"""Conversational lead qualification."""

from __future__ import annotations

import re
from typing import Any, Optional

from app.models import Lead

EMAIL_RE = re.compile(
    r"[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+"
)
PHONE_RE = re.compile(r"\+?\d[\d\s\-()]{7,}\d")

BUDGET_HINTS = (
    "budget",
    "€",
    "$",
    "eur",
    "usd",
    "rub",
    "₽",
    "тысяч",
    "euros",
    "dollars",
)

NEED_HINTS = (
    "need",
    "besoin",
    "нужн",
    "want",
    "looking",
    "cherche",
    "ищ",
    "order",
    "commande",
    "заказ",
)

CONTACT_HINTS = (
    "email",
    "mail",
    "phone",
    "téléphone",
    "телефон",
    "whatsapp",
    "call",
    "звон",
)


def lead_to_dict(lead: Optional[Lead]) -> dict[str, Any]:
    """Serialize lead fields for prompts/UI."""
    if lead is None:
        return {
            "name": None,
            "need": None,
            "budget": None,
            "contact_channel": None,
            "email": None,
            "phone": None,
            "complete": False,
        }
    return {
        "name": lead.name,
        "need": lead.need,
        "budget": lead.budget,
        "contact_channel": lead.contact_channel,
        "email": lead.email,
        "phone": lead.phone,
        "complete": lead.complete,
    }


def update_lead_from_message(
    lead: Lead,
    message: str,
    previous_bot: Optional[str] = None,
) -> Lead:
    """Extract lead fields from the latest user message."""
    text = message.strip()
    lowered = text.lower()
    bot = (previous_bot or "").lower()

    email = EMAIL_RE.search(text)
    if email and not lead.email:
        lead.email = email.group(0)
        if not lead.contact_channel:
            lead.contact_channel = "email"

    phone = PHONE_RE.search(text)
    if phone and not lead.phone:
        lead.phone = re.sub(r"\s+", "", phone.group(0))
        if not lead.contact_channel:
            lead.contact_channel = "phone"

    if not lead.name and (
        "name" in bot
        or "nom" in bot
        or "зовут" in bot
        or "зовут" in bot
        or "call me" in lowered
        or "je m'appelle" in lowered
        or "меня зовут" in lowered
    ):
        lead.name = _extract_name(text)

    if not lead.name and _looks_like_name(text):
        lead.name = text.strip()[:80]

    if not lead.budget and (
        any(h in lowered for h in BUDGET_HINTS)
        or "budget" in bot
        or "бюджет" in bot
    ):
        lead.budget = text[:64]

    if not lead.need and (
        any(h in lowered for h in NEED_HINTS)
        or "need" in bot
        or "besoin" in bot
        or "помощь" in bot
    ):
        lead.need = text[:500]

    if not lead.contact_channel and (
        any(h in lowered for h in CONTACT_HINTS)
        or "reach" in bot
        or "contacter" in bot
        or "связаться" in bot
    ):
        if "whatsapp" in lowered:
            lead.contact_channel = "whatsapp"
        elif "mail" in lowered or "email" in lowered:
            lead.contact_channel = "email"
        elif "phone" in lowered or "tél" in lowered or "телефон" in lowered:
            lead.contact_channel = "phone"
        else:
            lead.contact_channel = text[:64]

    lead.complete = all(
        [
            lead.name,
            lead.need,
            lead.budget,
            lead.contact_channel,
        ]
    )
    return lead


def _looks_like_name(text: str) -> bool:
    words = text.strip().split()
    if not (1 <= len(words) <= 3):
        return False
    if any(ch.isdigit() for ch in text):
        return False
    if len(text) > 40:
        return False
    return text[:1].isupper() or all(
        w[:1].isupper() for w in words if w
    )


def _extract_name(text: str) -> str:
    patterns = [
        r"(?:je m'appelle|my name is|i am|i'm|меня зовут)\s+(.+)",
        r"(?:call me)\s+(.+)",
    ]
    lowered = text.strip()
    for pattern in patterns:
        match = re.search(pattern, lowered, flags=re.I)
        if match:
            return match.group(1).strip(" .,!")[:80]
    return text.strip()[:80]