"""Client for the AER's public "Get Generic Plans" / "Get Generic Plan
Detail" Consumer Data Right APIs.

These are unauthenticated, government-operated endpoints (no accreditation
required), but they are hosted per-retailer-brand rather than as one
aggregated feed: each retailer publishes its own plans under
`https://cdr.energymadeeasy.gov.au/<brand-slug>/cds-au/v1/energy/plans`.
There is no single "give me every QLD plan" call -- this client queries a
maintained list of known retailer brand slugs and merges the results.

Confirmed against the live API while building this:
- The plans-list endpoint only supports API version 1 (`x-v: 1`); the
  plan-detail endpoint supports version 3 (`x-v: 3`). Using the wrong
  version returns an HTTP 406.
- Distributor names in `geography.distributors` are plain strings like
  "Energex" (QLD's south-east distributor); Ergon's exact string should be
  confirmed for a given retailer/plan once one is found, hence the
  case-insensitive substring match used when filtering by distributor.
"""

from __future__ import annotations

import time

import httpx

BASE_HOST = "https://cdr.energymadeeasy.gov.au"

# Seed list of retailer CDR "brand" slugs confirmed to respond while
# building this. Not exhaustive, and retailers can add/rename/retire brands.
# To add one: find the retailer's own published CDR base URI (usually
# linked from their "Consumer Data Right" policy page) or check the AER's
# register at
# https://www.aer.gov.au/documents/consumer-data-right-energy-retailer-base-uris-and-cdr-brands
KNOWN_RETAILER_BRANDS: list[str] = [
    "agl",
    "origin",
    "energyaustralia",
    "alintaenergy",
    "redenergy",
    "powershop",
    "tango",
    "globird",
    "sumo",
    "dodo",
    "click",
    "ovoenergy",
    "simplyenergy",
    "qenergy",
    "nectr",
    "amberelectric",
]


class AERClient:
    def __init__(self, brands: list[str] | None = None) -> None:
        self.brands = brands or KNOWN_RETAILER_BRANDS
        self._client = httpx.Client(timeout=30)

    def fetch_all_plans(self, *, fuel_type: str = "ELECTRICITY") -> list[dict]:
        """Fetch every current, generally-available plan summary across all
        configured retailer brands (paginating each retailer's own list)."""
        plans: list[dict] = []
        for brand in self.brands:
            plans.extend(self._fetch_brand_plans(brand, fuel_type))
        return plans

    def _fetch_brand_plans(self, brand: str, fuel_type: str) -> list[dict]:
        url = f"{BASE_HOST}/{brand}/cds-au/v1/energy/plans"
        params = {"type": "ALL", "fuelType": fuel_type, "effective": "CURRENT", "page-size": 100, "page": 1}
        plans: list[dict] = []
        while True:
            resp = self._client.get(url, params=params, headers={"x-v": "1"})
            if resp.status_code == 404:
                # Brand slug no longer valid, or this retailer hasn't published a CDR endpoint.
                return plans
            resp.raise_for_status()
            body = resp.json()
            for plan in body["data"]["plans"]:
                plan.setdefault("brand", brand)
                plans.append(plan)
            total_pages = body.get("meta", {}).get("totalPages", 1)
            if params["page"] >= total_pages:
                break
            params["page"] += 1
            time.sleep(0.2)  # be a polite citizen of a public government API
        return plans

    def fetch_plan_detail(self, brand: str, plan_id: str) -> dict:
        url = f"{BASE_HOST}/{brand}/cds-au/v1/energy/plans/{plan_id}"
        resp = self._client.get(url, headers={"x-v": "3"})
        resp.raise_for_status()
        return resp.json()["data"]