (yani en az {min_age} yas). "
        "Sadece JSON dondur. Baska metin yazma. "
        "Format tam olarak su olsun: "
        "{\"people\":[{\"first_name\":\"...\",\"last_name\":\"...\",\"gender\":\"E|K\",\"birth_date\":\"YYYY-MM-DD\"}]}"
    )


def _validate_people(items, min_age):
    valid = []
    today = date.today()
    for item in items:
        first_name = str(item.get('first_name', '')).strip()
        last_name = str(item.get('last_name', '')).strip()
        gender = str(item.get('gender', '')).strip().upper()
        birth_date_raw = str(item.get('birth_date', '')).strip()

        if not first_name or not last_name:
            continue
        if gender not in {'E', 'K'}:
            continue
        try:
            birth_date = datetime.strptime(birth_date_raw, '%Y-%m-%d').date()
        except ValueError:
            continue

        age = today.year - birth_date.year - ((today.month, today.day) < (birth_date.month, birth_date.day))
        if age < min_age:
            continue

        valid.append({
            'first_name': first_name,
            'last_name': last_name,
            'gender': gender,
            'birth_date': birth_date,
        })

    return valid


def generate_people_with_llm(count, min_age=20):
    """LLM API'den kisi verisi alir, validate edip dondurur."""
    api_url = getattr(settings, 'LLM_API_URL', None)
    model = getattr(settings, 'LLM_MODEL', None)
    timeout = getattr(settings, 'LLM_TIMEOUT', 30)
    api_key = getattr(settings, 'LLM_API_KEY', None)

    if not api_url or not model:
        raise RuntimeError('LLM_API_URL veya LLM_MODEL ayari eksik.')

    prompt = _build_prompt(count=count, min_age=min_age)
    headers = {'Content-Type': 'application/json'}
    if api_key:
        headers['Authorization'] = f'Bearer {api_key}'

    # OpenAI uyumlu endpoint
    if '/v1/chat/completions' in api_url:
        payload = {
            'model': model,
            'response_format': {'type': 'json_object'},
            'messages': [
                {'role': 'system', 'content': 'JSON disinda metin uretme.'},
                {'role': 'user', 'content': prompt},
            ],
            'temperature': 0.8,
        }
        resp = requests.post(api_url, headers=headers, json=payload, timeout=timeout)
        resp.raise_for_status()
        content = resp.json()['choices'][0]['message']['content']
    else:
        # Varsayilan: Ollama /api/chat
        payload = {
            'model': model,
            'stream': False,
            'format': 'json',
            'messages': [
                {'role': 'system', 'content': 'JSON disinda metin uretme.'},
                {'role': 'user', 'content': prompt},
            ],
        }
        resp = requests.post(api_url, headers=headers, json=payload, timeout=timeout)
        resp.raise_for_status()
        body = resp.json()
        content = body.get('message', {}).get('content') or body.get('response')

    if not content:
        raise RuntimeError('LLM bos cevap dondurdu.')

    parsed = json.loads(content)
    people = parsed.get('people') if isinstance(parsed, dict) else None
    if not isinstance(people, list):
        raise RuntimeError('LLM cevabi beklenen JSON formatinda degil.')

    valid_people = _validate_people(people, min_age=min_age)
    if not valid_people:
        raise RuntimeError('LLM gecerli kisi verisi dondurmedi.')

    return valid_people