# -----------------------------------------------------------------------------
# Immo-Ka — Agrégateur de maisons à vendre (province de Québec)
# Auteur : Simon-Pierre Boucher — contact@spboucher.ai
# mortgage/providers/eq_bank.py : Banque EQ / Équitable — dictionnaire JSON
#   global embarqué dans le payload Next.js de la page des taux (marqueur
#   \"rates\":{ échappé). Clés CMS stables ; les clés « Adjustable » sont des
#   ÉCARTS vs prime (jamais interprétées comme des taux).
# -----------------------------------------------------------------------------
from __future__ import annotations

import json

from .base import RateProvider

# clé CMS -> (rate_type, terme mois, kind, nom, clé APR éventuelle)
KEY_MAP: dict[str, tuple] = {
    "mortgage-rate-fixed-5-year": ("fixed", 60, "special",
                                   "Fixe 5 ans (vitrine EQ)",
                                   "mortgage-rate-fixed-5-year-APR"),
    "mortgage-rate-variable-5-year": ("variable", 60, "special",
                                      "Variable 5 ans (vitrine EQ)",
                                      "mortgage-rate-variable-5-year-APR"),
    "es-fixed-12-month": ("fixed", 12, "special", "Evolution Suite — fixe 1 an", None),
    "es-fixed-24-month": ("fixed", 24, "special", "Evolution Suite — fixe 2 ans", None),
    "es-fixed-36-month": ("fixed", 36, "special", "Evolution Suite — fixe 3 ans", None),
    "es-fixed-48-month": ("fixed", 48, "special", "Evolution Suite — fixe 4 ans", None),
    "es-fixed-60-month": ("fixed", 60, "special", "Evolution Suite — fixe 5 ans", None),
    "Standard-Mortgage-Rate-1-Year-Fixed": ("fixed", 12, "posted", "Fixe affiché 1 an", None),
    "Standard-Mortgage-Rate-2-Year-Fixed": ("fixed", 24, "posted", "Fixe affiché 2 ans", None),
    "Standard-Mortgage-Rate-3-Year-Fixed": ("fixed", 36, "posted", "Fixe affiché 3 ans", None),
    "Standard-Mortgage-Rate-4-Year-Fixed": ("fixed", 48, "posted", "Fixe affiché 4 ans", None),
    "Standard-Mortgage-Rate-5-Year-Fixed": ("fixed", 60, "posted", "Fixe affiché 5 ans", None),
}
PRIME_KEY = "equitable-prime-rate"


def extract_rates_blob(html: str) -> dict:
    """Isole le dictionnaire {clé: {name, rate}} du payload Next.js.
    Le JSON est échappé dans le HTML (\\\" -> \")."""
    marker = '\\"rates\\":{'
    i = html.find(marker)
    if i < 0:
        marker = '"rates":{'
        i = html.find(marker)
        if i < 0:
            raise ValueError("marqueur rates introuvable (structure changée)")
    seg = html[i:i + 400_000].replace('\\"', '"')
    start = seg.find("{")
    depth = 0
    for j, ch in enumerate(seg[start:], start):
        if ch == "{":
            depth += 1
        elif ch == "}":
            depth -= 1
            if depth == 0:
                return json.loads(seg[start:j + 1])
    raise ValueError("JSON rates non équilibré (structure changée)")


class EqBankProvider(RateProvider):
    provider_id = "eq_bank"
    institution = "Banque EQ"
    source_url = "https://www.eqbank.ca/residential/mortgage-rates"
    request_delay = 1.0

    def fetch(self) -> list[dict]:
        return self.parse(self.get(self.source_url).text)

    def parse(self, payload: str) -> list[dict]:
        rates = extract_rates_blob(payload)

        def val(key: str) -> float | None:
            cell = rates.get(key)
            if isinstance(cell, dict) and isinstance(cell.get("rate"), (int, float)):
                return float(cell["rate"])
            return None

        out: list[dict] = []
        for key, (rtype, term, kind, name, apr_key) in KEY_MAP.items():
            rate = val(key)
            if rate is None:
                continue  # clé absente : produit omis, jamais deviné
            apr = val(apr_key) if apr_key else None
            out.append(self.make_product(
                rate=rate, rate_type=rtype, term_months=term, kind=kind,
                product_name=name, apr=apr,
                raw={"key": key, "rate": rate, "apr": apr}))
        prime = val(PRIME_KEY)
        if prime is not None:
            out.append(self.make_product(
                rate=prime, rate_type="other", term_months=12, kind="posted",
                product_name="Taux préférentiel Banque Équitable",
                purpose="unknown", raw={"key": PRIME_KEY, "rate": prime}))
        return out